Jane O'Grady provides a brilliant demolition of the claims of neuroscientists and neurophilosophers to be able to locate mental phenomena, even complex ones such as thoughts and beliefs, in certain areas of the brain and to infer from observation of brain activity what people are imagining or thinking and whether or not they are telling the truth. To complement the philosophical argument, I want to focus (mainly) on specific claims made on behalf of imaging of the activity of the waking human brain. I do so from the position of one who has been using technologies such are fMRI and Transcranial Magnetic Stimulation in my research for over a decade. An intimate knowledge of this technology, as well as a familiarity with the philosophical arguments, has made me a convinced ‘neurosceptic’.
Raymond Tallis is a specialist in the neurology of old age. He has written widely, including works of philosophy, fiction and criticism.
openDemocracy's neurosceptisism debate was opened by Jane O'Grady's Can a machine change your mind? and includes Graeme Mitchison's Science in the clear.
'The apparent localisation of human feelings in bits of the brain is the result of a multi-layered artefact. First, when it is asserted that such-and-such a part of the brain lights up in relation to a particular stimulus, this conclusion is arrived at by subtraction. Much more of the brain is already busy or lit up; all the scientist can observe is the additional activity associated with the stimulus. Minor changes noted diffusely are overlooked.
Secondly, the additional activity can be identified only by a process of averaging the results of subtractions after the stimulus has been given repeatedly: variations in the response to successive stimuli are ironed out.
Finally, and most importantly, the experiments look at the response to very simple stimuli – for example, a picture of the face of a loved one compared with that of the face of one who is not loved. But love is not like a response to a stimulus. It is not even a single enduring state, like being cold. It encompasses many things, including not feeling in love at that moment; hunger, indifference, delight; wanting to be kind, wanting to impress; worrying over the logistics of meetings; lust, awe, surprise; imagining conversations, events; speculating what the loved one is doing when one is not there; and so on. (The most sophisticated neural imaging, by the way, cannot distinguish between physical pain and the pain of social rejection: they seem to ‘light up’ the same areas!)
The general point, also made by O'Grady, is this: the components of ordinary human consciousness are profoundly interconnected: they belong to a self-world that is not itself made up of atoms or separate components.
The appeal to brain science as an explain-all has at its heart a myth that results from confusing necessary with sufficient conditions. Experimental and naturally occurring brain lesions have shown how exquisitely holes in the brain are correlated with holes in the mind. Decapitation plays merry Hell with the IQ. Everything in our life-world, from the faintest twinge of sensation to the most exquisitely constructed sense of self, requires a brain; but it does not follow from this that neural activity is a sufficient condition of human consciousness, even less that it is identical with it. Although direct stimulation of the brain in the waking adult may generate quite complex hallucinations – even rather elaborate patches of memory – this occurs only because neural activity is associated with such experience under normal conditions: the experiences arrived at by the anomalous route are parasitic on those that are had in the normal way.
Under normal circumstances, experiences are had by a person, not by a stand-alone brain. The brain of an experiencing person is not isolated like the famous ‘brain in a vat’ of Hilary Putnam’s thought experiment: it is in a body. Corresponding to this is the fact that when, for example, I see something I like, or someone I love, my brain, or some small part of it, is not the only part of me to light up. My heart may beat faster, or more thickly; a smile may appear on my face; and my step may be a little jauntier. Things do not stop there. My body is located in a currently experienced environment; and, since I am human, that environment is situated in a world that is extended in all spatial, temporal, cultural directions. This world, too, may be transformed by my encounter with the loved one’s face and I may think differently about it. For the extraordinary thing about human brains – and what captures what is human – is that they transcend themselves; that human experience is not solitary sentience but has a public face; it belongs to a community of minds. This is a process that has developed over many hundreds of thousands, perhaps millions, of years since hominids parted company from the monkeys.
The neuromythologists, trying to find citizens and their worlds in neurons, try to stuff all that has been created by the collective of brains back into a stand-alone brain; indeed into a small part of such a brain. Yes we require a brain to participate in the community of minds; but that participation is not to be reduced to activity in bits of brains.The errors of the neurophilosophers do not even have the virtue of novelty. According to Hippocrates, writing in 500 BC in his treatise on Epilepsy On the Sacred Disease: "Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, grief and tears. Through it, in particular, we think, see, hear and distinguish the ugly from the beautiful, the bad from the good, the pleasant from the unpleasant." Everyday observation as well as the results of sophisticated research render plausible the hypothesis that the brain is a necessary condition for our consciousness, selfhood, personhood, free will, responsibility, belief-holding, lying etc. That is why they can be influenced, altered, impaired or even obliterated by brain damage. The stand-alone brain is not sufficient to account for these things: they are to be found in the whole human being functioning in the community of minds - in the human world - in society, to which the brain gives access. Consequently, newer, cleverer ways of visualising brain activity will not give us direct access to selves, thoughts, beliefs and so on.