Psychogenic amnesia
Encyclopedia
Psychogenic amnesia, also known as functional amnesia or dissociative amnesia, is a memory disorder
Memory disorder
Memory can be defined as an organism's ability to encode, retain, and recall information. Disorders of memory can range from mild to severe, yet are all a result of damage to neuroanatomical structures; either in part or in full. This damage hinders the storage, retention and recollection of memories...

 characterized by extreme memory loss that is caused by extensive psychological stress and that cannot be attributed to a known neurobiological cause. Psychogenic amnesia is defined by (a) the presence of retrograde amnesia
Retrograde 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....

 (the inability to retrieve stored memories leading up to the onset of amnesia), and (b) an absence 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...

 (the inability to form new long term memories). Dissociative amnesia is due to psychological rather than physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 causes and can sometimes be helped by therapy.

There are two types of psychogenic amnesia, global and situation-specific. Global amnesia, also known as fugue state
Fugue state
A fugue state, formally dissociative fugue or psychogenic fugue , is a rare psychiatric disorder characterized by reversible amnesia for personal identity, including the memories, personality and other identifying characteristics of individuality...

, refers to a sudden loss of personal identity that lasts a few hours to days, and is typically preceded by severe stress and/or depressed mood. Fugue state is very rare, and usually resolves over time, often helped by therapy. In most cases, patients lose their autobiographical memory and personal identity even though they are able to learn new information and perform everyday functions normally. Other times, there may be a loss of basic semantic knowledge and procedural skills such as reading and writing. Situation-specific amnesia occurs as a result of a severely stressful event, as in post-traumatic stress disorder
Post-traumatic stress disorder
Posttraumaticstress disorder is a severe anxiety disorder that can develop after exposure to any event that results in psychological trauma. This event may involve the threat of death to oneself or to someone else, or to one's own or someone else's physical, sexual, or psychological integrity,...

, child sex abuse, military combat or witnessing a family member's murder or suicide, and is somewhat common in cases of severe and/or repeated trauma.

Overview

There are three types of memory – sensory, short-term, and long-term memory. Sensory memory lasts up to hundreds of milliseconds; short-term memory lasts from seconds to minutes; while anything else longer than short-term memory is considered to be a long-term memory.

Information obtained from the peripheral nervous system
Peripheral nervous system
The peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...

 (PNS) is processed in four stages - encoding, consolidating, storage, and retrieval. During encoding, the limbic system is responsible for "bottlenecking" or filtering information obtained from the PNS. According to the type of information being processed in a given instance, the duration of consolidating stage varies drastically. The majority of consolidated information gets stored in the cerebral cortical networks where the limbic system record episodic-autobiographical events. These stored episodic and semantic memories can be obtained by triggering the uncinate fascicle that interconnects the regions of the temporofrontal junction area.

Emotion seems to play an important role in memory processing in structures like the cingulated gyrus, the septal nuclei, and the amygdala that is primarily involved in emotional memories. Functional imaging of normal patients reveal that right-hemisperic amygdala and ventral prefrontal regions are activated when they were retrieving autobiographical information and events. Additionally, the hippocampal region is known to be linked to recognizing faces.

Researchers have found that emotional memories can be suppressed in non-mentally ill individuals via 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...

 in two stages - an initial suppression of the sensory aspects of the memory, followed by a suppression of the emotion
Emotion
Emotion is a complex psychophysiological experience of an individual's state of mind as interacting with biochemical and environmental influences. In humans, emotion fundamentally involves "physiological arousal, expressive behaviors, and conscious experience." Emotion is associated with mood,...

al aspect. It has also been proposed that glucocorticoid
Glucocorticoid
Glucocorticoids are a class of steroid hormones that bind to the glucocorticoid receptor , which is present in almost every vertebrate animal cell...

s can impair memory retrieval; rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...

s and human males have been shown to be affected by this mechanism.

