Neurontic

Decoding Consciousness

“It is better to tackle ten fundamental [scientific] problems and succeed in only one, than to tackle ten trivial ones and solve them all,” Francis Crick once told his devoted pupil V.S. Ramachandran, director of San Diego State’s Center for Brain and Cognition.

Ramachandran, apparently, took this advice to heart. The man who contends that neuroscience is ushering in “the greatest [scientific] revolution of all” believes that understanding the circuitry of the brain will soon allow us to tackle the existential questions that have plagued philosophers for centuries. He is so confident, in fact, that he’s started to consider the problem of consciousness.

This ambitious project is not purely an exercise in hubris. Ramachandran is picking up where his mentor left off.

After decoding DNA, Crick turned his attention to the study of self-awareness. He was convinced that he’d found a way to decode the biological underpinnings of consciousness. The correct way to approach the slippery problem, in Crick’s view, was to understand how we process visual information.

It seems an odd way to start. But it makes more sense when you learn about a phenomenon called “blind sight.”

It all started with a patient known as GY. GY suffered from a peculiar vision problem. He was completely blind on his left side due to damage to his right visual cortex. When you and I close one of our eyes, the other eye compensates, offering us a fairly broad spectrum of vision. But if a person’s right visual cortex is impaired, he is blind to everything on the left side of his nose. It’s an odd–and I imagine–extremely disorienting condition.

In the late ’90s, two Oxford researchers, Larry Weiscrantz and Alan Cowey, became preoccupied with this vision problem and recruited GY to undergo a series of tests.

Here’s what happened:

When examining [GY], Weizcrantz noticed something really strange. He showed the patient a little spot of light in the Blind region. Weiscrantz asked him “what do you see”? The patient said “nothing” [but then] he told the patient: “I know you can’t see it but please reach out and touch it” The patient . . . must have thought this is a very eccentric request.

So [GY] said . . . I can’t see it how can I point to it? Weiscrantz said: “Well, just try anyway, take a guess.” The patient reached out to touch the object and imagine the researcher’s surprise when the patient reached out and pointed to it accurately–pointed to the dot that he [could not] consciously perceive. After hundreds of trials, it became obvious that he could point accurately on 99 percent of trials even though he claimed on each trial that he was just guessing . . . From [GY’s] point of view it might as well have been an experiment on ESP.

From BBC 2003 Reith Lecture: Synapses and the Self)

Based on these findings, Weizcrantz and Cowey came to a startling conclusion: the patient was, in fact, “seeing.” He simply wasn’t conscious of it. How is that possible, you ask? Vision is a complex mechanism involving multiple parts of the brain. GY’s visual cortex was damaged, but another key brain region involved in seeing remained in tact: “the pathway going through his brain stem and superior colliculus.” What the researchers eventually concluded was that GY was “seeing” with the pathway to the superior colliculus.

By evolutionary standards, the visual cortex is relatively new. The pathway leading to the superior colliculus is old–practically primordial. GY’s ability to consistently perceive the spot of light, without being consciously aware of it, suggested something astounding: it suggested that only the newer visual cortex contributed to “conscious awareness.” The ancient colliculus pathway, on the other hand, could “do its job perfectly well without being conscious.” This implies that humans were not always self-aware, and that consciousness was an evolutionary adaptation.

The discovery of blindsight spurred a flurry of research in the field of consciousness. Crick was hardly the only scientist concerned with consciousness, but he was the most vocal. He believed that consciousness “hinged on the behavior of neurons” and that it might “be clustered within either one or multiple areas of the brain.” (Princeton.edu)

I know. It’s a little vague. But applying the scientific method to the study of consciousness is a dodgy business and scientists are reluctant to make grand proclamations. The mere suggestion that consciousness was a function of neuron activity was highly controversial. (It does, after all, challenge traditional beliefs about the soul.)

Ramachandran has continued Crick’s study of consciousness, but he’s approaching it from a different angle. He believes that a cluster of cells called mirror neurons might be responsible for self-awareness. He discussed his nascent theory in a 2003 BBC lecture, Neuroscience-The New Philosophy. According to Ramachandran:

. . . our brains [are] essentially model-making machines. We need to construct useful . . . simulations of the world that we can act on. Within the simulation, we need also to construct models of other people’s minds because we’re intensely social creatures, us primates. We need to do this so we can predict their behavior.

Evolution, Ramachandran says, imbued us with the power to intuit other people’s intentions, enabling us to forge social connections and defend ourselves against potential aggressors. It did this by engineering the cells we’ve come to call mirror neurons.

Put simply, mirror neurons are “empathic” cells. They allow us to emotionally simulate another person’s internal reality. (For more on this see: Mirror Neurons Revisited)

Ramachandran believes that this ability to “read” the intentions of others may have predated consciousness. He surmises that once humans became adept at reading the emotions of others, they turned this power inward and began analyzing their own intentions. Thus, consciousness was born.

If he’s right (and, at present, we have no way of knowing), consciousness may be a relatively simple phenomenon. Increased understanding of the behavior of mirror neurons may unlock the mysteries of the self.

The idea that self-awareness is the product a complex set of chemical reactions in your brain may be unsettling to some. There are people who feel that this clinical approach to understanding the psyche robs life of its magic. But comprehending the biological underpinnings of “the self” makes it no less miraculous, in my view. The more I learn about neuroscience, the more I marvel at nature’s ingenuity and creativity.