Examining the lateralization of electrophysiological correlates of auditory awareness

The neurological basis for perceptual awareness remains unclear, and theories disagree as to whether sensory cortices per se generate awareness. Critically, neural activity in the sensory cortices is only a neural correlate of consciousness (NCC) if it closely matches the contents of perceptual awareness. Research in vision and touch suggest that contralateral activity in sensory cortices is an NCC. Similarly, research in hearing with two sound sources (left and right) presented over headphones also suggests that a candidate NCC called the auditory awareness negativity (AAN) matches perceived location of sound. The current study used 13 different sound sources presented over loudspeakers for natural localization cues and measured event-related potentials to a threshold stimulus in a sound localization task. Preregistered Bayesian mixed models provided moderate evidence against an overall AAN and very strong evidence against its lateralization. Because of issues regarding data quantity and quality, exploratory analyses with aggregated data from multiple loudspeakers were conducted. Results provided moderate evidence for an overall AAN and strong evidence against its lateralization. Nonetheless, the interpretations of these results remain inconclusive. Therefore, future research should reduce the number of conditions and/or test over several sessions to procure a sufficient amount of data. Taken at face value, the results may suggest issues with AAN as an NCC of auditory awareness, as it does not laterally map onto experiences in a free-field auditory environment, in contrast to the NCCs of vision and touch. In vision and touch, contralateral activity in sensory cortices is a neural correlate of consciousness (NCC) as the neural activity matches lateralized percepts. In hearing, this has not been thoroughly investigated. Here, we measured event-related potentials from 13 free-field sound sources. The neural correlate of auditory consciousness (AAN) was found; however, results do not resolve whether AAN is lateralized in response to lateral stimuli. Taken at face value, results may suggest that AAN is not an NCC of lateralized auditory experience to free-field sound sources.