Brain perturbation to reveal causal contributions of executive networks to the mechanisms of auditory attention

Abstract

Listeners face the challenge of understanding speech every day. A key cognitive strategy for parsing speech in noisy environments relies on auditory selective attention, which recruits a network of multiple cortical regions. Our recent studies identified at least two different neural mechanisms of auditory attention. Space-based attention engages alpha oscillations in the parietal cortex, which are thought to cause lateral suppression of streams in the ignored portion in space. In contrast, talker identity-based attention modulates beta oscillations in the temporal lobe, suggesting that a neural pitch prediction mechanism in the middle temporal gyrus (MTG) focuses attention to talker. Based on these findings, here we use a brain perturbation method to establish causal links between such oscillatory activity and control of different forms of auditory attention. We hypothesize that perturbing alpha oscillations in parietal cortex will impair spatial attention while perturbing beta oscillations in the MTG will impair speaker identity-based attention. Our ongoing study utilizes repetitive transcranial magnetic stimulation (rTMS) to induce such perturbations in the pre-determined regions of interests non-invasively and safely. This presentation will provide proof-of-concept data to validate the feasibility of this approach.