Something to Consider • 197have proposed that after a memory is reactivated, it must undergo reconsolidation,
which is similar to the consolidation that occurred after the initial learning but
apparently occurs more rapidly (Dudai, 2006; Dudai & Eisenberg, 2004; Nadel &
Land, 2000; Nader, 2003; Sara, 2000). Just as the original memory is fragile until
it is consolidated for the fi rst time, a reactivated memory becomes fragile until it is
reconsolidated.
Looked at in this way, memory becomes susceptible to being changed or disrupted
every time it is retrieved. You might think that this is not a good thing. After all, putting
your memory at risk for disruption every time you use it doesn’t sound particularly use-
ful. However, everyday memory retrieval isn’t usually accompanied by injection with a
protein synthesis inhibitor, as in Nader’s experiment, or getting hit on the head, as hap-
pens with football players, which would eliminate the memory. It is therefore unlikely
that, in everyday experience, reactivation and subsequent reconsolidation will eliminate
or selectively change memories after they have been retrieved.
Reconsolidation might, however, provide an opportunity for reinforcing or updat-
ing memories. For example, consider an animal that returns to the location of a food
source and fi nds that the food has been moved to a new location nearby. Returning
to the original location reactivates the original memory, new information about the
change in location updates the memory, and the updated memory is then reconsoli-
dated. Looked at in this way, reactivation and reconsolidation makes memory a more
dynamic and adaptable process. Rather than being fi xed, memories can evolve to deal
with new situations.
Does this process of reconsolidation occur in humans? There is some evidence that
it does (Nader, 2003). For example, in an experiment by Almut Hupbach and coworkers
(2007), participants learned a list of words (List 1) on Day 1. On Day 2, one group (the
no-reminder group) learned a new list of words (List 2). Another group (the reminder
group) also learned the new list on Day 2, but just before learning the list, they were
asked to remember their Day 1 training session (without actually recalling the List 1
words), thus reminding them of their learning.
● Figure 7.24 shows what happened on Day 3, when these two groups
were asked to remember List 1. The left pair of bars indicates that the no-
reminder group recalled 45 percent of the words from List 1 and mistakenly
recalled only 5 percent of the words from List 2. (Remember that their task
was to only remember the words from List 1).
The right pair of bars shows that something quite different happened for
the reminder group. They recalled 36 percent of the words from List 1, but in
addition mistakenly recalled 24 percent of the words from List 2. According
to Hupbach and coworkers, what happened was that the reminder on Day 2
reactivated the memory for List 1, making it vulnerable to being changed.
Because participants immediately learned List 2, some of the words from
List 2 became integrated into the participants’ memory for List 1. Another
way to express this idea is to say that the reminder reactivated memory for
List 1 and “opened the door” for changes to occur in the participants’ mem-
ory for that list.
One practical outcome of research on reconsolidation is a possible
treatment for posttraumatic stress disorder (PTSD), a condition that
occurs when, following a traumatic experience, a person experiences
“fl ashbacks” of the experience, often accompanied by extreme anxiety
and physical symptoms. The clinical psychologist Alain Brunet (2008) has
tested the idea that reactivation of a memory followed by reconsolida-
tion can provide a way to help alleviate these symptoms. The basis of his
idea is to reactivate the person’s memory for the traumatic event and then
administer the drug probanolol. This drug blocks production of a stress
hormone in the amygdala, a part of the brain important for determining
the emotional components of memory. This procedure is equivalent to the
administration of anisomycin on Day 2 in Condition 3 of Nader’s experi-
ment (Figure 7.23c).Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.Image not available due to copyright restrictions