Sleepless nights can have a detrimental effect on us in many different ways but did you know that even one sleepless night could affect your focus? A study conducted by Willamette University in Oregon, USA suggests that a sleepless night may affect your ability to filter out information and focus on what’s important.
Sleep deprivation can impair what’s known as ‘selective attention’, which is the ability to focus on specific information when other things are occurring at the same time. A classic example of selective attention would be the ability to focus on a conversation you’re having with someone, even though you can hear other conversations going on around you.
In the study, participants were divided into two groups. One group were allowed to sleep as normal, whilst the other group were sleep deprived and kept awake for 24 hours. Both groups were then asked to listen to two different stories at the same time – each played through headphones into a different ear, and asked to selectively pay attention to just one of the stories. By measuring their brain activity researchers were able to tell that those who had received a full night’s sleep were able to focus on the requested story, with one brain signal that was clearly enhanced. This showed that they were paying attention to one story. Another separate brain signal was suppressed, showing that they were ignoring the other story.
But in the group that were sleep deprived, there was less of a difference between the two signals, meaning that these people had more difficulty focusing on just one story.
Sleep deprivation causes elevated cortisol levels that, over time, can lead to impaired cognitive function. Studies have shown that elevated cortisol has an adverse effect on the brain’s hippocampus – the area of the brain associated in acquiring information and consolidating that information into long-term memory. This in turn explains why sleep deprived people frequently exhibit poor memory and a distinct lack of focus.
Quite apart from the problems with memory, a lack of focus can lead to mistakes being made and can even cause serious accidents. A lack of focus combined with drowsiness slows our reaction times and it’s thought that sleep deprivation is a cause in around 100,000 car crashes a year in the US alone.
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