The Science and Technology section of this week’s Economist brought a rather fascinating article to my attention. The study, on the relation between brain activity and human cognition, seems to show that the brain activity linked to problem-solving occurs before the person is actually aware of having had the insight. So if humans are able to solve problems before being consciously aware of the solution… what is the point of conscious thought?

In the study, the researchers asked volunteers to solve a set of simple puzzles, which lacked methodical solutions, in the hope of synthesizing some of those ‘eureka!’ moments characteristic of the insight process. The volunteers had to respond as soon as they reached the solution, and their brainwaves were monitored with an on-going electroencephalogram (EEG).

An analyses of the EEG showed that up to 8 seconds before the response, brain activity was different when the volunteers got the insight, i.e. reached the correct solution either with or without a hint, compared when they didn’t. I don’t think there are many takers on what these differences in brain activity (reduction in posterior beta oscillation power and increase in anterior gamma power) functionally mean, but the finding remains: unconscious background processing delivers the answer to consciousness only once it has been arrived at.

Although this may come as a shock to many, there have in fact been similar reports published over the last three decades. The seminal work of Libet in the 1980s demonstrated that the brain activity for the self-initiated movement of a finger begins 300ms before one is even aware of wanting to move the finger. Moreover, at our own Univeristy of Oxford, Hakwan Lau et al. recently showed that a human’s conscious perception of when a movement is initiated is actually open to TMS manipulation up to 200msec after the action took place.

You have to wonder what kind of implications this build-up of evidence has for topics such as free will, ethics and responsibility. If my brain has already made a decision before I am consciously aware of it, would this imply that I do not have a conscious free will? People who commit crimes whilst under the influence of mental illness, for example, receive lighter treatment on grounds of diminished responsibility, because it is argued that they weren’t really in control of their actions at the time. But if my consciousness tunes into a decision (to commit a crime, or otherwise!) only after the decision has already been made, can I be said to be in control of my actions?

Representation of consciousness from the 17th Century

For millenia, philosophers and scientists have debated the question of what conscious experience is and what its function might be, from Descartes’ dualism to modern scientists who try to find its possible evolutionary function. There is not space for a full discussion here, but opinions range from those who think that conscious awareness has no purpose “so just enjoy the ride“, to those who propose that it is necessary for the human species’ unique ability to pursue complex goals. However, this latter theory is certainly in contention, not least from the EEG article I’ve described here but also by the fact that Deep Blue, a computer that is arguably not conscious, can beat world Grandmasters at chess, the ultimate game of abstract goal pursuit.

Setting aside for the moment the problem of what consciousness is (i.e. how something subjective can come out of something physical), I am currently very perplexed by the second question: what is consciousness for? If not for controlling our actions or helping us achieve cognitive insights, why on earth do we have it? None of the current explanations around are particularly satisfying. Answers on a postcard, please.