Episodic memory illusions: Suggestibility Def.: suggestibility individual’s tendency to incorporate misleading info from external sources into personal recollections from episodic memory [external sources; e.g., other people’s oral or written statements, pictures, films]

Episodic memory illusions: Suggestibility groundbreaking research by E. Loftus on suggestibility in memory: demonstration of misinformation effect when people who witness an event are later exposed to new and misleading info about it, their recollections often become distorted classic experiment with slides showing situation that leads to car accident (Loftus, Miller, & Burns, 1978)

Misinformation effect

even with short delay less accurate memory after misleading info with delay (i.e. fading of original memory), higher susceptibility to memory errors

Misinformation effect Further research questions How can the effect best be explained? actual memory impairment (over-writing) versus demand characteristics of situation (compliance) related question: Do subjects really remember misleading info as original? (i.e. is it truly memory illusion?) Or can they keep sources apart if asked directly?

Misinformation effect Further research research by Lindsay & Johnson addresses nature of errors change of questions at time of memory testing: + simple recognition vs source monitoring question Did you see info in slide? Did you see info in slide, read it, both, or neither? ->more memory errors with recognition than with source monitoring questions -> suggests when demand characteristics are changed and source info is emphasized, people make less errors BUT some errors occur even on source questions -> suggests that some but not all errors reflect actual mis-remembering (illusions)

Misinformation effect Further research further support that subjects cannot always resist memory illusions: research by Lindsay with Jacoby’s opposition procedure in combination with misleading post-event info ‘Recall info from original slides!’ ‘Try to avoid all info provided afterwards; it was incorrect!’ -> some illusions occur despite subjects actively trying trying to avoid them

Misinformation effect Further research general research outcome: memory errors after suggestive misleading info can reflect both demand characteristics and actual illusions under some conditions misleading info can impair people’s ability to remember what they witnessed and lead them to believe that they witnessed things they did not

Legal issue: false confessions after coerced interrogations, do people sometimes falsely confess a crime they did not commit, while actually believing in their own confession (i.e. having memory illusion for crime)? -> yes, in extreme cases ‘memory distrust syndrome’ (e.g. due to intoxication at event or if person believes she could have repressed it) -> demand characteristics of social situation also play role Suggestibility Can it even effect memory for our own actions?

study by Kassin & Kiechel (1996) on evoking false confession of unwanted action (no crime) in psychology lab setting + involves deception presumed goal: measuring reaction time in typing + involves confederate + try to type as fast the words you hear from other subject (confederate) but avoid to hit ‘ALT’ key + after 1 min fake crash of computer; accusation that subject erroneously pressed ‘ALT’ key Suggestibility Can it even effect memory for our own actions?

study by Kassin & Kiechel (1996) +two variables manipulated in study: - fast or slow typing speed - confederate acts as false witness of presumed error or not + three different types of behaviour examined: - compliance: willingness to sign form admitting error - internalization: comments to other person on what happened - confubulation: provision of details on how error occurred Suggestibility Can it even effect memory for our own actions?

Results from study by Kassin & Kiechel No witness Witness Slow pace Fast pace Slow pace Fast pace Compliance Internalization Confabulation00635 percentage of subjects showing various behaviours -> false witness report can induce false confessions with person believing in his/her own guilt (memory illusion)

Childhood amnesia / infantile amnesia observed in all healthy individuals -> no acquired brain damage involved despite the acknowledged importance of the first 3 years of life in shaping the cognitive capacities and personality of human adults, almost no reportable memories are retained from this period

Childhood amnesia: How can it be studied? different research approaches: (1) study of earliest childhood memory reported “what is the first episode of your life you can recall?” (2) study of childhood events with known date of occurrence “ what do you remember about your youngest sibling’s birth?” (3) examination of temporal distribution of memories across life-span in relation to cue words “ describe a distinct episode that has to do with a dog”

Childhood amnesia: How can it be studied? study by Howes et al. (1993) of earliest childhood memory reported in undergraduate students Negative affect Positive affect No info on emotion Other people’s emotion n(800) % > most memories contain emotionally salient info -> average age at episode (memory acquisition): 3.07 for female 3.40 for males

Childhood amnesia: How can it be studied? study by Howes et al. (1993) of earliest childhood memory reported in undergraduate students AllPartialNo info avail. DistortedDifference (unclear whether distorted) Disconfirmed n(800) % > data suggest generally high accuracy for gist e.g. see example from paper verification through other person present in episode:

Childhood amnesia: How can it be studied? study by Usher & Neisser (1993) of childhood events with known date of occurrence earliest memory: 2 – 3 years

Childhood amnesia: How can it be studied? study by Rubin & Schulkind (1997) of childhood events in response to cue words

Explanations of childhood amnesia many explanations suggested in literature term ‘infantile amnesia’ introduced by Freud: ‘it is impossible to avoid a suspicion that the beginnings of sexual life which are included in that period have provided the motive for its being forgotten – that is forgetting, in fact, is an outcome of repression’ modern theories: psychology: linked to qualitative changes in cognitive abilities as children develop into preschool years neuroscience: linked to major changes in brain development (maturation of hippocampus and frontal lobes) -> both are not mutually exclusive!

Relevant background to explain childhood amnesia general consensus: infants and toddlers have ability to encode and acquire event-specific information e.g. research by Rovee-Collier long lasting memory for kicking of mobile in early childhood more than 2 weeks in 6 month olds unclear: nature of memory; likely not episodic but implicit

further demonstrations of early memory capacities: + 2 year olds can express memory through spontaneous ‘delayed imitation’ year olds show retention of unique laboratory procedure (reaching in dark for sounding object) from single 20 min session acquired at age 7 month -> again likely implicit memory at work + toddler’s spontaneous (limited) talking at age 2 – 3 years reveals memory for episodes that happened 6 months earlier -> perhaps first truly episodic recollections? Relevant background to explain childhood amnesia

Explanations of childhood amnesia what else is special in cognitive development between age 2 and 3: + emergence of self-concept (organizing function for episodic memory) + emergence of theory of mind (perspective taking) + emergence of language and critical conceptual knowledge: - distinction between you/me, I/me - use of past-tense + emergence of social interactions based on telling of past episodes (personal stories) -> likely all related to emergence of episodic memory -> popular theory: childhood amnesia occurs due to lack of episodic memory abilities before age 2 – 3

Explanations of childhood amnesia problems with explanations that link childhood amnesia to emergence of specific new cognitive abilities at age 2-3 -> evidence only indirect -> no demonstration of causal link in retrospective research -> difficult even to determine how to test different explanations (i.e., emergence of what specific cognitive function is critical) against each other -> longitudinal studies most promising to provide deeper understanding