memory Seven stages in memory1. Adequate perception , comprehension, and response to the material to be learned.2. Short term storage3. Formation of durable trace4. Consolidation5. Recognition that certain materials need to be recalled6. Isolation of the relevant memory7. Using the recalled material
Types Memory is of 3 typesi. Sensoryii. Short termiii. Long term
Sensory type Registered for each of the sense and its purpose is to facilitate the rapid processing of incoming stimuli so that the comparison can be made with material already stored in short and long term memory. Fades within few seconds. Closely related to attention.
Short term memory Working memory/ primary memory For the storage of memory much longer than the few seconds available to sensory memory. Aids the constant updating of one’s surroundings.
Long term memory When memories are rehearsed in the short term they are encoded in the long term memory. Encoding is a process of placing information into what is believed to be a limitless memory reservoir. Storage of material in long term memory allows for recall of events from the past and for utilization of information learned through educational system.
Autobiographical memories- memories of events that relate to oneself Flashbulb memories- specific type of autobiographical memory in which the person becomes aware of an emotionally arousing event.
Explicit memory Declarative/rational memory Patient is conscious that they are remembering. Hippocampus - stored 2 typesi. Episodic memory- memory of specific eventsii. Semantic memory- memory of abstract facts
Implicit Memory Procedural/skills Limbic system (amygdala + cerebellum) Performance of tasks such as typing, swimming and cutting a loaf of bread are also expressions of prior learning but there is no active awareness of memory is being reached in undertaking the particular skill.
Process of remembering has 4 partsi. Registrationii. Retentioniii. Retrievaliv. Recall
AMNESIA Partial or total inability to recall part experience and events.1. Organic2. Psychogenic
Normal Memory failure If an item is not rehearsed the memory fades and therefore cannot be retrieved. Normal memory decayProactive interference – old memories interfere with new learning and hence recall.Retroactive interference – new memories interfere with learning of new material.
(ii) Katathymic amnesia Motivated forgetting A set of ideas which are disturbing when conscious are repressed in an attempt to avoid the affect which they would otherwise produce. More persistent and circumscribed Conscious motivation to forget – suppression or unconscious motivation – primary repression. No loss of personal identity Hysteria Normal persons with painful memories
(iii) Hysterical Amnesia Dissociative amnesia There is a complete loss of memory and personal identity but the patient can carry out complicated patterns of behavior and is unable to look after himself. Often associated with fugue or wandering state. More common in those with prior history of head injury.
2) ORGANIC AMNESIA (i)Acute coarse brain diseasePoor memory is due to disorders of perception and attention and the failure to make a permanent trace.Retrograde amnesiaAcute head injuryAmnesia which embraces the events just before the injuryDisturbance of short term memory loss
Post traumatic amnesia: the period between loss of consciousness and appearance of full awareness and memory duration is directly related to severity of the head injury.
Anterograde amnesiaEvents occurring after the injury.The patient is fully conscious ,but has no memory for the events which occur.Result of failure to make permanent traces.Seen in Alcoholic blackout Delirium Twilight state due to epilepsy Pathological drunkenness
Transient global amnesia A sudden onset of retrograde amnesia covering a period of few days upto several years. Perception and personal identity remain normal. An anterograde amnesia continues until recovery (up to several hours) The amnesia subsequently shrinks to a period of half to 5 hours. Some pts there is evidence of ischemia in the territory of the posterior cerebral circulation The immediate cause is probably b/l temporal or thalamic lesions.
Sub acute coarse brain disease The pt is unable to register new memories. The memory disorder is characterized by inability to earn new information (anterograde amnesia) and old information (retrograde amnesia) Memories from remote past remains intact. Seen in Korsakoff’s syndrome CVA Multiple sclerosis Head injury ECT
Chronic Coarse Brain disease The amnesia extends over many years. Ribot’s law of memory regression: In dementing illness the memory of recent events is lost before the memory for remote events.
Distortion of memories Paramnesia Falsification of memory by distortion.I. Distortion of recallII. Distortion of recognition.
