Oculomotor inhibition of return: Evidence against object-centered representation. Issue 9 (21st October 2018) - Redden, Ralph S.
ABSTRACT: Intermixing central, directional arrow targets with the peripheral targets typically used in the Posnerian spatial cueing paradigm offers a useful diagnostic for ascertaining the relative contributions of output and input processes to oculomotor inhibition of return (IOR). Here, we use this diagnostic to determine whether object-based oculomotor IOR comprises output and/or input processes. One of two placeholder objects in peripheral vision was cued, then both objects rotated smoothly either 90 or 180 degrees around the circumference of an imaginary circle. After this movement, a saccade was made to the location marked by a peripheral onset target or indicated by the central arrow. In our first three experiments, whereas there was evidence for IOR when measured by central arrow or peripheral onset targets at cued locations, there was little trace of IOR at the cued object. We thereafter precisely replicated the seminal experiment for object-based oculomotor IOR (Abrams, R. A., & Dobkin, R. S. (1994). Inhibition of return: Effects of attentional cuing on eye movement latencies. Journal of Experimental Psychology: Human Perception and Performance, 20(3), 467–477; Experiment 4) but again found little evidence of an object-based IOR effect. Finally, we ran a paradigm with only peripheral targets and with motion and stationary trials randomly intermixed. Here we again showed IOR at the cued location but not at the cued object. Together, the findings suggest that object-based representation of oculomotor IOR is much more tenuous than implied by the literature.