Neural Systems for Visual Orienting and Their Relationships to Spatial Working Memory

TLDR

The study investigates neural correlates of human visual orienting and proposes that a cortical network underlies reorienting to sensory events. Event‑related fMRI was used to record brain activity during voluntary attention shifts to peripheral locations. Robust, sustained activity in the intraparietal sulcus and superior frontal cortex—forming a dorsal network—was modulated by attention direction and maintained during a 7‑second delay, while a separate right‑hemisphere network, including the temporo‑parietal junction and inferior frontal gyrus, was activated by target detection regardless of visual field.

Abstract

Abstract We investigated neural correlates of human visual orienting using event-related functional magnetic resonance imaging (fMRI). When subjects voluntarily directed attention to a peripheral location, we recorded robust and sustained signals uniquely from the intraparietal sulcus (IPs) and superior frontal cortex (near the frontal eye field, FEF). In the ventral IPs and FEF only, the blood oxygen level dependent signal was modulated by the direction of attention. The IPs and FEF also maintained the most sustained level of activation during a 7-sec delay, when subjects maintained attention at the peripheral cued location (working memory). Therefore, the IPs and FEF form a dorsal network that controls the endogenous allocation and maintenance of visuospatial attention. A separate right hemisphere network was activated by the detection of targets at unattended locations. Activation was largely independent of the target's location (visual field). This network included among other regions the right temporo-parietal junction and the inferior frontal gyrus. We propose that this cortical network is important for reorienting to sensory events.