Abstract
To cope with the huge amount of incoming information, the visual system has to assign priorities to each stimulus in the visual field. Which stimulus is prioritized depends on bottom-up factors that are defined by physical properties inherent of the visual stimuli, e.g., local feature contrast, and top-down factors that are set ‘in the observer’, e.g., current intentions or goals. Recent results have challenged the classic dichotomy of bottom-up vs. top-down as control mechanisms and have suggested past selection history, e.g. evident in learning experience, as a third source of selection bias that can neither be accounted for by physical stimulus properties nor by goal-driven selection (Awh, Belopolsky, & Theeuwes, 2012). The present study used event-related potentials (N2pc and its subcomponents NT and PD) to examine the relationship between learning experience and selective attention. Participants performed a visual learning task which was combined with a visual search task in the course of the experiment. Results showed that color distractors impaired behavioral performance in the visual search task more when color rather than shape was learned as being predictive in the learning task. ERP results showed that this was due to differential attention deployment: when color was predictive in the learning task, color distractors captured attention also in the search task before they could be actively suppressed. When shape was predictive in learning, color distractors did not capture attention in the search task and suppression was possible earlier in time. These results revealed common underlying mechanisms of visual learning and selective attention and suggest that apart from bottom-up and top-down processing, learning experience changes the way the visual environment is perceived when different stimuli compete for priority.
Meeting abstract presented at VSS 2015