Levels-of-processing effect
Encyclopedia
The levels-of-processing effect, identified by Fergus I. M. Craik
and Robert S. Lockhart in 1972, describes memory
recall
of stimuli
as a function of the depth of mental processing. Depth of processing falls on a shallow to deep continuum. Shallow processing (e.g., processing based on phonemic and orthographic
components) leads to a fragile memory trace that is susceptible to rapid decay. Conversely, deep processing (e.g., semantic
processing) results in a more durable memory trace. This theory contradicts the multi-store Atkinson-Shiffrin memory model in its representation of memory strength as continuously variable.
, transfer-appropriate processing
, the self-reference effect, and the explicit nature of a stimulus modify the levels-of-processing effect by manipulating mental processing depth factors.
value if it is highly compatible with preexisting semantic structures (Craik, 1972). According to semantic network
theories, this is because such a stimulus will have many connections to other encoded memories, which are activated based on closeness in semantic network structure. This activation increases cognitive analysis, increasing the strength of the memory representation. The familiarity modifier has been tested in implicit memory
experiments, where subjects report false memories when presented with related stimuli.
creates the strongest recall value of all senses, and also allows the widest spectrum of levels-of-processing modifiers. It is also one of the most widely studied. Within visual studies, pictures have been shown to have a greater recall value than words – the picture superiority effect
. However, semantic associations have the reverse effect in picture memories appear to be reversed to those in other memories. When logical details are stressed, rather than physical details, an image’s recall value becomes lower. When comparing orthographic
(capitalization, letter and word shape), phonological (word sound) and semantic (word meaning) encoding
cues, the highest levels of recall were found with the meanings of the words, followed by their sounds and finally the written and shape-based cues were found to generate the least ability to stimulate recall.
value when compared with vision. Some studies suggest that auditory weakness is only present for explicit memory
(direct recall), rather than implicit memory
. When test subjects are presented with auditory versus visual word cues, they only perform worse on directed recall of a spoken word versus a seen word, and perform about equally on implicit free-association tests. Within auditory stimuli, semantic analysis produces the highest levels of recall ability for stimuli. Experiments suggest that levels-of-processing on the auditory level is directly correlated with neural activation.
memory is weaker than visual memory, achieving a successful identification rate of only 70-80% of visual memory. Levels-of-processing effects have been found within odor memory if subjects are asked to "visualize" smells and associate them with a particular picture. Subjects who perform this task have a different recall value on explicit memory tests than subjects who memorize smells using self-chosen methods. The difference in recall value, however, depends on the subject, and the subject’s ability to form images from odors. Attributing verbal attributes to odors has similar effects. Semantic processing of odors (e.g. attributing the "mud" odor to "smell like a puddle") has found to have the most positive effects on recall.
and functional magnetic resonance imaging
techniques have shown that higher levels of processing correlate with more brain activity and activity in different parts of the brain than lower levels. For example, in a lexical analysis task, subjects showed activity in the left inferior prefrontal cortex
only when identifying whether the word represented a living or nonliving object, and not when identifying whether or not the word contained an "a". Similarly, an auditory analysis task showed increased activation in the left inferior prefrontal cortex when subjects performed increasingly semantic word manipulations. Synaptic aspects of word recognition have been correlated with the left frontal operculum
and the cortex lining the junction of the inferior frontal and inferior precentral sulcus. The self-reference effect also has neural correlates with a region of the medial prefrontal cortex
, which was activated in an experiment where subjects analyzed the relevance of data to themselves. Specificity of processing is explained on a neurological basis by studies that show brain activity in the same location when a visual memory is encoded and retrieved, and lexical memory in a different location. Visual memory areas were mostly located within the bilateral extrastriate visual cortex
.
, selectively strengthened in panic disorder
patients, unaffected in Alzheimer's disease
patients, and reversed in autistic patients.
activity when words and images are presented to older subjects than with younger subjects, but roughly equal activity when assessing semantic connections.
words with threatening meanings over positive and neutral words. In one study, both implicit (free recall) and explicit (memory of emotional aspects) memorization of word lists were enhanced by threatening meanings in such patients.
processing created higher recall value in word list-recall tests. Other studies have explicitly found non-semantically processed stimuli to be more accurately processed by autistic patients than in healthy patients. No clear conclusions have been drawn as to the cause of this oddity.
Fergus I. M. Craik
Fergus Ian Muirden Craik FRS is a cognitive psychologist known for his groundbreaking research on levels of processing in memory. This work was done in collaboration with Robert Lockhart at the University of Toronto...
and Robert S. Lockhart in 1972, describes 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....
recall
Recollection
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...
of stimuli
Stimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
as a function of the depth of mental processing. Depth of processing falls on a shallow to deep continuum. Shallow processing (e.g., processing based on phonemic and orthographic
Orthography
The orthography of a language specifies a standardized way of using a specific writing system to write the language. Where more than one writing system is used for a language, for example Kurdish, Uyghur, Serbian or Inuktitut, there can be more than one orthography...
components) leads to a fragile memory trace that is susceptible to rapid decay. Conversely, deep processing (e.g., semantic
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....
processing) results in a more durable memory trace. This theory contradicts the multi-store Atkinson-Shiffrin memory model in its representation of memory strength as continuously variable.
