The study published in the journal Neuroscience provides
scientific evidence for what casino managers have long known --
that flashing lights and ringing slot machines encourage gamblers
to keep going until their money is gone.
Scientists used magnetic resonance imagining (MRI) to examine
the brains of people who had spent a night of disturbed and
shortened sleep compared to their better-rested counterparts.
The scans showed increased activity in the parts of the brain
that assess positive outcomes, and decreased activity in the areas
that process negative outcomes.
"Using a risky decision-making task, we showed that sleep
deprivation shifted most persons' bias from avoiding loss to
pursuing gain," said the study by Duke University researchers in
North Carolina and Singapore.
The study examined 29 healthy adult volunteers with an average
age of 22, and asked them to perform a series of economic
decision-making tasks after a normal night of sleep and again after
a night of sleep-deprivation.
Sleep deprivation "appears to create an optimism bias; for
example, participants behave as if positive consequences are more
likely (or more valuable) and as if negative consequences are less
likely (or less harmful)," it said.
Drinking caffeine, getting fresh air or exercising are not
enough to combat the effects of fatigue, said lead author Vinod
Venkatraman, a graduate student in Psychology and Neuroscience at
Duke.
"Late-night gamblers are fighting more than just the unfavorable
odds of gambling machines; they are fighting a sleep-deprived
brain's tendency to implicitly seek gains while discounting the
impact of potential losses," said Venkatraman.
