Poster F39, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Shifting auditory attention in perceptual and mnemonic space: an investigation of event-related EEG parameters in a sound localization and sound detection paradigm
Laura-Isabelle Klatt1, Stephan Getzmann1, Daniel Schneider1; 1Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund
Recently, the capacity to selectively focus on internal representations held in working memory has received a surge of interest. However, since the majority of studies stems from the visual domain, the neural underpinnings of auditory retroactive attention remain largely unknown. The present study compared neurophysiological markers of selective spatial attention during a perceptual and a retroactive auditory search task. In both conditions, participants completed two separate blocks, including a sound localization and a sound detection task. The pattern of results largely differed depending on the investigated EEG parameter and its associated stage of processing. Consistent with previous results, N2 anterior contralateral (N2ac) effects were obtained when participants searched through a perceptual sound array, reflecting the initial shift of attention towards the target, irrespective of task demands. Critically, the N2ac was absent during retroactive search. However, regarding parieto-occipital alpha-band oscillations, similar mechanisms of selective spatial attention seem to operate in perceptual and retroactive search: While we found a pronounced lateralization of alpha power for localization trials, there was no such asymmetry for detection trials. Thus, we conclude that at an early, modality-specific stage of processing, auditory perceptual and retroactive search do not recruit the same spatially-specific neural mechanisms of target selection (e.g. N2ac). In contrast, at a later, potentially supra-modal level of processing, there is a substantial overlap in the neural mechanisms of attentional selection in perception and working memory. Importantly, only sound localization (and not detection) is based on a map of supramodal representations in perceptual and mnemonic space.
Topic Area: EXECUTIVE PROCESSES: Working memory