Heightened activity in a key region of the ventral attention network is linked to reduced activity in a key region of the dorsal attention network during unexpected shifts of covert visual spatial attention

Abstract

To enable unexpected shifts of covert visual spatial attention, a ventral attention network is thought to dampen activity in a dorsal attention network that maintains the current focus of attention. However, direct evidence to support this view is scarce. In the present study, we investigated this hypothesis by asking healthy young adults to perform a covert visual spatial attention task while their brain activity was recorded with functional magnetic resonance imaging (fMRI). In each trial, participants discriminated the orientation of a target-colored letter in the cued visual field (valid trials) or, occasionally, in the uncued visual field (invalid trials). Consistent with prior work, the ventral attention network was more active in invalid trials than in valid trials. Most importantly, functional connectivity analyses revealed that an increase of activity in the right inferior frontal gyrus (a key region of the ventral attention network) was linked to smaller increases of activity in (a) the right inferior parietal lobe (a key region of the dorsal attention network) and (b) the left dorsolateral prefrontal cortex and dorsal anterior cingulate cortex (other regions enabling the control of attention) in invalid trials, relative to valid trials. These findings provide novel support for the view that key regions of the ventral attention network help to enable unexpected shifts of covert visual spatial attention by dampening activity in brain regions that participate in maintaining the current focus of attention.