Some may find that notion incredible—or even threatening. Others will wonder in awe at the complexity of that pulpy mass of cells and chemicals that determines who we are, while at the same time allowing us some control over who we can become and what we will do. Churchland describes the issue of free will as rather murky because the definition of the concept is too subject to misinterpretation. Rather, she suggests those who doubt should ask themselves a different question: "Do I have the capability of exercising self-control?" If the impulse to grab that donut comes up from my subconscious, can I say no I won’t, and send my subconscious the message that I prefer to respond differently to the image of a donut in the future? If I can, then I am exercising what most people would consider free will.
Churchland discusses at length many interesting and complex problems. She considers matters like mankind’s seeming propensity for violence, how evolution managed to create what we call "maternal instinct," and how evolution could develop what we might call moral behavior. For those discussions you will have to read the book. Here we will begin with the weighty question of why humans are unable to tickle themselves.
Components of our brain are described, for convenience, as being part of the conscious brain or part of the subconscious brain. In fact, the two are inseparable in the sense that they must function together in a coherent fashion or we have severe problems. The brain has many components. Some are focused on quite specific functions, while others are more integrative in nature. One of the mechanisms the brain uses to maintain coherence is to send out signals telling the components when an action is going to take place. If you are going to reach out and press a doorbell, the components that are responsible for responding to that sense of contact need to know to anticipate it or an incorrect conclusion may be drawn as to what that contact means.
The signal the brain sends out informing itself of an upcoming action is referred to as efference copy. This mechanism not only supports the stability of the interaction between brain and body, but also provides a way to economize on brain resources. We cannot tickle ourselves because our brain sends out the message that we are planning to use our fingers to stimulate ourselves and responds accordingly. If someone else tries to tickle us there is no efferent copy and the brain interprets the event differently. It is of interest to note that these efferent signals must be timed properly in order to be effective. If one creates a mechanism with which to tickle oneself, the mechanism will only be effective if it is delayed a few seconds before operating.
Consider the simple act of turning your head 90 degrees to the right. The efferent copy alerts your brain that the focus will be on what is in view at 90 degrees. As your head turns, your brain eliminates the need to understand what is being sensed as the head is turning and only delivers to our consciousness what is perceived after the turn is complete. Our subconscious is smart enough to let us know if something dangerous or otherwise interesting should happen to come into view during the turn.
This mechanism of efference copy is critical in placing us in the context of our surroundings. The intention to turn our heads tells the brain that our surroundings can be considered stationary. If someone else is doing the turning there is no efference signal and it has difficulty determining whether we are moving or the world is moving—a rather disorienting situation.
Churchland tells us that speech, both verbalized and non-verbalized, is accompanied by efference copy.
The development of the complex wiring required to attain a functioning brain in a growing embryo is fraught with uncertainty. Brain construction does not always follow the "normal" path. This leads to variations among individuals in addition to genetic variations, and it can lead to malfunctioning of certain capabilities.
One of the current areas of research involves investigating failure of the mechanism for efference copy as a possible cause of schizophrenia.
"Incidentally, it has been claimed that many schizophrenics can tickle themselves, another small piece of evidence in favor of the theory that attributes auditory hallucinations to imprecise timing of the efference copy signal,"
Thinking of schizophrenia in this manner makes the condition seem much less ominous than the "broken brain" image that became popular in scientific and popular media. One might conjure up ways of dealing with this malady if efference copy malfunction was in fact the source of the problem.
T. M. Luhrmann provided an interesting article in The American Scholar titled Living With Voices. She does not refer to the efference copy mechanism. Her topic is new knowledge about people who are learning how to deal with auditory hallucinations. Her observations are not inconsistent with Churchland’s suggestions.
The standard view was that voices were the symptom of disease and if people were sufficiently drugged that the voices disappeared, then the disease had been treated and the people had been helped.
Luhrmann describes the efforts of the Dutch psychiatrist Marius Romme and his wife Sandra Escher to look deeper into the meaning of these "voices."
Attributing meaning to these voices was a revolutionary concept.
It must have been startling to learn that most of those who claimed to hear voices learned how to cope with the issue on their own. This is what they learned from these people:
What Romme and Escher came to claim was that hearing voices is a normal phenomenon rather than a sign of "brain disease." It is just more common with some people and rare for most.
Romme and Escher have turned this new understanding into a movement.
"These days, the Hearing Voices Network is an international organization with members in many countries, including the United States, and 180 groups in Great Britain alone. It has a newsletter, a web page (intervoiceonline.org), and a society that meets annually."
Our brains are always bubbling away with thoughts—some of which occasionally pop up to the surface. Some of our thoughts can be disturbingly violent or things that we would never consider verbalizing. We deal with these thoughts because we know they are our own thoughts and they are private. Wouldn’t it be startling—even maddening— if some of our more shameful mental output actually seemed to be audibly expressed by some unknown and uncontrollable mechanism?
It may be that those who suffer from auditory hallucinations and have the most trouble dealing with them have some sort of life-experience or trauma that produces troubling thoughts that are particularly intense and frequent. It could also be true that the emotional stress associated with these "hallucinations" can augment their frequency and intensity.
The notion that "hearing voices" is, in some forms, common, supports the notion that efference copy can fail under certain conditions. Given variations in other brain functions among individuals, it would not be surprising to find a spectrum of people for whom this failure is more frequent.
There is no proof yet, but the findings discussed by Churchland and those presented by Luhrmann seem to be converging on a consistent description of the cause and treatment for auditory hallucinations. If this holds together, we have an entirely new—and better— way of dealing with people now labeled as schizophrenic.