Abstract
This study used a novel variation of the spatial cueing paradigm to investigate voluntary modulation of early and late inhibition in visual orienting. Color cues presented at a peripheral location indicated the likelihood of a target appearing at this location (Experiments 1 and 3). A red cue indicated that the target was more likely to appear at the cued location (80% of trials) than at the opposite, uncued location (20% of trials) while a green cue indicated the other way around. A noninformative central cue was also used in Experiment 1 to summon attention away from the periphery. Experiment 2 was similar to Experiment 1 except that the peripheral cue was noninformative while the central cue was a color one. Across the three experiments, significant inhibitory effects were observed in target detection for both red and green cues at both short (100 ms and 200 ms) and long (300 ms and 500 ms) SOAs between the cue and the target. Theses effects were larger for the green cue than for the red cue, demonstrating the voluntary modulation of inhibitory effects in visual orienting. Moreover, this modulation took different forms at short and long SOAs, as cue informativeness did not affect the speed of response to the target at the cued location at short SOAs while it did at long SOAs. At the uncued location, target detection was always faster following the green cue than following the red cue. These findings were interpreted as supporting the view that there is a separable IOR (inhibition of return) process in peripheral cueing parallel to reflexive and endogenous orienting, and that voluntary modulation of early and late inhibition may take different forms at different time windows.