Modifiers
FamiliarityFamiliarity heuristic
In psychology, a mental heuristic is a rule of thumb in which current behavior is judged to be correct based on how similar it is to past behavior and its outcomes. Individuals assume that the circumstances underlying the past behavior still hold true for the present situation and that the past...
, transfer-appropriate processing
Transfer-appropriate processing
Transfer-appropriate processing is a type of state-dependent memory specifically showing that memory performance is not only determined by the depth of processing , but by the relationship between how information is initially encoded and how it is later retrieved...
, the self-reference effect, and the explicit nature of a stimulus modify the levels-of-processing effect by manipulating mental processing depth factors.
Familiarity
A stimulus will have a higher recallRecollection
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...
value if it is highly compatible with preexisting semantic structures (Craik, 1972). According to semantic network
Semantic network
A semantic network is a network which represents semantic relations among concepts. This is often used as a form of knowledge representation. It is a directed or undirected graph consisting of vertices, which represent concepts, and edges.- History :...
theories, this is because such a stimulus will have many connections to other encoded memories, which are activated based on closeness in semantic network structure. This activation increases cognitive analysis, increasing the strength of the memory representation. The familiarity modifier has been tested in 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...
experiments, where subjects report false memories when presented with related stimuli.
Specificity of processing
Specificity of processing describes the increased recall value of a stimulus when presented in the method with which it was inputed. For example, auditory stimuli (spoken words and sounds) have the highest recall value when spoken, and visual stimuli have the highest recall value when a subject is presented with images. In writing tasks, words are recalled most effectively with semantic cues (asking for words with a particular meaning) if they are encoded semantically (self-generated by the subject as being related to a particular meaning). Words are recalled most effectively with data-driven cues (word completion) if they are read, rather than generated by a subject.Self-reference effect
Levels of processing have been an integral part of learning about memory. The self-reference effect describes the greater recall capacity for a particular stimulus if it is related semantically to the subject. This can be thought of as a corollary of the familiarity modifier, because stimuli specifically related to an event in a person’s life will have widespread activation in that person’s semantic network. For example, the recall value of a personality trait adjective is higher when subjects are asked whether the trait adjective applies to them than when asked whether trait adjective has a meaning similar to another trait.Implicit memory and levels-of-processing
Implicit memory tests, in contrast with explicit memory tests, measure the recall value of a particular stimulus based on later performance on stimulus-related tasks. During these tasks, the subject does not explicitly recall the stimulus, but the previous stimulus still effects performance. For example, in a word-completion implicit memory task, if a subject reads a list containing the word "dog," the subject provides this word more readily when asked for three-letter words beginning in "d." The levels-of-processing effect is only found for explicit memory tests. One study found that word completion tasks were unaffected by levels of semantic encodings achieved using three words with various levels of meaning in common. Another found that typical level-of-processing effects are reversed in word completion tasks; subjects recalled pictures pairs more completely if they were shown a word representing a picture rather than asked to rate a picture for pleasantness (semantic encoding). Typical level-of-processing theory would predict that picture encodings would create deeper processing than lexical encoding.Sensory modes
Different sensory modes, by their nature, involve different depths of processing, generally producing higher recall value in certain senses than others. However, there is significant room for the modifiers mentioned earlier to affect levels-of-processing to be activated within each sensory mode.Vision
Visual inputVisual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
creates the strongest recall value of all senses, and also allows the widest spectrum of levels-of-processing modifiers. It is also one of the most widely studied. Within visual studies, pictures have been shown to have a greater recall value than words – the picture superiority effect
Picture superiority effect
According to the picture superiority effect, concepts are much more likely to be remembered experientially if they are presented as pictures rather than as words....
. However, semantic associations have the reverse effect in picture memories appear to be reversed to those in other memories. When logical details are stressed, rather than physical details, an image’s recall value becomes lower. When comparing orthographic
Orthography
The orthography of a language specifies a standardized way of using a specific writing system to write the language. Where more than one writing system is used for a language, for example Kurdish, Uyghur, Serbian or Inuktitut, there can be more than one orthography...
(capitalization, letter and word shape), phonological (word sound) and semantic (word meaning) 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...
cues, the highest levels of recall were found with the meanings of the words, followed by their sounds and finally the written and shape-based cues were found to generate the least ability to stimulate recall.
Hearing
Auditory stimuli follow conventional levels-of-processing rules, although are somewhat weaker in general recallRecollection
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...
value when compared with vision. Some studies suggest that auditory weakness is only present for 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....
(direct recall), rather than 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...
. When test subjects are presented with auditory versus visual word cues, they only perform worse on directed recall of a spoken word versus a seen word, and perform about equally on implicit free-association tests. Within auditory stimuli, semantic analysis produces the highest levels of recall ability for stimuli. Experiments suggest that levels-of-processing on the auditory level is directly correlated with neural activation.
