The importance of sleep
The sleeping brain is highly active. It is processing information gained during the day that we don’t have time to make sense of at the time.
Our working memory can only deal with plus/minus seven items at a time and there is a constant demand with new data coming in.
It is during sleep that we store, make connections and make sense of what we experienced during the day.
I’m reminded of a library (the old fashioned kind, with paper books on the shelves). During the day books are taken off the shelves and are left lying on the tables. Then the librarian comes along and packs the books in the right place, depending on the code, so that they can be found again.
Stuff happens while we sleep
The areas of highest activity during sleep are the amygdala, hippocampus, anterior cingulate and the prefrontal cortex. These areas are involved with memory and emotion. It appears the hippocampus is more active during sleep than during wakefulness.
What is not active is the dorsal prefrontal cortex which is shut down during REM. This is the area of the brain that is highly rational and focuses on the detail. With this logical assessment ‘braking system’ shut down the brain is allowed to run amok and make distant connections that make little sense in a rational way. It appears this is when the lunatic is allowed free reign to live out those fantasies that would not be allowed, due to rational reasoning during wakefulness. It is a time to work through fears, old memories, perceptions and the stories we have told ourselves. Turn them on their heads, see what fits or doesn’t and generally play in an uncontrolled way with what we have experienced or remembered. Some people recall the detail of our dreams, nightmares and night-time dramas better than others. If we remember them we try and make sense of them. Often we wake having remembered something important that needs to be done, or have a brilliant idea to solve a problem that has been brewing for some time. Stuff happens while we sleep.
The link between stress and sleep
There is a strong link between stress, sleep and the positive effect of optimal brain performance. The impact of stress on the hippocampus (memory centre) is that it functions better with moderate stress but performance drops dramatically under high stress. Your ability to form accurate memories diminishes under high stress.
Stress enhances retention of anything attached to negative emotions and disrupts memory for neutral and positive emotion-linked information. High levels of stress can result in memory loss for everything except the negative. With sleep deprivation, only negative information is remembered, not the neutral or positive. It is easy to see how someone who is stressed and not sleeping well can become more negative and descend further into a negative spiral.
What impact does taking sleeping tablets have on the activity of the brain during sleep? Quite a lot. Your normal memory and sense making is reduced to almost zero. Only take sleeping tablets when absolutely necessary.
Turning out the lights
You would need to go on a camping trip in a remote and uninhabited place to experience the natural rhythms of light and dark (or experience a blackout).
We have been designed to start slowing down and settling in for sleep as it becomes dark and the light calls us from our sleep into wakefulness. As with all other individual unique attributes, some of us react more to light than others.
In our modern urban homes, there is such an abundance of light even when the lights are off. We have standby lights on our appliances, an electronic clock by our bedside to watch the hours tick by when we are restless and our streets are lit all night.
When designing the place you sleep, consider that we are designed to respond to light by waking up. You might be one of those people who needs complete dark to sleep well.