TED Talks Russell Foster: Why Do We Sleep?

“Sleep is for wimps” – Margaret Thatcher
“Money never sleeps” – Gordon Gekko from Wall Street

In our modern society, we are desperately sleep-deprived. People do not think much about sleep yet 36% of our life will be spent on sleeping.

In his persuasive talk, Russell Foster makes the argument from a neuroscience perspective that sleep is an incredibly important part of our biology. According to Russell, contrary to popular belief, your brain does not shut down while we are asleep. There is no consensus among scientists about why we sleep but Russell outlines three philosophical explanations about why we need sleep.

Firstly, there is good evidence for a restoration hypothesis, in that we need to restore, replace and rebuild our body during the night for what we have consumed in the day.

Secondly, an idea of energy conservation was proposed but he is less convinced about this given that we only save about 110 calories a night, which is equivalent of a hot dog bun.

Finally, Russell proposes a third idea, in that sleep is associated with our brain processing and memory consolidation. He explains that sleep deprivation impairs an individual’s memory, ability to learn a task, increase impulsivity whereas an individual who has a night of sleep has better memory, is more creativity and superior at problem solving. It seems that whilst we are sleeping, our brain is working hard in linking and strengthening our neural connection and synaptic connections, and at the same time, less important connections tend to fade away.

Sleep is not merely an indulgence but critical for our optimal functioning. However, we are more sleep deprived now sleeping around six-and-a-half hours a night compared with the generation before that were getting around eight hours a night. In fact, there are sectors of society including shift workers, teenagers and the elderly that generally receive even less – around five hours a night.

The impact of sleep deprivation is incredible. For instance, tiredness and involuntary micro-sleeps can have a dangerous impact on driving. Further, a tired brain craves stimulants such as caffeine and nicotine to wake it up. To switch off, some resort to alcohol but the sedation of alcohol does not provide sleep but rather, it sabotages some of the neural processing and affects memory. Not a good choice.

Also, sleep loss can have a profound and debilitating effect on a person’s physical healthy. There is an association found between loss of sleep and weight gain. It seems the release of ghrelin, the hunger hormone is increased in the context of sleep loss and this ultimately leads one to crave carbohydrates, especially sugar.

Stress is also linked to sleep deprivation and we know that sustained stress leads to a weakened immune system thereby increase a person’s risk of infection. It increases the risk of diabetes 2 and cardiovascular disease.

To achieve restful sleep, Russell recommends engaging in good sleep hygiene habits:
  1. Make your bedroom a haven for sleep: make your room dark and cool.
  2. Turn off mobile phones, turn off computers, turn off things that will excite the brain.
  3. No caffeine after lunch
  4. Increase light exposure in the morning to set your circadian system (biological clock) to the light-dark cycle
    Psychologically, we have known for a century that sleep disruption and mental health are connected. Russell extends this to propose that it is the brain, and more specifically the neural networks that physically links these two mechanisms. Evidence shows that individuals with mutated genes for sleep predisposes them to mental health problems. There are studies to demonstrate that sleep abnormality can precede mental health conditions, and also exacerbate mental health problems.

    This research has extraordinary implications for the treatment of mental health. Russell suggest that we can use sleep disruption as an early warning signal to detect people who are vulnerable to mental health and we can also target sleep as an intervention to attenuate mental health symptoms.

    In sum, Russell provides a informative and concise talk in 21-minutes on the significance of sufficient sleep on our physical and mental health, not just as an indulgence but as a necessity for quality of life. Well worth the watch.