Neural correlates of consciousness in an auditory no-report fMRI study

In the search for neural correlates of consciousness (NCC), prominent theories disagree about the role of sensory versus wide-spread fronto-parietal brain activity. Research on auditory awareness has been widely neglected, and isolating NCC from correlates of task-related post-perceptual processes (e.g., report) is an ongoing challenge. The present study addressed these issues using functional magnetic resonance imaging (fMRI) during a no-report inattentional deafness paradigm. Sixty-three participants performed an auditory distractor task while supra-threshold but task-irrelevant sounds were presented in the background. Whereas one group was aware of these stimuli, another group remained unaware. Comparing brain responses to the critical sounds between aware and unaware participants while controlling for correlates of sensory and postperceptual processing revealed that auditory awareness was associated with significantly increased activity in secondary auditory but not in fronto-parietal areas. These findings suggest a dominant role of stimulus-specific sensory processing rather than widespread fronto-parietal information broadcasting in conscious perception.