Abstract
Shifts of attention within mental representations based on retroactive cues (retro-cues) facilitate performance in working memory tasks. It was suggested that this retro-cue benefit is related to the concentration of working memory resources on a subset of representations, thereby improving storage and retrieval at the cost of non-cued items. However, the attentional mechanisms underlying this updating of working memory representations remain unknown. Here, we present EEG data for distinguishing between target enhancement and distractor suppression processes in the context of retroactive attentional orienting. Therefore, we used a working memory paradigm with retro-cues indicating a shift of attention to either a lateralized or non-lateralized item. Posterior and anterior asymmetries in the event-related potential suggested a contribution of both target enhancement and distractor suppression to retroactive attentional selection. Following this stage of selection, there was an increase of posterior alpha power contralateral compared to ipsilateral to the irrelevant item when a non-lateralized mental representation was cued. No comparable asymmetry was revealed when a lateralized item had to be selected. This suggests that the inhibition of the non-cued information is an important feature of attentional orienting within working memory. The current results thus enable a first impression on the interplay of attentional sub-processes in the context of retroactive cuing.