Recall (memory)
Encyclopedia
Recall in memory
refers to the retrieval of events or information from the past. Along with encoding
and storage
, it is one of the three core processes of memory. There are three main types of recall: free recall
, cued recall and serial recall. Psychologist
s test these forms of recall as a way to study the memory processes of humans and animals.
Two main theories of the process of recall are the Two-Stage Theory and the theory of Encoding Specificity.
process where the correct information is chosen from what has been retrieved. In this theory, recognition only involves the latter of these two stages, or processes, and this is thought to account for the superiority of the recognition process over recall. Recognition only involves one process in which error or failure may occur, while recall involves two. However, recall has been found to be superior to recognition in some cases, such as a failure to recognize words that can later be recalled.
Beginning with Hermann Ebbinghaus
in 1885, the study of memory has continued to be a popular topic among researchers. Ebbinghaus created nonsense syllable
s, combinations of letters that do not follow grammatical rules and have no meaning, to test his own memory. He would memorize a list of nonsense syllables and then test his recall of that list over varying time periods. He discovered that memory loss occurred rapidly over the first few hours or days, but showed a more steady, gradual decline over subsequent days, weeks, and months. Furthermore, Ebbinghaus discovered that multiple learning, over-learning, and spacing study times increased retention of information. Ebbinghaus’ research influenced much of the research conducted on memory and recall throughout the twentieth century.
Frederic Bartlett
was a prominent researcher in the field of memory during the mid-twentieth century. He was a British experimental psychologist who focused on the mistakes people made when recalling new information. One of his well known works was Remembering: A Study in Experimental and Social Psychology, which he published in 1932. He is well known for his use of North American Native folk tales, including The War of the Ghosts. He would provide participants in his study with an excerpt from a story and then asked them to recall it as accurately as they could. Retention intervals would vary from directly after reading the story to days later. Bartlett found that people strive for meaning, by attempting to understand the overall meaning of the story. Since the folk tale included supernatural elements, people would rationalize them to make them fit better with their own culture. Ultimately, Bartlett argued that the mistakes that the participants made could be attributed to schematic intrusions. Their current sets of knowledge intruded on their accurately recalling the folk tale.
In the 1950s there was a change in the overall study of memory that has come to be known as the cognitive revolution
. This included new theories on how to view memory, often likening it to a computer processing model. Two important books influenced the revolution: Plans and Structures of Behavior by George Miller, Eugene Galanter, and Karl H. Pribram
in 1960 and Cognitive Psychology by Ulric Neisser
in 1967. Both provided arguments for an information-processing view of the human mind. Allen Newell
and Herbert Simon
constructed computer programs that simulated the thought processes people go through when solving different kinds of problems.
In the 1960s, interest in short-term memory
(STM) increased. Before the 1960s, there was very little research that studied the workings of short-term memory and rapid memory loss. Lloyd and Margaret Peterson observed that when people are given a short list of words or letters and then are distracted and occupied with another task for few seconds, their memory for the list is greatly decreased.
Atkinson and Shiffrin (1973) created the short term memory model, which became the popular model for studying short term memory.
The next major development in the study of memory recall was Endel Tulving
’s proposition of two kinds of memory: episodic and semantic. Tulving described episodic memory
as a memory about a specific event that occurred at a particular time and place, for example what you got for your 10th birthday. Semantic memories
are abstract words, concepts, and rules stored in long-term memory
. Furthermore, Endel Tulving devised the encoding specificity principle in 1983, which explains the importance of the relation between the encoding of information and then recalling that information. To explain further, the encoding specificity principle means that a person is more likely to recall information if the recall cues match or are similar to the encoding cues.
The 1960s also saw a development in the study of visual imagery and how it is recalled. This research was led by Allan Paivio
, who found that the more image-arousing a word was the more likely it would be recalled in either free recall or paired associates.
There has been a considerable amount of research into the workings of memory, and specifically recall since the 1980s. The previously mentioned research was developed and improved upon, and new research was and still is being conducted.
describes the process in which a person is given a list of items to remember and then is tested by being asked to recall them in any order. Free recall often displays evidence of primacy
and recency effects
. Primacy effects are displayed when the person recalls items presented at the beginning of the list earlier and more often. The recency effect is when the person recalls items presented at the end of the list earlier and more often.
There are two basic experimental methods used to conduct cued recall, the study-test method and the anticipation method. In the study-test method participants study a list of word pairs presented individually. Immediately after or after a time delay, participants are tested in the study phase of the experiment on the word pairs just previously studied. One word of each pair is presented in a random order and the participant is asked to recall the item with which it was originally paired. The participant can be tested for either forward recall, Ai is presented as a cue for Bi, or backward recall, Bi is presented as a cue for Ai. In the anticipation method, participants are shown Ai and are asked to anticipate the word paired with it, Bi. If the participant cannot recall the word, the answer is revealed. During an experiment using the anticipation method, the list of words is repeated until a certain percentage of Bi words are recalled.
The learning curve for cued recall increases systematically with the number of trials completed. This result has caused a debate about whether or not learning is all-or-none. One theory is that learning is incremental and that the recall of each word pair is strengthened with repetition. Another theory suggests that learning is all-or-none, that is one learns the word pair in a single trial and memory performance is due to the average learned pairs, some of which are learned on earlier trials and some on later trials. To examine the validity of these theories researchers have performed memory experiments. In one experiment, Irwin Rock University of Illinois had a control group and experimental group learn pairs of words. The control group studied word pairs that were repeated until the participants learned all the word pairs. In the experimental group, the learned pairs remained in the list while unlearned pairs were substituted with recombinations of previous words. Rock believed that associations between two items would be strengthened if learning were incremental even when pairs are not correctly recalled. His hypothesis was that the control group would have a higher correct recall probability than the experimental group. He thought that repetition would increase the strength of the word pair until the strength reaches a threshold needed to produce an overt response. If learning were all or none, then the control group and the experimental group should learn the word pairs at the same rate. Rock found experimentally there was little difference in learning rates between the two groups. However, Rock’s work did not settle the controversy because in his experiment he rearranged replaced word pairs that could be either easier or harder to learn than the original words in the word- digit pair. In further experiments that addressed the question, there were mixed results. The incremental learning hypothesis is supported by the notion that awhile after Ai-Bi pairs are learned, the recall time to recall Bi decreases with continued learning trails.
Another theory that can be tested using cued recall is symmetry of forward and backward recall. Forward recall is generally assumed to be easier than backward recall, i.e. forward recall is stronger than backward recall. This is generally true for long sequences of word or letters such as the alphabet. In one view, the independent associations hypothesis, the strength of forward and backward recall are hypothesized to be independent of each other. To confirm this hypothesis, Dr. George Wolford tested participants’ forward and backward recall and found that forward and backward recall are independent of each other. The probability of correct forward recall was .47 for word pair associations and the probability of correct backward recall of word pair associations was .25. However in another view, the associative symmetry hypothesis, the strengths of forward and backward recall are about equal and highly correlated. In S.E Asch from Swathmore College and S. M Ebenholtz’s experiment, participants learned pairs of nonsense syllables by anticipation recall. After reaching a certain threshold of learning, the participants were tested by free recall to determine all pairs and single items they could remember. These researchers found that backward association was greatly weaker than forward association. However, when the availability of forward and backward recall were basically the same, there was little difference between forward and backward recall. Some scientists including Asch and Ebenholtz believe in the independent association hypothesis think that the equal strengths of forward and backward recall are compatible with their hypothesis because forward and backward recall could be independent but with equal strengths. However associative symmetry theorists interpreted the data to mean that the results fit their hypothesis.
Another study done using cued recall found that learning occurs during test trials. Mark Carrier and Pashler (1992) found that the group with a study-only phase makes 10% more errors than the group with a test-study phase. In the study-only phase, participants were given Ai-Bi, where Ai was an English word and Bi was a Siberian Eskimo Yupik word. In the test study phase, participants first attempted to recall Bi given Ai as a cue then they were shown Ai-Bi pair together. This result suggests that after participants learn something, testing their memory with mental operations helps later recall. The act of recalling instead of restudying creates new and longer lasting connection between Ai and Bi.
Another study showed that when lists are tested immediately after study, the last couple of pairs are remembered best. After a five second delay, the recall of recently studied words diminishes. However, word pairs at the beginning of a list still show better recall. Moreover, in a longer list, the absolute number of word pairs recalled is greater but in a shorter list of word pairs, the percentage of word pairs recalled is greater.
Sometimes, when recalling word pairs, there is an intrusion. An intrusion is an error that participants make when they attempt to recall a word based on a cue of that word pair. Intrusions tend to have either semantic attributes in common with the correct word not recalled or have been previously studied in another word pair on the current list or a previously studied list or were close in time to the cue item. When two items are similar, an intrusion may occur. Professor Kahana and Marieke Vugt at the University of Pennsylvania examined the effects of face similarity for face-name associations. In the first experiment, they wanted to determine if performance of recall would vary with the number of faces in the study set similar to the cue face. Faces were similar if the radius of the faces were within a range. The number of faces within a radius is called a neighborhood density. They found that the recall of a name to face exhibited a lower accuracy and slower reaction time for faces with a greater neighborhood density. The more similarity that two faces have, the greater the probability for interference between the two faces. When cued with face A name B may be recalled if face A and B are similar. The probability of correct recall came from the number of faces with similar faces.
