amnesia

(redirected from amnesic)
Also found in: Dictionary, Thesaurus, Medical.

amnesia

(ămnē`zhə), [Gr.,=forgetfulness], condition characterized by loss of memorymemory,
in psychology, the storing of learned information, and the ability to recall that which has been stored. It has been hypothesized that three processes occur in remembering: perception and registering of a stimulus; temporary maintenance of the perception, or short-term
..... Click the link for more information.
 for long or short intervals of time. It may be caused by injury, shock, senility, severe illness, or mental disease. Some cases of amnesia involve the unconscious suppression of a painful experience and everything remindful of it including the individual's identity (see defense mechanismdefense mechanism,
in psychoanalysis, any of a variety of unconscious personality reactions which the ego uses to protect the conscious mind from threatening feelings and perceptions.
..... Click the link for more information.
). Retrograde amnesia is loss of memory of events just preceding temporary loss of consciousness, as from head injury; it is evidence that memory proceeds in two stages, short term and long term. One form of the condition known as tropic amnesia, or coast memory, affecting white men in the tropics, is probably a variety of hysteriahysteria
, in psychology, a disorder commonly known today as conversion disorder, in which a psychological conflict is converted into a bodily disturbance. It is distinguished from hypochondria by the fact that its sufferers do not generally confuse their condition with real,
..... Click the link for more information.
. Aphasiaaphasia
, language disturbance caused by a lesion of the brain, making an individual partially or totally impaired in his ability to speak, write, or comprehend the meaning of spoken or written words.
..... Click the link for more information.
 of the amnesic variety is caused by an organic brain condition and is not to be confused with other forms of amnesia. To cure amnesia, attempts are made to establish associationsassociation,
in psychology, a connection between different sensations, feelings, or ideas by virtue of their previous occurrence together in experience. The concept of association entered contemporary psychology through the empiricist philosophers John Locke, George Berkeley,
..... Click the link for more information.
 with the past by suggestion, and hypnotismhypnotism
[Gr.,=putting to sleep], to induce an altered state of consciousness characterized by deep relaxation and heightened suggestibility. The term was originally coined by James Braid in 1842 to describe a phenomenon previously known as animal magnetism or mesmerism (see
..... Click the link for more information.
 is sometimes employed.

Amnesia

A significant but relatively selective inability to remember. Amnesia can be characterized along two dimensions with respect to its onset: an inability to remember events that occurred after the onset of amnesia is referred to as anterograde amnesia, and a deficit in remembering events that occurred prior to the onset of amnesia is referred to as retrograde amnesia. Amnesia can be due to a variety of causes and can be classified according to whether the cause is primarily neurological or psychological in origin. Neurological amnesias are the result of brain dysfunction and can be transient or permanent. They are usually characterized by a severe anterograde amnesia and a relatively less severe retrograde amnesia. Transient amnesias are temporary memory disturbances and can range in duration from hours to months, depending on the cause and severity. They can be caused by epilepsy, head injury, and electroconvulsive therapy (most frequently used for the treatment of depression). In cases of transient global amnesia, an extensive amnesia that is usually sudden in onset and resolves within a day, the cause is still not known, although many believe that it is vascular in origin.

Permanent amnesia usually occurs following brain damage to either the diencephalons or the medial temporal lobe. Amnesia resulting from impairment to the medial temporal lobe can occur following anoxia, cerebrovascular accidents, head injury, and viral infections to the brain. The primary structures involved in the processing of memory within the medial temporal lobe are the hippocampus and the amygdala. One of the most common causes of diencephalic amnesia is Wernicke-Korsakoff syndrome, a disorder caused by a thiamine deficiency, usually related to chronic alcoholism.

Memory impairment that is not associated with brain damage is referred to as functional amnesia. Functional amnesia can be classified according to whether the amnesia is nonpathological or pathological. Nonpathological functional amnesia is a normal memory loss for events occurring during infancy and early childhood, sleep, hypnosis, and anesthesia. Pathological functional amnesia is an abnormal memory loss found in cases of functional retrograde amnesia and multiple personality. In contrast to neurological amnesia, pathological functional amnesia is usually associated with more severe retrograde than anterograde amnesia. See Brain, Memory

amnesia

[am′nēzh·ə]
(medicine)
The pathological loss or impairment of memory brought about by psychogenic or physiological disturbances.

amnesia

a defect in memory, esp one resulting from pathological cause, such as brain damage or hysteria
References in periodicals archive ?
Pseudo-nitzschia (Bacillariophyceae) species, domoic acid and amnesic shellfish poisoning: revisiting previous paradigms.
The NIA-AA algorithm emphasizes the physio-pathologic processes of AD, divides AD spectrum into asymptomatic and symptomatic stages (describing preclinical manifestations in detail), retains the term amnesic MCI, considers subjective or objective memory impairment and biomarkers supportive features that are not required for the diagnosis of AD, and states that AD-like pathologic changes may occur in non-amnesic AD.
Memory deficits in early infantile autism: Some similarities to the amnesic syndrome.
They are not only blind and amnesic but also insane because they have not cheeped a single word against the silent economic genocide of the Iranian people who are being crushed under illegal and immoral sanctions.
Mike Sisson-Pell said in mitigation that his client suffered from a psychiatric illness, Amnesic Syndrome, which resulted in brain damage and which could be caused by alcohol misuse.
Possibly due to 'switching' to another personality state, he was losing track during the 'bloody' events, did not care who the victim was anymore and remained amnesic to this part of his act," the report said.
This discredits any claims that psychoanalysis fills in the amnesic blanks, supposedly occupied by symptoms, by linking past and present via transference interpretations of the patient-analyst relationship.
Due to the amnesic properties of many of the medications, patients have little-to-no memory of their time in the dental chair by the next day.
Reported first around 1978, it is extensively used as a systemic adjuvant in operating rooms and critical care medicine for its sedative, anxiolytic and amnesic effects.
A classical AD metabolic pattern was observed in 79% of MCI patients who presented with deficits in multiple cognitive domains and in 31% of patients with amnesic MCI.
ue tale gets the Hollywood treatment in this romantic drama about an amnesic woman.