Immunity for counterproductive attentional capture by reward signals among individuals with depressive symptoms.

Objectives: This study aimed to investigate the characteristics of attentional capture by reward signals in individuals with depression during classical conditioning.

Methods: A variant of the additional singleton paradigm was adopted with a high- or low-reward signal as the prominent distracting stimulus. In Experiment 1, 46 participants with depressive symptoms and 46 healthy controls were asked to conduct a keypress response to the visual target. In Experiment 2, 58 participants with depressive symptoms and 58 healthy controls were asked to conduct a fixation response to the visual target.

Results: In the keypress response task, the presence of high-reward signals slowed down the responses of participants in the control group, whereas the response times of individuals with depression were not significantly affected. In the fixation response task, when the high-reward signal was presented, individuals with depression were more likely to choose the target location as the first saccade destination, compared with healthy controls. In addition, individuals with depression exhibited fewer oculomotor capture by high-reward signals than healthy controls, a trait which was closely linked to the enhanced saccadic inhibition.

Conclusion: The results of our study indicated that individuals with depression exhibited an abnormality in attentional capture by reward-related conditioned stimuli during classical conditioning.