Abstract
Covert shifts of attention precede and direct overt eye movements to stimuli that are task-relevant or physically salient. We have recently shown that stimuli imbued with value via reward learning also capture attention involuntarily, even when they are not salient and irrelevant to the current task (Anderson, Laurent, & Yantis, 2011, PNAS). Although it is known that both salient and goal-related stimuli draw involuntary movements of the eyes, an effect termed oculomotor capture, it is unclear whether valuable stimuli can similarly capture the eyes. We assessed the effect of previously reward-predictive but currently irrelevant distractors on visual search for a salient target using eye tracking. The experiment consisted of a training phase in which participants were rewarded for identifying colored targets, and an unrewarded test phase in which nontarget items were occasionally rendered in the color of formerly reward-predictive targets (these constituted valuable distractors). Our results show that valuable stimuli both slow responses to the target and are significantly more likely than other nontargets to draw eye movements; they do so persistently throughout the test phase. By measuring dilations of the pupil evoked by target stimuli throughout the course of training, we also show that reward-predictive targets gradually come to evoke anticipatory arousal; this provides physiological evidence that the stimuli that elicit value-driven capture come to serve as reward-predictive cues. Our findings demonstrate that when a stimulus is learned to predict reward, that stimulus acquires incentive salience which in turn drives both attentional and oculomotor selection in a manner that persists into extinction. This normal cognitive process is similar to biases in stimulus selection found in drug addition, suggesting a potential link between value-driven capture and addiction.
Meeting abstract presented at VSS 2012