Abstract
Inhibition of return (IOR) is an inhibitory aftereffect of visuospatial orienting, typically observed in the spatial cueing paradigm by way of slower responses to cued rather than uncued targets. Early work on IOR using temporal order judgments (TOJ; Posner, Rafal, Choate & Vaughan, 1985; Maylor, 1985; Klein, Schmidt & Muller, 1998) showed no effect on arrival time judgments, suggesting IOR is acting at a post-perceptual information processing stage, although at precisely what stage - attentional or motoric - has been quite contested (Taylor & Klein, 2000; Abrams & Dobkin, 1994; Ivanoff & Klein, 2006; Ivanoff, Klein & Lupianez, 2002). Recent work, however, suggests that there are two forms of IOR (Chica, Taylor, Lupianez & Klein, 2010; Hilchey, Klein & Satel, 2014; Klein & Redden, in press; Redden, Hilchey & Klein, 2016); one operating nearer the input end of the information processing continuum affecting the quality of inputs and the other nearer the output end affecting responding, whereby the type of effect that is manifest is contingent upon the activation state of the reflexive oculomotor system at the time the effect is generated. We tested this theory in a TOJ task, where subjects were required to either make a prosaccade (output form) or antisaccade (input form) after the onset a spatially uninformative peripheral cue, and subsequently execute a TOJ or speeded colour identification response. Both groups showed inhibited RT for colour probes presented at the cued location. We saw dissociable effects on colour identification depending on whether input or output IOR was generated. Furthermore, we found inhibited perceptual processing in the TOJ task when the input form was generated, but no effect on TOJs in the group that elicited the output form. These findings provide converging evidence that there are two forms of IOR: an input effect operating on a saliency map, and an output effect operating on a priority map.
Meeting abstract presented at VSS 2018