Different Brain Activities Predict Retrieval Success during Emotional and Semantic Encoding

摘要

There is an increasing line of evidence supporting the ideanthat the formation of lasting memories involves neural activitynpreceding stimulus presentation. Following this line, we presentednwords in an incidental learning setting and manipulatednthe prestimulus state by asking the participants to performneither an emotional (neutral or emotional) or a semantic (animatenor inanimate) decision task. Later, we tested the retrievalnof each previously presented word with a recognition memoryntest. For both conditions, the subsequent memory effect (SME)nwas defined as ERP difference between subsequently rememberednand forgotten words. Comparing the prestimulus SMEnbetween and within the two conditions yielded topographic differencesnin the time interval from −1300 to −700 msec beforenstimulus onset. This indicates that the activity of brain areasninvolved in incidental encoding of semantic information variednin the spatial distribution of ERPs, depending on the emotionalnand semantic requirements of the task. These findings providenevidence that there is a difference in semantic and emotional preparatorynprocesses, which modulates successful encoding intonepisodic memory. This difference suggests that there are multiplentask-specific functional neural systems that support memorynformation. These systems differ in location and/or relative contributionnof some of the brain structures that generate the measurednscalp electric fields. Consequently, the cognitive processesnthat enable memory formation depend on the differential semanticnnature of the study task and reflect differences in thenpreparatory processing of the multiple semantic components ofna wordʼs meaning.