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Saturday, May 30, 2015

Neuroscience of Thinking 3

The main purpose of VI Rakmachandran's Brief Tour of Consciousness is to show that "the study of patients with neurological orders has implications far beyond the confines of medical neurology, implications even for the humanities, for philosophy, maybe even for aesthetics, and art." He proposes a new discipline--"evolutionary neuro-psychiatry." Neuroscience he proclaims is the new philosophy.

While I think that the last statement may claim too much, I do not see how an adequate philosophy that includes the study of human existence, of human knowing and actions, of ethics and politics, can not include the findings of neuroscience.

Consciousness is an essential element of human thinking. And so are unconscious memories and habits. For Ramachandran there are two facets of consciousness: qualia which are the perceived subjective sensations, e.g. color, taste, feel, and the sense of self where are the qualia are lumped together. The self has five characteristics:
1) continuity--a sense of the unbroken thread from past into present towards future.
2) unity--a coherence, sense of individuality and uniqueness.
3) embodiment or ownership--a sense that the perceptions and my body belong to me or even are me.
4) agency--a sense of being in charge of my actions, i.e. free will.
5) awareness--i.e. the "sense" in all the above, i.e. sense of existing as a unity, continuity, agency, owner.

He also points out how each of these characteristics can be disturbed through injury or experiment in the brain. The brain, he says, is a "model-making machine." It constructs "useful, virtual reality, simulations of the world that we can act on." It also constructs models of other peoples minds, i.e. "theory of mind." Through these models, the brain pulls together all the perceptions into the unity of the self aware of itself, of others, and of things in the world.

He describes the activity of thinking as both a representation, e.g. a model of the sensory stimuli from  the environment and a meta-representation, a representation of the representation through which new juxtapositions can be made among the representations and this ability is linked to language comprehension and meaning. He indicates the importance of culture in this activity of model making which he calls gene/cultural co-dependence. The brain is inextricably bound to its cultural milieu, languages, art forms, and other symbols, in its own development and in the development of its activity.

As a neurologist he shows how illness, injury, and experiment can disassociate different centers of the brain that connected make up the unified self-consciousness we discover in normal, well-adjusted, human minds. For example, Capgras Syndrome is a severing of the visual areas and emotional core of the brain so that when a patient sees his mother, he sees her as an imposter. Or blindsight when a patient says that he cannot see an object yet reacts to it because the visual information travels two paths of the brain which when severed makes the patient unable to see the object but still be aware of its presence. Certain experiments can induce a person to seemingly leave his body and see it from above. And there is an experiment that demonstrates that the brain makes the decision to an act before the person has any conscious intention to do so. And autism may be a deficiency in the mirror neuron system by which a person is incapable of constructing a "theory of other minds" and so lacks empathy.

But for my purposes his treatment of schizophrenia in which the representation and the meta-representation are disassociated. In other words, "schizophrenics cannot tell the difference between their own internally generated images and thoughts and perceptions that are evoked by real things outside." For example if I visualize a clown, I expect to see it but not confuse it with reality. However, if the expectation mechanism in my brain is faulty, I could not tell the difference.

And so when the schizophrenic imagines Napoleon or develop a theory of his mind, he become Napoleon.  Or a schizophrenic's mind is abducted by aliens because he is not in control. The schizophrenic is "unable to differentiate between internally generated actions and externally generated sensory stimuli." What he images and intends becomes real for him.

Because only humans among all the animals seem to have the ability to do symbolic thinking (or, in Ramachandran's terminology, make metarepresentations), only humans suffer from schizophrenia. I suggest therefore that those who confuse reality with their intentions and images, as do persons in a cult where beliefs are absolute, where what they are told is reality without question, where want they want or intend is the truth suffer from a kind of schizophrenia.

Clearly John Nash proves that schizophrenia can occur in people of very high intelligence. But I would hardly classify Michelle Bachmann and her followers as people of high intelligence. Persons who cannot or will not distinguish between what they believe and reality, whether they are right wing Tea Partiers, fundamentalist Christians, radical Islam jihadists, or devout American exceptionalists suffer from disturbance in their brains and in their thinking.

Are they responsible and culpable for this madness depends on whether we consider the self is an entity and has free will? We will come back to that.

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