Cues act as guides to what the person is supposed to remember. A cue can be virtually anything that may act as a reminder, e.g. a smell, song, color, place etc. In contrast to free recall, the subject is prompted to remember a certain item on the list or remember the list in a certain order. Cued recall also plays into free recall because when cues are provided to a subject, they will remember items on the list that they did not originally recall without a cue. Tulving explained this phenomenon in his research. When he gave participants associative cues to items that they did not originally recall and that were thought to be lost to memory, the participants were able to recall the item.
Serial recall in long-term memory
(LTM) differs from serial recall in short-term memory
(STM). To store a sequence in LTM, the sequence is repeated over time until it is represented in memory as a whole, rather than as a series of items. In this way, there is no need to remember the relationships between the items and their original positions. In STM, immediate serial recall (ISR) has been thought to result from one of two mechanisms. The first refers to ISR as a result of associations between the items and their positions in a sequence, while the second refers to associations between items. These associations between items are referred to as chaining, and according to research it is an unlikely mechanism. Position-item relationships do not account for recency and primacy effects, or the phonological similarity effect. The Primacy Model moves away from these two assumptions, suggesting that ISR results from a gradient of activation levels where each item has a particular level of activation that corresponds to its position. Research has supported the fact that immediate serial recall performance is much better when the list is homogenous (of the same semantic category) than when they are heterogeneous (of different semantic category). This suggests that semantic representations are beneficial to immediate serial recall performance. Short-term serial recall is also affected by similar sounding items, as recall is lower (remembered more poorly) than items that do not sound alike. This is true when lists are tested independently (when comparing two separate lists of similar sounding and not similar sounding items) as well as when tested using a mixed list. Alan Baddeley
first reported such an experiment in which items within a list were either mutually dissimilar or highly similar.
There is evidence indicating that rhythm is highly sensitive to competing motor production. Actions such as paced finger tapping can have an effect on recall as the disruptive impact of paced finger tapping, but lack of consistent effect of paced irrelevant sound, is indicative of motor feedback from the tapping task disrupting rehearsal and storage.
Seven different effects are generally seen in serial recall studies with humans:
1. List length effect: Performance for serial recall decreases as the length of the list or sequence increases.
2. Primacy and recency effects
: Primacy effects refer to better recall of items earlier in the sequence, while recency effects refer to better recall of the last few items. Recency effects are seen more with auditory stimuli rather than verbal stimuli as auditory presentation seems to protect the end of lists from output interference.
3. Transposition gradients: Transposition gradients refer to the fact that recall tends to be better for item identity rather than the order of items in a sequence. Basically, subjects tend to remember the correct items in the wrong order.
4. Item confusion errors: When an item is incorrectly recalled, there is a tendency to respond with an item that resembles the original item in that position. When tested with verbal stimuli, the mistakes tended to be phonological (e.g. DOG instead of FOG), while spatial stimuli tended to have spatial similarity (e.g. spatial proximity).
5. Repetition errors: These occur during the recall of a sequence when an item from an earlier position in the sequence is given again in another position. This effect is fairly rare in humans.
6. Fill-in effects: If an item is recalled incorrectly at an earlier position than its original place, there is a tendency for the next item recalled to be the item that was displaced by this error. For example, if the sequence is 'LMNOP' and recall began 'LMO', then the next item is likely to be ‘N’.
7. Protrusion effects: These occur when an item from a previous trial is recalled in a current trial. This item is likely to be recalled at its position from the original trial.
8. Word-length effects
Short words are recalled more accurately than longer words. The word-length effect is larger in serial recall than it is in probed recall.
, globus pallidus
, thalamus
, and cerebellum
show higher activation during recall than during recognition which suggests that these components of the cerebello-frontal pathway play a role in recall processes that they do not in recognition. Although recall and recognition are considered separate processes, it should be noted that they are both most likely constitute components of distributed networks of brain regions.
According to neuroimaging data, PET
studies on recall and recognition have consistently found increases in regional cerebral blood flow (RCBF) in the following six brain regions: (1) the prefrontal cortex
, particularly on the right hemisphere; (2) the hippocampal and parahippocampal regions of the medial temporal lobe; (3) the anterior cingulate cortex; (4) the posterior midline area that includes posterior cingulate, retrosplenial (see retrosplenial region
), precuneus
, and cuneus regions; (5) the inferior parietal cortex, especially on the right hemisphere; and (6) the cerebellum, particularly on the left.
The specific role of each of the six main regions in episodic retrieval is still unclear, but some ideas have been suggested. The right prefrontal cortex has been related to retrieval attempt; the medial temporal lobes to conscious recollection; the anterior cingulate to response selection; the posterior midline region to imagery; the inferior parietal to awareness of space; and the cerebellum to self-initiated retrieval .
In recent research, a group of subjects was faced with remembering a list of items and then measured when trying to recall said items. The evoked potentials and hemodynamic activity measured during encoding were found to exhibit reliable differences between subsequently recalled and not recalled items. This effect has been termed the subsequent memory effect (SME). This difference in these specific brain regions determines whether or not a item is recalled. A study by Fernandez et al. has shown that the differences that predict recall appear both as a negative deflection in the rhinal cortex
of an event-related potential (ERP)
400 m/sec after stimulus exposure, and as a positive hippocampal ERP beginning 800 m/sec after stimulus onset. This means that recall only occurs if these two brain regions (rhinal cortex and hippocampus) are activated in synchrony.
is demonstrated when material learned under the influence of a drug is best recalled in that same drug state. A study by Carter and Cassady (1998) showed this effect with antihistamine
. In other words, if you study while on hay fever tablets, then you will recall more of what you studied if you test yourself while on antihistamines in comparison to testing yourself while not on antihistamines after having studied on antihistamines.
A study by Block and Ghoneim (2000) found that, relative to a matched group of healthy, non-drug-using controls, heavy marijuana use is associated with small but significant impairments in memory retrieval.Cannabis
induces loss of internal control and cognitive impairment, especially impairment of attention and memory, for the duration of the intoxication period.
Stimulants, such as cocaine
, amphetamines or caffeine
are known to improve recall in humans. However, the effect of prolonged use of stimulants on cognitive functioning is very different from the impact on one-time users. Some researchers have found stimulant use to lower recall rates in humans after prolonged usage. MDMA users are found to exhibit difficulties encoding information into long-term memory, display impaired verbal learning, are more easily distracted, and are less efficient at focusing attention on complex tasks. The degree of executive impairment increases with the severity of use, and the impairments are relatively long-lasting. Chronic cocaine users display impaired attention, learning, memory, reaction time and cognitive flexibility. Whether or not stimulants have a positive or negative effect on recall depends on how much is used and for how long.
, or "knowing about knowing". This includes many states of conscious awareness known as feeling-of-knowing states, such as the tip-of-the-tongue state. It has been suggested that metacognition serves a self-regulatory purpose whereby the brain can observe errors in processing and actively devote resources to resolving the problem. It is considered an important aspect of cognition that can aid in the development of successful learning strategies that can also be generalized to other situations.
A tip of the tongue
(TOT) state refers to the perception of a large gap between the identification or knowledge of a specific subject and being able to recall descriptors or names involving said subject. There are two prevalent perspectives of TOT states: the psycholinguistic perspective and the metacognitive perspective.
Psycholinguistics views TOT states as a failure of retrieval from lexical memory (see Cohort Model
) being cued by semantic memory
(facts). Since there is an observed increase in the frequency of TOT states with age, there are two mechanisms within psycholinguistics that could account for the TOT phenomenon. The first is the degradation of lexical networks with age, where degrading connections between the priming of knowledge and vocabulary increases difficulty of successfully retrieving a word from memory. The second suggests that the culmination of knowledge, experience, and vocabulary with age results in a similar situation where many connections between a diverse vocabulary and diverse knowledge also increases the difficulty of successful retrieval of a word from memory.
The metacognitive perspective views TOT states simply as the awareness felt when such an event occurs and the perception of the experience involved. Mainly being aware of a TOT state can result in the rapid devotion of cognitive resources to resolving the state and successfully retrieving the word from memory. Such an explanation leaves much to be desired; however, the psycholinguistic perspective and the metacognitive perspective on TOT states are not mutually exclusive and both are used to observe TOT states in a laboratory setting.
An incubation effect can be observed in TOT states, where the passage of time alone can influence the resolution of the state and result in successful recall. Also, the presence of a TOT state is a good predictor that the problem can be resolved correctly, although this has been shown to occur more frequently with older-young-adults than young-adults or seniors. This is evidence for both the metacognitive perspective as well as the psycholinguistic perspective. It demonstrates the devotion of resources to searching memory, a source of cumulative information, for the desired correct information, and it also shows that we are aware of what information we know or do not know. This is why the current debate between the psycholinguistic view of TOTs as retrieval failure and the metacognitive view of TOTs as a tool for learning continues.
retrieval, and involuntary semantic memory retrieval. Both of these phenomena can be considered emergent aspects of otherwise normal and quite efficient cognitive processes.
