Daniel Bates

Listening in crowded environments: How attention shapes brain responses to unattended sounds

I will review recent work in my lab concerning the effect of attentional focus on brain responses to unattended sounds. The first series of experiments aimed to understand how the neural representations of tracked (attended) and ignored sources change with growing scene size. We used acoustic “scenes,” comprised of multiple concurrent tone-pip streams, and a task which required listeners to track one of the streams over a long duration (30 seconds). EEG results show that attention boosts/reduces responses to the tracked/ignored sources, manifested as enhanced/reduced spectral power at its AM rate. The strength of this effect is dependent on the number of competing sources. We also demonstrate increased power coupling between activity in the alpha band and the brain responses to ignored sounds, implicating alpha in the process of active suppression of task-irrelevant information. In the second series of experiments (Molloy et al., 2015), we investigate the effect of focused visual attention on responses to...