When is inhibition of return input- or output-based? It depends on how you look at it.

Two important diagnostics have been used to infer whether the effect of inhibition of return, when preceded by a saccade, is primarily upon input (i.e., attentional/perceptual level) or output (i.e., response/decision level) processes. Data from antisaccade paradigms involving luminance targets in peripheral vision suggest input effects whereas data from spatially compatible manual responses to centrally presented arrow targets suggest output effects. Here, we combine these diagnostics to resolve the discrepancy. In separate conditions participants made a pro- or antisaccade to a peripheral stimulus. Upon returning gaze to the original fixation, left and right manual responses were made to left- and right-pointing arrows at fixation, respectively. The primary objective of the prosaccade condition was to determine whether an eye movement toward a visual stimulus that was not associated with a manual localization response would bias spatially compatible manual responses against the prior saccade vector. Manual responses were slowest in the direction of the prior saccade, consistent with an output-based attribution (e.g., Posner, Rafal, Choate, & Vaughan, 1985). The primary objective of the antisaccade condition was to determine whether an eye movement away from a visual stimulus would also bias subsequent manual responses. No apparent response bias was detected, consistent with an input-based attribution (e.g., Fecteau, Au, Armstrong, & Munoz, 2004). Collectively, the findings indicate that there are 2, dissociable forms of inhibition depending on saccadic response demands. Converging evidence from other paradigms is discussed. (PsycINFO Database Record