bioclock

Having trouble sleeping is perfectly normal, especially as we age. It’s estimated that half of those older than 55 have trouble getting to sleep or staying asleep.

What to do if your sleep is poor

Let’s start with the easiest situation: you’re not getting enough sleep because you wilfully go to bed too late to achieve your needs.

This is unfortunately all too common. All I can do is point out how desperately important it is to get the sleep you need. By chronically depriving yourself of sleep, you not only are ensuring that your mental powers are under-par, but you have added significantly to the likelihood that you will develop cognitive problems in old age.

Life is a matter of priorities. To change this situation, you need to give sleep a higher priority than you’ve been doing.

Chances are, though, that your sleep deprivation is not wilful, but is caused by problems in getting to sleep, or staying asleep. If this is the case, you are probably aware of the standard advice, but let me bullet-point it first, before getting to less common solutions.

• Have a routine
• Have a regular schedule
• Get some exercise during the day
• Don’t do anything too stimulating before going too bed - this includes eating, drinking (caffeine or alcohol), smoking, working, playing games
• Make sure your room is quiet and dark (wear earplugs and/or a sleep mask, if you can’t do anything about the environment).

Alcohol and sleep

This needs a special mention, because many people see a ‘nightcap’ as an aid to sleep. It’s true that alcohol can shorten the time it takes to fall asleep. It also increases deep sleep in the first half of the night. However, sleep is more disrupted in the second half. While increased deep sleep is generally good, there are two down-sides here: first, it’s paired with sleep disruption in the second half of the night; second, those predisposed to problems such as sleep apnea may be more vulnerable to them. Additionally, at high doses of alcohol, REM sleep is significantly reduced, and in any dose, the first REM period is significantly delayed, producing less restful sleep.

All in all, then, while alcohol may give the illusion of improving sleep, it is not in fact doing so.

Stress & anxiety

Stress and anxiety are of course major factors in chronic sleep problems, and the reason would seem to be the thoughts that plague you.

A good strategy for dealing with this is to write all your worries down, preferably with a planned action. Your planned action doesn’t have to be a solution! It simply needs to be a first step. Write it down, give it a priority rating or action date.

If your worry  is completely fruitless, with no viable action that you can (or want to) take, it’s still worth writing it down, along with its possible consequences. You probably don’t want to think about those consequences, but this is part of why the worry is plaguing you so much. Write down the possible consequences, and their likelihood, and you will get rid of much of their power over you.

Unfortunately, it seems that worriers are not simply more likely to have sleep problems, but they are more affected by them.

A study in which 18 young adults viewed images that were either disturbing or neutral, which were cued by a red minus sign (something horrible coming up!), a yellow circle (don’t worry, nothing disturbing), or a white question mark (you’ll have to wait and see), found that activity in the brain’s emotional centers, the amygdala and insula, rose dramatically when the participant was sleep deprived, with this effect being most extreme when the participant was an anxious type of person.

Sleep deprivation, it appears, has an effect on emotion that is similar to what is seen in anxiety disorders, and those who are naturally anxious are more vulnerable to these effects.

This means that sleep therapy is even more important for the naturally anxious.

How to relax

If you’re prone to stress or anxiety, you’re probably familiar with relaxation techniques. They’re a great idea, but if you haven’t found them as effective as you’d like, the problem may like in the ‘mental churn’ you can’t get rid of. Try the writing strategy first, then follow it up with a relaxation strategy.

If you’ve been unsuccessfully trying a standard relaxation exercise, you may also find a more mentally challenging relaxation strategy works better for you. T’ai chi, for example, is a form of physical meditation that demands your attention, and thus leaves less room for you to fret about your worries. It’s well worth learning for that alone (although it also has physical and mental benefits).

Another less common strategy for dealing with sleep problems is rocking. It does require some expense and effort, given that you need a bed that rocks gently, but it may be worth considering if you’re desperate.

The evidence for this is a little sketchy, unfortunately, but it seems a nice idea, and it certainly seems plausible. A small study involving 12 youngish healthy men found that when they took a 45-minute afternoon nap on a bed that rocked slowly, they went to sleep faster, moved into deep sleep faster, and showed more slow brainwaves and sleep spindles, compared to a similar nap on the same bed, held still. It is a very small sample, and a restricted one, which doesn’t include anyone with sleep problems. But it’s worth noting because apparently every one of the participants showed these effects.

Quiet time

One of the big problems for insomniacs is that typically the more you worry about not being able to get to sleep, the harder it is to fall asleep. Here’s a suggestion: redefine your goal. Why do we need sleep? Because without it we feel lousy the next day; we’re weaker, and we’re less able to think or remember. This is your real goal: giving your mind and body the opportunity to refresh itself.

You need to process the day’s material, to discard what you don’t need, to file what you do need, to wipe the sheet clean so you can start again. Try focusing on that instead.

Lie quietly in your bed. Make sure that it’s quiet and dark. If you find it helpful, you can have gentle music, but not anything that is loud or in any way exciting. Traffic noise, bright light, and temperature extremes, are all common causes of what is termed “environmental sleep disorder”. Moreover, one study found that morning performance on a psychomotor vigilance task was significantly worse if the person had been exposed to traffic noise during the night. Light interferes with circadian rhythms, which are also important for learning and memory.

So, lie there quietly in the dark, and guide your mind through the events of the day. When you come to events of particular interest, focus on them, picking out the details that are important to you. Give the event/information a descriptive label. Pay little attention to events that aren’t worth remembering (you could try mentally dumping them in a trashcan or dumpster). When you’ve run through everything, go back to your labeled sets. (My Memory Journal provides a place and structure for you to do all this.)

