Object-based selection of irrelevant feature is not confined to the attended object

Hans-Jochen Heinze1,2, and Jens-Max Hopf1,2 ■ Attention to one feature of an object can bias the processing of unattended features of that object.Herewedemonstratewith ERPs in visual search that this object-based bias for an irrelevant feature also appears in an unattended object when it shares that feature with the target object. Specifically, we show that the ERP response elicited by a distractor object in one visual field is modulated as a function of whether a task-irrelevant color of that distractor is also present in the target object that is presented in the opposite vi-sual field. Importantly, we find this modulation to arise with a delay of approximately 80 msec relative to the N2pc—a component of the ERP response that reflects the focusing of attention onto the target. In a second experiment, we demonstrate that this modula-tion reflects enhanced neural processing in the unattended object. These observations together facilitate the surprising conclusion that the object-based selection of irrelevant features is spatially global even after attention has selected the target object.