Friday, June 26, 2015

Mentioning institute affiliations is not enough - III

Man is a Reasoning Animal. Such is the claim. I think it is open to dispute. - Mark Twain

In this post Sanjeev says, 'I could never get a satisfactory answer to what the source of this consciousness is. If I fear death, feel pain and pleasure, who is this I actually?' Many people think that we are more than just chemicals and electrical impulses. Thoughts, beliefs, choices etc. seem to suggest Decarte's concept of mind-body duality - the body is made of material stuff but the mind is not. It seems difficult to accept that the mind is the emergent property of the brain.

There is plenty of neurological evidence to show that all aspects of our mental lives depends solely on physiological activities in brain tissues. When some part of our brain tissue dies some part of the mind disappears. As I heard Sam Harris say in a discussion about life after death, when different bits of brain tissue is destroyed, people lose different abilities, yet they seem to think that when the whole brain is destroyed on death, they will rise up perfectly intact, recognising grandma and speaking English. As Steven Pinker says in The Blank Slate: is still tempting to think of the brain as it was shown in old educational cartoons as a control panel with gauges and levers operated by a user - the self, the soul, the ghost, the person, the "me". But cognitive neuroscience is  showing that the self, too, is just another network of brain systems.
The hint first came from the case of Phineas Gage, a 19th century railroad worker. While at work, a sudden explosion blasted a rod straight through his brain, left eye and skull and lay meters behind him. There was a hole in his head where his frontal cortex had been. Incredibly he was only briefly stunned and was able to walk and talk soon afterward. He seemed okay but from the next day, as one co-worker put it, 'Gage was no longer Gage'. His personality had changed.

From a pleasant, reliable, popular person, he had changed to someone who lied and cheated uncontrollably.He lost his sense of responsibility, his moral compass had degenerated and he was not able to hold a job for the rest of his life. In one lecture during his Human Behavioural Biology course at Stanford, Robert Sapolsky gives several instances of problems with frontal cortex damage.This shows that consciousness  is not some disembodied concept mediated only by culture and religion. Morality is as firmly grounded in neurobiology as anything else about us.

There isn't even a single 'I'; the brain just gives the illusion that a single 'I' is in control. It is not just in fiction that Dr. Jekyll turns into Mr. Hyde. In an earlier post, I had mentioned several brain disorders like anosognosia, hemineglect, blindsight, Capgras Sndrome, Cotard's syndrome etc. But the realisation that genes have a role to play in deciding one's morality need not make Sanjeev have such existential hopelessness as to make him say that his fate 'was decided in the first nanosecond of big-bang or even less'. In most cases the effects of genes are probabilistic in nature and depends on a complicated interaction with nurture. Moreover, most DNA are non-coding i.e. they don't seem to do anything.

Complex traits are affected by multiple genes with individually small and typically fickle effects. Most genes are pleotropic i.e. they have multiple effects, and most behaviours are polygenic i.e. they are mediated many genes working in a network having positive and negative feedback loops.Also some DNA sequences are regulatory elements i.e. they regulate the actions of genes near them, often under the influence of environmental factors.

 Thus most human behaviours can't be predicted with 100% accuracy. The reason is that the causation involved is so complex and deeply probabilistic that it is, in effect, unpredictable even if we were to try to enumerate all the contributing factors. Thus for all practical purposes, we are indeed free.As Robert Sapolsky says in Monkeyluv:'ve have got nature - neurons, brain chemicals, hormones, and, of course, at the bottom of the cereal box, genes. And then there's nurture, all those environmental breezes gusting about. And the biggest cliche in this field is how it is meaningless to talk about nature or nurture, only about their interaction.  And somehow, that truism rarely sticks.
Sgmund Freud said, “Humanity has in the course of time had to endure from the hands of science three great outrages upon its naive self-love. The first was when it realized that our earth was not the center of the universe, but only a tiny speck in a world-system of a magnitude hardly conceivable...The second was when biological research robbed man of his peculiar privilege of having been specially created, and relegated him to a descent from the animal world, implying an ineradicable animal nature in him...But man's craving for grandiosity is now suffering the third and most bitter blow from present-day psychological research which is endeavoring to prove to the ego of each one of us that he is not even master in his own house, but that he must remain content with the veriest scraps of information about what is going on unconsciously in his own mind." Neurological findings have increased the third outrage and many are not willing  to acknowledge it.

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