(Note: This part 1 of a 3 part series of posts on Human Consciousness)
The enigma of consciousness has been pestering scientists, philosophers and theologians for millennia. In a recent review Christof Koch of the Allen Institute for Brain Science defined consciousness as “having an experience — the subjective, phenomenal ‘what it is like’ to see an image, hear a sound, think a thought or feel an emotion.”[i] This definition allows for a very broad inclusion many edge conditions of what might be considered semi-conscious states such as where there has been great damage to the brain or in dreaming sleep. Presumably Koch does not want to dismiss those afflicted with near vegetative states if there is some activity in the areas of the brain, which correlate with consciousness. However with this over broad basic premise he has lost the essential essence of what is meant by conscious.
René Descartes wrote, “Cogito ergo sum,” that is “I think, therefore I am.” Self-awareness is intrinsic to consciousness. One may be able to think without being self aware, in that thinking is neural activity that is evaluating your perceptions. But perception is not consciousness. Descartes’ “I am” is the paramount statement. Without a sense of self we are automatons that merely react to our environment.
Koch asserts that dreams are “conscious experiences.”[ii] Sleep serves many purposes including the consolidation of skills and knowledge learned in the waking state.[iii] That there is neural activity among the neurons and pathways used by conscious processes is of no surprise. At times we may even become conscious while sleeping, but that does not equate to conscious and dreaming being one in the same.
Self-awareness is a stream of thought. It requires a chain of thoughts with each being substantially based off its immediate predecessors. Perception and awareness of one’s environment contribute to consciousness but alone these are not sufficient. Most people can recall a dream where they were some one else, or had the point view of an omniscient observer of an unfolding story. While these episodes may make use of shards of the system of neurons used by consciousness, they cannot be called a conscious experience.
[i] Koch, C., Massimini, M., Boly, M., & Tononi, G. (2016). Neural correlates of consciousness: progress and problems. Nature Reviews Neuroscience, 17(6), 307-321. doi:10.1038/nrn.2016.61, 307
[ii] Koch, “Neural correlates,” 309.
[iii] Harrison, Y. (2012). The Functions of Sleep . In Harrison The Oxford Handbook of Sleep and Sleep Disorders. Oxford: Oxford Univ. Press.