Neural underpinnnings of auditory salience in natural soundscapes

Abstract

Salience is the mechanism whereby attention is automatically directed towards critical stimuli. Measuring the salience of a stimulus using behavioral methods risks confounds with top-down attention, particularly in the case of natural soundscapes. A distraction paradigm is employed here to measure physiological effects of salient auditory stimuli using electroencephalography. Several such effects are presented. In particular, a stimulus entrainment response is reduced by the presentation of distractor salient sounds. A reduction in oscillatory neural responses in the gamma frequency band is also observed following salient stimuli. These measures are used to identify salient portions of the natural scene. Finally, envelope decoding methods also indicate that salient stimuli attract attention away from other, task-related sounds.