Traumas can interfere with several memory functions. Dr. Bessel van der Kolk
Bessel van der Kolk
Bessel van der Kolk has conducted research in the area of post-traumatic stress since the 1970s. His work focuses on the interaction of attachment, neurobiology, and developmental aspects of trauma’s effects on people. He has written the definitive work in the field of psychological trauma,...

 divided these functional disturbances into four sets: traumatic amnesia, global memory impairment, dissociative processes and traumatic memories' sensorimotor organization. Traumatic amnesia involves the loss of remembering traumatic experiences. The younger the subject and the longer the traumatic event is, the greater the chance of significant amnesia. Global memory impairment makes it difficult for these subjects to construct an accurate account of their present and past history. Dissociation refers to memories being stored as fragments and not as unitary wholes. Not being able to integrate traumatic memories seems to be the main element which leads to PTSD. In the sensorimotor organization of traumatic memories, sensations are fragmented into different sensory components.

Comparison with organic causes

Clinically, psychogenic amnesia is characterized by the loss of the ability to retrieve stored memory without any apparent neurological damage; while organic amnesia is characterized by damages to the medial or anterior temporal and/or prefrontal regions caused by stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

, 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...

, ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...

, and 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...

. Some characteristics that define organic amnesia is the maintenance of personal identity, basic semantic knowledge and procedural skills as well as neuroradiological images showing cerebral damage to the cortical and/or subcortical areas known to be associated with long-term memory while some characteristics that define psychogenic amnesia is the loss of personal identity, semantic knowledge, and procedural abilities at least in the early phase of amnesia as well as damage directly affecting cerebral areas critical for memory functioning that cannot be detected in clinical history or neuroradiological exams.

Imaging

Psychogenic amnesia is defined by the lack of structural damage to the brain, but upon functional imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...

, an abnormal brain activity can be seen. Tests using 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...

 suggest that patients with psychogenic amnesia are unable to retrieve emotional memories normally during the amnesic period, suggesting that changes in the limbic functions are related to the symptoms of psychogenic amnesia. By performing a positron emission tomography
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...

 activation study on psychogenic amnesic patients with face recognition
Face perception
Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face.The human face's proportions and expressions are important to identify origin, emotional tendencies, health qualities, and some social information. From birth, faces are...

, it was found that activation of the right anterior medial temporal region
Temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....

 including the amygdala
Amygdala
The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...

 was increased in the patient whereas bilateral hippocampal
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...

 regions increased only in the control subjects, demonstrating again that limbic
Limbic system
The limbic system is a set of brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix, which seemingly support a variety of functions including emotion, behavior, long term memory, and olfaction. The term "limbic" comes from the Latin...

 and limbic-cortical
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

 functions are related to the symptoms of psychogenic amnesia.

Risk factors

Patients exposed to physically or emotionally traumatic events are at a higher risk for developing psychogenic amnesia because they seem to have damaged the neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

s in the brain. Examples of individuals at greater risk of psychogenic amnesia due to traumatic events include soldier
Soldier
A soldier is a member of the land component of national armed forces; whereas a soldier hired for service in a foreign army would be termed a mercenary...

s who have experienced combat
Combat
Combat, or fighting, is a purposeful violent conflict meant to establish dominance over the opposition, or to terminate the opposition forever, or drive the opposition away from a location where it is not wanted or needed....

, individuals sexually
Sexual abuse
Sexual abuse, also referred to as molestation, is the forcing of undesired sexual behavior by one person upon another. When that force is immediate, of short duration, or infrequent, it is called sexual assault. The offender is referred to as a sexual abuser or molester...

 and physically abused
Physical abuse
Physical abuse is abuse involving contact intended to cause feelings of intimidation, injury, or other physical suffering or bodily harm.-Forms of physical abuse:*Striking*Punching*Belting*Pushing, pulling*Slapping*Whipping*Striking with an object...

 during childhood
Childhood
Childhood is the age span ranging from birth to adolescence. In developmental psychology, childhood is divided up into the developmental stages of toddlerhood , early childhood , middle childhood , and adolescence .- Age ranges of childhood :The term childhood is non-specific and can imply a...

 and individuals who have experienced domestic violence
Domestic violence
Domestic violence, also known as domestic abuse, spousal abuse, battering, family violence, and intimate partner violence , is broadly defined as a pattern of abusive behaviors by one or both partners in an intimate relationship such as marriage, dating, family, or cohabitation...

