Keynote lecture 3
Friday, Sep 11, 2015
Bottom-up triggered and top-down controlled attention to sounds
Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
Our functional magnetic resonance imaging (fMRI) studies, as well as those of other research groups, indicate that in addition to enhanced activity in the auditory cortex, task-irrelevant physical changes in the auditory environment elicit activity in the parietal and frontal cortices. These activations are likely to be associated with bottom-up triggered, involuntary attention and they are paralleled by the mismatch negativity and P3a event-related potentials (ERPs) with their generators in the auditory and frontal cortices, and at least for the P3a, even in the parietal cortex. According to fMRI, top-down controlled, voluntary shifts of auditory attention are associated with activation of even wider cortical network involved largely also in maintaining attention to particular sounds. Moreover, our meta-analysis of fMRI studies showed that both pitch changes in a repeating sound and voluntary attention to tones with a particular pitch activate predominantly posterior auditory-cortex areas. However, as suggested by our fMRI and ERP studies, in some cases, processing of task-irrelevant sounds may be actively suppressed in the auditory cortex. This suppression might be controlled in a top-down manner by a fronto-parietal network involved also in voluntary division of attention.