How a Flawed Experiment "Proved" That Free Will Doesn't Exist - Scientific American Blog Network
Steve Taylor December 6, 2019
In the second half of the 19th century, scientific discoveries—in
particular, Darwin’s theory of evolution—meant that Christian beliefs were no
longer feasible as a way of explaining the world. The authority of the Bible as
an explanatory text was fatally damaged. The new findings of science could be
utilized to provide an alternative conceptual system to make sense of the
world—a system that insisted that nothing existed apart from basic particles of
matter, and that all phenomena could be explained in terms of the organization
and the interaction of these particles.
One of the most fervent of late 19th century materialists, T.H.
Huxley, described human beings as “conscious automata” with no free will. As he
explained in 1874, “Volitions do not enter into the chain of causation…. The
feeling that we call volition is not the cause of a voluntary act, but the
symbol of that state of the brain which is the immediate cause."
This was a very early formulation of an idea that has become
commonplace amongst modern scientists and philosophers who hold similar materialist
views: that free will is an illusion. According to Daniel Wegner, for instance,
“The experience of willing an act arises from interpreting one’s thought as the
cause of the act.” In other words, our sense of making choices or decisions is
just an awareness of what the brain has already decided for us. When we
become aware of the brain’s actions, we think about them and falsely conclude
that our intentions have caused them. You could compare it to a king who
believes he is making all his own decisions, but is constantly being
manipulated by his advisors and officials, who whisper in his ear and plant
ideas in his head.
Many people believe that evidence for a lack of free will was
found when, in the 1980s, scientist Benjamin Libet conducted experiments that
seemed to show that the brain “registers” the decision to make movements
before a person consciously decides to move. In Libet’s experiments,
participants were asked to perform a simple task such as pressing a button or
flexing their wrist. Sitting in front of a timer, they were asked to note the
moment at which they were consciously aware of the decision to move, while EEG
electrodes attached to their head monitored their brain activity.
Libet showed consistently that there was unconscious brain
activity associated with the action—a change in EEG signals that Libet called
“readiness potential”—for an average of half a second before the participants
were aware of the decision to move. This experiment appears to offer evidence
of Wegner’s view that decisions are first made by the brain, and there is a
delay before we become conscious of them—at which point we attribute our own
conscious intention to the act.
However, if we look more closely, Libet’s experiment is full of
problematic issues. For example, it relies on the participants’ own recording
of when they feel the intention to move. One issue here is that there may
be a delay between the impulse to act and their recording of it—after all, this
means shifting their attention from their own intention to the clock. In
addition, it is debatable whether people are able to accurately record the
moment of their decision to move. Our subjective awareness of decisions is
very unreliable. If you try the experiment yourself—and you can do it right
now, just by holding out your own arm, and deciding at some point to flex your
wrist—you’ll become aware that it’s difficult to pinpoint the moment at which
you make the decision.
An even more serious issue with the experiment is that it
is by no means clear that the electrical activity of the “readiness potential”
is related to the decision to move, and to the actual movement. Some
researchers have suggested that the readiness potential could just relate to
the act of paying attention to the wrist or a button, rather the decision to
move. Others have suggested that it only reflects the expectation of some kind
of movement, rather being related to a specific moment. In a modified version
of Libet’s experiment (in which participants were asked to press one of two
buttons in response to images on a computer screen), participants showed
“readiness potential” even before the images came up on the screen, suggesting
that it was not related to deciding which button to press.
Still others have suggested that the area of the brain where the
"readiness potential" occurs—the supplementary motor area, or SMA—is
usually associated with imagining movements rather than
actually performing them. The experience of willing is usually associated with
other areas of the brain (the parietal areas). And finally, in another
modified version of Libet’s experiment, participants showed readiness potential
even when they made a decision not to move, which again casts
doubt on the assumption that the readiness potential is actually
registering the brain’s “decision” to move.
A further, more subtle, issue has been suggested by psychiatrist
and philosopher Iain McGilchrist. Libet's experiment seems to assume that the
act of volition consists of clear-cut decisions, made by a conscious, rational
mind. But McGilchrist points out that decisions are often made in a more fuzzy,
ambiguous way. They can be made on a partly intuitive, impulsive level, without
clear conscious awareness. But this doesn't necessarily mean that you haven't
made the decision.
As McGilchrist puts it, Libet’s apparent findings are only
problematic "if one imagines that, for me to decide something, I have to
have willed it with the conscious part of my mind. Perhaps my unconscious is
every bit as much 'me.'" Why shouldn't your will be associated with
deeper, less conscious areas of your mind (which are still you)? You might
sense this if, while trying Libet’s experiment, you find your wrist just
seeming to move of its own accord. You feel that you have somehow made the
decision, even if not wholly consciously.
Because of issues such as these—and others that I don’t have
space to mention—it seems strange that such a flawed experiment has become so
influential, and has been (mis)used so frequently as evidence against the idea
of free will. You might ask: why are so many intellectuals so intent on
proving that they have no free will? (As the philosopher Alfred North
Whitehead pointed out ironically, “Scientists animated by the purpose of proving
themselves purposeless constitute an interesting subject for study.”)
This is probably because the nonexistence of free will seems a
logical extension of some of the primary assumptions of the materialist
paradigm—such as the idea that our sense of self is an illusion, and that
consciousness and mental activity are reducible to neurological activity.
However, as I suggest in my book Spiritual Science, it is
entirely possible that these assumptions are false. The mind may be more than
just a shadow of the brain, and free will may not be an illusion but an
invaluable human attribute, which can be cultivated and whose development makes
our lives more meaningful and purposeful.
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