Can Too Little Sleep Leave You Laughing?

March 30, 2011— -- It's easy to spot someone who has missed an entire night of sleep. Grumpy. Irritable. Focusing on the negative. Now, add a new word to that list. Euphoric.

That's right, according to scientists at the University of California, Berkeley, and the Harvard Medical School. They've come up with startling evidence that the human brain, deprived of sleep, swings both ways, focusing on positive as well as negative experiences.

And, they add, that's not necessarily a good thing. According to their study, published in the current issue of the Journal of Neuroscience, sleep deprivation sensitizes the networks in the brain that have long been associated with rewards. And that, they suggest, could contribute to rash decisions and risky behavior.

"Our previous research showed that when you are sleep deprived your brain is excessively reactive to negative or unpleasant emotional experiences," psychologist Matthew Walker of UC Berkeley said in a telephone interview. "But what we didn't know at the end of that study is what happens on the other side of the coin. What happens when you are sleep deprived and you see rewarding stimuli or experiences?

"Does your brain just slide down toward the negative domain in the emotional spectrum, or does the pendulum swing to both extremes?"

The research adds to "a long-standing finding in clinical psychiatry, which is very perplexing," Walker said.

Some patients who are suffering from severe depression will get better if they are deprived of sleep, although the benefit is short lived. As soon as they get enough sleep it goes away, so it's a curious fact but not all that helpful in a clinical setting.

Walker, who has been studying sleep deprivation for many years, wondered if healthy adults would also look on the bright side of life if they missed an entire night of sleep. That may sound absurd, but he noted that people who have partied, or worked, through the night are sometimes giddy and prone to giggling. Is it real, or are they just punch drunk?