Neural correlates of top-down attention in auditory and visual contexts reflect individual differences in the population

Abstract

Individual variability in performance on selective attention tasks that require top-down control can be large. Recent neuroimaging and electroencephalography (EEG) experiments also suggest that auditory spatial selective attention engages the same fronto-parietal network used by visual spatial selective attention. We therefore hypothesized that individual differences in spatial selective attention would correlate for similar auditory and visual tasks and produce correlated changes in sensory responses in the two modalities. We calculated EEG-derived correlates of top-down, spatial attention during auditory and visual tasks that required subjects to sustain selective attention at one of two cued spatial locations (left or right) and report the auditory or visual sequence that appeared in that direction. Individual behavioral performance on the tasks correlated across sensory modalities. Spatial attention differentially modulated event-related potential N1 responses at the group level for both auditory and visual tasks. At the individual level, these attention-modulated N1 responses correlated with task performance for the auditory task; however, the ERP peaks were noisy and unreliable in the visual task. In contrast, the inter-trial coherence (ITC) in a time window encompassing the N1 correlated to performance for the visual, but not the auditory task. Our work highlights differences in how top-down attention modulates these representations across the two modalities.