INTRUSIONS, DISTORTIONS
AND ILLUSORY MEMORIES
• The “fundamental attribution error”
in memory
– When I was younger, I could remember
anything, whether it had happened or
not; but my faculties are decaying now
and soon I shall be so I cannot
remember any but the things that never
happened.
- Mark Twain's Autobiography
– It’s never too late to have a happy
childhood.
- Shel Silverstein, author of Where the
Sidewalk Ends
– How do you know a memory is real?
• Intrusions, False alarms and
misidentification
– Similarity-based errors in recall and
recognition (typically meaning-based)
– Cases of false identification
• Demjanjuk as Ivan the Terrible
(Wagenaar, 1988)
• Demand characteristics of lineups
• Consulting on an EW case
• Distortion and confabulation
– Event (at encoding) or Cue (at retrieval)
activates related semantic and episodic
information that gets integrated into
episode
• War of the Ghosts (Bartlett, 1932)
• Nancy & the Doctor (Owens et al. 1979)
• Historical vs. Narrative Truth
(Spence, 1984)
• Increasing vulnerability over time
– Reder (1982): Ss read short stories:
• [hamburger heir]
– Speed of “studied” versus “plausible”
decisions shifts over time:
3.4
exact
plausible
decision time
3.2
3
2.8
2.6
2.4
2.2
2
Immediate
20 Minutes
2 Days
Study-test delay
– “Fuzzy trace theory” (Brainerd & Reyna)
• Encoding includes both verbatim and
“gist” information
• Verbatim, as “superficial,” is less
distinctive and more vulnerable to
forgetting
• Source amnesia
– Cue activates correct target, wrong
context
• the misinformation effect (Loftus, 1985)
• The famous-overnight effect (Jacoby,
1989)
• Verbal overshadowing (Schooler ’90)
– Failure to distinguish experienced from
imagined events
• Failures of reality monitoring (Johnson,
1985)
• The false memory studies
– Roediger & McDermott : How sweet
it is (1995)
– Loftus & Ketcham: Lost in a shopping
mall (1994)
• Hypnosis and confabulation
– Evidence that hypnosis changes
bias, not sensitivity
– Increases in confidence
– Accepting of sometimes bizarre
“memories” as fact
Delusions and confabulations in
memory disorders
• Etiology
– Often associated with frontal lobe damage
• Rupture of anterior arteries
• Korsakoff’s syndrome
• Frontal degenerative diseases
• Symptoms
– Intensity, frequency, plausibility of
confabulations vary widely
– Content is often based on “real” episodes
– Not an obligatory “gap filling”
– May be believed obsessively despite
acknowledged contradictions
• Theory
– Loss of “executive control” over memory and
metamemory functions
– Impairment of memory for temporal order and
context
– Loss of “reality monitoring” and increase in
source amnesia
– Consolidation of false memories with rehearsal
• Some case studies
• The case of John Demjanjuk
– Ukranian immigrant, auto worker in
Cleveland
– On KGB list of German “war criminals”
– Exported and convicted in Israel of being
“Ivan the Terrible” of Treblinka, 1988
– Survivors confidently identified him as
Ivan
– Fall of USSR, KGB docs forgeries, 1991
– Acquitted and released, 1993
– Charged with similar crimes at other
camps, 1999
– stripped of U.S. Citizenship and slated for
deportation to Ukraine, 2005
“I said the photo was not particularly
sharp. It was older than the Ivan I knew,
but it was still him. The frame, the round
face, the short neck, the wide shoulders
and the protruding ears. I told them this
is the Ivan I remember,” Epstein said.
(Reuters, 23 February 1987.)