, natural disaster
Natural disaster
A natural disaster is the effect of a natural hazard . It leads to financial, environmental or human losses...

s, or terrorist acts
Terrorism
Terrorism is the systematic use of terror, especially as a means of coercion. In the international community, however, terrorism has no universally agreed, legally binding, criminal law definition...

; essentially any sufficiently severe psychological stress, internal conflict, or intolerable life situation. Child abuse, especially chronic child abuse starting at an early age has been related to the development of high levels of dissociative symptoms, including amnesia for abuse memories. The study strongly suggested that "independent corroboration of recovered memories of abuse is often present" and that the recovery of the abuse memories generally is not associated with psychotherapy.

Prevalence

Elliot's study of a randomized nationwide sample (n=505) found that situation-specific psychogenic amnesia was somewhat common in the general population. 72% of subjects reported a profoundly distressing emotional trauma; 32% of these reported amnesia about part or all of the trauma, followed by "delayed recall" of the event. Traumatic events most commonly associated with psychogenic amnesia were witnessing a suicide or murder, and being sexually abused. Elliott also found that psychogenic amnesia was most strongly associated with severe and/or repeated traumas, and with traumas during childhood. When encountering stimuli similar to the trauma(s), subjects often reported many episodes of dissociation
Dissociation
Dissociation is an altered state of consciousness characterized by partial or complete disruption of the normal integration of a person’s normal conscious or psychological functioning. Dissociation is most commonly experienced as a subjective perception of one's consciousness being detached from...

 prior to the delayed recall. The most common "trigger" for recalling the traumatic event was a media event (e.g., while watching television or a movie), the least common trigger was psychotherapy or counseling.

Several studies have found that situation-specific psychogenic amnesia is common in verified victims of severe child abuse:
  • In a 1994 study, Williams found that amongst women with confirmed histories of childhood sexual abuse, about one third of subjects did not recall the abuse during interviews as adults; because these same women were usually willing to discuss other potentially embarrassing or shameful incidents (e.g., abortions, prostitution, sexual assaults as adults) Williams concluded the women had genuinely lost access to the traumatic memories. In a follow-up study published the next year, Williams found that in women (n=129)with documented histories of childhood sexual abuse, 16% reported a period when they were unable to recall all or part of the abuse.
  • Widom and Morris found that in adults (n=450) with confirmed childhood histories of severe neglect and abuse (physical and/or sexual), 59.3% reported periods of partial or complete amnesia for the maltreatment. Amnesia for abuse was most associated with cases of multiple perpetrators and fears of death if the abuse was disclosed.
  • Dahlenberg studied 17 women who recovered memories of childhood sexual abuse while in therapy; six independent evaluators determined that all 17 women adequately corroborated the memories.

Theoretical explanations

Psychogenic amnesia is far from being completely understood and while several explanations have been proposed, none of them have been verified as the mechanism that fits all types of psychogenic amnesia. Different theories include:
  • Freudian psychology
    Psychoanalysis
    Psychoanalysis is a psychological theory developed in the late 19th and early 20th centuries by Austrian neurologist Sigmund Freud. Psychoanalysis has expanded, been criticized and developed in different directions, mostly by some of Freud's former students, such as Alfred Adler and Carl Gustav...

     states that psychogenic amnesia is an act of self-preservation, an alternative to suicide.
  • Cognitive
    Cognitive psychology
    Cognitive psychology is a subdiscipline of psychology exploring internal mental processes.It is the study of how people perceive, remember, think, speak, and solve problems.Cognitive psychology differs from previous psychological approaches in two key ways....

     point-of-view states that this disorder utilizes the body’s personal 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....

     belief system to repress unwanted memories from entering the consciousness by altering neuropeptide
    Neuropeptide
    Neuropeptides are small protein-like molecules used by neurons to communicate with each other. They are neuronal signaling molecules, influence the activity of the brain in specific ways and are thus involved in particular brain functions, like analgesia, reward, food intake, learning and...