Involuntary autobiographical memory (IAM) retrieval occurs spontaneously as the result of sensory cue
s as well as internal cues, such as thought or intention. These cues influence us in our day-to-day lives by constantly and automatically activating unconscious memories through priming
. It has been demonstrated in many studies that our specific goals and intentions will most frequently result in the retrieval of related IAM, while the second most frequent IAM retrievals result from physical cues in the surrounding context. Autobiographical memories that are unrelated to any specific cues, whether internal or external, are the least frequent to occur. It has been suggested that in this case, an error in self-regulation of memory has occurred that results in an unrelated autobiographical memory reaching the conscious mind. These findings are consistent with metacognition as the third type of experience is often identified as the most salient one.
Involuntary semantic memory retrieval (ISM), or "semantic-popping", occurs in the same fashion as IAM retrieval. However, the elicited memory is devoid of personal grounding and often considered trivial, such as a random word, image, or phrase. ISM retrieval can occur as a result of spreading activation
, where words, thoughts, and concepts activate related semantic memories continually. When enough related memories are primed that an interrelated concept, word, thought, or image "pops" into consciousness and you are unaware of the extent of its relatedness within your memory. Spreading activation is thought to build over a period of many hours, days, or even weeks before a random semantic memory "pops".
False memories result from persistent beliefs, suggestions via authority figures, or statements of false information. Repeated exposure to these stimuli influence the reorganization of a person's memory, affecting its details, or implanting vivid false accounts of an event. This is usually accounted for by source-monitoring error, where a person can recall specific facts, but cannot correctly identify the source of that knowledge because of apparent loss of the association between the episodic
(specific experience, or source) and semantic
(concept-based, or gist) accounts of the stored knowledge. An example of this is cryptomnesia
, or inadvertent plagiarism, where one duplicates a work that they have previously encountered believing it to be their original idea. False memories can also be accounted for by the generation effect
, which is an observable phenomena where repeated exposure to a belief, suggestion, or false information is better remembered with each subsequent generation. This can be seen with the misinformation effect
, where an eye-witness account of an event can be influenced by a bystander account of the same event, or by suggestion via an authority figure. It is also believed to influence the recovery of repressed shocking or abusive memories in patients under hypnosis, where the recovered memory, although possibly a vivid account, could be entirely false, or have specific details influenced as the result of persistent suggestion by the therapist.
is typically the result of physical or psychological trauma
which manifests itself as the inability to remember information preceding the traumatic event. It is usually accompanied by some type of anterograde amnesia
, or inability to acquire new knowledge. Focal retrograde amnesia (FRA), sometimes known as functional amnesia, refers to the presence of retrograde amnesia while knowledge acquisition remains intact (no anterograde amnesia). Memory for how to use objects and perform skills (implicit memory
) may remain intact while specific knowledge of personal events or previously learned facts (explicit memory
) become inaccessible or lost. Amnesia can result from a number of different causes, including encephalitis
, severe traumatic brain injury
, vitamin B1
deficiency as seen in Korsakoff's Syndrome
, and psychotic episodes, or by witnessing an emotionally traumatic event (Dissociative amnesia). Dysfunction of the temporal and frontal lobes have been observed in many cases of focal retrograde amnesia, whether metabolic or the result of lesions. However, this evidence only appears to correlate with the symptoms of retrograde amnesia as cases have been observed where patients suffering from minor concussions, showing no visible brain damage, develop FRA. It has been suggested that FRA could represent a variety of different disorders, cognitive deficits, or conditions that result in disproportionate loss of explicit memory, hence Disproportionate Retrograde Amnesia.
wrote the short story Funes the Memorious
in 1944. It depicts the life of Ireneo Funes, a fictional character who falls off his horse and experiences a head injury. After this accident, Funes has total recall abilities. He is said to recall an entire day with no mistakes, but this feat of recall takes him an entire day to accomplish. It is said that Borges was ahead of his time in his description of memory processes in this story, as it was not until the 1950s and research on the patient HM that some of what the author describes began to be understood. A more recent instance of total recall in literature is found in Dan Brown’s books The Da Vinci Code
and Angels & Demons, in which the main character, Dr. Robert Langdon, a religious iconography and symbology professor at Harvard University, has almost total recall ability. In The Curious Incident of the Dog in the Nighttime by Mark Haddon, the main character, Christopher Boone, is a 15-year old autistic boy with total recall abilities.
Total recall is popular in television. It can be seen in Season 4 of the television show "Criminal Minds
", in which the character Dr. Spencer Reid claims to have total recall ability. Agent Fox Mulder from the television show "The X-Files
" has a photographic memory, a popular term for total recall. Also, the character of hospital resident Lexie Grey on the television show "Grey’s Anatomy" has total recall ability.
(2003). This fish, like Leonard, shows memory problems faced by most amnesics where she forgets names, has difficulty storing and recalling information, and often forgets what she is doing, or why she is doing something.
Movies tend to show amnesia as a result of head injury from accidents or attacks. The loss of identity and autobiographical memory shown in Santa Who?
(2000) in which Santa suffers from amnesia that destroys his identity and memory of himself is very unlikely in the real world. This is also portrayed in The Bourne Identity
(2002) and The Bourne Supremacy
(2004) where the main character forgets he is a trained assassin. Another misrepresentation of the reality of memory loss in the movies can be seen in Clean Slate (1994) and 50 First Dates
(2004) where the characters are able to encode memory during the day but lose all memory of that day at night, while sleeping.
Movies often restore victim’s memory through a second trauma, or through a kind of cued recall when they revisit familiar places or see familiar objects. The phenomenon of the second trauma can be seen in Singing in the Dark (1956) where the victim experiences the onset of amnesia because of the trauma of the Holocaust, but memory is restored with a blow to the head. Although neurosurgery is often the cause of amnesia, it is seen as a solution in some movies, including Deluxe Annie (1918) and Rascals (1938).
Memory erasure is portrayed in Eternal Sunshine of the Spotless Mind
(2004) and in the Men in Black
movies. Men in Black features a device to erase the potentially harmful memories of extraterrestrial interactions in members of the general public. Eternal Sunshine of the Spotless Mind describes a process that targets and erases memories of interpersonal relationships the patients would rather forget so that they are no longer able to recall the experience. In Paycheck
(2003) and Total Recall
(1990) memory suppression is used to control and the characters are able to overcome the attempts and recall pieces of their memory.
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
refers to the retrieval of events or information from the past. Along with encoding
Encoding (Memory)
Memory has the ability to encode, store and recall information. Memories give an organism the capability to learn and adapt from previous experiences as well as build relationships. Encoding allows the perceived item of use or interest to be converted into a construct that can be stored within the...
and storage
Storage (memory)
Storage in human memory is one of three core process of memory, along with Recall and Encoding. It refers to the retention of information, which has been achieved through the encoding process, in brain for prolonged period of time until it is accessed by the recall process...
, it is one of the three core processes of memory. There are three main types of recall: free recall
Free recall
Free recall is a basic paradigm in the psychological study of memory. In this paradigm, participants study a list of items on each trial, and then are prompted to recall the items in any order...
, cued recall and serial recall. Psychologist
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...
s test these forms of recall as a way to study the memory processes of humans and animals.
Two main theories of the process of recall are the Two-Stage Theory and the theory of Encoding Specificity.
Two-stage theory
The two-stage theory states that the process of recall begins with a search and retrieval process, and then a decision or recognitionRecognition memory
Recognition memory is a subcategory of declarative memory Essentially, recognition memory is the ability to recognize previously encountered events, objects, or people...
process where the correct information is chosen from what has been retrieved. In this theory, recognition only involves the latter of these two stages, or processes, and this is thought to account for the superiority of the recognition process over recall. Recognition only involves one process in which error or failure may occur, while recall involves two. However, recall has been found to be superior to recognition in some cases, such as a failure to recognize words that can later be recalled.
Encoding specificity
The theory of encoding specificity finds similarities between the process of recognition and that of recall. The encoding specificity principle states that memory utilizes information from the memory trace, or the situation in which it was learned, and from the environment in which it is retrieved. Encoding specificity helps to take into account context cues because of its focus on the retrieval environment, and it also accounts for the fact recognition may not always be superior to recall.History
Philosophical questions regarding how people acquire knowledge about their world spurred the study of memory and learning. Recall is a major part of the study of memory and often comes into play in all research. For this reason, the main studies on memory in general will also provide a history to the study of recall.Hermann Ebbinghaus
Hermann Ebbinghaus was a German psychologist who pioneered the experimental study of memory, and is known for his discovery of the forgetting curve and the spacing effect. He was also the first person to describe the learning curve...
in 1885, the study of memory has continued to be a popular topic among researchers. Ebbinghaus created nonsense syllable
Nonsense syllable
In cognitive psychology, a nonsense syllable is a word-like string of letters that is not intended to have any established meaning; it is a special case of a non-lexical vocable...
s, combinations of letters that do not follow grammatical rules and have no meaning, to test his own memory. He would memorize a list of nonsense syllables and then test his recall of that list over varying time periods. He discovered that memory loss occurred rapidly over the first few hours or days, but showed a more steady, gradual decline over subsequent days, weeks, and months. Furthermore, Ebbinghaus discovered that multiple learning, over-learning, and spacing study times increased retention of information. Ebbinghaus’ research influenced much of the research conducted on memory and recall throughout the twentieth century.
