Why Do We Sleep?
Scientists have not reached a consensus on why humans need sleep. We spend approximately one-third of our lives with our consciousness turned off. Moreover, 'sleep' is not a phenomenon exclusive to humans. Every living being with a nervous system, including invertebrates, sleeps. However, from an evolutionary perspective, sleep is a highly disadvantageous state. In the wild, animals are extremely vulnerable while asleep, in an unconscious state. So why do organisms sleep, risking their lives?
There are many theories about why we sleep. Although there is no consensus on this issue, some details about sleep have begun to be clarified. Research has shown that sleep is crucial for the brain to organize itself.
The renewal theory suggests that the brain replaces and renews everything it burns during the day. Research has revealed that many genes in the brain become active during sleep, and these genes are related to renewal and metabolism. Although this theory dates back to Aristotle, current research findings support its validity.
Energy conservation theory posits that we sleep to save energy. However, research to prove this theory shows that the difference in energy consumption between a sleeping individual and an individual staying awake during sleep hours is only 110 calories. This calorie difference is insufficient to explain sleep as an energy-saving mechanism.
Brain processing and memory enhancement: If sleep needs are not adequately met, it becomes more difficult to complete the learning process after starting to learn something, and this process does not complete healthily. It is at this point that the conclusion that sleep strengthens memory and learning becomes clear. Sleep is not only functional for enhancing memory recall but more importantly for finding specific solutions to complex problems. Our ability to do this develops with a single night's sleep. So, sleeping at night emerges as an event that enhances our creativity. Significant neural connections in our brain, as well as synaptic connections, are connected to and strengthened. The less important ones disappear.
Of course, the answer to why we sleep is not limited to these three explanations. In summary, sleep is a biological necessity. Sleep cleans up all the problems and question marks we experience while awake. While asleep, we secrete many hormones and perform many processes in our body. Building processes develop faster than destruction processes, and they even develop while muscles are at rest, not working. Information learned throughout the day is stored in long-term memory, waste in the brain is cleared, intercellular connections are strengthened, or unnecessary connections are weakened. Thus, abilities such as learning, memory, problem-solving, creativity, decision-making, focus, and concentration develop. Those who do not sleep enough show serious impairment in these functions. People who sleep less than four hours a day become unable to perform even the simplest tasks and unknowingly enter a state called microsleep. Those who sleep less than six hours show symptoms similar to those who do not sleep for several days after a few weeks. If this is repeated for a long time, the brain gets used to it and normalizes working at a lower cognitive level. The longer you sleep inadequately, the longer it takes to achieve real cognitive performance. There is even evidence that it harms brain functions in the long run. Having a sufficient and comfortable sleep routine is a prerequisite for a healthy life.
