How early does attention modulate visual information processing? The importance of experimental protocol and data analysis approach

Whether attention can influence afferent information processing in primary visual cortex (V1) has long been topic of scientific debate. Findings from a recent study by Baumgarter et al. (this issue) add to this debate by providing a null replication of an influential study that reported that spatial attention can enhance feedforward information processing in human V1, as reflected in the amplitude of the C1 ERP component (Kelly, Gomez- Raminez, & Foxe, 2008). Here we discuss several factors, including analytic approach, experimental design, and motivational factors, that, once scientifically tested, may help resolve discrepancies in the current literature.