Frederic Bartlett
Frederic Bartlett
Sir Frederic Charles Bartlett FRS was a British psychologist and the first professor of experimental psychology at the University of Cambridge. He was one of the forerunners of cognitive psychology...
was a prominent researcher in the field of memory during the mid-twentieth century. He was a British experimental psychologist who focused on the mistakes people made when recalling new information. One of his well known works was Remembering: A Study in Experimental and Social Psychology, which he published in 1932. He is well known for his use of North American Native folk tales, including The War of the Ghosts. He would provide participants in his study with an excerpt from a story and then asked them to recall it as accurately as they could. Retention intervals would vary from directly after reading the story to days later. Bartlett found that people strive for meaning, by attempting to understand the overall meaning of the story. Since the folk tale included supernatural elements, people would rationalize them to make them fit better with their own culture. Ultimately, Bartlett argued that the mistakes that the participants made could be attributed to schematic intrusions. Their current sets of knowledge intruded on their accurately recalling the folk tale.
In the 1950s there was a change in the overall study of memory that has come to be known as the cognitive revolution
Cognitive revolution
The cognitive revolution is the name for an intellectual movement in the 1950s that began what are known collectively as the cognitive sciences. It began in the modern context of greater interdisciplinary communication and research...
. This included new theories on how to view memory, often likening it to a computer processing model. Two important books influenced the revolution: Plans and Structures of Behavior by George Miller, Eugene Galanter, and Karl H. Pribram
Karl H. Pribram
Karl H. Pribram is a professor at Georgetown University, in the United States, and an emeritus professor of psychology and psychiatry at Stanford University and Radford University...
in 1960 and Cognitive Psychology by Ulric Neisser
Ulric Neisser
Ulric Neisser is an American psychologist and member of the National Academy of Sciences. He is a faculty member at Cornell University. In 1995, he headed an American Psychological Association task force that reviewed The Bell Curve and related controversies in the study of intelligence. The task...
in 1967. Both provided arguments for an information-processing view of the human mind. Allen Newell
Allen Newell
Allen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...
and Herbert Simon
Herbert Simon
Herbert Alexander Simon was an American political scientist, economist, sociologist, and psychologist, and professor—most notably at Carnegie Mellon University—whose research ranged across the fields of cognitive psychology, cognitive science, computer science, public administration, economics,...
constructed computer programs that simulated the thought processes people go through when solving different kinds of problems.
In the 1960s, interest in short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
(STM) increased. Before the 1960s, there was very little research that studied the workings of short-term memory and rapid memory loss. Lloyd and Margaret Peterson observed that when people are given a short list of words or letters and then are distracted and occupied with another task for few seconds, their memory for the list is greatly decreased.
Atkinson and Shiffrin (1973) created the short term memory model, which became the popular model for studying short term memory.
The next major development in the study of memory recall was Endel Tulving
Endel Tulving
Endel Tulving is an experimental psychologist and cognitive neuroscientist whose research on human memory has influenced generations of psychological scientists, neuroscientists, and clinicians...
’s proposition of two kinds of memory: episodic and semantic. Tulving described episodic memory
Episodic memory
Episodic memory is the memory of autobiographical events that can be explicitly stated. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory...
as a memory about a specific event that occurred at a particular time and place, for example what you got for your 10th birthday. Semantic memories
Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. The conscious recollection of factual information and general knowledge about the world is generally thought to be independent of context and personal relevance...
are abstract words, concepts, and rules stored in long-term memory
Long-term memory
Long-term memory is memory in which associations among items are stored, as part of the theory of a dual-store memory model. According to the theory, long term memory differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 20–30...
. Furthermore, Endel Tulving devised the encoding specificity principle in 1983, which explains the importance of the relation between the encoding of information and then recalling that information. To explain further, the encoding specificity principle means that a person is more likely to recall information if the recall cues match or are similar to the encoding cues.
The 1960s also saw a development in the study of visual imagery and how it is recalled. This research was led by Allan Paivio
Allan Paivio
Allan Urho Paivio is an emeritus professor of psychology at the University of Western Ontario. He earned his Ph.D. from McGill University in 1959 and taught at the University of Western Ontario from 1963 until his retirement.-Early life:...
, who found that the more image-arousing a word was the more likely it would be recalled in either free recall or paired associates.
There has been a considerable amount of research into the workings of memory, and specifically recall since the 1980s. The previously mentioned research was developed and improved upon, and new research was and still is being conducted.
Free recall
Free recallFree recall
Free recall is a basic paradigm in the psychological study of memory. In this paradigm, participants study a list of items on each trial, and then are prompted to recall the items in any order...
describes the process in which a person is given a list of items to remember and then is tested by being asked to recall them in any order. Free recall often displays evidence of primacy
Serial position effect
The serial position effect, a term coined by Hermann Ebbinghaus through studies he performed on himself, refers to the finding that recall accuracy varies as a function of an item's position within a study list . When asked to recall a list of items in any order , people tend to begin recall with...
and recency effects
Serial position effect
The serial position effect, a term coined by Hermann Ebbinghaus through studies he performed on himself, refers to the finding that recall accuracy varies as a function of an item's position within a study list . When asked to recall a list of items in any order , people tend to begin recall with...
. Primacy effects are displayed when the person recalls items presented at the beginning of the list earlier and more often. The recency effect is when the person recalls items presented at the end of the list earlier and more often.
Cued recall
Cued Recall is an experimental procedure during which a person is given a list of items to remember and is then tested with the use of cues in order to study memory. Participants are given pairs, usually of words, A1-B1, A2-B2…AL-BL, (L is the number of pairs in a list) to study. Then the experimenter gives the participant a word to cue the participant to recall the word with which it was originally paired. The word presentation can either be visual or auditory.There are two basic experimental methods used to conduct cued recall, the study-test method and the anticipation method. In the study-test method participants study a list of word pairs presented individually. Immediately after or after a time delay, participants are tested in the study phase of the experiment on the word pairs just previously studied. One word of each pair is presented in a random order and the participant is asked to recall the item with which it was originally paired. The participant can be tested for either forward recall, Ai is presented as a cue for Bi, or backward recall, Bi is presented as a cue for Ai. In the anticipation method, participants are shown Ai and are asked to anticipate the word paired with it, Bi. If the participant cannot recall the word, the answer is revealed. During an experiment using the anticipation method, the list of words is repeated until a certain percentage of Bi words are recalled.
The learning curve for cued recall increases systematically with the number of trials completed. This result has caused a debate about whether or not learning is all-or-none. One theory is that learning is incremental and that the recall of each word pair is strengthened with repetition. Another theory suggests that learning is all-or-none, that is one learns the word pair in a single trial and memory performance is due to the average learned pairs, some of which are learned on earlier trials and some on later trials. To examine the validity of these theories researchers have performed memory experiments. In one experiment, Irwin Rock University of Illinois had a control group and experimental group learn pairs of words. The control group studied word pairs that were repeated until the participants learned all the word pairs. In the experimental group, the learned pairs remained in the list while unlearned pairs were substituted with recombinations of previous words. Rock believed that associations between two items would be strengthened if learning were incremental even when pairs are not correctly recalled. His hypothesis was that the control group would have a higher correct recall probability than the experimental group. He thought that repetition would increase the strength of the word pair until the strength reaches a threshold needed to produce an overt response. If learning were all or none, then the control group and the experimental group should learn the word pairs at the same rate. Rock found experimentally there was little difference in learning rates between the two groups. However, Rock’s work did not settle the controversy because in his experiment he rearranged replaced word pairs that could be either easier or harder to learn than the original words in the word- digit pair. In further experiments that addressed the question, there were mixed results. The incremental learning hypothesis is supported by the notion that awhile after Ai-Bi pairs are learned, the recall time to recall Bi decreases with continued learning trails.
Another theory that can be tested using cued recall is symmetry of forward and backward recall. Forward recall is generally assumed to be easier than backward recall, i.e. forward recall is stronger than backward recall. This is generally true for long sequences of word or letters such as the alphabet. In one view, the independent associations hypothesis, the strength of forward and backward recall are hypothesized to be independent of each other. To confirm this hypothesis, Dr. George Wolford tested participants’ forward and backward recall and found that forward and backward recall are independent of each other. The probability of correct forward recall was .47 for word pair associations and the probability of correct backward recall of word pair associations was .25. However in another view, the associative symmetry hypothesis, the strengths of forward and backward recall are about equal and highly correlated. In S.E Asch from Swathmore College and S. M Ebenholtz’s experiment, participants learned pairs of nonsense syllables by anticipation recall. After reaching a certain threshold of learning, the participants were tested by free recall to determine all pairs and single items they could remember. These researchers found that backward association was greatly weaker than forward association. However, when the availability of forward and backward recall were basically the same, there was little difference between forward and backward recall. Some scientists including Asch and Ebenholtz believe in the independent association hypothesis think that the equal strengths of forward and backward recall are compatible with their hypothesis because forward and backward recall could be independent but with equal strengths. However associative symmetry theorists interpreted the data to mean that the results fit their hypothesis.
