Sep 4, 2007

no brain is an island

Stuart Derbyshire, reviewing Chris Frith's Making up the Mind: How the Brain Creates our Mental World, wants to rescue free will from neuroscience. He focuses on schizophrenia because of its challenge to stable conceptions of the self, and because of its mysterious etiology and causality.

In doing so, however, Derbyshire makes two minor but bothersome errors. First, he ignores the vast number of pathologies where causality is better understood. Second, following Frith, he ignores the vast body of recent neuroscientific research on schizophrenia. Considering the plight of schizophrenic patients, Derbyshire quotes Frith, who writes,
‘There are no objective physical signs of schizophrenia. The diagnosis is based on what the patient tells the doctor. Patients say that they hear voices when no one is there (false perceptions – hallucinations). Patients describe how they are persecuted by their colleagues at work when there is no evidence that this is the case (false beliefs – delusions). Patients with hallucinations and delusions are sometimes described as being out of touch with reality. But it is the mental world, rather than the physical world, that they have lost touch with.’
Their fragmented consciousness is hidden from immediate view, but that doesn't make it impervious to objective measurement.

Schizophrenia, according to recent research, is associated with reduced cerebral laterality, reduced amygdala volume, frontal-subcortical circuit dysfunction, gray matter excesses in the caudate nucleus--the list goes on and on. Some of these differences might even be heritable.

In summary:
Until recently, the dominant view was that schizophrenia patients have limited, if any, neuropsychological impairments, and those that are observed are only secondary to the florid symptoms of the disorder. This view has dramatically changed.
Errors aside, what about Derbyshire's broader point, the underappreciated role of the will? Current neurosciencelooks for cause and effect in patterns of brain activity. This, according to Derbyshire, takes too narrow a view.
Frith’s dual contentions that reality is illusory and free will is just a manufactured state of mind are both far too strong. Our limited direct access to the world ‘as it truly is’ is certainly a real problem. It is a problem because the world does not divide itself into fact-sized chunks that can be consumed by our senses. Whether a forest is perceived as a unit or an aggregation of many trees is arbitrary, just as it is arbitrary whether we observe leaves as independent or continuous with twigs and whether the twigs are independent or continuous and so on ad infinitum. Nature does not inherently divide itself into salient pieces, and what is salient or important is only revealed in the relationships within nature....

[I]t is only through our relationship with the world that we can come to divide the world and begin to describe it. The facts that we can lay claim to about the world are arbitrary in so far as they are selected from an almost infinite number of potential facts, but we can, nevertheless, have great confidence that the facts we are gathering are real. We can have this confidence because our actions based upon those facts generally lead to expected outcomes – trains move forward through space, telephones transmit recognisable voice signals, medical intervention saves lives, and so on. These happy outcomes indicate that our division of the world is grounded in reality and that although our facts are arbitrarily selected we are not making them up as we go along.

In short, Frith misses, or understates, the role of inquiry in constructing a real representation of the world. Inquiry brings human beings into an understanding of the world that continues to more closely approximate the way the world truly is. The constraints that our brain places upon inquiry do not dictate reality but rather allow us the freedom to interrogate reality....

The fundamental mistake that Frith makes – and this is a common error – is to believe that agency or free will are products only of the human brain. The brain is necessary but it is not sufficient, and chasing agency into the brain will only yield disappointment or, in this case, a sense that agency is illusory. If agency is not merely a product of ordinary brains, then it follows that abnormal brains might not be the whole or only answer when there are psychiatric problems and delusions of agency such as in schizophrenia.
Derbyshire hints at, but never fleshes out, the processes involved in "inquiry." For this, we have to turn to other writings, for example, an attempt to answer the politically charged question, "Can fetuses feel pain?"
[C]onscious function can only emerge if the proper psychological content and environment has been provided. Before infants can think about objects or events, or experience sensations and emotion, the contents of thought must have an independent existence in their mind. This is something that is achieved through continued brain development in conjunction with discoveries made in action and in patterns of mutual adjustment and interactions with a caregiver. The development of representational memory, which allows infants to respond and to learn from stored information rather than respond to material directly available, may be considered a building block of conscious development. Representational memory begins to emerge as the frontal cortex develops between two and four months of age, supported by developments in the hippocampus that facilitate the formation, storage, and retrieval of memories. From this point tagging in memory is possible, or labelling as "something," all the objects, emotions, and sensations that appear or are felt. When a primary caregiver points to a spot on the body and asks "does that hurt?" he or she is providing content and enabling an internal discrimination and with it experience. This type of interaction provides content and symbols that allow infants to locate and anchor emotions and sensations. It is in this way that infants can arrive at a particular state of being within their own mind. Although pain experience is individual, it is created by a process that extends beyond the individual.
I sense an affinity between Derbyshire's position and what Russian developmental psychologist described as cultural mediation. We form and re-form the experiences of those around us, shaping and re-shaping the brain--ours and others'. In grand metaphysical style, you might say that every "I" is a "we."

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