Jesse J Bengson, Javier Lopez-Calderon, and George R Mangun (2012). Psychophysiology, 49(8):1101-8.
A well-replicated finding is that visual stimuli presented at an attended location are afforded a processing benefit in the form of speeded reaction times and increased accuracy (Mangun, ; Posner,). This effect has been described using a spotlight metaphor, in which all stimuli within the focus of spatial attention receive facilitated processing, irrespective of other stimulus parameters. However, the spotlight metaphor has been brought into question by a series of combined expectancy studies that demonstrated that the behavioral benefits of spatial attention are contingent on secondary feature-based expectancies (Kingstone,). The present work used an event-related potential (ERP) approach to reveal that the early neural signature of the spotlight of spatial attention is not sensitive to the validity of secondary feature-based expectancies.