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Cracking Consciousness

May 23, 2016

A few recent pieces about consciousness appeared recently that I’d like to comment on. A blog post by Carson Chow discusses a New York times opinion piece by Galen Strawsen that scoffs at the age old idea that consciousness is more than just a physical phenomenon. Being a philosopher, Strawsen is satisfied letting the argument about physics remain at the level of the physicist, as opposed to moving into neuroscience. I can accept that, but I don’t know that it’s helpful to those who aren’t philosophers. Since I’m an engineer and a theoretical neuroscientist, I believe neuroscience offers a more satisfying perspective.

That leads to a second, recent publication on this topic which is by Christof Koch, along with Giulio Tononi, both of whom are relatively famous scientists. (Well, in my world, they’re relatively famous.) If you don’t know, Koch declared his obsession with consciousness, along with Francis Crick of DNA fame, in a 2003 article casually named “A framework for consciousness”.

Koch also published a book in 2012 titled Consciousness: Confessions of a Romantic ReductionistIn between, and since then, he has been trying to tackle the issue of consciousness using science, which I personally prefer over the philosophical approach. One reason why I like Koch’s approach is that he is clear about establishing a working definition of the term “consciousness” that can actually be used to move forward, as opposed to spending all of one’s time arguing about vague or abstract definitions that can’t be used in a scientific experiment.

Koch’s 2016 review article gives this initial definition to start with:

Being conscious means that one is having an experience….

Note that we are not talking about sentience here. In his research, his goal is to discover what he calls the “neural correlates of consciousness”, which he defines as:

The minimum neural mechanisms jointly sufficient for any one specific conscious experience.

He points out that the review article focuses on visual and auditory studies, which is important because other sensory experiences may involve different correlates. He offers some references for metacognition, body, tactile and olfactory experiences.

The article criticizes two proposed factors of consciousness: gamma frequency synchrony and a fronto-parietal response called Pb3. I honestly don’t know much about this area, so I can’t speak about the significance of the criticism. It is interesting to me that he basically concludes that the primary marker that still has value, despite its limitations, is desynchronized electroencephalogram (EEG). Interestingly, the article describes REM sleep and dreaming, which have an EEG very similar to that of awake state, as also being a form of consciousness. I had not heard this before.

After hastily reading Koch’s paper, it seems to me the most important argument the authors have is that the higher-level areas of the frontal lobe are not essential components for consciousness. They find that certain “hot spots” of sensory areas are essential, which is not surprising, considering their basic definition of consciousness depends on sensory experience. They point out that sensory integration, including relevant brainstem areas, is also essential. I suppose that the importance of the brain stem is also an argument against those that view consciousness exclusively as a high level function.

Finally, I will point out a third writing of interest (in addition to Chow’s blog post and Koch et al. 2016). Chow’s post criticizes a pathetic essay on https://aeon.co that I won’t bother discussing here. However, I discovered a different essay on the Aeon site that has a respectable relevance to Koch’s scientific pursuit of consciousness. It is a piece titled “Bring them back” by Joseph J Fins, professor of medicine at Weill Cornell Medical College in New York.

Fins discusses the category of a “minimally conscious state” (MCS), which he points out is a “new diagnostic category that came into the medical literature in 2002.” He goes on to discuss the case of Terry Wallis who was considered to be unconscious or vegetative for 19 years before suddenly speaking and interacting. Fins argues that there is actually a spectrum of consciousness, with the locked-in state being at the far end of the spectrum. He also describes that patients may transition back and forth between moments of consciousness and unconsciousness.

It is interesting to me that consciousness is so strongly coupled to our sense of time. A 2006 article by Helen Phillips in New Scientist claims that Wallis thought it was still the same year as when he had the accident. This seems to be the norm for people who wake from comas. However, I am surprised that a partially conscious person would not have some sense of time elapsing. Maybe some day I’ll have time to explore this.

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