Probability manipulations can modulate but not reverse reflective inhibition-of-return effects

Abstract

Inhibition of return (IOR) is a phenomenon of perceptual attention characterized by delayed shifts in attention toward previously cued target locations. In reflective (internally directed) attention studies, response times (RTs) to cued items are sometimes facilitated, but other times IOR-like effects are observed wherein RTs to probed items are slower when the items had been mentally attended (refreshed) earlier in the trial. Perceptual IOR is known to be modulated by the probability that target and cued locations match. If the same is true for reflective attention, it could account for why sometimes reflective attention can lead to facilitation and other times inhibition. In the current study, four experiments examined the potential facilitative or inhibitory influence of probe predictability in reflective attention. We first replicated the design and IOR like pattern of results originally reported by Johnson et al. (2013). In subsequent experiments, when the proportion of unrefreshed probes was increased, the IOR-like effect increased in magnitude. When the proportion of refreshed probes was increased, the IOR-like effect was eliminated, but there was no evidence for facilitation. Altogether, these results are consistent with perceptual IOR literature implicating underlying inhibitory and facilitative attentional processes that can either interact synergistically or nullify each other. Further work will be needed to fully understand the paradoxical effects of why reflective attention is sometimes inhibitory and other times facilitative, but the current results demonstrate that expectation can play a significant role in the size of the effect.