IMPORTANT! This is NOT about dwelling on things you need to do! Those should all be in your written list. They’re done.

This is about processing the day’s events and wiping the slate clean for tomorrow.

Let me say again: Bedtime is not, ever, for thoughts of the future.

Nor is it for dwelling on the past, in the sense of emotional wallowing or fretting. What you are doing is housekeeping. You are discarding, filing, and wiping the desk clean.

When you’ve done that, now is your time for your relaxation exercise. Fill your mind with your meditational image; progressively relax your muscles. Whether or not you fall asleep, your aim is to provide the quiet place your mind needs in order to get on with the processing at an unconscious level. You’ve done your bit, giving it the best possible start. Now let it do its job.

Providing a quiet place for your mind to process new information is also an excellent strategy during the day, and this is particularly true for those whose sleep is less than optimal. If you’re learning a new skill or wanting to remember new information, giving yourself 10-15 minutes of quiet reflection (optimally in a darkened environment) helps consolidate it.

If you’re prone to stress-related sleep disturbance, you may also find this strategy useful after any emotionally stressful event.

Sleep and health

It’s a truism that sleep gets worse with age, but a recent study suggests that age may not be the main culprit. The main problem is health - which of course also tends to get worse with age. Medications can cause daytime sleepiness; pain and discomfort can interfere with nighttime sleep.

Weight, too, can be a factor in sleep problems. A study of overweight and obese people found that weight loss improved their overall sleep score by about 20%. Interestingly, the loss of belly fat was particularly useful.

Sleep and diet

Sleep length has also been linked to diet. Data from the very large 2007-2008 National Health and Nutrition Examination Survey (NHANES) found that those who slept 5 to 6 hours a night had the largest calorie intake, followed by those who slept the ‘standard’ 7-8 hours, then those getting less than 5 hours, with those sleeping most (9 hours or more), eating least.

While there were many differences in the make-up of those diets, analysis revealed just a few nutrients that were critically linked to sleep differences. Very short sleep was associated with less intake of tap water, lycopene (found in red- and orange-colored foods, especially tomatoes), and total carbohydrates. Short sleep was associated with less vitamin C, tap water, selenium (found in nuts, meat and shellfish), and more lutein/zeaxanthin (found in green, leafy vegetables). Long sleep was linked to less intake of theobromine (found in chocolate and tea), dodecanoic acid (a saturated fat) choline (found in eggs and fatty meats), total carbohydrates, and more alcohol.

Whether you can change your sleep patterns by changing your diet is as yet unknown, but it is an intriguing speculation.

I’ve always been interested in the body’s clocks — and one of the most interesting things is that it is clocks, in the plural. It appears the main clock is located in a part of the brain structure called the hypothalamus (a very important structure in the brain, although not one of much importance to learning and memory). The part of the hypothalamus that regulates time is called the suprachiasmatic nuclei. These cells contain genes that switch on, off, and on again over a 24-hour period, and send electrical pulses and hormones through the body. This is the body’s master clock.

But it is not the only clock in the body. Each organ in the body uses the time signal from the master clock to set its own clock. As a consequence, different systems in the body operate on different schedules. Thus blood pressure peaks at one particular time of the day, and levels of the stress hormone cortisol rise and fall in accordance with the clock that governs this.

The effect of this is that certain physical disorders are more likely to occur at particular times, and, more significantly, that certain medications may be far more effective at certain times.

What does all this have to do with learning and memory?

Well, not a whole lot of research has been done on the effects of time of day on cognitive performance, but what has been done is reasonably consistent. It seems clear that, for many people (but not all), there are significant time of day effects. The most reliable is that, in general, teenagers and young adults perform best (mentally) in the afternoon, while older adults (seniors) perform best in the morning.

Having said that, let’s qualify it a little.

Let’s start with a table. Now, this represents the findings of one study [4], so let’s not get carried away with the illusion of precision cast by actual numbers. Nevertheless, it is interesting. These percentages represent the preferences reported by the young and old participants in the study. These preferences correlated with improved performance on a memory test.

	Young	Old
Definite morning	0%	34%
Moderate morning	8%	49%
No preference	57%	10%
Moderate evening	29%	6%
Definite evening	6%	1%

Now the first thing to note is how marked the differences are between young and old. Of particular interest is how many of the younger adults had no preference. Compare this with that of older adults. The second finding of particular note is how pronounced the preference for the morning is in older adults — 83% preferred morning. And, most interesting of all, is a finding from another study by the same researchers [5]: when tested at their preferred time, older adults performed comparably to younger adults on a memory task. Younger adults, by contrast, seem able to perform well at all times.

There is also some evidence [3] that the deleterious effect of interference (the intrusion of irrelevant words, objects, events) is worse for older adults at those times of day when their performance is poorer. Older adults are more vulnerable to interference than younger adults.

The findings for teenagers and young adults may also apply to children. One study [2] found that below-grade-level students who received reading instruction in the afternoon improved their performance more than those students who received instruction in the morning.

But it must always be remembered that this general principle that morning is better for the aged, and afternoon better for the young, does not apply to each and every individual. As the table tells us, time of day affects some people more than others, and time preference is an individual matter, not entirely predicted by age. This is underscored by a study [1] that found improved performance when students were taught at times that matched their preferences. There was also some evidence that, for some students at least, achievement was greater when they were taught during their teacher's ideal time of day.

None of this is an argument that you should resign yourself to learning only at your preferred time of day! But you could use the information to modify your strategies. For example, by scheduling difficult work for your optimal time (assuming you have an optimal time, and are not one of those fortunate people who have no strong preference). You can also try and counteract the effect by, for example, drinking coffee during your nonoptimal time of day (this was found to be effective in one study with older adults [6]).