New evidence and challenges in ERP and MEG correlates of consciousness in vision: A systematized review.

The most reliable brain-activity markers of visual consciousness, measured with EEG, are an early component called visual awareness negativity (VAN) and a later component called late positivity (LP). Three prior reviews concluded that VAN is specifically tied to awareness, while LP also reflects other mental processes. This review of 53 new studies published since 2020 confirms that VAN remains the most robust neural correlate of visual consciousness, whereas LP is not uniquely linked to consciousness. However, questions remain about how VAN relates to attention and other physiological factors.

Study at a glance

Abstract

The past twenty years of research have revealed two event-related potential (ERP) components to be the most reliably occurring neural correlates of consciousness (NCC) in vision: an early visual awareness negativity (VAN) in the N2 and late positivity (LP) in the P3 time window. Three previous extensive reviews concluded that VAN is a proper visual NCC, which is solely modulated by awareness. During the last five years since the latest review was published, a large body of new evidence has emerged about the ERP correlates of visual consciousness. In this systematized review we update the results of the previous reviews by analyzing new studies published since 2020 (N = 53) and discussing their findings. The new evidence is consistent with the earlier reviews: VAN is still found to be the most reliable and robust ERP NCC in vision, whereas LP reflects also many other processes, not consciousness as such. However, several aspects of VAN, for example, its relationship to attention and simultaneous physiological factors, require further investigation.