A spark of free will may exist in even the tiny brain of the humble
fruit fly, 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."
Helping people
Better understanding aspects of free will in humans could also help
treat 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 (ADHD), 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, 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 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 how emails, letters and money travel and "in the paintings
of Pollock," Brembs said.
These strategies in flies appear to arise spontaneously and not result
from outside cues, findings detailed in the May 16 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."
"Even a fly brain possesses a function which makes it easier to imagine
a brain that creates the impression of free will," Brembs said. "If
even flies show the capacity for spontaneity, can we really assume it
is missing in humans?"
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 an 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 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."
