Lecture by Michael Pitts: Isolating neural correlates
of conscious perception from task-related processing

Studies comparing conscious versus unconscious neural processing almost exclusively rely on subjects’ reports in order to link brain activity with perceptual experience. However, this reliance on report-based measures introduces an important confound: In nearly all previous studies, whenever subjects report having seen a stimulus, they are required to make a judgment about that stimulus, e.g., was the image an animal or object? was the number greater or less than 5? These judgments are used to objectively confirm that the subject did indeed perceive the critical stimulus. However, in conditions when the stimulus is not perceived, such judgments cannot be made. Therefore, the “aware” condition requires additional steps in post-perceptual processing that the “unaware” condition does not. This talk will review recent attempts in my lab to address this issue by modifying inattentional blindness paradigms to incorporate “no report” conditions in which subjects conscious perceive or fail to perceive task-irrelevant stimuli. EEG data from these experiments have begun to challenge and help refine leading theories of consciousness, such as global neuronal workspace theory. Extensions of these task manipulations to other consciousness paradigms and neuroimaging techniques will be introduced and discussed.