Consciousness Blog 30 March 2013



Benjamin Libet's experiments that seemingly showed motor decisions being taken by the brain well before the conscious mind was involved in the process have often been questioned, but his conclusions have been backed up by numerous subsequent studies.

Now a study has shown the same effect in relation to abstract cognitive tasks. Research by a team led by Dr John-Dylan Hayes from Berlin's Charite-Universitatsmedizin and reported in the Proceedings of the National Academy of Sciences employed functional magnetic imaging (fMRI) to track neural events involved in a conscious arithmetical decision process, and showed that the decisions were being made unconsciously up to four seconds before the subject had conscious knowledge of the decision.

Says Hayes: "From an everyday person's perspective you would think it's obvious that there are all these unconscious processes going on," he says. "But in science there is a lot of sceptical debate about this. The problem is that unconscious processes are so difficult to nail down."

17 participants in the study were shown sequences of single-digit numbers on a computer screen while inside the MRI scanner, and could choose freely what arithmetical processes (adding or subtraction) should apply to following numbers.

The fMRI data showed that a medial frontopolar region and an area straddling the precuneus and posterior cingulate were busy encoding the decision well before before the participant was aware of making any decision.

Co-researcher Chun Siong Soon said: "The predictions aren't perfect, but we can predict considerably better than you would expect by chance."

Says Hayes: "Our study shows that unconscious preparation in the brain definitely exists, but it doesn't mean we can predict each and every choice. For example, in some cases something might let a person change their mind."

Believers in free will have great difficulty with such conclusions, but really that's only because they persist in imagining that it is the conscious mind which is the repositary of free will. The conscious is no more than a shadow cast by the bigger, underlying brain, for social purposes, and it is perfectly possible to believe that the whole brain has free will. Determinists, the believers in the 'butterfly's wingbeat', will still deny free will, although their position has been undermined by Heisenberg and quantum theory. But for an average person, the argument is sterile anyway, unless you still believe in hellfire. The mind, mostly unconsciously, assembles the evidence from memory, sensory perception and emotional agendas and reaches a fact-based decision (a task whose complexity is utterly beyond the conscious mind) and implements it. The conscious mind may have an opportunity to rescind the decision, although usually there is no time for that. Decisions that can be taken at leisure do involve conscious agonizing over optimal results, and often end up by over-riding the sensible unconscious decision that had already been taken. Unfortunately for us humans, the unconscious has no means of communicating with the conscious, other than through vague, troubling qualia which the rational mind dismisses.

"I had a bad feeling about it; but everybody agreed it was the obvious thing to do."

Read more about conformity in Agent Human Chapter Eight by Michael Bell, The Con of Consciousness and the Illusion of Individuality.


 

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