Abstract: Some philosophers maintain that consciousness as subjective experience has no biological function. However, conscious brain events seem very different from unconscious ones. For example, the cortex and thalamus support the reportable qualitative contents of consciousness. Subcortical structures like the cerebellum do not. Likewise, attended sensory stimuli are typically reportable as conscious, while accurate memory traces of the same stimuli are not reportable, unless they are specifically recalled. Like other major adaptations, conscious and unconscious brain events have distinctive biological pros and cons. These involve information processing efficiency, metabolic costs, and behavioral pros and cons. The well-known momentary limited capacity of conscious contents is an example of an information processing cost, while the very large and energy-hungry corticothalamic system makes costly metabolic demands. Limited capacity can cause death and injury in humans and other animals, as in the case of traffic accidents and predation by ambush. Sleep is a state of high vulnerability among prey animals. We can begin to sketch out some of the biological costs and benefits of conscious states and their stream of reportable contents.
Baars, B.J. & Gage, N.M. (2011) Fundamentals of Cognitive Neuroscience: A Beginner's Guide. Elsevier/Academic Press. (See Chapter 8 for the brain basis of consciousness and attention.)
Baars, B.J. (2012) The biological costs of consciousness. Nature Precedings. http://precedings.nature.com/documents/6775/version/1
Edelman, G.M., J. Gally & B.J. Baars (2011) Biology of consciousness. Frontiers in Psychology. January, Vol. 2. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3111444/
Franklin, S., S. Dï¿½ Mello, B. J. Baars & U. Ramamurthy (2011) Evolutionary Pressures for Perceptual Stability and Self as Guides to Machine Consciousness. Int Jnl Machine Consciousness. http://www.theassc.org/files/assc/Evolutionary-Pressures-2009.pdf