Lack of sleep can change your personality

Just one sleepless night can make you emotionally detached, irrational, and willing to take unnecessary risks…

lack-of-sleep-can-change-your-personality

In 1959, Peter Tripp (pictured) a popular DJ on a New York radio station, pledged to stay awake for 201 hours – that’s eight days and nine hours – for charity, while continuing to host his radio show. It was a publicity stunt that attracted millions of listeners.

After days sat in a glass booth in Times Square, Tripp began to hallucinate. During the last 66 hours the observing scientists and doctors had administered drugs to help him stay awake. Tripp suffered psychologically and some observers, including close friends and colleagues commented that he was never the same again. Afterwards, he started to think he was an imposter of himself and retained that idea for some time. Part of his self-inflicted ordeal can be seen at https://www.youtube.com/watch?v=4MT8ekBGyM4

Studies into sleep deprivation were rare at the time so no one really had much of an idea of what to expect. Unknown to Tripp, his stunt was a major event, not only for his millions of listeners, but also for the scientific community. The subsequent impact of the Wakeathon on Tripp’s mind was far more dramatic than anyone had imagined – Tripp’s personality, normally described as cheerful and upbeat, appeared to change significantly as time went by.

Parallels were inevitably drawn with Phineas Gage, a railway worker who, in 1848, accidentally set off an explosive charge and ended up with a steel rod stuck in his head that remained there until his death. Gage, who has always been a happy and social individual turned into a cynical, curmudgeonly and withdrawn man, although his condition improved after a few years.

But by the third day Tripp had become highly irritable, cursing and insulting even his closest friends. Towards the end of his endeavour, he began to hallucinate and exhibit paranoid behaviours. But despite the concerns of the doctors monitoring him (and with the help of the stimulants they gave him) he persisted before finally going to bed.

Modern laboratory studies have replicated some of the behaviours seen in Tripp as a consequence of sleep loss. Sleep deprivation, or prolonged periods of severely restricted sleep results in worsening mood, increasing irritability, and feelings of depression, anger, and anxiety. Some experts argue that sleep deprivation leads to heightened emotional reactivity.

Just like Tripp, who lashed out at his friends at the smallest inconvenience, sleep deprived participants in similar studies have experienced greater levels of stress and anger when asked to complete simple cognitive tests than control participants who had normal amounts of sleep.

Modern brain imaging techniques reveal why sleep deprivation can lead to irrational emotional responses. The amygdala, a baked bean-size area deep within the brain, is the centre for emotional control. When sleep deprived participants were shown emotionally negative images, activity levels in the amygdala were as much as 60% higher than levels in those who were fully rested.

Researchers have found that sleep deprivation disrupted the connection between the amygdala and the medial prefrontal cortex, an area believed to be a centre of critical and rational thinking. The medial prefrontal cortex itself regulates amygdala function.  Sleep deprivation appears to cause the amygdala to overreact to negative stimuli because it becomes disconnected from brain areas, such as the medial prefrontal cortex, that normally moderate its response.

Casinos have long known that tired gamblers are far more likely to make risky decisions. Bright lights, noise, a lack of natural light and clocks are some of the casino’s methods of sensory deprivation specifically designed to stop gamblers noticing the passage of time.

In 2011, researchers at Duke University, a private research establishment in Durham, North Carolina, recruited volunteers to take part in a gambling experiment which was designed to improve chances of winning by taking, or not taking, risks. They could do this by improving the probability of winning or increasing the size of the highest possible win, in which case the risk would also increase, or decreasing the size of the worst loss, in which case the risk would be reduced.

When participants had been deprived of sleep for just one night, they started do make fewer decisions that avoided loss, and more decisions that maximized potential gain.  In other words, sleep deprivation made their gambles more optimistic and thus, more risky.

This change in risk taking behaviour was accompanied by changes in activity in brain areas that evaluate negative and positive outcomes.

Another area of the brain that suffers dramatically from sleep deprivation is the hippocampus. This is a region critical for storing new memories. When people are deprived of sleep for even one night, their ability to memorise new information drops significantly. This is due to an impairment in the hippocampus caused by sleep deprivation.

When memorising a set of pictures, sleep deprived participants showed less activation in the hippocampus compared to rested participants. It is possible that this deficit in the hippocampus could be caused by sleep deprivation reducing its ability to write in new information. Alternatively, the hippocampus may need sleep to move new information to be stored in other areas of the brain. It might be that lack of sleep causes the storage capacity of hippocampus to fill up, preventing new information from being stored.

Paul Tripp’s story has an unhappy ending. Shortly after his Wakeathon his marriage broke down, and he eventually lost his job and his career in radio. Worse was to come – in 1964, Tripp’s record was broken – a high school student from San Diego called Randy Gardner, managed to stay awake for 264 hours, beating Tripp by two days and 6 hours.

However, Gardner and others who tried to beat the record did not report any of the long-term effects encountered by Tripp.

Nonetheless, there are lessons to be learned from Tripp’s experience and from the latest discoveries in sleep science. For instance, many people are sacrificing sleep and rest time to work, especially on devices that emit blue light. This light makes falling asleep more difficult, further reducing the quality and quantity of sleep.

We need to rediscover the value of sleep and appreciate the benefits it brings to our brains. Time spent sleeping is an essential investment towards being smarter, making better decisions, and leading a happier life.

Lack of sleep is also known to cause unease, dissatisfaction with life and lack of motivation. Around 30% of people do not get enough sleep and people who sleep for less than five hours will start to take risks without realising they are doing it.

A study of 14 men aged 18 to 28 were subjected to just five hours of sleep a night before playing a game in which they gambled for cash. In the game, the riskier the decision, the higher the possible reward – and the greater the possibility of loss. As the week went on, 11 of the 14 men began to take more risks than previously, while six people who previously were risk-averse changed their behaviour to become risk-seeking.

The researchers took brain scans during the tests and found slow sleep waves were reduced in the right prefrontal cortex. Not being able to recover properly due to a chronic lack of sleep has been shown in previous studies and is linked to higher risk-seeking behaviour. This suggests that the rise in risky behaviour is due to changes in the brain and that these changes are caused by a lack of sleep.

At the end of the trial, the participants were asked if they thought they were behaving more recklessly than usual, or taking more chances, and they said they were not.

The researchers at the University of Zurich say that the same applies to everyone – including politicians, pilots, business leaders, musicians, truck drivers – everyone! Politicians, who take decisions that impact people’s lives, business leaders who think missing out on sleep makes them more productive – take note!

The study, published in the journal Annals of Neurology, ends with a warning. ‘While we cannot exclude that individuals in positions that require high-impact decision-making may be more resilient to the effects of sleep restriction, our results suggest that all of us, but particularly leaders of companies and countries, are well advised to work and make decisions only when fully sleep-satiated.’ 

Copyright Andrew Newton 2016. All rights reserved.