A healthy mind in a healthy body

With the discovery of electricity, industrial and technological development, control over energy, food production, telecommunications, etc; and with social paradigms turning towards “having” and “success”, international society has changed and developed new habits and new tendencies towards work. Society is now continuous, first 24h per day, and then 7 days per week. Enjoyment changed and extended through the night. In this setting, Sleep became and embarrassment for work, productivity and economic interests.

Therefore, since last century, people have been sleeping less and less, and this deficit extends to all age categories.

Previously, no one questioned how much a baby should sleep, now I am asked if 8 hours are enough?! During my teenage years, we would have dinner early and TV broadcasts ended at midnight with the national anthem, now dinner is had later and later, and TV broadcasts never end. We would go out on a date with a “chaperon” and our parent’s permission, and now sweethearts are together by starting at each other through their cellphones. We would thank God for our “daily bread” and nothing went to waste, nowadays there’s food in abundance inside shopping malls and supermarkets.

We convinced ourselves that we have no limits.

The number of poor is increasing, and millions are beneath the poverty threshold; divorce and single parent families increase; and so do Sleep related illnesses.

The warnings about the risks of this behavior are many, but in global society they do not speak loud enough, choked by the systematic challenges and incentives in the opposite direction

However, the risks and consequences are serious. In all ages and in all continents, not enough sleep or too much sleep increases the risk of obesity, hypertension, type II diabetes, accidents, cancer, depression, insomnia, and early death. Superimposed on all these risks are those that affect the brain, reducing the memory, learning, creativity, problem solving and affecting emotions and emotional stability.

Why?

Because during sleep, our brain, released from the focus given to the outside, shifts said focus towards itself and towards our body; and both these dialogues are essential to our health.

During Sleep, the millennia old paradigm “a sound mind in a sound body” reaches its maximum intensity.

Our brain takes care of itself, increasing the intensity of sleep in more stimulated areas while awake (areas related to learning, for example), reconnecting important circuits and bonding quick interconnections between zones that speak with one another, disconnecting circuits in order to rest, deleting irrelevant information and strengthening that which matters.

Since one does not learn what one does not like, a sleeping brain stabilizes emotions; since to learn one must experiment, our brain creates, through dreams, virtual realities where, without risk, one can argue, run, fight, talk or cry; and since one must innovate, dreams are about the impossible, without forgetting the root of that which is real.

In teenagers and children, loss of sleep increases distractibility and irritability, in opposition to adequate sleep which consolidates memory.

On the other hand, sleep deprivation affects memory of neutral and positive stimuli. This effect leads to remembering negative stimuli, and enhances behavioral tendencies towards impulsiveness to negative stimuli, and relating to a lesser degree of expression towards emotional stimuli.

Sleep deprivation also has behavioral consequences such as higher chance of trauma, unintentional accidents in children, adolescents and adults.

The connection between Sleep and Intellect has been indirectly appraised through connections between Sleep Characteristics, having been found certain correlations between sleep zones and IQ.

It is known that a sleep episode following a learning period will enhance said learning. This is said to be true for verbal tasks, motor tasks, special orientation tasks and more specialized performances, such as playing music.

On the other hand, the daytime apprenticeship of a motor task is related and linearly correlated with the increase of Delta activity and Time Zones, in the following sleeping period, in the contralateral motor region.

The effects of sleep in memory consolidation have been described in early 19^th and 20^th century, but there is presently a significant quotient of papers on the matter, that restates the function and effect of sleep in memory consolidation, procedure consolidation and also in declarative memory. On the other hand, not only does sleep enhance but also protects declarative memory.

It is known since the 1960’s that declarative memory is affected by sleep or by sleep deprivation. A 36h sleep deprivation significantly diminishes the temporal sequence retention, even if aided by heavy doses of caffeine, and also affects the correct perception of said performance.

The idea that sleeps enhances creativity is sprung by tales concerning several scientists and artists who have disclosed having created their masterpieces right after waking up, or after a dream or a hypnagogic stage.

A more detailed disclosure is due to Kekulé, concerning a dream that leads him to the discovery of the Benzene Ring. Others can be also mentioned: Singer’s discovery of the sewing machine gearings, Dali’s paintings, Mr. Jeckyll’s Book by Stevenson, Paul McCartney’s Imagine, Kurosawa’s “Dreams” film, amongst many others.

The effect of sleep is not only to code and consolidate memories or learning, but rather to integrate in into new associative schemes, that through generalization or integration, could show new perspectives or directions, giving reason to the popular saying: “Night brings good counsel”.

Several experiments were conducted towards proving this integration capacity “again”, in adults as well as in pre-lingual children.

Having been taken into account, nocturnal sleep allows, for all age groups, the consolidation of memories, and enhances concepts of information generalization, and the identification of hidden solutions.

Knowledge concerning the effects of sleep on emotions comes from the increase in irritability and bad temper after a sleep deprivation night, characteristics that worsen if said deprivation is repeated. Nonetheless, it is also known that acute deprivation can also have an antidepressant effect, used years prior in the treatment of serious depressions.

On the other hand, it is known that both stress and positive or negative emotions happening during the day both affect sleep.

An increase in positive events contributes to a better subjective sleep, and a good night’s sleep enhances the recognition of images with emotional components. Negative events worsen sleep to many, good or bad, sleepers.

In this perspective, sleep deprivation functions both as a time bomb for irritability outbreaks in normal life and may explain depressive humor in many psychiatric disturbances.

At last, multiple sleep related diseases, or medical diseases, both neurologic and psychiatric that impact sleep in a primordial way, systematically affect memory, attention and executive functions.

Thus, the habit of sleeping less in intellectual workers significantly affects reasoning capabilities (memory, learning, creativity), executive functions and emotional abilities, which are essential to the execution of the intellectual tasks at hand.

Therefore, if body and brain are our tools, to put them in jeopardy equals killing “the hen with the golden eggs” in every professional.

In conclusion: to think right, it’s important to sleep right!

What about our body?

Risks to our body related to sleep deprivation have already been said. Why?

During sleep periods, anabolic hormones are systematically and regularly produced, meaning the growth hormone, prolactin and testosterone, and catabolizing hormones are regulated, particularly cortisol and the thyroidal hormone.

It all happens in a way that you either grow or repair tissues in different organs while you sleep, and reproductive functions are regulated. It all happens so that, in the morning while waking up, cortisol is at an adequate level, in order for the day to start well. But if you do not get enough sleep, anabolic hormones diminish and catabolizing hormones increase, and health risks start to appear.

On the other hand, sleep is essential in energy regulation and in homeostasis, for temperature control, which goes down while we sleep, and for energy control through nourishment, in a balance that diminishes our hunger or increases our hunger. For all this, having not enough sleep leads to fatigue, and increases height gain risk in all age groups.

Sleep as also a narrow and complex relation with immunities, and not sleeping increases the chance for infectious diseases and eventually auto-immune diseases.

While asleep, cell division is controlled, therefore little sleep or out of hours or irregular sleep increase the chance of cancer in both genders.

No limits - The technological age’s grandest illusion.

Not sleeping is in fact risking a roman aphorism: “A healthy mind in a healthy body”.

Professor Teresa Paiva
Lisbon, June 7th 2013