Abstract
Recent research has suggested the flexible nature of attentional control; observers are able to enhance a target feature or suppress a distractor feature, depending on context (Chang & Egeth, 2019). The present study tested whether the initial processing of a probe letter on a neutral-colored item is modulated by enhancement and suppression. On search trials, participants searched for a shape target when two items including a target were always in a target color and the other two items were in a distractor color; these search trials enabled participants to learn the target and distractor colors. On interleaved probe trials, participants searched for a probe letter that was presented on a target-colored, distractor-colored, or neutral-colored oval. The behavioral data showed that when a target color was present responses were faster when the probe letter was on a target-colored item than on a neutral-colored item, while when a distractor color was present responses were slower for the probe letter on a distractor-colored item than on a neutral-colored item. Critically, processing of a probe letter on a neutral-colored item was modulated by the presence of a target-colored or a distractor-colored item. When the target color was present, a lateral probe letter on a neutral-colored item did not elicit an N2pc, perhaps because neutral-colored items are initially suppressed in the presence of a target-colored item. In contrast, when the distractor color was present, a lateral probe letter on a neutral-colored item elicited a significant N2pc, suggesting that when a distractor-colored item is present, neutral-colored items may be initially processed, and a probe letter on a neutral-colored item provides an additional boost, resulting in the presence of an N2pc. These results provide evidence that enhancement and suppression can alter processing of neutral items.