Control of attention shifts between vision and audition in human cortex

Abstract

Selective attention contributes to perceptual efficiency by modulating cortical activity according to task demands. Visual attention is controlled by activity in posterior parietal and superior frontal cortices, but little is known about the neural basis of attentional control within and between other sensory modalities. We examined human brain activity during attention shifts between vision and audition. Attention shifts from vision to audition caused increased activity in auditory cortex and decreased activity in visual cortex and vice versa, reflecting the effects of attention on sensory representations. Posterior parietal and superior prefrontal cortices exhibited transient increases in activity that were time locked to the initiation of voluntary attention shifts between vision and audition. These findings reveal that the attentional control functions of posterior parietal and superior prefrontal cortices are not limited to the visual domain but also include the control of crossmodal shifts of attention.

Figure 1.

Attention shift task. The visual display contained a target stream of letters at fixation and four surrounding distractor streams. A binaural target stream of spoken letters was accompanied by a monaural distracting stream in each ear. Either vision or audition was attended at the beginning of a run. Participants pressed a button whenever a digit was detected. If the digit was 2, they were to maintain attention on the currently attended modality; if it was 4, they were to switch attention to the other modality.

Figure 2.

Cortical activity in auditory and visual sensory regions during the attention shift task. a, Group activation pattern for regions more active during attention to audition than attention to vision (Heschl's gyrus). b, c, Mean event-related BOLD time course from activated voxels in the right (b) and left (c) auditory cortices, respectively, time locked to each of the four target types. d, Group activation pattern for regions more active during attention to vision than attention to audition (fusiform gyrus). e, f, Mean event-related BOLD time course from activated voxels in the right (e) and left (f) fusiform gyrus, time locked to each of the four target types.

Figure 3.

a, Cortical activity in precuneus/superior parietal lobule during the attention shift task reveals greater activity when attention was shifted from one modality to another compared with when attention was maintained within a single modality. IPL, Inferior parietal lobe. b, Mean event-related BOLD time course from activated voxels within the precuneus/SPL, time locked to each of the four target types.