Touch
Tactile memory representations are similar in nature to visual representations, although there is not enough data to reliably compare the strength of the two kinds of stimuli. One study suggests that there is a difference in mental processing level due to innate differences between visual and tactile stimuli representations. In this study, subjects were presented with an object in both visual and tactile form (a subject is shown a sphere but cannot touch it, and later is given a similar sphere to only hold and not view). Subjects had more trouble identifying size difference in visual fields than using tactile feedback. A suggestion for the lower level of size processing in visual fields is that it results from the high variance in viewed object size due to perspective and distance.Smell
OdorOdor
An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...
memory is weaker than visual memory, achieving a successful identification rate of only 70-80% of visual memory. Levels-of-processing effects have been found within odor memory if subjects are asked to "visualize" smells and associate them with a particular picture. Subjects who perform this task have a different recall value on explicit memory tests than subjects who memorize smells using self-chosen methods. The difference in recall value, however, depends on the subject, and the subject’s ability to form images from odors. Attributing verbal attributes to odors has similar effects. Semantic processing of odors (e.g. attributing the "mud" odor to "smell like a puddle") has found to have the most positive effects on recall.
Neural evidence
Several brain imaging studies using positron emission tomographyPositron 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...
and functional magnetic resonance imaging
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI is a type of specialized MRI scan used to measure the hemodynamic response related to neural activity in the brain or spinal cord of humans or other animals. It is one of the most recently developed forms of neuroimaging...
techniques have shown that higher levels of processing correlate with more brain activity and activity in different parts of the brain than lower levels. For example, in a lexical analysis task, subjects showed activity in the left inferior 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...
only when identifying whether the word represented a living or nonliving object, and not when identifying whether or not the word contained an "a". Similarly, an auditory analysis task showed increased activation in the left inferior prefrontal cortex when subjects performed increasingly semantic word manipulations. Synaptic aspects of word recognition have been correlated with the left frontal operculum
Operculum (brain)
Operculum, derived from Latin, meaning "little lid", refers to the cerebral cortex on the outside surface of the brain bordering the lateral sulcus, and the roof and floor of the lateral sulcus. Neuroscience divides the operculum into orbital, frontal, parietal and temporal regions, after the...
and the cortex lining the junction of the inferior frontal and inferior precentral sulcus. The self-reference effect also has neural correlates with a region of the medial 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...
, which was activated in an experiment where subjects analyzed the relevance of data to themselves. Specificity of processing is explained on a neurological basis by studies that show brain activity in the same location when a visual memory is encoded and retrieved, and lexical memory in a different location. Visual memory areas were mostly located within the bilateral extrastriate visual cortex
Extrastriate cortex
The extrastriate cortex is the region of the occipital cortex of the mammalian brain located next to the primary visual cortex, which is also named striate cortex because of its appeareance in the microscope. The extrastriate cortex encompasses multiple functional areas, including V3, V4, V5/MT...
.
Mental disorders
Levels-of-processing effects interact in various ways with mental disorders. In particular, levels-of-processing effects appear to be strengthened in patients with age-related memory degradationMemory and aging
One of the key concerns of older adults is the experience of memory loss, especially as it is one of the hallmark symptoms of Alzheimer's disease. However, memory loss is qualitatively different in normal aging from the kind of memory loss associated with a diagnosis of Alzheimer's...
, selectively strengthened in panic disorder
Panic disorder
Panic disorder is an anxiety disorder characterized by recurring severe panic attacks. It may also include significant behavioral change lasting at least a month and of ongoing worry about the implications or concern about having other attacks. The latter are called anticipatory attacks...
patients, unaffected in Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
patients, and reversed in autistic patients.
Age-related memory degradation
Memory encoding strength derived from higher levels-of-processing appears to be conserved despite other losses in memory function with age. Several studies show that, in older individuals, the ability to process semantically in contrast with non-semantically is improved by this disparity. Neural imaging studies show decreased left-prefrontal cortexPrefrontal 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...
activity when words and images are presented to older subjects than with younger subjects, but roughly equal activity when assessing semantic connections.
Panic disorders
Panic disorders appear to modify levels-of-processing by increasing ability to recallRecollection
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...
words with threatening meanings over positive and neutral words. In one study, both implicit (free recall) and explicit (memory of emotional aspects) memorization of word lists were enhanced by threatening meanings in such patients.
Alzheimer’s disease
Modern studies show an increased effect of levels-of-processing in Alzheimer patients. Specifically, there is a significantly higher recall value for semantically encoded stimuli over physically encoded stimuli. In one such experiment, subjects maintained a higher recall value in words chosen by meaning over words selected by numerical order.Autism
In autistic patients, levels-of-processing effects are reversed in that semantically presented stimuli have a lower recall value than physically presented stimuli. In one study, phonological and orthographicOrthography
The orthography of a language specifies a standardized way of using a specific writing system to write the language. Where more than one writing system is used for a language, for example Kurdish, Uyghur, Serbian or Inuktitut, there can be more than one orthography...
processing created higher recall value in word list-recall tests. Other studies have explicitly found non-semantically processed stimuli to be more accurately processed by autistic patients than in healthy patients. No clear conclusions have been drawn as to the cause of this oddity.