01 March 2014

'Touching a Nerve' by Patricia Churchland (2013):

 A personal, non-academic review of the life physical.  In general I found 'Touching a Nerve' a good read - the subtitle 'The Self as Brain' is a kind of undertone to her (largely common-sensical) look at a variety of subjects, all based on a neuroscientific outlook.  Here are a few points of special interest to me.

On free will - she comes out pretty strongly against the Harris line that "free will is an illusion" - she says if it means there's no "contra-causal free will" then the observation is "only marginally interesting."
But what if free will is illusory means something else? What if it means, for example, that because there is a neural substrate for our deliberations and choices, we cannot have free will? Now I am totally at a loss. Why would anyone say such a thing? So what do they think is required to make genuine choices? A non-physical soul? Says who? (184)
What is not illusory is self-control, even though it can vary as a function of age, temperament, habits, sleep, disease, food and many other factors that affect how nervous systems function. (185) 
Churchland gives credit to Freud for being an early adopter (circa 1895) of the view that the unconscious processes are both mental and physical.
He understood that unconscious reasoning and intentions and thoughts need to be invoked to explain such things as complex perception (for example, heard speech as having a specific meaning) and complex motor acts (for example, speaking intelligibly and purposefully).
He realized that he had essentially no idea what a vocabulary spanning the brain and behavioral science would look like. His conclusion was that we have no choice but to make do with what we know is a flawed and misleading vocabulary, namely, that of intentions, reasons, beliefs, and so on, to describe unconscious states. (201)
I liked this bit, on the interplay of conscious and unconscious:
Your conscious brain needs your unconscious brain, and vice versa. The character and features of your conscious life depend on your unconscious activities. And of course, conscious events can in turn have an effect on unconscious activities. (207) 
And this bit on conscious decision-making as a constraint satisfaction process:
Precisely what my dear old brain is doing as I go through these exercises is not entirely known. That is, we can think of it in terms of constraint satisfaction, but we are still a bit vague about what constraint satisfaction is in neural terms. Roughly speaking, we do know that in constraint satisfaction operations, the brain integrates skills, knowledge, memories, perceptions, and emotions and somehow, in a manner we do not precisely understand, comes to a single result. (219)
She disputes Dennett's position that language has to be part of consciousness, partly on personal grounds:
A further problem is that consciousness - mine, anyhow - involves so much more than speech. Indeed, we may experience much for which we have no precise linguistic characterization at all, such as the difference between the smell of cinnamon and the smell of cloves or the difference between feeling energetic and feeling excited, or what an orgasm is like. (250)
While other mammals do not have our kind of language, they do seem to communicate, and in terms of brain structure, they have very similar organs and patterns of activity.  She feels this indicates that many animals have some level of conscious awareness.

The overall picture she draws is of the brain as a looping structure, with some highly networked neurons able to convey signals to many other areas, to support the type of integration that we see.

I noticed that the book initially got a number of one-star reviews at Amazon, mostly short critiques of her overly reductionist viewpoint (an organized effort I presume!).  I did not find her to be overly reductionist in this book.  While she doesn't explicitly take on emergence as a topic, in the epilogue she does make this argument:
If, as seems increasingly likely, dreaming, learning, remembering, and being consciously aware are activities of the physical brain, it does not follow that they are not real. Rather, the point is that their reality depends on a neural reality. If reductionism is essentially about explanation, the lament and the lashing out are missing the point. Nervous systems have many levels of organization, from molecules to the whole brain, and research on all levels contributes to our wider and deeper understanding. (262)
Accessible, personal, and a good overview - I recommend it.