Visuospatial attention allows observers to focus awareness on one or several pieces of information within the visual world. Recent evidence suggests that superior frontal, inferior parietal and superior temporal cortices are involved in voluntarily orienting visuospatial attention. The goal of these experiments was to determine whether this network mediates the top-down control of attention in different visual frames of reference (FORs), or whether partially separable neural systems underlie attentional orienting in each. Participants were cued to locations defined within viewer- or object-centered FORs and made form discriminations on targets subsequently presented at those locations. Cortical responses to attention-directing cues were recorded with event-related fMRI. Consistent with previous work, a network involving superior frontal, inferior parietal, and superior temporal cortices was activated by attention-directing cues. Critically, this network was differentially engaged when attention was grounded in different FORs. Whereas superior frontal and inferior parietal regions were similarly engaged when attention was deployed in viewer- and object-centered FORs, superior temporal regions were more responsive when attention was deployed in object-centered space. Moreover, similar activity was observed in parietal cortex in both hemispheres across conditions, indicating that right and left parietal cortices were not differentially involved in viewer- and object-based attention. We conclude that an overlapping network of brain regions mediates our ability to orient spatial attention, but that this network is differentially engaged when attention is deployed in different reference frames.


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