EP 119. Neural correlates of attention allocation during episodic long-term memory encoding and retrieval

Abstract

Directing mental resources, i.e. attention, to a relevant stimulus forms a critical part in the formation and retrieval of memory traces – be it in working memory (WM) or long-term memory (LTM). For the formation of episodic memories the relevant stimuli furthermore need to be processed in relation to each other and/or to their context. Research into the neural correlates of the allocation of attention in mnemonic processing has received increasing interest in the last few years. The EEG correlates of attention allocation to item and context information during episodic encoding, on the other hand, are not yet fully understood. We designed an episodic LTM EEG experiment where we examined the activity in and interactions of prefrontal and posterior cortical areas associated with WM and attention allocation as well as the binding of items and their context in episodic LTM encoding and retrieval. Participants saw a background picture of mountain scenes and a word in a central position on a computer screen and were instructed to memorise either the picture, the word, both individually or both and that they were presented together. Here, we will present evidence indicating that the manipulation of the distribution of attentional resources to the different stimuli and their relation led to differences in the performance on a later LTM recognition test. Furthermore, we will present EEG oscillatory correlates – on scalp as well as source level – for the different encoding strategies highlighting activity representing the binding of an item and its context in episodic memory encoding as well as retrieval. Interactions between various cortical areas will be discussed in terms of phase coupling within circumscribed frequency bands.