Neurobiology of consciousness
Our research has also investigated the neural substrate of consciousness using neuroimaging in humans. In addition to studying the loss and recovery of monitoring functions in REM sleep, sleep in general (particularly NREM sleep) can be operationalized to study the neural substrate of consciousness. Recent research has highlighted the value of using within-state paradigms in studying consciousness (Koch et al., 2016), which can bypass confounds commonly associated with other experimental designs such as changes in global shifts in vigilance or arousal. This “no-task within-state” paradigm has unique advantages for separating the neural correlates of consciousness from its background conditions, as diagramed in the figure above. Using a within-state sleep paradigm, our recent research (e.g., Siclari*, Baird* et al., 2017) has shown that conscious experience is consistently associated with reduced slow wave activity in posterior cortical regions. Furthermore, we found that it is possible to predict whether an individual will report having a conscious experience during sleep by monitoring slow wave activity in posterior cortex in real time. Such evidence could prompt a shift in our understanding of the neural correlates of consciousness toward a “posterior hot zone” (Koch et al., 2016). Our current research is continuing to evaluate bistability between ON and OFF periods of cortical neurons as a potential mechanism of loss of consciousness.
Siclari, F.*, Baird, B.*, Perogamvros, L., Bernardi, G., LaRocque, J. J., Riedner, B., ... & Tononi, G. (2017). The neural correlates of dreaming. Nature Neuroscience, 20(6), 872-878.
Lee, M., Baird, B., Gosseries, O., Nieminen, J. O., Boly, M., Postle, B. R., Tononi, G., & Lee, S. W. (2019). Connectivity differences between consciousness and unconsciousness in non-rapid eye movement sleep: a TMS–EEG study. Scientific Reports, 9(1), 5175.
Elliott, J. C., Baird, B., Giesbrecht, B. (2016). Consciousness isn’t all-or-none: Evidence for partial awareness during the attentional blink. Consciousness and Cognition, 40, 79-85.
Schooler, J.W., Mrazek, M.D., Baird, B., & Winkielman, P. (2015). Minding the mind: The value of distinguishing between unconscious, conscious, and meta-conscious processes. In P. Shaver & M. Mikulincer (Eds.), APA handbook of personality and social psychology. Vol. 1: Attitudes and social cognition (pp. 179-202). Washington, DC: APA Press.