Another study done using cued recall found that learning occurs during test trials. Mark Carrier and Pashler (1992) found that the group with a study-only phase makes 10% more errors than the group with a test-study phase. In the study-only phase, participants were given Ai-Bi, where Ai was an English word and Bi was a Siberian Eskimo Yupik word. In the test study phase, participants first attempted to recall Bi given Ai as a cue then they were shown Ai-Bi pair together. This result suggests that after participants learn something, testing their memory with mental operations helps later recall. The act of recalling instead of restudying creates new and longer lasting connection between Ai and Bi.
Another study showed that when lists are tested immediately after study, the last couple of pairs are remembered best. After a five second delay, the recall of recently studied words diminishes. However, word pairs at the beginning of a list still show better recall. Moreover, in a longer list, the absolute number of word pairs recalled is greater but in a shorter list of word pairs, the percentage of word pairs recalled is greater.
Sometimes, when recalling word pairs, there is an intrusion. An intrusion is an error that participants make when they attempt to recall a word based on a cue of that word pair. Intrusions tend to have either semantic attributes in common with the correct word not recalled or have been previously studied in another word pair on the current list or a previously studied list or were close in time to the cue item. When two items are similar, an intrusion may occur. Professor Kahana and Marieke Vugt at the University of Pennsylvania examined the effects of face similarity for face-name associations. In the first experiment, they wanted to determine if performance of recall would vary with the number of faces in the study set similar to the cue face. Faces were similar if the radius of the faces were within a range. The number of faces within a radius is called a neighborhood density. They found that the recall of a name to face exhibited a lower accuracy and slower reaction time for faces with a greater neighborhood density. The more similarity that two faces have, the greater the probability for interference between the two faces. When cued with face A name B may be recalled if face A and B are similar. The probability of correct recall came from the number of faces with similar faces.
Cues act as guides to what the person is supposed to remember. A cue can be virtually anything that may act as a reminder, e.g. a smell, song, color, place etc. In contrast to free recall, the subject is prompted to remember a certain item on the list or remember the list in a certain order. Cued recall also plays into free recall because when cues are provided to a subject, they will remember items on the list that they did not originally recall without a cue. Tulving explained this phenomenon in his research. When he gave participants associative cues to items that they did not originally recall and that were thought to be lost to memory, the participants were able to recall the item.
Serial recall
Serial recall refers to our ability to recall items or events in the order in which they occurred. The ability of humans to store items in memory and recall them is important to the use of language. Imagine recalling the different parts of a sentence, but in the wrong order. The ability to recall in serial order has been found not only in humans, but in a number of non-human primate species and some non-primates. Imagine mixing up the order of phonemes, or meaningful units of sound, in a word so that “slight” becomes “style." Serial-order also helps us remember the order of events in our lives, our autobiographical memories. Our memory of our past appears to exist on a continuum on which more recent events are more easily remembered in order.Serial recall in long-term memory
Long-term memory
Long-term memory is memory in which associations among items are stored, as part of the theory of a dual-store memory model. According to the theory, long term memory differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around 20–30...
(LTM) differs from serial recall in short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
(STM). To store a sequence in LTM, the sequence is repeated over time until it is represented in memory as a whole, rather than as a series of items. In this way, there is no need to remember the relationships between the items and their original positions. In STM, immediate serial recall (ISR) has been thought to result from one of two mechanisms. The first refers to ISR as a result of associations between the items and their positions in a sequence, while the second refers to associations between items. These associations between items are referred to as chaining, and according to research it is an unlikely mechanism. Position-item relationships do not account for recency and primacy effects, or the phonological similarity effect. The Primacy Model moves away from these two assumptions, suggesting that ISR results from a gradient of activation levels where each item has a particular level of activation that corresponds to its position. Research has supported the fact that immediate serial recall performance is much better when the list is homogenous (of the same semantic category) than when they are heterogeneous (of different semantic category). This suggests that semantic representations are beneficial to immediate serial recall performance. Short-term serial recall is also affected by similar sounding items, as recall is lower (remembered more poorly) than items that do not sound alike. This is true when lists are tested independently (when comparing two separate lists of similar sounding and not similar sounding items) as well as when tested using a mixed list. Alan Baddeley
Alan Baddeley
Alan David Baddeley FRS, CBE is a British psychologist. He is professor of psychology at the University of York. He is known for his work on working memory, in particular for his multiple components model.-Education:...
first reported such an experiment in which items within a list were either mutually dissimilar or highly similar.
There is evidence indicating that rhythm is highly sensitive to competing motor production. Actions such as paced finger tapping can have an effect on recall as the disruptive impact of paced finger tapping, but lack of consistent effect of paced irrelevant sound, is indicative of motor feedback from the tapping task disrupting rehearsal and storage.
Seven different effects are generally seen in serial recall studies with humans:
1. List length effect: Performance for serial recall decreases as the length of the list or sequence increases.
2. Primacy and recency effects
Serial position effect
The serial position effect, a term coined by Hermann Ebbinghaus through studies he performed on himself, refers to the finding that recall accuracy varies as a function of an item's position within a study list . When asked to recall a list of items in any order , people tend to begin recall with...
: Primacy effects refer to better recall of items earlier in the sequence, while recency effects refer to better recall of the last few items. Recency effects are seen more with auditory stimuli rather than verbal stimuli as auditory presentation seems to protect the end of lists from output interference.
3. Transposition gradients: Transposition gradients refer to the fact that recall tends to be better for item identity rather than the order of items in a sequence. Basically, subjects tend to remember the correct items in the wrong order.
4. Item confusion errors: When an item is incorrectly recalled, there is a tendency to respond with an item that resembles the original item in that position. When tested with verbal stimuli, the mistakes tended to be phonological (e.g. DOG instead of FOG), while spatial stimuli tended to have spatial similarity (e.g. spatial proximity).
5. Repetition errors: These occur during the recall of a sequence when an item from an earlier position in the sequence is given again in another position. This effect is fairly rare in humans.
6. Fill-in effects: If an item is recalled incorrectly at an earlier position than its original place, there is a tendency for the next item recalled to be the item that was displaced by this error. For example, if the sequence is 'LMNOP' and recall began 'LMO', then the next item is likely to be ‘N’.
7. Protrusion effects: These occur when an item from a previous trial is recalled in a current trial. This item is likely to be recalled at its position from the original trial.
8. Word-length effects
Short words are recalled more accurately than longer words. The word-length effect is larger in serial recall than it is in probed recall.
Neuroanatomy
The anterior cingulate cortexAnterior cingulate cortex
The anterior cingulate cortex is the frontal part of the cingulate cortex, that resembles a "collar" form around the corpus callosum, the fibrous bundle that relays neural signals between the right and left cerebral hemispheres of the brain...
, globus pallidus
Globus pallidus
The globus pallidus also known as paleostriatum, is a sub-cortical structure of the brain. Topographically, it is part of the telencephalon, but retains close functional ties with the subthalamus - both of which are part of the extrapyramidal motor system...
, thalamus
Thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...
, and cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
show higher activation during recall than during recognition which suggests that these components of the cerebello-frontal pathway play a role in recall processes that they do not in recognition. Although recall and recognition are considered separate processes, it should be noted that they are both most likely constitute components of distributed networks of brain regions.
Positron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...
studies on recall and recognition have consistently found increases in regional cerebral blood flow (RCBF) in the following six brain regions: (1) the prefrontal cortex
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
, particularly on the right hemisphere; (2) the hippocampal and parahippocampal regions of the medial temporal lobe; (3) the anterior cingulate cortex; (4) the posterior midline area that includes posterior cingulate, retrosplenial (see retrosplenial region
Retrosplenial region
The retrosplenial region is a brain area and part of the cingulate cortex. It is defined by Brodmann area 26, Brodmann area 29 and Brodmann area 30.-Function:...
), precuneus
Precuneus
The precuneus is a part of the superior parietal lobule hidden in the medial longitudinal fissure between the two cerebral hemispheres. It is sometimes described as the medial area of the superior parietal cortex. It is involved with episodic memory, visuospatial processing, reflections upon self,...
, and cuneus regions; (5) the inferior parietal cortex, especially on the right hemisphere; and (6) the cerebellum, particularly on the left.
The specific role of each of the six main regions in episodic retrieval is still unclear, but some ideas have been suggested. The right prefrontal cortex has been related to retrieval attempt; the medial temporal lobes to conscious recollection; the anterior cingulate to response selection; the posterior midline region to imagery; the inferior parietal to awareness of space; and the cerebellum to self-initiated retrieval .
