Ideally, many science notables would like to “naturalize” human consciousness—to make it the same sort of phenomenon as the wind in the trees in a universe where nothing has any intrinsic meaning that sets it apart from anything else or points to a higher order of things.
That would, of course, make calculation easier. But is it true?
Here’s the abstract:
Electrical stimulation of the human cortex, undertaken for brain surgery, triggers percepts and feelings. A new study documents an ordering principle to these effects: the farther removed from sensory input or motor output structures, the less likely it is that a region contributes to consciousness.– Koch, C. Hot or not. Nat Hum Behav 4, 991–992 (2020). https://doi.org/10.1038/s41562-020-0925-7 (paywall)
So things we are not aware of do not contribute that much to our consciousness. Reviewer Tam Hunt is a fan but curiously unsure about some aspects of the new buzz:
But what if there’s more to the story? What if the electromagnetic fields generated by, but which are not identical to, the neuroanatomy of the brain, are in fact the primary seat of consciousness? The brain’s fields are generated by various physiological processes in the brain, but primarily by trans-membrane currents moving through neurons. These fields are always oscillating and they come in various speeds, clustered around certain bands, from delta on the lower end at 1-2.5 cycles (oscillations) per second (Hertz) up to gamma at 40-120 cycles per second.
Some neuroscientists have long considered the brain’s oscillating electromagnetic fields to be interesting but merely “epiphenomenal” features of the brain—like a train whistle on a steam-powered locomotive. Electromagnetic fields may just be noise that doesn’t affect the workings of the brain. Koch still seems to lean this way.
“While at this early stage of the exploration of the brain it would be foolish to categorically rule out any physical process,” he told me, “as an electrophysiologist I’m less enthused about ascribing specific functions to specific frequency bands, let alone experience. The causal actors between neurons that act at the time scale relevant for consciousness (5-500 milliseconds) are action potentials that cause, in turn, synaptic release of packets of neurotransmitters.” He thinks the extent to which oscillations affect neuronal firing patterns remains an open question. “Consider the sounds the beating heart makes,” he said. “These can be picked up by a stethoscope and can be used to diagnose cardiac conditions. However, there is no evidence that the body exploits these sounds for any function.”Tam Hunt, “Are the Brain’s Electromagnetic Fields the Seat of Consciousness?” at Nautilus
Hmm. Does “the body” not exploit the sounds of the heartbeat for any function? If you heard your heart beating especially rapidly, would you not wonder why?
Consciousness is especially difficult to study because we are trying to think about ourselves thinking about what we are thinking about. There is no evidence that consciousness is analogous to a “natural” process, the way the startled mouse thinks about escaping the cat. Chances are, the mouse needn’t think much. If he escapes the cat, he never thinks about what he is thinking about, let alone anything more complex.
Searching for the origin of consciousness in the brain, Christof Koch has written a book, The Feeling of Life Itself (2019) . Koch’s publisher, MIT Press, tells us,
Koch gives us stories from the front lines of modern research into the neurobiology of consciousness as well as his own reflections on a variety of topics, including the distinction between attention and awareness, the unconscious, how neurons respond to Homer Simpson, the physics and biology of free will, dogs, Der Ring des Nibelungen, sentient machines, the loss of his belief in a personal God, and sadness. All of them are signposts in the pursuit of his life’s work—to uncover the roots of consciousness.
And that is where we must leave the subject. We are back where we started but we have interesting books.
You may also want to consider: Can we develop tests of the brain for consciousness? The paper proposing the tests reads like an ambitious but hopeless project that offers some genuinely interesting moments.