Researchers have found that the part of the brain involved in pleasure and motivation is also involved in producing sleep. These new findings may explain why we feel sleepy when bored.
It's certainly a head-scratcher. When something has our full attention, we don't feel as tired as we would be if we were bored. We can stay up until dawn playing Call of Duty or gabbing away with our friends, but we can't keep our eyes open longer than 30 minutes into that boring college seminar we had to take. It doesn't matter if we had a full eight hours of sleep during the night and we woke up refreshed. When boredom hits, so does sleepiness.
Scientists don't yet fully understand why this is, but they're making progress. For one thing, it seems that regular sleep and boredom-induced aren't different. It's also likely that the brain's nucleus accumbens is the culprit behind our bored sleepiness.
Sleepiness comes and goes in accordance with our biological clocks. Our nucleus accumbens, a part of the forebrain, has several receptors that respond to the neurotransmitter adenosine. Adenosine is what helps regulate our sleeping and waking patterns. However, according to a new study, cognitive and emotional factors can also make us sleepy.
The researchers say that adenosine is likely responsible for triggering sleepiness in our nucleus accumbens. They tested this theory by using chemo-genetic and optical techniques—drugs and light—to control the activities of the nucleus accumbens in mice. Doing so showed that the nucleus accumbens is particularly capable of inducing sleep that's indistinguishable from regular sleep. Regular sleep can be characterized by slow and high-voltage brain waves. Thus, we feel sleepy when bored even after we've had a full night's sleep.
Coffee is your friend.
However, this also means that we can keep ourselves alert even when bored by simply consuming caffeine, in the same way we keep sleepiness away when we haven't gotten enough sleep. The nucleus accumbens is densely packed with A2A receptors, a type of adenosine receptor. Caffeine can block A2A receptors, thus inducing alertness.
These findings can also help those who suffer from insomnia, since there are compounds that can bolster the activity of A2A receptors. And if you're susceptible to easily feeling sleepy when bored, it seems that all you need is a cup of joe.
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