Sleep loss and emotional fatigue

Posted by Ricki Sharpe on October 25, 2007
Filed Under Work Behaviour

Getting a good night’s sleep is important for everyone, particularly for those who do shift work and where safety, health and security are paramount. While past studies have revealed that sleep loss can impair our immune system and cognitive processes such as learning and memory, there has been surprisingly little research into why sleep deprivation affects our emotions.

“When we’re sleep deprived, it’s really as if the brain is reverting to more primitive behaviour, regressing in terms of the control humans normally have over their emotions,” said researcher Matthew Walker, a neuroscientist at the University of California, Berkeley.

Walker and his colleagues had 26 healthy volunteers either get normal sleep or avoid sleep, making them stay awake for nearly 35 hours. On the following day, the researchers scanned brain activity in the volunteers using functional magnetic resonance imaging (fMRI) while they viewed 100 images. These started off as emotionally neutral, such as photos of spoons or baskets, but they became increasingly negative in tone over time â€” for instance, pictures of attacking sharks or snakes.

“While we predicted that the emotional centres of the brain would overreact after sleep deprivation, we didn’t predict they’d overreact as much as they did,” Walker said. “They became more than sixty percent more reactive to negative emotional stimuli. That’s a whopping increase â€” the emotional parts of the brain just seem to run amok.”

“Human beings are one of the few species that deprive themselves of sleep, almost on a daily basis. It’s a real oddity in nature,” Walker said. “Alarm bells should be ringing about that behaviour.”

If you have to go without sleep, try to avoid any unpleasant events that are likely to trigger a negative emotional response. We have known for long time that we should sleep on it when important decisions have to be made, now it seems we should also avoid arguments, frustration, stress and pictures of snakes as well.

Reference

Yoo, S., Gujar, N., Hu, P., Jolesz, F. A. & Walker, M. P. (2007). The human emotional brain without sleep â€” a prefrontal amygdala disconnect. Current Biology, 17, R877-R878.

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