Kerri Smith knows that the concept of free will is no stranger to the hurdles of debates regarding scientific facts and philosophical conjectures. Covered in this past September issue of Nature, Kerri’s careful research surrounding the issue of free will prompts the curious philosopher in all of us. Apparently, a recent study by Dr. Haynes from the Bernstein Center for Computational Neuroscience in Berlin has prompted neuroscientists to re-evaluate the notion that actions are predetermined. Using functional magnetic resonance imaging (fMRI), the study investigated participant button responses to a display screen of random letters. The results were startling — the fMRI data seemed to suggest that brain activity heightened prior to button-pressing. The brain, it seems, had already decided which button to press long before executing the decision. These scientists posit that free will, the ability to act at one’s own discretion, is nothing more than an illusion, a rather heavy claim from a philosopher’s point of view. As put by Patrick Haggard, a neuroscientist at University College, London, “we feel we choose, but we don’t.” This idea goes as far as suggesting that the decision to have coffee in the morning may have been made long before entering conscious awareness.
In the past, other neuroscientists have conducted studies which resulted in a similar outcome. Benjamin Libet, a neuropsychologist at the University of California, San Francisco, performed a study in which participants were asked to watch a clock-face with a dot sweeping around it while their brain activity was monitored by an electroencephalogram (EEG). The participants were then instructed to note the position of the dot upon feeling the urge to point at it. Libet’s EEG findings indicated that brain activity occurred several hundred milliseconds prior to the study participant’s movement.
Critics of Libet’s study point out that the observed brain activity may not have been causal and instead may be indicative of the brain preparing to make a decision before executing the decision — in this case, moving one’s finger.
If the results of these studies prove that humans lack free will, the outcome would be troubling for everyone, including philosophers. Humans have a sense of security in presuming that they can control their thoughts and actions consciously. Some philosophers with a scientific background do not regard these types of studies as sufficient evidence of free will as an “illusion.” According to them, the decision to have a coffee in the morning is arguably more complex than the decision to press a button or move one’s finger.
Using a more precise method, neuroscientist and surgeon, Itzhak Fried, at the University of California, Los Angeles and the Tel Aviv Medical Center in Israel, studied individuals with electrodes implanted in their brains, detecting activity from single neurons. Fried’s experiments demonstrated activity at the level of individual neurons about a second and a half prior to the study subject’s conscious decision to press a button. With about 700 milliseconds to go, the researchers could predict the timing of these conscious decisions with greater than 80 per cent accuracy. Fried suggests that consciousness of decisions may occur after the fact. “At some point, things that are predetermined are admitted into consciousness.”
The concept of free will ultimately diminish if neuroscientists discover that unconscious neural activity drives decision-making. But from the perspective of many current philosophers, free will has a physical basis with decisions and actions stemming from physical phenomena in the brain. This means that the recent neuroscientific data may not preclude free will. Many philosophers today are more concerned with the relationship between freedom and determinism than free will in its entirety. Currently, neuroscientific results cannot yet completely close the case in favour of determinism. Adina Roskies, a neuroscientist and philosopher working on free will at Darmouth College in New Hampshire, states that results from neuroscience may yield insight into the predictability of actions, but not the issue of determinism.
It appears that the major contention with the neuroscientific perspective on determinism is the extent to which experimental models accurately reflect complex human decision-making. Pressing a button is arguably distinct from more abstract decisions such as making coffee, making career choices, or deciphering right from wrong. The presence of heightened brain activity is not necessarily an indication that a decision has been made. If, as the neuroscientists heading these studies suggest, these data indicate that the world is deterministic, what initiates such bursts of brain activity? Are they spontaneous or are they predetermined? Divorcing the discussion from philosophical conjecture may not be the answer.
Here’s the link to the original Nature feature: http://www.nature.com/news/2011/110831/full/477023a.html
