The
concept of free will has been a topic of debate, even in relation to
humans. Some scientists believe that the purpose of human consciousness
is merely to rationalise every decision made by chemical processes in
the brain a few milliseconds after the fact. Others believe that once
enough is known about the human brain, it will be possible to explain
and even predict a person’s behaviour.
"Given this strong claim
for humans, it is surprising if prediction should be principally
impossible in flies," said Björn Brembs, a biologist from the Free
University Berlin and senior author of the fruit fly study. "[But] our
work shows that for flies such a prediction will not be possible to the
extent claimed."
Together with an international team of
researchers, Brembs tethered fruit flies in completely uniform white
surroundings and recorded their turning behaviour. In this setup, the
flies do not receive any visual cues from the environment, and since
they are fixed in space, their turning attempts have no effect.
Without
any external stimuli from their surroundings, the scientists expected
the flies’ behaviour to resemble random noise, similar to a radio tuned
between stations. However, researchers observed the flies behaving
non-randomly.
The researchers then tested a plethora of
increasingly complex random computer models, all of which failed to
adequately model fly behaviour, leading to the conclusion that
variability in fruit fly behaviour is not due to simple random events,
but is generated spontaneously and non-randomly by the brain.
As a biologist,
Brembs is interested in the biological aspects that might enable or
prevent the existence of free will. While he believes that absolute
freedom is impossible, Brembs questions the extent to which humans and
animals are free, and expects this to be where the species differ.
"There is tentative
evidence that such a function may be very widespread in the animal
kingdom, including humans. If this were indeed the case, we might
have discovered the first evidence for something truly fundamental," he said.
The
next step will be to use genetics to localize and understand the brain
circuits responsible for the spontaneous behaviour. This step could
lead directly to the development of robots with the capacity for
spontaneous non-random behaviour and may help combating disorders
leading to compromised spontaneous behavioural variability in humans
such as depression, schizophrenia or obsessive compulsive disorder.
Monday, 21 May 2007
Do fruit flies have free will?
Björn
Brembs came up with the idea to study spontaneous behaviour almost 10
years ago in 1998, as part of his work on operant conditioning.
However, as he lacked the tools required to conduct experiments, the
study was put on hold until late 2004, when discussions with colleague
Mark Frye sparked his interest in fruit flies.
"Scientifically,
the most important aspect is that we found evidence for a brain
function which appears evolutionarily designed to always spontaneously
vary ongoing behaviour," Brembs explained.
Labels:
Animals,
Liz,
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