    s and neurotransmitter
    Neurotransmitter
    Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

    s released during stressful events, affecting the formation and recall of memory.
  • "Betrayal trauma theory suggests that psychogenic amnesia is an adaptive response to childhood abuse. When a parent or other powerful figure violates a fundamental ethic of human relationships, victims may need to remain unaware of the trauma not to reduce suffering but rather to promote survival. Amnesia enables the child to maintain an attachment with a figure vital to survival, development, and thriving. Analysis of evolutionary pressures, mental modules, social cognitions, and developmental needs suggests that the degree to which the most fundamental human ethics are violated can influence the nature, form, and processes of trauma and responses to trauma."
  • Normal autobiographical memory processing is blocked by imbalance or altered release of stress hormone
    Stress hormone
    Stress hormones such as cortisol, GH and norepinephrine are released at periods of high stress. The hormone regulating system is known as the endocrine system...

    s such as glucocorticoid
    Glucocorticoid
    Glucocorticoids are a class of steroid hormones that bind to the glucocorticoid receptor , which is present in almost every vertebrate animal cell...

    s and mineralocorticoid
    Mineralocorticoid
    Mineralocorticoids are a class of steroid hormones characterised by their similarity to aldosterone and their influence on salt and water balances.-Physiology:...

    s in the brain. The regions of expanded limbic system
    Limbic system
    The limbic system is a set of brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix, which seemingly support a variety of functions including emotion, behavior, long term memory, and olfaction. The term "limbic" comes from the Latin...

     in the right hemisphere
    Cerebral hemisphere
    A cerebral hemisphere is one of the two regions of the eutherian brain that are delineated by the median plane, . The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter called the cerebral cortex that is...

     are more vulnerable to stress and trauma, affecting the body's opioid
    Opioid
    An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...

    s, hormone
    Hormone
    A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

    s, and neurotransmitters such as norepinephrine
    Norepinephrine
    Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...

    , serotonin
    Serotonin
    Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

    , and neuropeptide Y
    Neuropeptide Y
    Neuropeptide Y is a 36-amino acid peptide neurotransmitter found in the brain and autonomic nervous system."NPY has been associated with a number of physiologic processes in the brain, including the regulation of energy balance, memory and learning, and epilepsy." The main effect is increased food...

    . Increased levels of glucocorticoid and mineralocorticoid receptor density may affect the anterior temporal, orbitofrontal cortex
    Orbitofrontal cortex
    The orbitofrontal cortex is a prefrontal cortex region in the frontal lobes in the brain which is involved in the cognitive processing of decision-making...

    , hippocampal
    Hippocampus
    The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...

    , and amygdala
    Amygdala
    The ' are almond-shaped groups of nuclei located deep within the medial temporal lobes of the brain in complex vertebrates, including humans. Shown in research to perform a primary role in the processing and memory of emotional reactions, the amygdalae are considered part of the limbic system.-...

    r regions. These morphological changes may be caused by loss of regulation of gene expression
    Gene expression
    Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...

    s in those receptors along with inhibition of neurotrophic factors during chronic stress conditions.
  • Stress
    Stress (medicine)
    Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...

     may directly affect the medial temporal
    Temporal lobe
    The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....

    /diencephalic
    Diencephalon
    The diencephalon is the region of the vertebrate neural tube which gives rise to posterior forebrain structures. In development, the forebrain develops from the prosencephalon, the most anterior vesicle of the neural tube which later forms both the diencephalon and the...

     system, inhibiting the retrieval of autobiographical memories and producing a loss of personal identity. Negative feedback
    Negative feedback
    Negative feedback occurs when the output of a system acts to oppose changes to the input of the system, with the result that the changes are attenuated. If the overall feedback of the system is negative, then the system will tend to be stable.- Overview :...

     produced by this system may dampen the patient's emotions, giving a perplexed or 'flat' appearance.

Treatments

Currently, various treatments are available for patients with psychogenic amnesia although no well-controlled studies on the effectiveness of different treatments exist.
  • Psychoanalysis
    Psychoanalysis
    Psychoanalysis is a psychological theory developed in the late 19th and early 20th centuries by Austrian neurologist Sigmund Freud. Psychoanalysis has expanded, been criticized and developed in different directions, mostly by some of Freud's former students, such as Alfred Adler and Carl Gustav...

