The Self as Brain: Efferent Copy, Voices, and Schizophrenia

Patricia S. Churchland has produced a fascinating book discussing some of what is known about the interaction between our brain and what we consider to be our mind: Touching a Nerve: The Self as Brain. Her message, of course, is that the two are one and the same. The brain is all there is:

"….we are what we are because our brains are what they are."

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.

"When you say out loud, ‘I need to buy milk,’ then a signal leaves the movement-planning brain and loops back to the sensory brain to indicate the source of the sound. When you merely think, ‘I need to buy milk,’ this is covert speech (inner speech). Again, a movement-planning signal informs the sensory brain about the source of the covert speech—me."

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.

"So sometimes a person may think ‘I need to buy milk,’ but because there is no efference copy signal or none with the right timing, he may fail to realize that his thought is actually his thought. He may in time come to believe that the FBI has put a radio in his brain and is transmitting voices into his brain. Auditory hallucinations are a not uncommon feature of schizophrenia, and a leading hypothesis to explain them refers to the failure of the mechanism for efference copy…."

"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.

"Modern American psychiatry treats auditory hallucinations as the leading symptom of serious psychotic disorder, of which the most severe form is schizophrenia….These days, schizophrenia is often imagined as the quintessential brain disease, an expression of underlying organic vulnerability perhaps exacerbated by environmental stress, but as real and as obdurate as kidney failure. The new post-psychoanalytic psychiatric science that emerged in this country in the 1980s argued that mental illnesses were physical illnesses. Many Americans and most psychiatrists took away from this science a sense that serious mental illnesses were brain dysfunctions and that the best hope for their treatment lay in the aggressive new drugs that patients often hated but that sometimes held symptoms at bay."

Luhrmann describes the efforts of the Dutch psychiatrist Marius Romme and his wife Sandra Escher to look deeper into the meaning of these "voices."

"More than 20 years ago he was working with a patient who had been struggling with her voices. She came in one day and told him that a book she had been reading had helped her because it made her feel that her voices had meaning."

Attributing meaning to these voices was a revolutionary concept.

"In the mid-1980s, Romme advertised for voice-hearers on national television in the Netherlands. The local network ran a segment on Romme and his patient….and asked voice hearers to send postcards. Seven hundred cards arrived.　More than half were from people who seemed to experience audible voices, and many of them had never seen a psychiatric professional. They coped with their voices just fine."

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:

"The people who were comfortable with hearing voices told the same story; their experience had a trajectory. Some voices had started out mean and difficult, and the hearers had first responded with startled fear, but once they had chosen to interact with them, the voices settled down and became more manageable, sometimes even useful….That was the kernel Romme and Escher took away from the event: if people could accept their voices and create a relationship with them, they could get their voices to change."

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.

"Its method, to treat voices like people, is almost the inverse of the biomedical understanding of psychotic voices and a completely different perspective on how to handle them. The organization insists that hearing voices is a normal human experience, which indeed it is, although what is common (and thus "normal") is hearing a voice as you slip into sleep, perhaps calling your name, perhaps your mother’s voice. About half of a standard subject pool (read: university undergraduates) will say that they have had some experience like that at least once. Many more will say so if the experimenter gives them examples."

Romme and Escher have turned this new understanding into a movement.

"In 1993 they published Accepting Voices, with techniques, case studies, and commentary by mental health professionals and patient activists (the activists sometimes call themselves survivors of psychiatric care). More detailed manuals and books followed. The workshops grew into conferences. Soon Romme and Escher were the unofficial leaders of 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.