Functional neuroimaging has revealed a bilateral fronto-parietal network involved in the top-down deployment of visuospatial attention. Further, a right temporal-parietal region (rTPJ) is known to be engaged for reorienting attention to targets when prior cue information incorrectly predicts target location. Behavioral studies have shown that reorienting attention to an invalidly cued location within an object is faster than reorienting attention to an equidistant location within a different object. These “object-based” effects have been demonstrated repeatedly for reorienting shifts of attention, suggesting the involvement of rTPJ. It is unclear, however, whether similar object-based effects are associated with top-down fronto-parietal attentional control mechanisms. Here we provide evidence for distinct, object-based effects associated with the initial deployment of attention in response to spatial pre-cues. Using a modified double-rectangle paradigm, participants performed a simple detection task with either endogenous or exogenous spatial pre-cues. Initial shifts of attention could either be within an attended object, or to an equidistant location on a different object. This allowed us to compare initial (top-down) as well as reorienting (bottom-up) shifts of attention to locations either within or between objects. Object-based effects were observed for initial shifts of attention in response to both exogenous and endogenous cues. In contrast, object-based effects were observed during reorienting shifts of attention only when exogenous cues were used. These findings suggest that the fronto-parietal attention control network employs distinct object-based representations than the rTPJ-mediated reorienting network. Results are further discussed in terms of neuronal distinctions between top-down and bottom-up attentional control networks.


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