     - uses dream analysis, interpretation and other psychoanalytic methods to retrieve memories; may also involve placing patients in threatening situations where they are overwhelmed with intense emotion.
  • Medication
    Medication
    A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

     and relaxation technique
    Relaxation technique
    A relaxation technique is any method, process, procedure, or activity that helps a person to relax; to attain a state of increased calmness; or otherwise reduce levels of anxiety, stress or anger...

    s - in conjunction with benzodiazepine
    Benzodiazepine
    A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...

    s and other hypnotic medications, the patient is urged to relax and attempt to recall memories. With the help of psychotherapy and learning their autobiographies from family members, most patients recover their memories completely.
  • It has been proposed that abreaction
    Abreaction
    Abreaction is a psychoanalytical term for reliving an experience in order to purge it of its emotional excesses; a type of catharsis. Sometimes it is a method of becoming conscious of repressed traumatic events....

     could be used in conjunction with midazolam
    Midazolam
    Midazolam is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potent anxiolytic,...

     to recover memories. This technique was used during the second World War
    World War II
    World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

     but is currently much less popular. The technique is thought to work either through depressing the function of the cerebral cortex
    Cerebral cortex
    The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

     and therefore making the memory more tolerable when expressed, or through relieving the strength of an emotion attached to a memory which is so intense it suppresses memory function.
  • Some studies about psychogenic amnesia have concluded that psychotherapy
    Psychotherapy
    Psychotherapy is a general term referring to any form of therapeutic interaction or treatment contracted between a trained professional and a client or patient; family, couple or group...

     is not connected to recovered memories of child sexual abuse
    Child sexual abuse
    Child sexual abuse is a form of child abuse in which an adult or older adolescent uses a child for sexual stimulation. Forms of child sexual abuse include asking or pressuring a child to engage in sexual activities , indecent exposure with intent to gratify their own sexual desires or to...

    . Data suggests that one’s amnesic recovered memory
    Recovered memory
    Recovered memory is the description given to the apparent resurrection of the memory of events that had been forgotten or suppressed for a relatively long time. Retrograde amnesia secondary to physical or emotional trauma , or the suppression of painful memories from any cause, is an accepted concept...

     is spontaneous, and that this is triggered by abuse-related stimuli.

In popular culture

Memory loss due to emotional upset or shock has been recognized since at least the first century: Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 wrote, “Nothing whatever, in man, is of so frail a nature as the memory; for it is affected by disease, by injuries, and even by fright; being sometimes partially lost, and at other times entirely so.”

Psychogenic amnesia is a common plot device in many films and books and other media. Examples include Shakespeare’s King Lear
King Lear
King Lear is a tragedy by William Shakespeare. The title character descends into madness after foolishly disposing of his estate between two of his three daughters based on their flattery, bringing tragic consequences for all. The play is based on the legend of Leir of Britain, a mythological...

who experienced amnesia and madness following a betrayal by his daughters; the title character Nina
Nina (Dalayrac)
Nina, ou La folle par amour is an opera in one act by the French composer Nicolas Dalayrac. It was first performed at the Comédie-Italienne in Paris on 15 May 1786...

in Nicolas Dalayrac
Nicolas Dalayrac
Nicolas-Marie d'Alayrac, known as Nicolas Dalayrac , was a French composer, best known for his opéras-comiques.- Biography :...

's opera of 1786 and the character of Jason Bourne
Jason Bourne
Jason Charles Bourne is a fictional character and the main protagonist in the novels of Robert Ludlum and subsequent film adaptations. He first appeared in the novel The Bourne Identity...

 as depicted in the Bourne film series
Bourne (film series)
The Bourne films are a series of dramatic films based on the character Jason Bourne, a former CIA assassin suffering from extreme memory loss, created by author Robert Ludlum. All three of Ludlum's novels were adapted for the screen, featuring Matt Damon as the titular character in each...

