Abstract
Previous studies on priming of pop-out have shown that when the target color is repeated, an odd-colored target among uniformly colored distractors can be selected faster for attention and saccadic and reaching movements. Here we examine whether invisible stimuli can prime the subsequent oddity target selection for visually-guided reaching. Using a continuous flash suppression paradigm, we subliminally presented a prime array consisting of an odd-colored target with three distractors. The colors of the target and distractors were randomly switched in each trial between red and green. A blank screen was then presented, followed by a visible response array consisting of an odd-colored target with three distractors as in the prime array. The odd-colored target in the prime and response arrays was either repeated or switched. Participants were asked to reach for an odd-colored target in the response array using a stylus pen on a touch pad. In contrast to the phenomenon of priming of pop-out, we observed that subliminal color repetition resulted in an inhibitory effect. When the target color was repeated between the prime and response arrays, the initial latency and movement time of reaching became slower, and reaching trajectories were more curved towards the location of distractors rather than the target, compared to when the target color was switched. Furthermore, we also observed the same inhibitory effect by target color repetition when perceptual discrimination was required instead of reaching. These results suggest that attention is attracted to the invisible oddity target, which subsequently modulates both goal-directed movements and perceptual discrimination in the same manner. Specifically, in contrast to the classical pop-out priming by visible stimuli, we demonstrate that attention captured by subliminal stimuli inhibits subsequent target selection. We suggest that the inhibitory effect is due to a suppressed response towards an odd-colored item in the invisible prime array.
Meeting abstract presented at VSS 2015