Electrical stimulation of sensory cortex locations by electrodes in awake subjects undergoing neurosurgery gives a sensation in a related body part, so stimulating a left-cortex point might give a brief right-hand tingle that subjects consciously report about 500ms later (Libet, 2005). This raises the old issue of whether consciousness is cause or effect:
“How are nerve cell activities in the brain related to conscious subjective experience and to unconscious mental functions?” (Libet, 2005) p32.
To find out, subjects were asked to flick a wrist when they felt like it. The EEG showed a movement readiness potential in the prefrontal cortex about 200ms before subjects reported their intention to act. Conventional neuroscience immediately took this to mean that consciousness follows the brain, like a king who thinks he rules when his advisors really run everything. If brain processes do everything, consciousness exists but does nothing:
“A systematic exploration suggests that every cortical site holds its own knowledge. Consider the insula, a deep sheath of cortex that is buried beneath the frontal and temporal lobes. Stimulating it can have a diversity of unpleasant effects, including a sensation of suffocation, burning, stinging, tingling, warmth, nausea or falling. Move the electrode to a location farther below the surface of the cortex, the subthalamic nucleus, and the same electrical pulse may induce an immediate state of depression, complete with crying and sobbing, monotone voice, miserable body posture, and glum thoughts. Stimulating parts of the parietal lobe may cause a feeling of vertigo and even the bizarre out of body experience of levitating to the ceiling and looking down on one’s own body.
If you had any lingering doubts that your mental life arises entirely from the activity of the brain, these examples should lift them.” (Dehaene, 2014) p153.
These results don’t mean what Dehaene thinks they do, that we are just a bunch of nerves, because none of the nerve regions stimulated are capable of observing or experiencing anything. Explaining how a movie gets onto a screen doesn’t explain how it is observed. It is true that:
“… a whole array of mental processes can be launched without consciousness…” (Ibid, p86)
But to say that consciousness does nothing because less conscious parts of the brain can act without it is like saying that the sun does nothing because I can switch on a light at night. It is true that parts of the brain can act without global consciousness, as we can react to stimuli in 200ms before the 500ms it takes to be fully conscious, but this just means that there are lower and higher degrees of consciousness. It doesn’t mean that there is no consciousness at all.
The relation between consciousness and the brain is like a viewer watching a TV. Nothing can be seen until the TV is turned on but even so, a TV can’t view itself. Physical realism claims that TVs exist without viewers while “viewer realism” is that viewers also exist. One can imagine a conversation between these two points of view as follows:
VR: A TV can’t view itself, so there must be a viewer out there.
PR: Not at all. When the TV is turned on, we just imagine that someone is viewing it.
VR: But a network of TVs that no-one watched would be pointless!
PR: Exactly! It’s all pointless, that’s why it doesn’t matter what we show.
VR: But we can talk to viewers watching TV by long-distance phone calls.
PR: Yes, but they are also imaginary. It’s all fake.
VR: How do TV channels change if there are no viewers?
PR: The remote control changes the channels randomly. Who knows, maybe a fly sits on it?
VR: So how do you know that viewers don’t change the channel?
PR: We did an experiment. We asked a “viewer” to call us when he changed channels and the remote control came out of standby a second before his call arrived. Hence, he didn’t do it.
VR: But how long does it take a long-range phone call to arrive?
PR: About a second.
VR: So that’s not really conclusive, is it?
PR: Its near enough. Machinery does everything, viewers don’t exist.
VR: But you watch TV so you’re a viewer too, does that mean you don’t exist?
PR: Don’t be ridiculous, of course I exist.
Libet’s flawed experiment led to a consensus among scientists that the brain is a machine, just as nineteenth century scientists agreed the universe was a machine until quantum theory proved it isn’t. This desire of scientists to prove they have no choice should be a subject of study:
“… why are so many intellectuals so intent on proving that they have no free will? (As the philosopher Alfred North Whitehead pointed out ironically, ‘Scientists animated by the purpose of proving themselves purposeless constitute an interesting subject for study.’)” (Taylor, 2019)
Evolution doesn’t do pointless. The long and short-range nerve synchronies we find in every brain wouldn’t have evolved if they did nothing. That it takes time and effort to create the nerve synchronies that correlate with consciousness suggests that it is useful..