Reward-driven attention alters perceived salience

Inversion of pop-out for a distracting feature dimension in monkey visual cortex

During visual search, it is important to reduce the interference of distracting objects in the scene. The neuronal responses elicited by the search target stimulus are typically enhanced. However, it is equally important to suppress the representations of distracting stimuli, especially if they are salient and capture attention. We trained monkeys to make an eye movement to a unique "pop-out" shape stimulus among an array of distracting stimuli. One of these distractors had a salient color that varied across trials and differed from the color of the other stimuli, causing it to also pop-out. The monkeys were able to select the pop-out shape target with high accuracy and actively avoided the pop-out color distractor. This behavioral pattern was reflected in the activity of neurons in area V4. Responses to the shape targets were enhanced, while the activity evoked by the pop-out color distractor was only briefly enhanced, directly followed by a sustained period of pronounced suppression. These behavioral and neuronal results demonstrate a cortical selection mechanism that rapidly inverts a pop-out signal to "pop-in" for an entire feature dimension thereby facilitating goal-directed visual search in the presence of salient distractors.

Testing reward-cue attentional salience: Attainment and dynamic changes

A great wealth of studies has investigated the capacity of motivationally relevant stimuli to bias attention, suggesting that reward predicting cues are prioritized even when reward is no longer delivered and when attending to such stimuli is detrimental to reward achievement. Despite multiple procedures have been adopted to unveil the mechanisms whereby reward cues gain attentional salience, some open questions remain. Indeed, mechanisms different from motivation can be responsible for the capture of attention triggered by the reward cue. In addition, we note that at present only a few studies have sought to address whether the cue attractiveness dynamically follows changes in the associated reward value. Investigating how and to what extent the salience of the reward cue is updated when motivation changes, could help shedding light on how reward‐cues attain and maintain their capacity to attract attention, and therefore on apparent irrational attentive behaviors.