by Anneli Rufus
Pulling all-nighters can make you euphoric — but it won't last, and your euphoria might trigger joy-killingly risky behavior, according to a study just published by UC Berkeley researchers.
According to a report from UC Berkeley's Newscenter, UCB and Harvard researchers discovered that a night spent awake rather than asleep created heightened activity in the mesolimbic pathway, a brain circuit driven by dopamines, those neurotransmitters associated with happiness, decision-making, and motivation. The findings were published this week in the Journal of Neurosciencehttp://www.jneurosci.org/.
The researchers were motivated by curiosity over why so many patients with clinical depression feel more positive after sleepless nights. So they used functional MRIs to study the brains of 27 healthy young adults, half of whom had slept well the previous night and the other half of whom had stayed awake all night.
"Participants viewed numerous images, including pleasant scenes (for example, bunnies or ice cream sundaes), and were asked to rate the pictures as either neutral or positive. Across the board, those who had skipped a night’s sleep gave more positive ratings for all the images while the well-rested participants gave more moderate scores," reads the UCB Newscenter report.
The trouble is that the type of positivity prompted by all-nighters is based on short-term dopamine spikes and can thus spur overly optimistic choices that might have disastrous results. A new tattoo, a dip in the bay, or a motorcycle ride with a stranger can seem like great ideas in the blaze of that morning-after buzz.
“When functioning correctly, the brain finds the sweet spot on the mood spectrum. But the sleep-deprived brain will swing to both extremes, neither of which is optimal for making wise decisions,” said Matthew Walker, associate professor of psychology and neuroscience at UC Berkeley and lead author of the study.
“After a good night’s sleep, the frontal lobe regions are strongly connected to the dopamine reward regions, but that’s not the case after a night of no sleep,” said Walker, who is also the principal investigator at UC Berkeley's Sleep and Neuroimaging Laboratory. Located in UC Berkeley's psychology department, the sleep lab focuses on cognitive aspects of the sleeping brain using a multimodal imaging approach, including functional MRI, neurophysiological, and psychophysical techniques.
“The elastic band of sleep deprivation can only be stretched so far before it breaks," Walker warned.