Oscillatory correlates of prioritization of emotional stimuli in WM: The interaction between bottom-up and top-down processes

Abstract

Working memory can be enhanced by directing attention to task-relevant representations. Alpha oscillations are a neural correlate of spatial attention either to the perceptual or the mnemonic domain. Specifically, an enhancement of alpha power is observed in the ipsilateral posterior cortex to the locus of attention, along with a suppression in the contralateral hemisphere. In this study we aim to unravel the contribution of bottom-up processes in the top-down guidance of attention inside WM. In this way, emotionality of the memoranda was manipulated in a retro-cue task. Behaviorally, we found a recognition advantage for emotional cued items, and significantly, that the emotionality of the non-cued items did not influence accuracy. We found that bilateral alpha power was greater for the emotional irrelevant condition, which could be reflecting the greater demands to suppress an emotional item from the focus of attention. Critically, we found that alpha power lateralization was not modulated by neither the emotionality of the cued or the non-cued items. However, we found that the latency at which alpha lateralization emerged was modulated by the emotionality of the memory representations. In conclusion, we propose that while alpha power lateralization might be reflecting a general spatial orienting mechanism, in our experiment it is influenced by the selection of relevant information within WM.