Rhinal cortex
The rhinal cortex is the cortex surrounding the rhinal fissure, including the entorhinal cortex and the perirhinal cortex.It is a cortical region in the medial temporal lobe that is made up of Brodmann areas 28, 34, 35 and 36....
of an event-related potential (ERP)
Event-related potential
An event-related potential is any measured brain response that is directly the result of a thought or perception. More formally, it is any stereotyped electrophysiological response to an internal or external stimulus....
400 m/sec after stimulus exposure, and as a positive hippocampal ERP beginning 800 m/sec after stimulus onset. This means that recall only occurs if these two brain regions (rhinal cortex and hippocampus) are activated in synchrony.
Attention
The effect of attention on memory recall has surprising results. It seems that the only time attention largely affects memory is during the encoding phase . During this phase, performing a parallel task can severely impair retrieval success. It is believed that this phase requires much attention to properly encode the information at hand, and thus a distractor task does not allow proper input and reduces the amount of information learned. Experiments have been done that suggest that the early encoding phase, in which words are identified, is the source of the word frequency effect. Because rarer words (low frequency) are composed of unusual and features that may be difficult to encode, they require more attention. Differences in letter frequency were controlled for. Next, we considered the late phase of encoding, in which meaning is elaborated and connected to the participants’ semantic network. The experimenters explored the hypothesis that semantic information does not contribute to the word frequency effect and found a mirror patterned normative frequency effect when words were studied and tested. When study, test, or both involved objects, the mirror pattern was disrupted and normative frequency had little or no effect on recognition memory. Much of the recognition memory literature has focused on distinguishing between memory models based on the nature of retrieval from memory. However, when looking at the effect of attention on memory retrieval, it has been found that there are only slight inconsistent impairments. This evidence suggests that memory retrieval is an automatic process. One effect of attention on memory recall is that of latency and retrieval time. This is especially evident in free recall. The competition provided at the time of recall due to divided attention slows down the process, yet has little to no effect on its accuracy. Another possible finding for the minimal effect of divided attention is that the process of recall may include less parallel processing than other memory processes. It has also been observed that different parts of the brain are at work depending on whether one is recalling with full rather than divided attention. Evidence for this comes from fMRI data. Performing a secondary task concurrently with a study task has a detrimental effect on later memory for studied items. To investigate the mechanisms underlying this effect, the processing resources available for an incidental encoding task were varied by manipulating secondary task difficulty. Greater activity at study for words later remembered versus words later forgotten-were identified in the left ventral inferior frontal gyrus and the left anterior hippocampus. These effects did not vary according to whether the encoding task was performed concurrently with the easy or the hard secondary task. However, as secondary task difficulty increased, study-item activity declined and auditory-item activity increased in dorsolateral prefrontal and superior parietal regions that have been proved to be in the support of executive and control functions. The findings suggest that dividing attention during encoding influences the probability of engaging the encoding operations that support later episodic memory, but does not alter the nature of the operations themselves. The findings further suggest that the probability of engaging these encoding operations depends on the level of general processing resources engaged in service of the study task.Motivation
Motivation is a factor that encourages a person to perform and succeed at the task at hand. It can be in the form of presented incentive, or personal fear of failure. Any form of motivation thus generally leads a person to better recall. In an experiment done by Roebers, Moga and Schneider (2001), participants were placed in either forced report, free report or free report plus incentive groups. In each group, they found that the amount of correct information recalled did not differ, yet in the group where participants were given an incentive they had higher accuracy results. This means that presenting participants with an encouragement to provide correct information motivates them to be more precise. However, this is only true if the perception is that success is providing correct information. When it is believed that success is the completion of the task rather than the accuracy of that completion, the number of responses is higher, yet its accuracy is lowered. This shows that the results are dependent on how success is defined to the participant. In the Roebers, Moga and Schneider (2001) experiment, the participants that were placed in the forced response group had the lowest overall accuracy. They had no motivation to provide accurate responses and were forced to respond even when they were unsure of the answer. Another study done by Hill RD, Storandt M, Simeone C tests the impact of memory skills training and external reward on free recall of serial word lists. In contrast to older learners, similar effects were seen in children. Two studies were conducted to test incentive magnitude effects on free recall. Experiment I examined whether two incentive levels would differentially influence rehearsal of words paired with the incentive values. Fifth and eighth graders and college adults were tested in conditions in which they were instructed to (a) do all rehearsal overtly or (b) engage in a counting task subsequent to item presentation and refrain from overt and covert rehearsal. College subjects rehearsed and recalled significantly more 10¢ than 1¢ words. Eighth graders tended to favor 10¢ items in recall and rehearsal, but the differences were of questionable reliability. Fifth graders failed to produce reliable Incentive Level effects. Experiment II showed that fifth graders, as well as older subjects, recalled more high-incentive words under standard free-recall instructions in which rehearsal was presumed to be covert. Results support theories emphasizing rehearsal as a mediator of incentive level effects on learning. These results lead to the conclusion that depending on how success is defined to the person, motivation increases a person’s inclination to succeed at appropriate recall.Interference
In the absence of interference, there are two factors at play when recalling a list of items: the recency and the primacy effects. The recency effect occurs when the short-term memory is used to remember the most recent items, and the primacy effect occurs when the long-term memory has encoded the earlier items. The recency effect can be eliminated if there is a period of interference between the input and the output of information extending longer than the holding time of short-term memory (15–30 seconds). This occurs when a person is given subsequent information to recall preceding the recall of the initial information. The primacy effect, however, is not affected by the interference of recall. The elimination of the last few items from memory is due to the displacement of these items from short term memory, by the distracting task. As they have not been recited and rehearsed, they are not moved into long-term memory and are thus lost. A task as simple as counting backwards can change memory recall; however an empty delay interval has no effect. This is because the person can continue to rehearse the items in their working memory to be remembered without interference. Cohen (1989) found that there is better recall for an action in the presence of interference if that action is physically performed during the encoding phase. It has also been found that recalling some items can interfere and inhibit the recall of other items. Another stream of thought and evidence suggests that the effects of interference on recency and primacy are relative, determined by the ratio rule (retention interval to inter item presentation distractor rate) and they exhibit time-scale invariance. Three experiments investigated serial position effects in immediate and final free recall. Each word in a 10-item list was both preceded and followed by a 15-sec period of distraction activity. In Experiment 1, half of the lists were immediately followed by either a recall test or a recognition test; the remaining lists were not tested, but were followed by a different distraction activity. After presentation of all lists, a final recall or recognition test was given. Primacy was observed only in immediate free recall and in all final tests following immediate free recall, demonstrating that primacy develops from a free-recall storage strategy. No recency was observed in Experiment 1. In Experiment 2, every list was followed by an immediate free-recall test, with a final free-recall test after the last list. The primacy results of Experiment 1 were replicated. Furthermore, the appearance of recency in Expriment 2 suggests that recency results from a retrieval strategy that failed to develop in Experiment 1 because some lists were not tested immediately. To eliminate an artifact account, Experiment 3 used an experimenter-paced distractor task and replicated the findings of Experiment 2, which used a subject-paced distractar task. Contrary to previous claims, the pattern of results in the continuous distractor paradigm is seen as completely consistent with the account offered by multistore models of serial position effects in standard free recall.Context
Context-dependency effects on recall are typically interpreted as evidence that the characteristics of the environment are encoded as part of the memory trace and can be used to enhance retrieval of the other information in the trace. In other words, you can recall more when the environments are similar in both the learning and recall phases. Context cues appear to be important in the retrieval of newly learned meaningful information. In a classic study by Godden and Baddelley (1975), they demonstrated that deep-sea divers recalled their training more effectively when trained underwater, rather than being trained on land. An academic application would be that students may perform better on exams by studying in silence, because exams are usually done in silence.State-dependent memory
State-dependent retrievalState-dependent learning
State-dependent learning is a notion that learning and recalling are based upon the physiological and mental state of the organism....
is demonstrated when material learned under the influence of a drug is best recalled in that same drug state. A study by Carter and Cassady (1998) showed this effect with antihistamine
Antihistamine
An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...
. In other words, if you study while on hay fever tablets, then you will recall more of what you studied if you test yourself while on antihistamines in comparison to testing yourself while not on antihistamines after having studied on antihistamines.
A study by Block and Ghoneim (2000) found that, relative to a matched group of healthy, non-drug-using controls, heavy marijuana use is associated with small but significant impairments in memory retrieval.Cannabis
Cannabis
Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a...
induces loss of internal control and cognitive impairment, especially impairment of attention and memory, for the duration of the intoxication period.
Stimulants, such as cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
, amphetamines or caffeine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...
are known to improve recall in humans. However, the effect of prolonged use of stimulants on cognitive functioning is very different from the impact on one-time users. Some researchers have found stimulant use to lower recall rates in humans after prolonged usage. MDMA users are found to exhibit difficulties encoding information into long-term memory, display impaired verbal learning, are more easily distracted, and are less efficient at focusing attention on complex tasks. The degree of executive impairment increases with the severity of use, and the impairments are relatively long-lasting. Chronic cocaine users display impaired attention, learning, memory, reaction time and cognitive flexibility. Whether or not stimulants have a positive or negative effect on recall depends on how much is used and for how long.
