Challenging emotional memory

Emotional experiences tend to be very well remembered. The ability to recall the important events in life is crucial to adaptively respond to future situations. The strength of emotional memories may, however, also become harmful and maladaptive when it constraints daily functioning, such as in patients suffering from post-traumatic stress disorder. From an evolutionary perspective, stability of our memory system is essential to recognize important predictors (i.e., stimulus or context) of imminent threat and reward. However, since it is unlikely that a stimulus or context will keep its predictive value forever, memories need to be malleable as well. Recently it has been shown that upon recall, memories can enter a labile state where they are sensitive to change before being restabilized again. This process is referred to as reconsolidation. In the current thesis, we aimed to gain more insight into the malleable nature of emotional memory. In five empirical chapters we experimentally challenged emotional memory using different experimental paradigms and pharmacological and behavioral manipulations to alter the strength of emotional memory. We showed that 1) there are certain boundary conditions under which reconsolidation does not occur and emotional memory cannot be weakened 2) stress exposure after memory reactivation can strengthen memory and enhance the contextual embedding of emotional memory. These findings indicate that the process of reconsolidation plays a key role in keeping our memories up to date.