La sindrome amnesica - France Traumatisme Crânien

Cognition et délire: de la croyance à la fabulation Gianfranco Dalla Barba

Phénomènes Délirants et Traumatismes crâniens Paris13/12/2013

Délire et confabulation

- Similarités: - Délires et confabulations sont des fausses croyances - Le patient délirant « croit » en son délire - Le confabulateur « croit » en ses confabulations - Le délire et la confabulation sont résistants aux critiques - Mais il y a une ambigüité: en réalité dans le délire et dans la confabulation il s’agit de « vrais » croyances subjectives considérées comme « fausses » croyances objectives.

Fausses croyances « normales »

Confabulations « normales » -Kopelman, 1987 -Confusion entre réalité et imagination -Convictions erronée sur les souvenirs

-Faux souvenirs des enfants

Délire et confabulation

- Différences: - Signes psychiatriques vs signes neurologiques - Les confabulations concernent la mémoire et la temporalité en général - Les confabulations sont rarement accompagnées par d’autres phénomènes psychotiques - Il n’y a pas ou peu de traitements cognitifs ou pharmachologiques

Distorsions Mnésiques • Confabulations • Intrusions • Fausses reconnaissances

• Paramnesies • “Déjà vu” • Etc….

Distorsions mnésiques ? • Sociales • Médicales • Théoriques

False memories: Social • Eyewitness misattribution – 75,000 criminal trials/year decided on the basis of eyewitness testimony – 36/40 (90%) cases in which DNA evidence established the innocence of wrongfully imprisoned individuals involved mistaken eyewitness identification

False memories: Medical • False memories may impair the ability of patients to live independently • For example, patients may believe that they turned off the stove when they have only thought about turning it off.

False memories: Theoretical • The study of false memories may provide valuable information on the functions of normal memory

• The role of executive functions • The role of encoding and retrieval processes

• Temporal Consciousness

Definition of confabulation • ”falsification of memory” (Berlyne, 1972) • ”an extreme form of lying or deception” (Joseph, 1986) • ”an honest lying” (Moscovitch, 1989) •

…

Definition of confabulation • A particular symptom, observable in amnesic patients unaware of their memory deficit, which consists of both actions and verbal statements that are unintentionally incongruous to the patients’ history, background, present and future situation. (Dalla Barba, 1993)

Hypotheses on the origin of confabulation • Moscovitch, 1989, 1995 – Associative vs Strategic retrieval

• Confabulation = deficit of strategic retrieval

Hypotheses on the origin of confabulation • Johnson 1991: Reality monitoring • Schnider & Ptak 1999: Reality filtering

Hypotheses on the origin of confabulation • Conway & Tacchi, 1996 • Wishful thinking

Temporal Consciousness (TC) - A specific form of consciousness that allows individuals to remember their personal past, to be oriented in their present world and to predict their personal future. - It is specific because it cannot be confounded with other forms of consciousness, perception, imagination

Temporal Consciousness (TC) - If, for instance the average person perceive a tiger in front of them, they will be scared, but if they remember or imagine such an event, they may not be scared at all. - "Re-experiencing the past" - TC is opposed to KC which allows individuals to address the past, the present and the future impersonally

Temporal Consciousness (TC) - It is experimentally measurable and and dissociable from impersonal temporality - It is lost in amnesia following bilateral hippocampal damage and it is malfunctioning in confabulation

% correct

% conf

Examples of confabulations in IDKE questions • Do you remember what you did on March 13, 1985? • We spent the day at the Senart Forest

Examples of confabulations in IDKE questions • Do you remember what you had for dinner on Tuesday two weeks ago? • Steak with French fries

Examples of confabulations in IDKE questions • Do you remember what you did on October 9, 1991? • We spent the day with our children. We played cards and talked about next holydays

Examples of confabulations in IDKE questions • Do you remember what you did for your 27th birthday?

• Wait a minute… I came back from the army when I was 23, so the 27th birthday… I think… Yes! I had dinner at my future wife’s place

Examples of confabulations in IDKE questions • Do you remember what you were doing one year ago? • One year ago… I was with my wife and my children

Examples of confabulations in IDKE questions • Do you remember what you were wearing on the first day of summer in 1979? • A short and a T-shirt

La Corte, et al., 2010

Cognition et délire: de la croyance à la fabulation Gianfranco Dalla Barba

Phénomènes Délirants et Traumatismes crâniens Paris13/12/2013

• Délire • Confabulation • Croyances sociales • Croyances politiques

• Idéologies • Croyances religieuses • Amour

• Délire, confabulation… religion… • Psychopathologie = « Connaissance Totale » Périphérie

Noyau