Session Eight (Anomalies of Autobiographical Memory) Flashcards
(32 cards)
What are the 4 important anomalies of autobiographical memory?
1) Psychogenic Amnesia
2) Confabulation
3) Delusional Memory
4) False Confession
What are the factors strongly associated with Psychogenic Amnesia?
- Extreme emotion or stress
- Depression
- Past history of transient organic amnesia
- (possibly) Damage to the frontal lobe control mechanisms
Distinguish Confabulation from Delusional Memory?
Confabulation has a Neurocognitive cause
Delusional Memory is caused by Psychosis
What are the two forms of Confabulation?
- Spontaneous (a persistent and unprovoked outpouring of erroneous memories. patients will normally launch right into these without being asked a question)
- Momentary (fleeting intrusion errors or distortions, produced in response to a challenge to memory. seen in memory tests)
Very briefly outline the factors that can lead someone into making a false confession?
- Individual factors, such as depression and low self-esteem
- Situational factors, such as police interviews or the crime being widely publicised
- These combine to produce source memory errors, which lead to the person internalising these false memories and confessing to something they didn’t do.
Define Psychogenic Amnesia and outline the two broad types?
PA = A disorder characterised by abnormal memory functioning in the absence of structural brain damage or a known neurobiological cause.
Two types:
- Global (which includes Focal Retrograde Amnesia and Fugue States)
- Situation-Specific (seen most commonly relating to crimes, either in victims or perpetrators. Common in PTSD as well)
What is a ‘Fugue State’?
A syndrome consisting of:
- Sudden memory loss, of both autobiographical memory AND the sense of personal identity
- Normally associated with a period of ‘wandering’
- Lasting a few hours-days and no longer
- And leaving the patient with a subsequent amnesic gap on recovery for the period of the fugue
What factors predispose someone to entering a Fugue State?
- Severe precipitating stress (e.g. Marital, Financial, War)
- Depression (especially Suicidal Ideation)
- History of transient organic amnesia (e.g. previous head injury, alcohol issues, epilepsy)
+/- some possible personality factors
Give some of the key features of Psychogenic Amnesia?
- Islets of preserved memory (will remember some small details e.g. “I’m here to meet someone but I can’t remember my name”)
- Semantic knowledge is sometimes preserved, sometimes impaired.
- Procedural knowledge unaffected
- Responsive to cueing (i.e. will recover memory based on random cues in the world around them)
What are the two important types of global psychogenic amnesia?
Fugue State and Focal Retrograde Amnesia. Main difference is in FRA you don’t see Antegrade amnesia and the memory disorder is more persistent.
What is Focal Retrograde Amnesia?
- RA in the absence of any antegrade memory loss
- Sometimes accompanied by an initial loss of personality identity
- Unlike fugue state, memory disorder persists
- Often follows a mild concussion or other such cerebral event
- Brain imaging usually normal
How common is amnesia in homicide suspects?
23-47% of cases.
Also quite common in other violent crimes, rarely seen in non-violent crimes
In what sorts of homicide cases is amnesia sometimes seen?
- Crimes of Passion (tend to be unpremeditated, committed in a state of extreme emotional arousal, often against a family member or spouse. Amnesia usually lasts a few minutes to an hour)
- Alcoholic or Drug Intoxication cases (normally in someone with a prolonged history of abuse)
- Psychotic Paramnesia (delusional or deluded account of the offence)
- Organic/Brain based Disorders (e.g. epileptic automatism, hypoglycaemia)
What evidence is there to suggest that homicide amnesia is a real thing not just a simulation?
- Consistent story in many people who report it
- Often give themselves up once they realised what they’ve done
- Subjective accounts are very similar to proven amnesias
- Victims and eyewitnesses also quite commonly show impaired recall
- No legal advantage to claiming amnesia
Outline the normal ‘Hierarchy of Memory’?
- Conscious recollection of events (remembering)
- Knowing that events or incidents happened without explicit recollection
- Familiarity judgements (recognition)
- Implicit unaware memory (comes from priming, skill learning and conditioning)
What is Confabulation?
A symptom of brain disease whereby gaps in memory are patched up with made up stories, often ridiculous in nature but sometimes ‘real’ memories that have become jumbled up or retrieved inappropriately.
Caused by Neurological Amnesia.
What has research suggested to be the cause of Spontaneous Confabulation?
Frontal Lobe Pathology.
- Luria showde how medial frontal lesions caused memory ‘contamination’
- Stuss showed that EEG, CT and psych testing of 5 patients with confabulation were all consistent with frontal lobe damage.
- Kapur showed that as scores on measures of frontal lobe function improved, confabulation decreased.
- More recent research by turner showed Ventro-medial and/or Orbito-frontal lesions could lead to Confabulation
Describe the confabulations of patients with frontal lobe pathology?
- Spontaneous (not limited to test situations)
- Strong conviction
- Extreme resistance to persuasion
- Preoccupying
- Often bizarre
In what patients do you see Momentary or Provoked Confabulation?
All. Test found provoked confabulation behaviour could be elicited immediately in patients with Korsakoff’s or Alzheimer’s BUT given enough time healthy controls begin to show it as well. About 50% of all patients displayed it, and equal amounts of K’s and controls showed it by the end of the trial.
Suggests confabulation is a normal response to a weak or failing memory.
What is a ‘full house’ of Wernicke features?
- Confusion
- Ataxia
- Nystagmus
- Ophthalmoplegia
What are the 6 features of a Confabulation Battery?
1) Personal Semantic Memory (where were you born)
2) Episodic Memory (what did you do last xmas)
3) Orientation in Time and Space (what month is it)
4) General Semantic Memory (when did WW1 start)
Then two ‘Don’t Know’ tests, where the patient is supposed to say they don’t know the answer to these questions, but if they are confabulating they may make stuff up:
5) Episodic ‘don’t know’ (what did you do on the 13th of March 1998)
6) Semantic ‘don’t know’ (what I Marilyn Monroe’s father do)
Give some examples of confabulations (within the context of the confabulation battery)
Several different types of confabulation:
- Personal Semantic; Misremembering facts about oneself e.g. I’ve just come back from Canada.
- Episodic; Misremembering events in their life e.g. Married a local girl
- Orientation; Date and location
- General Semantic; knowledge like Princess Di died in a car crash
Respond to Don’t Know tests by making up stuff.
What are the 4 main theories explaining confabulation?
1) Context Memory Confusions (or source monitoring deficits)
2) Trace Specification or Verification
3) Motivational Theory
4) Interactionist Theory (combination of the above)
Outline the Context Memory Confusion/ Source Monitoring Deficit theory of Confabulation?
In these theories, confabulation occurs when individuals incorrectly attribute memories as reality, or incorrectly attribute memories to a certain source. Thus, an individual might claim an imagined event happened in reality, or that a friend told him/her about an event he/she actually heard about on television.
“Old recollections with present impressions”
Suggests the patients ‘temporal consciousness’, their location in space and time, as intact but malfunctioning. Patients are aware of their past present and future (this is in contrast to severe amnesia) but misattribute information from it.
