Study
Finds How False Memories Are Formed
Researchers literally
have peered into the human brain to offer new evidence on the existence
of false memories and how they are formed, according to a new study
in the journal Psychological Science.
False memories
are the controversial subject of arguments about the validity of repressed
memories that can surface years after a traumatic event and about the
credibility of eyewitness accounts in criminal trials.
Because memories
are imperfect under ordinary circumstances - forming, storing, and retrieving
them, with great variations in factors influencing those processes -
it is unlikely that a one-answer-fits-all will settle those controversies
soon.
Imagined
Event Vs. Experienced Event
The new study
used MRI (magnetic resonance imaging) technology during the presentation
of words and photos to pinpoint how people form a memory for something
that did not actually happen.
"Our challenge
was to bring people into the laboratory and set up a circumstance in
which they would remember something that did not happen," says Dr. Kenneth
A. Paller, professor of psychology at Northwestern University and co-investigator
of the study.
"We measured
brain activity in people who looked at pictures of objects or imagined
other objects that we asked them to visualize," Dr. Paller says. "Later
we asked them to discriminate what they actually saw from what they
imagined."
Building on
research regarding what happens in the brain when people remember
versus forget, the researchers were interested in what happens differently
in the brain when false memories are produced.
"We learned
that the particular parts of the brain critical for generating visual
images are highly activated when people imagine images such as those
we presented to our study participants," explains Dr. Paller.
Many of the
visual images that the subjects were asked to imagine were later misremembered
as actually having been seen.
"We think parts
of the brain used to actually perceive an object and to imagine an object
overlap," says Dr. Paller. "Thus, a vividly imagined event can
leave a memory trace in the brain that's very similar to that of an
experienced event.
"When memories
are stored for perceived or imagined objects, some of the same brain
areas are involved," he notes.
Take a real
life example in which a police interrogator asks if a person saw a particular
person at a crime scene. That induces putting that person in a
person's imagination and possibly corrupts later questioning.
"Just the fact
of looking back into your memory and thinking about whether an event
happened is tantamount to imagining that event happening," Dr. Paller
says. "If I ask you if something happened, you imagine it happening.
Later on - a day or a year later - if I ask about that event, you have
the tough judgment of deciding what happened and what was imagined."
It is important
to know that memory is fallible, Dr. Paller says.
"We know that
we forget quite a bit, but we're not always in touch with the idea that
our memories can sometimes can be misleading," he explains.
Brain
Activity Reflects False Memory Creation
During the study,
participants generated a visual image of a common object in response
to each word, Dr. Paller says.
"They sometimes
claimed to have seen photos of specific objects they had imagined but
not actually seen," Dr. Paller writes in his report. The study findings
indicate "that brain activity reflecting the engagement of visual imagery
can lead to falsely remembering something that was only imagined.
"The remarkable
finding is that brain activity during the study phase could predict
which objects would subsequently be falsely remembered as having been
seen in a photograph," Dr. Paller concludes.
Always consult
your physician for more information.
|
December 2004
Study
Finds How False Memories Are Formed
Imagined
Event Vs. Experienced Event
Brain
Activity Reflects False Memory Creation
Laughter
During Therapy Improves Communication
Online
Resources
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Laughter During
Therapy Improves Communication
Mental
health therapists and their patients can develop a stronger relationship
by sharing a laugh, says a new study in the Journal of Nervous
and Mental Disease.
Many
therapists try not to show emotion, since it could influence patients
and may be seen as judgmental, but this study found that showing emotion
may have a positive effect, especially if it happens mutually.
The
current study found that laughter is used to communicate an emotion,
"much like an exclamation point at the end of a sentence," says lead
researcher Dr. Carl Marci, the director of social neuroscience at Massachusetts
General Hospital.
Moreover,
patients and therapists laughing together increases the intensity of
the emotion and may help build feelings of rapport between them, Dr.
Marci says.
Dr.
Marci's team has been studying many aspects of psychophysiology and
empathy.
In
the current study, the group videotaped therapy sessions and took physiologic
measurements of both therapists and patients. The patients were being
treated for common mood and anxiety disorders.
The
therapists used what is called psychodynamic therapy, which uses the
relationship between patient and therapist to help patients develop
insight into their emotions.
The
physiologic responses of patients and therapists were measured using
skin conductance recordings. This method is commonly used to measure
the activity of the sympathetic nervous system, which controls physiologic
arousal and rates of blood pressure and the heart.
In
10 recorded sessions, the research team identified 145 episodes of laughter.
They found that patients laughed more than twice as often as therapists.
And patients were more likely to laugh at their own comments. In addition,
therapists were more likely to laugh in response to what patients said.
The
actual meaning of laughter needs to be placed in the context of what
was being said before and after it occurred, Dr. Marci explains. "It
could be anything from happiness to anxiety and nervousness."
According
to Dr. Marci, "This combination of psychology and biology can help us
understand how we interrelate."
Always
consult your physician for more information.
Online
Resources
American
Psychoanalytic Association
American
Psychological Association
Centers
for Disease Control and Prevention (CDC)
National
Institute of Mental Health
National
Institutes of Health (NIH)
National
Library of Medicine
US
Department of Health and Human Services
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