Abstract
Recent studies have shown that reward learning affects attentional and oculomotor selection. Irrelevant distractor stimuli indicating the availability of reward can capture the eyes. It is assumed that this oculomotor capture effect is due to the operation of an attentional mechanism that is feature-specific, such that the relationship between a stimulus feature and reward enhances that feature's representation on an internal priority map. The current study examined in detail the effects of enhanced feature representation due to reward association in a new continuous, fast-paced eye movement task in which participants made saccadic eye movements to follow a target around the visual field. A colored distractor signaling high, low or no monetary reward appeared either in close or far proximity from the target, at an equal distance as the target from the current gaze position. Distractors associated with high reward led to more erroneous saccades to the distractor, resulting in no reward for those trials, and smaller saccadic amplitudes to the target. Moreover, the eyes landed closer to high reward-associated distractors in close proximity to the target (30° polar angle) compared to less rewarding distractors at that location. Distractors close to the target (30°) resulted in quicker saccadic onsets with smaller saccadic amplitudes to the target, and more erroneous saccades to the distractor, compared to distractors at more distant locations (120° or 180°). Furthermore, distractors in the same hemifield as but far from the target (120°) resulted in faster saccades to the target, with fewer erroneous saccades and less curvature towards the distractor than distractors at the same physical distance from the target, but in the opposite hemifield. These results are explained in terms of oculomotor competition in which distractors associated with high reward may gain higher priority within the oculomolotor map than equally salient distractors associated with lower reward.
Meeting abstract presented at VSS 2016