It has been claimed that one of the top unsolvable problems in science is how the brain generates basic conscious experience. We are here talking about the basic conscious experience of any kind, including what it is like (to use the philosopher Thomas Nagel's terminology) to experience the color red, breathlessness, nostalgia, or pain. How do subjective feelings come from brain processes? The problem is much more challenging than what non-scientists assume. Not only do scientists not have an inkling regarding how the human brain generates something like basic conscious experience, scientist also do not have an inkling regarding how any possible thing could ever instantiate something similar to a conscious state. Thus, the puzzle is an intractable and deep "hard problem" (to use the philosopher David Chalmer's term).
Some initial progress has been made by looking to the neuroanatomy of the brain. There is a consensus that conscious states are constituted by only a subset of all brain processes/regions. With this in mind, scientists have begun to identify the brain regions whose nonparticipation ("nonparticipation" because the regions are damaged, absent, or temporarily deactivated through some technological means) does not result in the brain being incapable of engendering some form of consciousness. This strategy, which employs the process of elimination, could be thought of as a way of
homing in on the neuranatomical loci constituting conscious states. As documented in the scientific literature (for further information, the reader is referred to Morsella et al., 2010,
Neural Networks, and to Godwin et al.; see bibliographic entries below), the nervous regions whose nonparticipation leaves the brain still capable of generating some form of consciousness are the following. Spinal cord, cerebellum, amygdala, hippocampus, right cerebral cortex, mammillary bodies, mediodorsal nucleus of the thalamus, and probably the insula and basal ganglia (again, for corroborating evidence, the reader is referred to Morsella et al., 2010,
Neural Networks, and Godwin et al.; see bibliographic entries below). (It is worth pointing out that it may well be that interactions among at least a subset of these regions may be essential for there to be a consciousness of any kind.)
Importantly, these findings also indicate that consciousness of some kind can survive even if the functions that are unique to these regions are absent. Thus, the anatomical account also sheds light on the functional mechanisms that are critical for engendering conscious states. Now that we have an idea of what neuroanatomical regions may not be needed to generate consciousness, we can begin to hypothesis which regions of the brain must be in working in order to generate these elusive states. This will be the topic of our next blog.
Morsella, E., Krieger, S. C., & Bargh, J. A. (2010). Minimal neuroanatomy for a conscious brain: Homing in on the networks constituting consciousness. Neural Networks, 23, 14-15. For an update regarding this line of research, see Godwin, Gazzaley, & Morsella's (invited chapter), Homing in on the Brain Mechanisms Linked to Consciousness. This articles can be requested at the following webpage. http://bss.sfsu.edu/emorsella/publications.html
