Sigmund Freud proposed
that memories from a traumatic event can be forced from awareness
through a process he called repression.
Now, reporting in the January 9, 2004, issue of Science, a
team of neuroscientists claim they have observed this process—now
known as "suppression" of memories—on brain
scans. They also found that pushing memories out of consciousness
helps to gradually extinguish them. In other words, to forget
Participants in the study first memorized pairs of words
such as jaw/gum and ordeal/roach. Then, while in a brain
scanner, they were presented with only one member of a
series of the word pairs. Some participants were asked to
recall the other word in the pair, while others were asked
to consciously suppress the matching word from their awareness
for 4 seconds.
The scans indicated that two brains regions were unusually
active when study participants were actively blocking memories:
prefrontal cortex and the hippocampus.
The hippocampus, in particular, is central to the process
of creating new memories of events and then consciously recalling
them later. Later, the people were tested for how well they
could accurately recall word pairs. Compared to previously
memorized word pairs not presented during the study, recall
for the suppressed pairs was less accurate. If confirmed,
the study could offer insight into how we subtly edit traumatic
and upsetting memories.
“Neural systems underlying the suppression of unwanted
memories,” by Michael C. Anderson, PhD, and others.
(Science, January 9, 2004, Volume 303, Number 20, pp. 232-235.)