Dreaming of Tetris

“Human beings spend on average one third of our lives asleep.”

That is one statistic that most of us have come across at some point or another. But most of us have never given a whole lot of thought to why we need to sleep. What really happens inside our brains while we’re sleeping that causes us to dream?
 

Let me be frank. Scientists don’t really have a clue. The science behind dreaming is about as complex as the brain itself. Having said that, neurobiologists and psychologists do have some theories on dreaming. Here are some of the more popular ones:

• Helps restore our body and mind
• Helps with learning and memory
• Allows us some time to explore new and unusual areas of ourselves
• Helps to resolve conflicts that occur during the day
• Allows us contextualize emotions experienced during waking
• Helps practice dealing with threats.

So while it may seem like your friend who falls asleep during a class lecture is completely unconscious and inactive, some of their brain functions may be more active than when they’re awake. 

 

The interactive sleep lab set up by Harvard helps understand some of these aspects of sleep using examples of healthy sleep patterns in people of various ages. For example, different stages of sleep may be pertinent to different types of learning. Studies by Robert Stickgold of Harvard Medical School show that subjects who had slept for six hours or more after learning a new task, such as spotting a visual target on a screen as quickly as possible, improved, whereas those who didn’t sleep on it didn’t improve. Moreover, it was found that those who improved the most slept for eight hours, with ample time for both slow-wave and rapid eye movement (REM) periods of sleep.

Another very interesting study, also carried out by Stickgold, had subjects play the computer game Tetris, which requires directing falling blocks into the correct positions as they reach the bottom of the screen. At night, the subjects who were amnesiacs didn’t remember playing the game. But, they did describe seeing falling, rotating blocks during hypnagogic sleep, the transitional state between wakefulness and sleep.

What these studies demonstrate, is that when the brain puts dreams together, it does it without knowledge of and access to memories of actual events in our life. Yet dreams often serve the purpose of making important emotional connections among new pieces of information. So it is no wonder that our dreams can be wildly illogical even if they are related to something we already experienced!