Brain and Awareness – The Secret You (Horizon)

November 7, 2009

Mathematician Marcus du Sautoy is becoming an increasingly regular front-man for the BBC science documentary Horizon and, to date, his contributions have always been satisfyingly informative. The recent episode The Secret You is no exception.

In his quest to discover the underlying biochemistry and physiology of consciousness, du Sautoy visits a number of laboratories around the world where self-awareness and the notion of “the inner me” are being investigated. In doing so, he frequently participates in experiments; at one point he quips “another day, another scanner”(50:49).

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Marcus du Sautoy takes part in many experiments as part of his search for the basis of consciousness

There are a raft of ethical questions which arise from functional Magnetic Resonance Imaging (fMRI) and other neuroimaging methods, some of which I have written about elsewhere (see Disorders of consciousness: do state-of-the-art neuroimaging techniques shed new light on the brain-injured patient?).

For me, the most interesting ethical questions in the programme arise from the work of Professor Adrian Owen. du Sautoy and Owen discuss experiments conducted with patients in PVS, a Persistent Vegetative State (16:44 to 19:22, though the discussion makes most sense if you start at 15:30).

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Prof Adrian Owen of Cambridge University has made exciting discoveries about the awareness of a patient in PVS

Previously our abililty to tell whether or not a PVS patient was genuinely conscious was constrained by the fact that they had no physical ability to demonstrate their awareness. In ground-breaking experiments, however, Owen and his colleagues have communicated with patients by asking them to imagine performing certain tasks, for example playing tennis, and using fMRI to show that the appropriate areas of their brains are activate. By developing this further, it is possible to get the patient to imagine two different activities which are clearly distinguishable from one another in terms of brain activity. These can then serve as proxy signals as “yes” and “no” answers to questions posed.

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A patient could be trained to make certain areas of her brain active as a proxy answer to questions posed by researchers (e.g. by imaging she was playing tennis or walking around her house)

These experiments have revolutionised our understanding of brain-injured patients. In particular it brings into question the practice of withdrawing food and water from patients in PVS on the assumption that the are not aware.

Horizon: The Secret You (TRILT code 01210858) was first broadcast on BBC2 on 20th October 2009.


Epigenetics – The ghost in your genes

June 30, 2008

 
Epigenetics – Turning genes on and off  

The BBC Horizon documentary The ghost in your genes, successfully explains a particularly complex field of science. Genetic inheritance has historically been thought of as involving the transmission of DNA from one generation to the next affected by occasional mutations in the DNA itself (00:04:37 – 00:05:50). “Up to now, inheritance is just the genes, the DNA sequence. I suspect that we’re going to be able to demonstrate that inheritance is more than that”, explains Professor Marcus Pembrey from the Institute of Child Health, UCL. A few scientists had hypothesised that the conventional genetic model and mode of inheritance was too simplistic to explain the complexity of human beings. The revelation that the human genome likely contains only about 30,000 genes (00:08:54 – 00:11:33), coupled with increasing experimental evidence, now leads scientists to believe that other factors allow genes to be switched on and off in response to environmental stimuli. The consequences of which may affect subsequent generations.

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