Gender
Consistently, females perform better than males on episodic memory tasks including delayed recall and recognition. However, males and females do not differ on working, immediate and semantic memory tasks. In general, neuro-psychological observations suggest that anterior lesions cause greater deficits in females than in male. It has been proposed that the gender differences in memory performance reflect underlying differences in the strategies used to process information, rather than anatomical differences. However, gender differences in cerebral asymmetry received support from morphometric studies showing a greater leftward asymmetry in males than in females, meaning that men and women use each side of their brain to a different extent. There is also evidence for a negative recall bias found in women, which means females in general are more likely than males to recall their mistakes. In a eyewitness study done by Dan Yarmey (1991) from the University of Guelph, he found that women were significantly more accurate than men in accuracy of recall for weight of suspects.Phenomena
The phenomenological account of recall is referred to as metacognitionMetacognition
Metacognition is defined as "cognition about cognition", or "knowing about knowing." It can take many forms; it includes knowledge about when and how to use particular strategies for learning or for problem solving...
, or "knowing about knowing". This includes many states of conscious awareness known as feeling-of-knowing states, such as the tip-of-the-tongue state. It has been suggested that metacognition serves a self-regulatory purpose whereby the brain can observe errors in processing and actively devote resources to resolving the problem. It is considered an important aspect of cognition that can aid in the development of successful learning strategies that can also be generalized to other situations.
Tip-of-the-tongue
Main page: Tip of the tongueTip of the tongue
The tip-of-the-tongue phenomenon is the failure to retrieve a word from memory, combined with partial recall and the feeling that retrieval is imminent...
A tip of the tongue
Tip of the tongue
The tip-of-the-tongue phenomenon is the failure to retrieve a word from memory, combined with partial recall and the feeling that retrieval is imminent...
(TOT) state refers to the perception of a large gap between the identification or knowledge of a specific subject and being able to recall descriptors or names involving said subject. There are two prevalent perspectives of TOT states: the psycholinguistic perspective and the metacognitive perspective.
Psycholinguistics views TOT states as a failure of retrieval from lexical memory (see Cohort Model
Cohort model
The cohort model in psycholinguistics and neurolinguistics is a model of lexical retrieval first proposed by William Marslen-Wilson in the late 1980s. It attempts to describe how visual or auditory input is mapped onto a word in a hearer's lexicon...
) being cued by semantic memory
Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. The conscious recollection of factual information and general knowledge about the world is generally thought to be independent of context and personal relevance...
(facts). Since there is an observed increase in the frequency of TOT states with age, there are two mechanisms within psycholinguistics that could account for the TOT phenomenon. The first is the degradation of lexical networks with age, where degrading connections between the priming of knowledge and vocabulary increases difficulty of successfully retrieving a word from memory. The second suggests that the culmination of knowledge, experience, and vocabulary with age results in a similar situation where many connections between a diverse vocabulary and diverse knowledge also increases the difficulty of successful retrieval of a word from memory.
The metacognitive perspective views TOT states simply as the awareness felt when such an event occurs and the perception of the experience involved. Mainly being aware of a TOT state can result in the rapid devotion of cognitive resources to resolving the state and successfully retrieving the word from memory. Such an explanation leaves much to be desired; however, the psycholinguistic perspective and the metacognitive perspective on TOT states are not mutually exclusive and both are used to observe TOT states in a laboratory setting.
An incubation effect can be observed in TOT states, where the passage of time alone can influence the resolution of the state and result in successful recall. Also, the presence of a TOT state is a good predictor that the problem can be resolved correctly, although this has been shown to occur more frequently with older-young-adults than young-adults or seniors. This is evidence for both the metacognitive perspective as well as the psycholinguistic perspective. It demonstrates the devotion of resources to searching memory, a source of cumulative information, for the desired correct information, and it also shows that we are aware of what information we know or do not know. This is why the current debate between the psycholinguistic view of TOTs as retrieval failure and the metacognitive view of TOTs as a tool for learning continues.
Involuntary memory retrieval
Until recently, research on this phenomenon has been relatively rare, with only two types of involuntary memory retrieval identified: involuntary autobiographical memoryAutobiographical memory
Autobiographical memory is a memory system consisting of episodes recollected from an individual's life, based on a combination of episodic and semantic memory.-Formation:Conway and Pleydell-Pearce proposed that autobiographical...
retrieval, and involuntary semantic memory retrieval. Both of these phenomena can be considered emergent aspects of otherwise normal and quite efficient cognitive processes.
Sensory cue
A sensory cue is a statistic or signal that can be extracted from the sensory input by a perceiver, that indicates the state of some property of the world that the perceiver is interested in perceiving....
s as well as internal cues, such as thought or intention. These cues influence us in our day-to-day lives by constantly and automatically activating unconscious memories through priming
Priming (psychology)
Priming is an implicit memory effect in which exposure to a stimulus influences a response to a later stimulus. It can occur following perceptual, semantic, or conceptual stimulus repetition...
. It has been demonstrated in many studies that our specific goals and intentions will most frequently result in the retrieval of related IAM, while the second most frequent IAM retrievals result from physical cues in the surrounding context. Autobiographical memories that are unrelated to any specific cues, whether internal or external, are the least frequent to occur. It has been suggested that in this case, an error in self-regulation of memory has occurred that results in an unrelated autobiographical memory reaching the conscious mind. These findings are consistent with metacognition as the third type of experience is often identified as the most salient one.
Involuntary semantic memory retrieval (ISM), or "semantic-popping", occurs in the same fashion as IAM retrieval. However, the elicited memory is devoid of personal grounding and often considered trivial, such as a random word, image, or phrase. ISM retrieval can occur as a result of spreading activation
Spreading activation
Spreading activation is a method for searching associative networks, neural networks, or semantic networks. The search process is initiated by labeling a set of source nodes with weights or "activation" and then iteratively propagating or "spreading" that activation out to other nodes linked to...
, where words, thoughts, and concepts activate related semantic memories continually. When enough related memories are primed that an interrelated concept, word, thought, or image "pops" into consciousness and you are unaware of the extent of its relatedness within your memory. Spreading activation is thought to build over a period of many hours, days, or even weeks before a random semantic memory "pops".
False memories
Main page: False memory syndromeFalse memories result from persistent beliefs, suggestions via authority figures, or statements of false information. Repeated exposure to these stimuli influence the reorganization of a person's memory, affecting its details, or implanting vivid false accounts of an event. This is usually accounted for by source-monitoring error, where a person can recall specific facts, but cannot correctly identify the source of that knowledge because of apparent loss of the association between the episodic
Episodic memory
Episodic memory is the memory of autobiographical events that can be explicitly stated. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory...
(specific experience, or source) and semantic
Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. The conscious recollection of factual information and general knowledge about the world is generally thought to be independent of context and personal relevance...
(concept-based, or gist) accounts of the stored knowledge. An example of this is cryptomnesia
Cryptomnesia
Cryptomnesia occurs when a forgotten memory returns without it being recognised as such by the subject, who believes it is something new and original...
, or inadvertent plagiarism, where one duplicates a work that they have previously encountered believing it to be their original idea. False memories can also be accounted for by the generation effect
Generation effect
The generation effect refers to the robust finding that information will be better remembered if it is generated rather than simply read. For example, you are more likely to remember the word "orangutan" if you generate it from the fragment "or_ng_ta_" than if you simply see the word in its...
, which is an observable phenomena where repeated exposure to a belief, suggestion, or false information is better remembered with each subsequent generation. This can be seen with the misinformation effect
Misinformation effect
The misinformation effect refers to the finding that exposure to misleading information presented between the encoding of an event and its subsequent recall causes impairment in memory. This effect occurs when participants' recall of an event they witnessed is altered by introducing misleading...
, where an eye-witness account of an event can be influenced by a bystander account of the same event, or by suggestion via an authority figure. It is also believed to influence the recovery of repressed shocking or abusive memories in patients under hypnosis, where the recovered memory, although possibly a vivid account, could be entirely false, or have specific details influenced as the result of persistent suggestion by the therapist.
Focal retrograde amnesia
Retrograde amnesiaRetrograde amnesia
Retrograde amnesia is a loss of access to events that occurred, or information that was learned, before an injury or the onset of a disease....
is typically the result of physical or psychological trauma
Psychological trauma
Psychological trauma is a type of damage to the psyche that occurs as a result of a traumatic event...
which manifests itself as the inability to remember information preceding the traumatic event. It is usually accompanied by some type of anterograde amnesia
Anterograde amnesia
Anterograde amnesia is a loss of the ability to create new memories after the event that caused the amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. This is in contrast to retrograde amnesia, where memories...
