Section Days abstract book 2010.indd - RUB Research School ...

TEMPORALLY GRADED MEMORY
RECONSOLIDATION IN HUMANS
Sonja Wichert 1,2 , Oliver T. Wolf 1,2 , Lars Schwabe 1
1
Department of Cognitive Psychology, Faculty of Psychology, Ruhr-Universität Bochum,
44780 Bochum, Germany
2
International Graduate School of Neuroscience, Ruhr-Universität Bochum,44780
Bochum, Germany
e-mail: sonja.wichert@rub.de
Background:
The phenomenon of memory reconsolidation has made researchers question the traditional
view that consolidated memories are safely stored in the brain, being resistant to disruptions.
According to the concept of memory reconsolidation, the retrieval of a consolidated,
apparently stable memory can return it to a labile state, necessitating another period of
stabilization, named reconsolidation [1-3]. Memory reconsolidation suggests that
modifications during or shortly after retrieval may provide a means of changing unwanted
emotional or traumatic memories.
Indeed, recent studies indicate that psychological and pharmacological manipulations
shortly after the reactivation of a conditioned fear memory reduce the fear significantly and
lastingly in healthy participants [4, 5]. These promising findings raise the question whether
there is a critical time window for such manipulations: Are younger and older memories
likewise sensitive to modifications during reconsolidation?
Evidence from rodent studies shows that older memories are less susceptible to postreactivation
manipulations than younger ones and that the vulnerability of memories
decreases as the time interval between initial learning and memory retrieval increases [6, 7].
However, these findings remain controversial, as other animal studies did not find an effect of
memory age [8, 9]. Evidence for a temporal gradient in human memory reconsolidation is
missing.
Methods:
To assess whether recent and older memories are likewise susceptible to alterations after
reactivation, healthy participants learned a set of pictures and reactivated it 1, 7, or 28 days
later. Immediately after retrieval of the previously learned pictures, participants learned a
second set of pictures, a manipulation that altered memory performance in earlier studies [10,
11]. Twenty-four hours later, participants completed a free recall test for the pictures they had
initially learned. Memory performance was expressed as (i) the number of remembered
pictures and (ii) the number of remembered details.
Results:
New learning after memory reactivation reduced memory performance when there was a 1day-interval
between initial learning and reactivation. After an interval of 7 days, the effect of