The Global Workspace Model
This is the third part of a multi-part post (originally intended to be two parts) on Bernard Baars' Global Workspace Theory and the future evolution of consciousness (Part One is here).
In Part One, I outlined the basic ideas of GWT, suggesting that it may be the cognitive model that is closest to being integral while still being able explain the actual brain circuitry involved in creating self-awareness, the sense of an individual identity, the development of consciousness through stages, the ability of introspection to revise brain wiring, and the presence of multiple states of consciousness.
In Part Two, I established a foundation for a paper that seeks to explain how our consciousness will evolve in the future - The Future Evolution of Consciousness by John Stewart (ECCO Working paper, 2006-10, version 1: November 24, 2006). His work assumes some specialized knowledge of cognitive developmental theory, so that post attempted to provide a little more solid understanding for the ideas that will come up in the next posts.
This post features a very recent video of Dr. Baars speaking about GWT - The Biological Basis of Conscious Experience: Global Workspace Dynamics in the Brain - a talk given at the Evolution and Function of Consciousness Summer School ("Turing Consciousness 2012") held at the University of Montreal.
Here is the conference abstract:
Bernard Baars - The biological basis of conscious experience: Global workspace dynamics in the brain
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 Proceedings. 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. D'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
- Some philosophers maintain that consciousness as subjective experience has no biological function. However, conscious brain events seem very different from unconscious ones. 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 memories of those stimuli are not so reportable until they are specifically recalled.
- Reports of conscious experiences in normal humans always involve subjectivity and an implicit observing ego. Unconscious brain events are not reportable, even under optimal conditions of report. While there are claimed exceptions to these points, they are rare or poorly validated.
- Normal consciousness also implies high availability (rapid conscious access) of the questions routinely asked of neurological patients in the Mental Status Examination, such as common sense features of personal identity, time, place, and social context. Along with “current concerns,” recent conscious contents, and the like, these contents correspond to high frequency items in working memory. While working memory contents are not immediately conscious, they can be rapidly re-called to consciousness.
- The anatomy and physiology of reportable conscious sensorimotor contents are ultraconserved over perhaps 200 million years of mammalian evolution. By comparison, full-fledged language is thought to arise some 100,000 years ago in homo sapiens, while writing, which enables accel-erated cultural development, dates between 2.5 and 6 millennia. Contrary to some claims, therefore, conscious waking precedes language by hundreds of millions of years.
- Like other major adaptations, conscious and unconscious brain events have distinctive biological pros and cons. These involve information processing efficiency, metabolic costs and benefits, 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.
- After a century of scientific neglect, fundamental concepts like “conscious,” “unconscious,” “voluntary” and “non-voluntary” are still vitally important, because they refer to major biopsychological phenomena that otherwise are difficult to discuss.
The whole paper is definitely worth reading as an adjunct this talk. With all of that as background, here is the video:
In the next post, I will return to the topic of evolving our consciousness - there are actually a couple of bran new papers to read that are related to that topic.