Retrospective falsification The subject modifies his memories in terms of his general attitudes. Unintentional and dependent on person’s current emotional experiential and cognitive state. Seen in Normal people - degree of retrospective falsification is inversely related to the degree of insight and self criticism of the individual Hysterical personality Depressive illness Agitated depression Mania
Retrospective delusions The pt dates back his delusions. Could be regarded as delusional retrospective falsification. schizophrenia
Confabulations Pictorial thinking (Leonard) , Memory Hallucinations (Bleuler) A false description of an event , which is alleged to have occurred in the past. Filling in of gaps in memory by imagined or untrue experiences. Diminishes as the impairment worsens. 2 broad patterns emerge – embarrassed type in which the patient tries to fill in gaps as memory as a result of an awareness of a deficit , fantastic type in which the lacunae is filled by details exceeding the need of memory impairment.
Embarrased is more common. Seen in Organic states Hysterical psychopaths Amnestic syndrome Chronic schizophrenia
False memory- recollection of an event which did not occur which the individual believes did take place. Screen memory- recollection that is partially true and partially false. Pseudologia fantastica- fluent plausible lying that occurs in those without organic brain pathology such as personality disorder of anti social and hysterical type.
Munchausen’s syndrome- variant of pathological lying in which the individual presents to the hospital with bogus medical illness , complex medical histories and often multiple surgical scars.
Ganser’s Syndrome Voibereden/ approximate answers - Pt understands the question but deliberately avoids the correct answer Clouding of consciousness with disorientation Auditory and visual hallucination Amnesia during the period for which symptoms were manifest. Seen in hysterical pseudo dementia Conversion symptoms Recent head injury Infection Severe emotional stress
Cryptamnesia- experience of not remembering that one is remembering. Hyperamnesia – Exaggerated registration, retention and recall.
Disorders of recognition.Déjà vu The subject has the experience that he has seen or experienced the current situation before, although it has no basis in fact. The sense of recognition is never absolute. Normal people Temporal lobe lesions
Jamais vu – event that has been associated before is not experienced with appropriate feelings of familiarity. Déjà entendu : feeling of auditory hallucination Deja pense – new thought as having been previously occurred.
Positive misidentification Pt recognizes strangers as his friends and relatives Some pts assert that all of the people whom they meet are doubles of real people. Confusional state Acute schizophrenia Chronic schizophrenia
Negative misidentification Pt denies that his friends and relatives are people whom they say they are and insists they are strangers in disguise Excessive concretization of memory images.
consciousness A state of awareness of the self and the environment. Active consciousness – when the subject focuses his attention on some internal or external event. Passive consciousness: when the same events attract the subject’s attention without any conscious effort on his part.
Distractability Disturbance of active attention the pt is diverted by almost all new stimuli and habituation to new stimuli takes longer than usual. Seen in Fatigue Anxiety Severe depression Mania Schizophrenia Organic states
Orientation Capacity of a person to gauge accurately the time space and person in his current setting. Time – Is labile Quite readily disturbed by rapt concentration. Strong emotion Organic brain factors.
Space Disturbed later than time Unable to find his way or place Person Patient fails to remember his own name and identity. Lost with greatest difficulty,
Ways which consciousness can be changed Dream like changes of consciousness Lowering of consciousness Restriction of consciousness
Dream like changes ofconsciousness There is a lowering of the level of consciousness which is a subjective experience of a rise in the threshold for all incoming stimuli Pt is disoriented for time place , but not for person. Clinical features Visual hallucination Unable to distinguish between mental image and perceptions.
Disordered thinking as in dream showing excessive displacement, condensation and misuse of symbols. Auditory hallucinations – common elementary rarely continuous voices, organized hallucinations take form off odd disconnected words or phrases. Other hallucinations of touch , pain, electric feelings, muscle sense and vestibular sensations often occur. When underlying physical illness is severe, insomnia is marked.
Occupational delirium : when the pt is restless and carries out the actions of his trade. Subacute delirious state : mild degree of delirium , where pt may have a general lowering of consciousness during the day and be incoherent and confused, while at night delirium often occurs with visual hallucinations.
Lowering of consciousness Pt is apathetic, generally slowed down , unable to express himself clearly and may perseverate. After some weeks there is remarkable partial recovery and the pt is left with mild organic defect. Seen in Severe infections, like typhoid and typhus Arteriosclerotic disease following CVA
Restriction of consciousness There is some lowering down of level of consciousness and the awareness is narrowed down to few ideas and attitudes which dominate the pts mind. Twilight state : there is a• A restriction of the morbidity changed consciousness• A break in the continuity of consciousness• Relatively well ordered behaviour.• Commonest- epilepsy
Hysterical twilight state: the restriction of consciousness resulting from unconscious motives