Investigating the neural signature of multi-modal inhibition of return


Inhibition of Return (IOR) is a behavioral phenomenon wherein one is slower to respond to targets that are presented at a previously cued location. Early work looking at the event-related potential (ERP) components of IOR using electroencephalography (EEG) suggested that P1 reductions might be an electrophysiological marker of IOR. However, the observation of P1 reductions with and without IOR, and vice versa, made the role of P1 in IOR unclear. We hypothesized that P1 component reductions, and, more generally, early ERP component modulations, are the result of repetitive stimulation along an input (sensory) pathway, not IOR. To test this hypothesis, the neural signature of IOR was investigated in a multi-modal cueing paradigm using all possible pairings of touch and vision. IOR (slower responses to targets in a previously cued location) was obtained in all 4 conditions. In the visual modality, P1 cueing effects were not observed. However, in the tactile modality, an early component (defined as the N80/P100 complex) showed a robust reduction on the cued side, but only following tactile cues. Overall, these results support the hypothesis that repetitive sensory stimulation may be driving the early ERP component modulations originally thought to be indicative of IOR.

Acknowledgments: NSERC