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Study hints that fruit flies have free will
Posted on Thursday, May 17, 2007 (CDT) by Thoth
 A spark of free will may exist in even the tiny brain of the humble fruit fly, based on new findings that could shed light on the nature and evolution of free will in humans.
Future research delving further into free will could lead to more advanced robots, scientists added. The result, joked neurobiologist Björn Brembs from the Free University Berlin, could be "world robot domination."
"Seriously though," Brembs said that programming robots with aspects of free will "may lead to more realistic and probably even more efficient behavior, which could be decisive in truly autonomous robots needed for planetary exploration."
Better
understanding aspects of free will in humans also could aid in the
treatment of mental disorders where people face problems controlling
how they feel, think or act, such as depression, obsessive-compulsive
disorder, anorexia nervosa, schizophrenia or attention deficit
hyperactivity disorder, Brembs told LiveScience.
For centuries, the question
of whether or not humans possess free will — and thus control their own
actions — has been a source of hot debate.
"Free will is essentially
an oxymoron — we would not consider it 'will' if it were completely
random and we would not consider it 'free' if it were entirely
determined," Brembs said. In other words, nobody would ascribe
responsibility to one's actions if they were entirely the result of
random coincidence. On the other hand, if one's actions were completely
determined by outside factors such that no alternative existed, no one
would hold that person responsible for them.
"We speculate that if free
will exists, it is in this middle ground" between randomness and
determinism "that is currently not well understood or characterized,"
said mathematical biologist George Sugihara at the University of
California at San Diego.
Insects and other animals
are often seen just "as very complex robots," Brembs said, for which
behavior is determined solely by reactions to the outside world. When
scientists observe animals responding in different ways to the same
outside cues, such variations are typically attributed "to random
errors in a complex brain," he said.
Not just random
Brembs and his colleagues
reasoned that if fruit flies (Drosophila melanogaster) were simply
reactive robots entirely determined by their environment, in completely
featureless rooms they should move completely randomly. To investigate
this idea, the international team of researchers glued the insects to
small copper hooks in completely uniform white surroundings, a kind of
visual sensory deprivation tank. These flies could still beat their
wings and attempt to turn.
A plethora of increasingly
sophisticated computer analyses revealed that the way the flies turned
back and forth over time was far from random. Instead, there appeared
to be "a function in the fly brain which evolved to generate
spontaneous variations in the behavior," Sugihara said.
Specifically, their
behavior seemed to match up with a mathematical algorithm called Levy's
distribution, commonly found in nature. Flies use this procedure to
find meals, as do albatrosses, monkeys and deer. Scientists have found
similar patterns in the flow of e-mails, letters and money, and in the
paintings of Jackson Pollock, Brembs said.
These strategies in flies
appear to arise spontaneously and do not result from outside cues,
according to findings detailed in Wednesday's issue of the journal PLoS
ONE. This makes their behavior seem to lie somewhere between completely
random and purely determined, "and could form the biological foundation
for what we experience as free will," Sugihara added. "This function
appears to be common to many other animals."
Brembs said that "even a
fly brain possesses a function which makes it easier to imagine a brain
that creates the impression of free will."
"If even flies show the capacity for spontaneity, can we really assume it is missing in humans?" he asked.
Condition for free will
Neuroscientist Gonzalo de
Polavieja at the Independent University of Madrid said these findings
in flies point "to a complex decision-making processing underlying
behavior. This seems a necessary condition for free will."
Brembs did not think flies
had free will, per se. He also stressed their results did not suggest
free will existed in humans or elsewhere. "We only showed that brains
might possess a faculty which free will could potentially be based on,"
Brembs said.
The degree of spontaneity that animals evolve could be linked with the niches they occupy in nature, Brembs added.
"There is a hypothesis out
there which claims that only the flexible birds [with more spontaneous
behavior] remain in a seasonal habitat, while less flexible,
stereotyped or deterministic birds migrate," Brembs said. "Animals in
very tightly constrained niches, such as maybe gut parasites, have
among the most deterministic behavioral repertoire compared to other
animals, because any variation in behavior might be deadly.
"The epitomes of
indeterministic behavior are humans, who are very flexible. Flies are
somewhere in between the extremes with a large set of very inflexible
and rather predictable behaviors, with spontaneity only coming to the
fore if either you look very closely or provide the animals with a
situation where the spontaneity is easy to study — that is, when you
remove all the stimuli which could trigger a response."
UCLA neurobiologist Mark
Frye noted that future work should isolate and understand the brain
circuitry and genetic pathways responsible for this spontaneous
behavior in flies "and whether or not they are conserved in other
animals."
Copyright: MSNBC
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