Impact of Reward on Visual Search Performance: An Event-Related Potential Investigation

Feedback, rewarding and non-rewarding, received from the environment can facilitate learning, influence motivation and shape behavior (i.e., Skinner, 1963; Thorndike, 1898). Recent research has indicated that reward can enhance cognitive processes such as visual selective attention (Della Libera et al., 2011; Anderson et al., 2011a,b; Krebs et al., 2011). Depression is one of the most common, debilitating, and costly forms of mental illness (Kessler et al., 2005; Mathers & Boerma, 2008; Katon, 1996) and has been characterized by reduced responsiveness to reward (Henriques et al., 1994; Henriques and Davidson, 2000). The current study aims to investigate the influence of reward on selective attention in adults with a history of Major Depressive Disorder (MDD). Participants will complete a battery of self-report measures on mood, personality and behavior as well as a clinical interview and a computer-based visual search task. During the first part of visual search task participants will be asked to determine if a designated target is present during an array of distractors. The second part of the task will be the same as the first except that the participant will have the opportunity to earn monetary rewards if performance is accurate. EEG event-related potentials will be used to measure selective attention (N2pc) and response to feedback (FRN). We hypothesize that if the target stimuli are more salient in the second part of the task, then the N2pc component will occur earlier and be larger in amplitude for target present trials in the second part than in the first part of the task. We also hypothesize that participants with a history of MDD will have a smaller mean FRN amplitude post positive feedback than those with no history of MDD. The results of this study may provide further insight into the function of reward in individuals with a history of MDD