19th Ping: Sheeply Sleepy — Script

And I’m Peter. A kind of virtual host, I suppose.

Incidentally, Jesse, how much do you know about sleep?

Indeed.

Most people simply perform the act of sleeping without conscious thought,
and seldom have occasion, I suspect, to reflect deeply upon sleep itself.

Those troubled by sleep itself, or with a keen interest in it, may of course be exceptions.

So, on this occasion, I propose we seek to understand sleep,
drawing upon information with as sound an evidential basis as possible.

First, let us establish what sort of phenomenon sleep is.

A sound question.

First, let there be no misunderstanding: sleep is not a state in which the brain or body ceases to function.

Responsiveness to external stimuli does diminish, of course; nonetheless, brain activity and physiological processes continue, in forms distinct from those of wakefulness.

Sleep is also thought to bring about adjustments to memory and neural circuits, alongside various changes in hormone secretion and immune responses.

Indeed.

It is commonly regarded as rest, and subjectively, that is precisely what it is. The body's functions, however, are not resting at all.

It may be more accurate to regard it simply as a mode distinct from wakefulness.

Incidentally, have you encountered the terms 'REM sleep' and 'non-REM sleep'?

In terms of externally observable physical characteristics… correct.

Sleep comprises two phases, non-REM sleep and REM sleep; these are understood to recur several times over the course of a night.

There is a slight complication: non-REM sleep consists of three stages.

First comes stage one, the sleep-onset or transitional stage; then stage two, a stable state of sleep; and then stage three.

Then comes REM sleep. As Jesse noted earlier, it is a state in which the eyes move at tremendous speed.

During REM sleep, brainwaves exhibit patterns resembling those of wakefulness. Many muscles, however, are profoundly relaxed; the state is therefore distinct from being awake.

Not so, in fact.

Such an account tends to suggest an orderly progression through the stages. Yet neither the non-REM stage from which REM sleep begins nor the non-REM stage to which one returns after REM sleep is fixed.

What is certain is merely that non-REM sleep and REM sleep alternate.

No single answer will serve everyone; there are, nonetheless, approximate guidelines.

For example, the CDC sets them out as follows.

From birth to around three months, 14 to 17 hours; from then until around 12 months, 12 to 16 hours; at around one to two years of age, 11 to 14 hours; and at around three to five years, 10 to 13 hours.

Those totals, incidentally, include naps.

For those a little older, the figures are nine to 12 hours at around six to 12 years of age; eight to 10 hours at around 13 to 17; and seven hours or more at around 18 to 60.

These are, however, guidelines only: neither universal optima nor prescribed upper and lower limits on sleep duration.

To put it very crudely: get plenty of sleep in childhood, and roughly seven to nine hours in adulthood.

Drowsiness increases, quite simply.

…But enough levity.

First, bear in mind that even with an ongoing sleep deficit, one may not accurately recognise the decline in one's own functioning. Nor will everyone find themselves in the same state or circumstances.

With that understood, delayed reactions and lapses of attention are, I would say, likely to arise.

Driving or operating machinery in a state of pronounced drowsiness is exceedingly dangerous.

Emotions and glucose metabolism are also thought to be affected.

A meta-analysis pooled 154 studies, with a combined total of 5,717 participants, in which sleep was experimentally curtailed or fragmented. It reportedly indicated, among other findings, an overall reduction in positive affect and an increase in anxiety symptoms.

This is not to say that insufficient sleep makes one aggressive; rather, it may alter the regulation and experience of emotion.

A randomised crossover trial involving 38 women reportedly found a deterioration in measures of insulin resistance.

That is, of course, a finding confined to a limited scope and particular conditions; it does not mean that short sleep duration causes diabetes.

Various other studies exist; nonetheless, within the bounds of my knowledge, I have found no data indicating that insufficient sleep has beneficial effects.

The first consideration is securing time for sleep. Thereafter, one should strive for regularity.

As for one's surroundings, it is important to be active in bright conditions during the day and avoid exposure to strong light before retiring.

Those partial to caffeinated drinks such as coffee might consider moving consumption from the afternoon or later to an earlier time, or reducing the quantity consumed.

There are also such suggestions as avoiding vigorous exercise just before bed; warming oneself with a bath or shower before sleep; keeping the bedroom quiet, dark and at a comfortable temperature; and limiting alcohol consumption. Quite a number, it would seem.

We have examined sleep in some depth, albeit in very broad terms. What did you make of it?

Indeed. A subject of considerable depth, I would say.

The single word 'sleep' encompasses numerous interwoven factors; one can hardly explain them all in such a short time.

On this occasion, we have selected our topics and simplified them considerably. For a deeper understanding, you might consider enrolling at—or taking up employment with—a university or research institute specialising in sleep research.