Reversible amnesia induced by crowding, a naturalistic stressor

LUIS SÚAREZ; DELORENZI ALEJANDRO

HG

Congreso; SAN 2013; 2013

SAN

After reversible amnesia, not expressed memories can be updated during reconsolidation. Because memories should be reactivated to reconsolidate, lack of expression can not be explained as a deficit in accessibility but in expression of reactivated traces. Searching for an adaptive value for mechanisms that allows the consolidation of accessible but inexpressible memory traces, we are studying the effects on memory consolidation of a naturalistic stressor: crowding. In the Context-Signal Memory model in Chasmagnathus, a Visual Danger Stimulus (VDS) is associated with the training context. The constraints of a reminder to induce reconsolidation were well described in this model: a short non-reinforced re-exposure to the training context labilizes the memory, while presentation of the VDS after the same re-exposure time impedes the labilization of memory. We found that four hours of crowding can block the expression of acquired performance in the long-term if the stressor is applied immediately after training but not before. Memory expression can be rescued after induced amnesia by a non-reinforced exposure to the training context, but not when the VDS is presented. Also, this effect is only seen in the long-term but not immediately after the induction of reconsolidation. These results support the idea that experiences close to learning can modulate how memories are going to be expressed in the future. However, unexpressed experiences must remain available for future evaluation.