; Jackie Chan
Jackie Chan
Jackie Chan, SBS, MBE is a Hong Kong actor, action choreographer, comedian, director, producer, martial artist, screenwriter, entrepreneur, singer and stunt performer. In his movies, he is known for his acrobatic fighting style, comic timing, use of improvised weapons, and innovative stunts...

 in Who Am I?; the character Teri Bauer
Teri Bauer
Teri Bauer is a fictional character played by Leslie Hope on the first season of the television series 24.-Characterization:Teri Bauer was born in 1969. She is the wife of Jack Bauer and the mother of Kim Bauer...

 in 24
24 (TV series)
24 is an American television series produced for the Fox Network and syndicated worldwide, starring Kiefer Sutherland as Counter Terrorist Unit agent Jack Bauer. Each 24-episode season covers 24 hours in the life of Bauer, using the real time method of narration...

; Goldie Hawn
Goldie Hawn
Goldie Jeanne Hawn is an American actress, film director, producer, and occasional singer. Hawn is known for her roles in Rowan & Martin's Laugh-In, Private Benjamin, Foul Play, Overboard, Bird on a Wire, Death Becomes Her, The First Wives Club, and Cactus Flower, for which she won the 1969...

 in Overboard
Overboard (1987 film)
Overboard is a 1987 American romantic comedy film starring Goldie Hawn and Kurt Russell. It was directed by Garry Marshall, produced by Roddy McDowell and loosely inspired by the 1974 Italian film Swept Away...

; Leroy Jethro Gibbs
Leroy Jethro Gibbs
Leroy Jethro Gibbs is a fictional character and the main protagonist of the CBS TV series NCIS. He is portrayed by Mark Harmon.-Background:...

 in NCIS
NCIS (TV series)
NCIS, formerly known as NCIS: Naval Criminal Investigative Service, is an American police procedural drama television series revolving around a fictional team of special agents from the Naval Criminal Investigative Service, which conducts criminal investigations involving the U.S...

and the character Victoria Lord
Victoria Lord
Victoria "Viki" Lord is the principal fictional character and matriarch of the Lord family on the ABC soap opera One Life to Live...

 in One Life to Live
One Life to Live
One Life to Live is an American soap opera which debuted on July 15, 1968 and has been broadcast on the ABC television network. Created by Agnes Nixon, the series was the first daytime drama to primarily feature racially and socioeconomically diverse characters and consistently emphasize social...

.

Real life examples

  • A man later identified as Edward Lighthart woke up in Seattle's Discovery park
    Discovery Park (Seattle)
    Discovery Park is a 534 acre park in the peninsular Magnolia neighborhood of Seattle, Washington. It is the city's largest public park and contains 11.81 miles of walking trails. United Indians of All Tribes' Daybreak Star Cultural Center is within the park's boundaries...

    , with supposed dissociative amnesia, on July 30, 2009, and briefly became a local mystery.
  • A man discovered unconscious on August 31, 2004, in Richmond Hill, Georgia
    Richmond Hill, Georgia
    Richmond Hill is a city in Bryan County, Georgia, United States. The population was 6,959 at the 2000 census. It is part of the Savannah Metropolitan Statistical Area.-Geography:Richmond Hill is located at ....

     who adopted the pseudonym
    Pseudonym
    A pseudonym is a name that a person assumes for a particular purpose and that differs from his or her original orthonym...

     Benjaman Kyle.

See also

  • Depersonalization
    Depersonalization
    Depersonalization is an anomaly of the mechanism by which an individual has self-awareness. It is a feeling of watching oneself act, while having no control over a situation. Sufferers feel they have changed, and the world has become less real, vague, dreamlike, or lacking in significance...

  • Dissociative disorders
    Dissociative disorders
    Dissociative disorders are defined as conditions that involve disruptions or breakdowns of memory, awareness, identity and/or perception. See also dissociation. People with dissociative disorders are able to escape from reality involuntarily...

  • Fugue state
    Fugue state
    A fugue state, formally dissociative fugue or psychogenic fugue , is a rare psychiatric disorder characterized by reversible amnesia for personal identity, including the memories, personality and other identifying characteristics of individuality...

  • Repressed memory
    Repressed memory
    Repressed memory is a hypothetical concept used to describe a significant memory, usually of a traumatic nature, that has become unavailable for recall; also called motivated forgetting in which a subject blocks out painful or traumatic times in one's life...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK