Functional localization of the system for visuospatial attention using positron emission tomography

TLDR

PET imaging of six right‑handed male subjects performing covert attention tasks with reflexive and controlled shifts revealed the neural system underlying visuospatial attention. The PET data showed superior anatomical resolution, with activations in the right anterior cingulate, intraparietal sulcus, and premotor cortices that matched the core spatial‑attention network and demonstrated overlapping yet regionally specialized patterns for reflexive and controlled shifts.

Abstract

PET was used to image the neural system underlying visuospatial attention. Analysis of data at both the group and individual-subject level provided anatomical resolution superior to that described to date. Six right-handed male subjects were selected from a pilot behavioural study in which behavioural responses and eye movements were recorded. The attention tasks involved covert shifts of attention, where peripheral cues indicated the location of subsequent target stimuli to be discriminated. One attention condition emphasized reflexive aspects of spatial orientation, while the other required controlled shifts of attention. PET activations agreed closely with the cortical regions recently proposed to form the core of a neural network for spatial attention. The two attention tasks evoked largely overlapping patterns of neural activation, supporting the existence of a general neural system for visuospatial attention with regional functional specialization. Specifically, neocortical activations were observed in the right anterior cingulate gyrus (Brodmann area 24), in the intraparietal sulcus of right posterior parietal cortex, and in the mesial and lateral premotor cortices (Brodmann area 6).