Date:   Wed Jun 01 1994  23:34:42
From:   Sheldon Wernikoff
Subj:   False Memory 

Miscoding Seen as Root of False Memories
Daniel Goleman
New York TImes, May 31/94

In a scientific nod to the frailty of memory, neorologists and
cognitive scientists are coming to a consensus on the
mental mechanisms that can foster false memories.

The leading candidate is "source amnesia," the inability to
recall the origin of the memory of a given event.  Once the
source of a memory is forgotten, scientists say, people can
confuse an event that was only imagined or suggested with
a true one.  The result is a memory that though false, carries
the feeling of authenticity.
This has been an epic month for false memory.  Three new
books have been published that investigate the
phenomenon and its mirror opposite, repressed memory.  In
mid-May, a California court awarded $500,000 to the father
of a woman who had accused him of sexual abuse after
supposedly recovering memories of childhood incidents
during therapy.  The plaintiff, Gary Ramona, had asked for
$8 million in damages against his daughter's therapists and
the medical center where they worked.

Earlier in the month new scientific agreement on the most
likely neurological and cognitive bases of false memory
emerged during a conference on the issue at Harvard
Medical School.

Part of the fragility of memory is due to the way the mind
encodes a memory, distributing aspects of the experience
over far-flung parts of the brain, various researchers said at
the meeting.  The brain stores the memory of each sense in
different parts of the neocortex -- sound in the auditory
cortex, sight in the visual cortex, and so on, reports at the
meeting pointed out.  Another part of the brain, the limbic
system, has the job of binding these dispersed parts of the
memory together as a single experience.

One of the more frail parts of a memory is its source -the
time, place, or way the memory originated.  Based on
careful observations of neurological patients to see which
mental operations are harmed by damage to different parts
of the brain, the frontal lobes seem to be the main site for
source memory, according to a report at the Harvard
meeting by Dr. Morris Moscovitch, a neurospychologist at
the University of Toronto.

Patients with damage to specific zones of the frontal lobes
are prone to confabulate, concocting stories to make sense
of the shards of memory they retrieve, and are unable to
evaluate the reasonableness of their fabrications.  The
confabulator picks out a bit or piece of an actual memory,
but confuses its true context,  and draws on other bits of
experience to construct a story that makes sense of it," said
Dr. Daniel Schacter, a Harvard psychologist and another
organizer of the meeting.

Such a  plausible scientific explanation has been missing
until now in the debates about false memory.  The
conclusion of scientists at the meeting call into question the
methods not only of many therapists who specialize in
helping patients retrieve memories of childhood sexual
abuse but also those commonly used by officials
investigating such charges.  Scientists say these methods
can inadvertently plant a false memory, and are based on
naive or distorted assumptions about how memory works.

"The lay expectation is that whatever we remember should
be true, but memory does not work like a video camera,"
said Dr. Marsel Mesulam, head of the urology department at
Beth Israel Hospital at Harvard Medical School, and one of
those who convened the meeting.  "From the point of view of
neuroscience, every memory is a fragile reconstruction of
what the nervous system actually witnessed."

For example, one of Dr. Marcovitch's patients with frontal
lobe damage said he had been married for just four months,
although he had actually been married nearly four decades.
When confronted with the discrepancy, he explained it away
by saying he had been married twice - a confabulation that
arose to make sense of the initial mistaken memory.

"Source memory defects - retrieving he content without
knowing its origin - are a major cause of distorted
memory," said Dr. Schacter, "with people confusing whether
they heard about, imagined or had something happen to
them."

Source amnesia is common, and usually benign, as when
one recognizes a face but has no idea where one has seen
the person before - the memory for the face is retained, but
not the memory for the time and place the face was first
seen.

This kind of forgetfulness is a natural result of the constant
reshuffling and gradual decay of memories in the brain.
"What we witness is encoded over neurons that were
involved in remembering things we witnessed earlier, and
later ones will be encoded over the new one," said Dr.
Mesulam.  "There are no fresh neurons, like a clean
diskette:  There's a constant remolding of memory in the
brain as older memories are redistributed by newer ones."

Gradually, aspects of a memory are degraded by the normal
wear and tear of brain function.  "As time goes on, pieces of
the memory may not bind together so well, thought most of
the individual pieces themselves are alive and well in
memory," Dr. Mesulam said.

This means the source of a memory may fade even as the
rest of the memory can be retrieved, said Dr. Stephen Ceci,
a psychologist at Cornell University.  In his presentation at
the Harvard meeting, Dr. Ceci cited the experimental work of
Dr. Charles Brainerd at he University of Arizona, which
shows that "the context - the time and place - in which
you acquire a memory is the quickest part of the memory to
decay and the easiest to interfere with."

Another reason for confusion in memory, said Dr. Schacter,
is that all memories are subject to contamination by leakage
from related bits of information.   In recalling a memory, for
example, people typically make inferences about what may
have happened to fill in gaps, and can then confuse the
sources, melding what they inferred with the actual memory.
In addition, Dr. Schacter warned, "just because a memory is
vivid does not mean it is more accurate."

