PRESCRIPTION (2). DEEP SLEEP
The foundation of a healthy brain is regular sleep. For most adults the average requirement is 7:5 hours, with a thirty minute variance (7-8 hours). Some people require less than 7 hours, some more – around 8 hours. There are still many mysteries to glorious sleep including the need and purpose for dreaming. Somehow, the body and brain when asleep continues to digest and metabolise, the heart beats and the lungs exhales and inhales.
But in deep sleep, consciousness is switched off, we cannot see or hear or smell or taste or feel sensations of touch. We are unaware of internal body states or position. When we awake, all that is switched off, and in an instant conscious awareness is switched on again. We are not aware that we are dreaming; only when we wake up do we realise we were in a dream state.
And during the deep sleep phase, it seems that the waste products of daily activity is vacuumed away, that the thinking brain sorts out the inputs, and hormones especially those involved in hunger and satiety are rebalanced. We wake up refreshed, a cleansed cortical real estate creates space for novelty, new learning and memory formation. Perceived as a battery, the brain is recharged.
From the moment we wake up there is a build up of a brain chemical called adenosine, that after its volume crosses a certain threshold, a feeling of tiredness becomes apparent. Good sleep decreases the levels of adenosine. Caffeine inhibits the buildup of adenosine, so creating an energetic sensation. Most refreshing beverages – tea, coffee and sodas – induce an energy burst, but disallows the natural levels of adenosine to rise. Then, to counteract against caffeine wakefulness, downers are imbibed: alcohol, sedatives, sleeping tablets … A visciuos cycle, indeed.
Lesson): Make deep sleep a dear friend. Be very careful about caffeine use as a brain stimulant. Restrict use to certain hours, a number of hours before trying to go to sleep every night.