We live in a very sleep deprived society, sleeping on average 1-2 hours less than we did in 1950s. A recent study by the research firm Rand Europe, highlighted how sleep deprivation is costing the UK £40billion due to the impact on work productivity. Sleep is crucial for our mind and bodies. Rather than being a passive process, sleeping is an active period of time when memory consolidation, body restoration, repair and hormone synthesis occurs. Sleep plays a significant role in brain function and development.
Sleep and the brain
Sleep plays a significant role in brain function and development. When we sleep, new brain cells are formed leading to the construction of new neural pathways, as well as the re-organization of existing networks. This ‘morphing’ ability of the brain, referred to as neuroplasticity, is far more prolific when we are relaxed, particularly when we sleep. Functional Magnetic Resonance Imaging (fMRI) scans have demonstrated how our brains are constantly changing, making these new connections – literally the brain you go to bed with tonight will be different to the one you wake up with.
Neuroplasticity makes our brain very resilient and enables all new learning, such as playing a musical instrument, or learning a language. It is pivotal in memory consolidation and enhances problem solving and creativity. In fact a good night’s sleep can increase our creativity threefold, which solves the mystery of why those ‘aha moments’ and creative ideas tend to appear after slumber.
Consequences of sleep loss
The prefrontal cortex of the adult brain which is responsible for ‘executive function’ (planning, problem solving and reasoning), can only recover in deep sleep. Therefore when we are sleep deprived, our ability to make rapid decisions, perform well in emergency situations or challenging negotiations is impaired. A recent survey among Junior doctors revealed one in four doctors felt sleep-deprived from their heavy work schedule. This increased the likelihood of patient safety being put at risk.
The consequences of sleep deprivation cannot be overestimated. Lack of sleep was thought to be a contributory factor in several international disasters including Chernobyl, Three Mile Island and the Challenger Shuttle explosion. Sleep loss also poses a public safety hazard on the roads every day. Drowsiness can impair reaction time to the same extent as if driving drunk.
It is not only the brain’s cognitive processes that are affected by sleep loss. The link between sleep and our mental and emotional health is well established. Numerous studies have shown individuals suffering from chronic insomnia have significantly higher rates of depression.
Other research looking at sleep disruption in people with schizophrenia, has demonstrated that mental illness and sleep disruption share overlapping brain pathways. Scientists have found that stabilizing sleep in individual’s suffering from schizophrenia, reduced the number of psychotic episodes by 50%. This highlights the importance of sleep in mental illness and how sleep pathways in the brain provide an invaluable therapeutic target.
There is still more to discover about what happens to the brain when we sleep, as this dynamic physiological state has a direct influence on our waking hours. The negative impact of sleep loss on cognitive and emotional wellbeing, reaffirms the importance of good quality sleep.