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Is free will an illusion?

Your subconscious mind knows what you're going to do before 'you' do. Dr Karl ponders what this means for the idea of 'free will'.

The concept of 'free will' is something that philosophers have been worrying about for thousands of years. free will is our ability to make a choice — for example, you might suddenly decide to walk to work rather than take the bus, because the Sun feels so nice on your face.

But what if neuroscientists could tell you what your spontaneous decision was before you made it? Would that mean that free will was an illusion? Are we making decisions, or is there a homunculus (a little man) sitting inside our brain making decisions for us, and then later, letting us know about them?

Now the idea of free will has all kinds of implications.

On one hand, we have thinkers like Martin Luther who rejected free will. On the other hand, thinkers like Thomas Ried and Robert Kane accepted free will.

In a legal setting, if there is no free will, are we to blame for our actions? And from an ethics point-of-view, how morally accountable are we for our actions?

In a religious setting, both Christianity and Islam believe in a Creator who is both all-powerful and all-knowing, and therefore knows what the future will be. But the dogma also states that the Creator allows us individually to decide to either follow the Path of Righteousness, or to reject it.

And finally, from a scientific point-of-view, what do we make of the latest research where neuroscientists can predict what you will do four seconds before you do it?

The original research goes back to the 1970s, when Benjamin Libet (from the Physiology Department at the University of California) got his volunteers to tap a finger whenever they happened to feel the urge — it was entirely up to their free will as to when this would happen. Amazingly, thanks to sensing electrodes on the head, he actually picked up a spike in electrical activity about half a second before the volunteers decided to tap a finger.

Now one problem with this research is that tapping a finger is just a gross motor activity, not a higher-level intellectual activity. Another problem is that trying to sense the activity of the brain by what you pick up with electrodes on the skin is pretty crude — like listening to a recording of a concert, and trying to work out what colour shoes the singer is wearing.

This latest research by Dr Soon and colleagues was in a paper called "Predicting Free Choices for Abstract Intentions". They monitored brain activity by testing the 17 volunteers inside a Magnetic Resonance Image scanner. The scanner looked at the metabolic activity of various parts of their brains. (This is called fMRI, or functional Magnetic Resonance Imaging).

The task the volunteers had to do was predominantly intellectual. They were shown images at the rate of one per second. Each image had a number in the centre of the image. Using their free will, the volunteers had two decisions to make. The first decision was to decide when to start doing arithmetic with these numbers. The second decision was whether to add the numbers on one image and, one second later, the next image — or whether they would subtract them. And all the time, their brains were being scanned.

Amazingly, by looking at the fMRI scans, the neuroscientists could predict when the volunteers would make a decision, and whether they would do an addition or a subtraction. And even more amazing, they could make this prediction up to three or four seconds before the volunteers were aware of the decisions.

Interestingly, different parts of the brain were involved. The regions of the brain that predicted when the volunteers would make the decision were quite different from the regions that predicted whether the arithmetic would be addition or subtraction.

This research is a step in trying to understand the ancient problem of whether 'free will' exists, and if it does, how to define what it is. It will be a long time (if ever) before we solve this problem. After all, if our human brain was simple enough for us to understand it, then we not would be smart enough to figure it out...

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