Part of the new scientific evidence for the vulnerability of
memory to suggestion comes from studies in which false
memories are implanted through experimental manipulations.

Many of these studies have involved young children, who
are particularly susceptible to false memories.  At the
Harvard meeting, Dr. Ceci reported a series of recent
experiments, none of which have yet been published,
showing the surprising ease with which children can become
convinced that something they only imagined or was
suggested to them really happened.

In an earlier study involving 96 preschool children reported
last year, Dr. Ceci showed that with repeated questioning
about events that had never occurred, many children
gradually came to believe that the events had happened.
The false memories were  so elaborate and detailed that
psychologists who specialize in interviewing children about
abuse were unable to determine which memories were true,
Dr. Ceci said.

At the Harvard meeting, Dr. Ceci reported on five more
studies with a total of 574 preschool chlordane, all of which
confirm his earlier results.  After 10 weeks, 58% of the
children in those studies had made up a false account for at
least one fictitious event repeatedly suggested to them, and
a quarter of them had concocted false stories for most of the
phony events.  Three of the studies are scheduled for
publication next year, one in The Journal of Child
Development.

"Each time you encourage a person to create a mental
image ,it becomes more familiar," said Dr. Ceci.  "Finally
they see the imagined image as an actual memory, with the
same feel of authenticity.  In our studies there are about a
quarter of the chlordane we can't talk out of the fact that the
memory we implanted was real, even though we explain
their parents helped us concoct the false memory."

Commenting on Dr. Ceci's findings, Dr. Moscovitch said,
"Young children may be led into concocting memories so
easily because their frontal lobes are immature.  Until age 7
or 8, children respond to neurological tests like adults with
frontal lobe damage."

Source amnesia is also frequent in the elderly whose frontal
lobes have deteriorated.  "There is some anatomical
evidence that in aging the frontal lobes deteriorate faster
than other brain regions," said Dr. Schacter.  In an artile
published earlier this year in The Journal of Psychology and
Aging, Dr. Schacter reported that failures of source memory
in the elderly seem to be associated with decline in their
frontal lobe function.

But adults whose brains presumably are intact can also be
led to believe in memories of fictitious events.  Dr. Elizabeth
Loftus, a psychologist at the University of Washington,
reported at the Harvard meeting on the final results of a
study in which false memories about childhood events were
created in 24 men and women ages 18 to 63.

Dr. Loftus reported that the parents of volunteers in the
experiment cooperated to produce a list of events that had
supposedly taken place in the volunteer's early life; three
were true and one, a description of the person becoming lost
on a shopping trip, was fictitious....

...Most adults do not readily concoct false memories in
response to suggestion.  "About 10 percent of adults will
come up with a specific elaborated memory from childhood,
and another 15 percent or so will say they feel a vague
sense of certainty that it occurred if you keep asking them
about it," said Dr. Loftus.  But she also fund that about 75%
of those studied did not manufacture false memories in this
experimental situation, despite the implicit pressure to
produce one.

But that can change under conditions that foster an
openness to suggestions.  "Some therapists unabashedly
recommend 'suggestion'; as a means of pursuing
memories," said Dr. Loftus.  "Yet decades of memory
research has shown these are sure-fire ways to implant
false memories."

Dr. Ceci said: " Our study asking children each week about
a supposed memory is an analog of the therapist who asks
you to think back to a time when you felt uncomfortable in
your childhood, and says, 'focus on some image that floats
to mind,' and not to worry if you're mixing imagination with
different episodes of memory.  They say you can sort all that
out later, but that's a naive view of memory.  Once they're
mingled, it's very hard to separate their source."

Psychotherapy patients who undergo methods like hypnosis,
which heighten suggestibility, can easily become "honest
liars,": convincing themselves of the truth of a false memory,
said Dr. David Spiegel, a psychiatrist at Stanford University,
in a report at the Harvard meeting.  In a 1983 study, for
example, 27 people were told while hypnotized that as they
sleep the night before they had been awakened by the
sound of a car backfiring; when questioned a week after the
hypnotic session, 13 reported having heard the backfiring on
that night.  Six of those in the study were so convinced they
had heard the fictitious backfiring that they persisted in the
false belief even after the experimenters explained to them
how the memory had originated.

"Under hypnosis people can experience themselves as
retrieving a memory when in fact they are creating it, and
also develop an inflated conviction that the fabricated
recollection is accurate,: Dr. Spiegel said.

This conviction of truth becomes stronger the more intensely
people work at retrieving details of the event.  "It's a real
concern about using hypnosis to retrieve memories," said
Dr. Spiegel.  "It inflates your confidence in your accuracy
more than it improves your accuracy.  You don't need
hypnosis to get the same effect - a therapist pressing a
highly suggestible patient to try to remember could do the
same."

Given the scientific evidence fro the frailty of memory, "the
miracle is that anything we remember is true," said Dr.
Mesulam, "not that there is distortion."

