Brain Reading

There was a troubling BBC news story recently: " Brain scan 'sees hidden thoughts'." The subtitle reads "Scientists say they can read a person's unconscious thoughts using a simple brain scan."

The actual results are a bit less sensational, but the scientists' reactions deserve a headline in themselves.

The news story is based on two studies in Nature Neuroscience, one by Dr. Frank Tong and Dr. Yukiyasu Kamitani, the other by Dr Geraint Rees and Dr John-Dylan Haynes. Both studies used functional magnetic resonance imaging (fMRI), which finds the brain's active regions as shown by blood flow. Tong & Kamitani were able to discriminate the orientation of a visual image (a series of parallel bars) a research subject was thinking about. Rees & Haynes were able to tell the orientation of a visual image whose duration was too short to register in the consciousness of the subject (that is, a subliminal image).

The responses of scientists the news story records reflect problems with our society's view of the world. Dr. Burgess's comments are downright alarming:

"It could potentially be used to find out people's latent attitudes and beliefs that they are not aware of.

"You could use it to detect people's prejudices, intuition and things that are hidden and influence our behaviour."

He said it might be possible to dip into people's repressed memories or even see people's hidden fears and phobias.

"That's a long way off, but it is exciting."

(Sure: exciting like being tied to a railroad tie with a train rapidly approaching!)

So, you could use a machine to detect what Orwell called "thoughtcrime"? That's frightening enough (assuming it's even possible), but this oblivious scientist tops himself by gushing enthusiastically about achieving such menacing power over nature. As C.S. Lewis wrote: "what we call Man's power over Nature turns out to be a power exercised by some men over other men with Nature as its instrument." And then scientists wonder why people don't trust them about embryonic stem-cell research and vaccines!

Dr Rees said: "This is the first basic step to reading somebody's mind. If our approach could be expanded upon, it might be possible to predict what someone was thinking or seeing from their brain activity alone."

It could be that Rees's statement is taken out of context, but at face value it equates "thinking" and "seeing." There is a big difference between the two. Seeing is a primarily sensory, as is recalling a sensory image (or phantasm), so it would make sense that the brain would be deeply involved, and so there should be detectable indications of what is being seen. In contrast, thinking involves universals, which cannot be corporeal; thus it would seem that thinking is largely a "private" happening, i.e., one that cannot be "read" empirically. Seeing primarily involves the brain, but thinking primarily involves the incorporeal mind. Thus these researchers are engaged not in mind reading, but rather in "brain reading."

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As might be expected, the "peer-written summary (by Geoffrey Boynton) of the two results is more measured in its appraisal of the implications of the research:

These two studies have interesting implications about the role of V1 [the visual cortex] in consciousness. Being just two synapses away from the eye, V1 is usually considered an early visual area. Early visual areas tend to represent properties of the physical stimulus, whereas visual areas later in the processing stream seem to hold our conscious percept, or our brain's interpretation of the stimulus. The finding by Haynes and Rees is consistent with this idea, and supports the theory that we are not consciously aware of all of the processing going on in V1.

Even the New York Times's article is more measured than the Beeb's article. Perhaps the BBC is not content to leave Tony Blair alone to "sex up" the news.

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C.S. Lewis, The Abolition of Man, ch 3.

John-Dylan Haynes and Geraint Rees, "Predicting the orientation of invisible stimuli from activity in human primary visual cortex," Nature Neuroscience 8, 686–691 (2005).

Yukiyasu Kamitani and Frank Tong, "Decoding the visual and subjective contents of the human brain," Nature Neuroscience 8, 679–685 (2005).

Geoffrey M. Boynton, "Imaging orientation selectivity: decoding conscious perception in V1," Nature Neuroscience 8, 541-542 (2005).

Anthony Rizzi, The Science Before Science (Baton Rouge, LA: IAP Press, 2004).