, or inability to acquire new knowledge. Focal retrograde amnesia (FRA), sometimes known as functional amnesia, refers to the presence of retrograde amnesia while knowledge acquisition remains intact (no anterograde amnesia). Memory for how to use objects and perform skills (implicit memory
Implicit memory
Implicit memory is a type of memory in which previous experiences aid in the performance of a task without conscious awareness of these previous experiences. Evidence for implicit memory arises in priming, a process whereby subjects show improved performance on tasks for which they have been...
) may remain intact while specific knowledge of personal events or previously learned facts (explicit memory
Explicit memory
Explicit memory is the conscious, intentional recollection of previous experiences and information. People use explicit memory throughout the day, such as remembering the time of an appointment or recollecting an event from years ago....
) become inaccessible or lost. Amnesia can result from a number of different causes, including encephalitis
Encephalitis
Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...
, severe traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...
, vitamin B1
Thiamine
Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...
deficiency as seen in Korsakoff's Syndrome
Korsakoff's syndrome
Korsakoff's syndrome is a neurological disorder caused by the lack of thiamine in the brain. Its onset is linked to chronic alcohol abuse and/or severe malnutrition...
, and psychotic episodes, or by witnessing an emotionally traumatic event (Dissociative amnesia). Dysfunction of the temporal and frontal lobes have been observed in many cases of focal retrograde amnesia, whether metabolic or the result of lesions. However, this evidence only appears to correlate with the symptoms of retrograde amnesia as cases have been observed where patients suffering from minor concussions, showing no visible brain damage, develop FRA. It has been suggested that FRA could represent a variety of different disorders, cognitive deficits, or conditions that result in disproportionate loss of explicit memory, hence Disproportionate Retrograde Amnesia.
In popular culture
Memory phenomena are rich sources of storylines and novel situations in popular media. Two phenomena that appear regularly are total recall abilities and amnesia.Total recall
The Argentinean author, Jorge Luis BorgesJorge Luis Borges
Jorge Francisco Isidoro Luis Borges Acevedo , known as Jorge Luis Borges , was an Argentine writer, essayist, poet and translator born in Buenos Aires. In 1914 his family moved to Switzerland where he attended school, receiving his baccalauréat from the Collège de Genève in 1918. The family...
wrote the short story Funes the Memorious
Funes the Memorious
"Funes the Memorious" is a fantasy short story by Argentine writer Jorge Luis Borges. First published in La Nación in June 1942, it appeared in the 1944 anthology Ficciones, part two . The first English translation appeared in 1954 in Avon Modern Writing No. 2...
in 1944. It depicts the life of Ireneo Funes, a fictional character who falls off his horse and experiences a head injury. After this accident, Funes has total recall abilities. He is said to recall an entire day with no mistakes, but this feat of recall takes him an entire day to accomplish. It is said that Borges was ahead of his time in his description of memory processes in this story, as it was not until the 1950s and research on the patient HM that some of what the author describes began to be understood. A more recent instance of total recall in literature is found in Dan Brown’s books The Da Vinci Code
The Da Vinci Code
The Da Vinci Code is a 2003 mystery-detective novel written by Dan Brown. It follows symbologist Robert Langdon and Sophie Neveu as they investigate a murder in Paris's Louvre Museum and discover a battle between the Priory of Sion and Opus Dei over the possibility of Jesus having been married to...
and Angels & Demons, in which the main character, Dr. Robert Langdon, a religious iconography and symbology professor at Harvard University, has almost total recall ability. In The Curious Incident of the Dog in the Nighttime by Mark Haddon, the main character, Christopher Boone, is a 15-year old autistic boy with total recall abilities.
Total recall is popular in television. It can be seen in Season 4 of the television show "Criminal Minds
Criminal Minds
Criminal Minds is an American police procedural drama that premiered September 22, 2005, on CBS. The series follows a team of profilers from the FBI's Behavioral Analysis Unit based in Quantico, Virginia. The BAU is part of the FBI National Center for the Analysis of Violent Crime...
", in which the character Dr. Spencer Reid claims to have total recall ability. Agent Fox Mulder from the television show "The X-Files
The X-Files
The X-Files is an American science fiction television series and a part of The X-Files franchise, created by screenwriter Chris Carter. The program originally aired from to . The show was a hit for the Fox network, and its characters and slogans became popular culture touchstones in the 1990s...
" has a photographic memory, a popular term for total recall. Also, the character of hospital resident Lexie Grey on the television show "Grey’s Anatomy" has total recall ability.
Amnesia
Amnesia the damage or disruption of memory processes is a very popular subject in movies since 1915. Although its portrayal is usually inaccurate, there are some exceptions. Memento (2003) is said to be inspired by the condition of the famous amnesic patient known as HM. The main character Leonard suffers from anterograde amnesia after a traumatic attack in which his wife dies. He maintains his identity and shows very little retrograde amnesia. He also displays some of the daily memory problems that are experiences by most amnesics, such as forgetting names or where he is going. Another fairly accurate portrayal of memory disturbances is the non-human character Dory in Finding NemoFinding Nemo
Finding Nemo is a 2003 American comi-drama animated film written by Andrew Stanton, directed by Andrew Stanton and Lee Unkrich and produced by Pixar. It tells the story of the overly protective clownfish Marlin who, along with a regal tang called Dory , searches for his abducted son Nemo...
(2003). This fish, like Leonard, shows memory problems faced by most amnesics where she forgets names, has difficulty storing and recalling information, and often forgets what she is doing, or why she is doing something.
Movies tend to show amnesia as a result of head injury from accidents or attacks. The loss of identity and autobiographical memory shown in Santa Who?
Santa Who?
Santa Who? is a TV movie first shown in 2000 on ABC, starring Leslie Nielsen, and directed by William Dear. The plot centers on Santa Claus developing a case of amnesia right before Christmas...
(2000) in which Santa suffers from amnesia that destroys his identity and memory of himself is very unlikely in the real world. This is also portrayed in The Bourne Identity
The Bourne Identity (2002 film)
The Bourne Identity is a 2002 American spy film loosely based on Robert Ludlum's novel of the same name. It stars Matt Damon as Jason Bourne, an amnesiac attempting to discover his true identity amidst a clandestine conspiracy within the Central Intelligence Agency . The film also stars Franka...
(2002) and The Bourne Supremacy
The Bourne Supremacy
The Bourne Supremacy is the second Jason Bourne novel written by Robert Ludlum, first published in 1986. It was the sequel to Ludlum's bestseller The Bourne Identity and precedes Ludlum's final Bourne novel, The Bourne Ultimatum ....
(2004) where the main character forgets he is a trained assassin. Another misrepresentation of the reality of memory loss in the movies can be seen in Clean Slate (1994) and 50 First Dates
50 First Dates
50 First Dates is a 2004 American romantic comedy film directed by Peter Segal and written by George Wing. The film stars Adam Sandler as a woman-chasing veterinarian and Drew Barrymore as an amnesiac, along with Rob Schneider, Sean Astin, Lusia Strus, Blake Clark, and Dan Aykroyd.Most of the film...
(2004) where the characters are able to encode memory during the day but lose all memory of that day at night, while sleeping.
Movies often restore victim’s memory through a second trauma, or through a kind of cued recall when they revisit familiar places or see familiar objects. The phenomenon of the second trauma can be seen in Singing in the Dark (1956) where the victim experiences the onset of amnesia because of the trauma of the Holocaust, but memory is restored with a blow to the head. Although neurosurgery is often the cause of amnesia, it is seen as a solution in some movies, including Deluxe Annie (1918) and Rascals (1938).
Memory erasure is portrayed in Eternal Sunshine of the Spotless Mind
Eternal Sunshine of the Spotless Mind
Eternal Sunshine of the Spotless Mind is a 2004 American romantic science fiction film about an estranged couple who have each other erased from their memories, scripted by Charlie Kaufman and directed by the French director, Michel Gondry. The film uses elements of science fiction, psychological...
(2004) and in the Men in Black
Men in Black (film)
Men in Black is a 1997 science fiction comedy film directed by Barry Sonnenfeld, starring Tommy Lee Jones, Will Smith and Vincent D'Onofrio. The film was based on the Men in Black comic book series by Lowell Cunningham, originally published by Marvel Comics. The film featured the creature effects...
movies. Men in Black features a device to erase the potentially harmful memories of extraterrestrial interactions in members of the general public. Eternal Sunshine of the Spotless Mind describes a process that targets and erases memories of interpersonal relationships the patients would rather forget so that they are no longer able to recall the experience. In Paycheck
Paycheck (film)
Paycheck is a 2003 film adaptation of the short story of the same name by science fiction writer Philip K. Dick. The film was directed by John Woo and stars Ben Affleck, Uma Thurman and Aaron Eckhart...
(2003) and Total Recall
Total Recall
Total Recall is a 1990 American science fiction action film. The film stars Arnold Schwarzenegger, Rachel Ticotin, Sharon Stone, Michael Ironside, Ronny Cox & Mel Johnson, Jr.. It is based on the Philip K. Dick story “We Can Remember It for You Wholesale”...
(1990) memory suppression is used to control and the characters are able to overcome the attempts and recall pieces of their memory.