Why We Sleep - Chapters 9-12 Summary

In chapters 9 - 11, Dr. Walker delves into the science of dreams. MRI scans taken while individuals dream during REM sleep show that certain areas of the brain, including those associated with spatial perception and emotion, are more active while individuals dream compared to during deep NREM sleep. Researchers have even been able to generally determine certain patterns of brain activity identified by an MRI in response to specific objects. For example, a researcher may be able to identify from your brain activity while dreaming that you dreamt about a car, but not the specific type of car. The content of dreams and dream interpretations have long been of interest to the general public and scientists. It turns out that the function of dreaming, rather than the specific content of dream, is the most important factor of dreams.

 Dreams are integral to the ability of humans to process emotion and problem solve. Without proper time spent dreaming in REM sleep, our ability to process emotion and interpret the emotions conveyed in the facial expressions of other people decrease. There are numerous anecdotal examples in history that have hinted at the importance of dreams for creativity. Thomas Edison was known to take afternoon naps and quickly record any thoughts that crossed his mind upon waking. While dreaming during REM sleep, the brain works to connect stored memories to the experiences from the past day. These connections are what allow complex problems to be solved during sleep and learning to occur. Due to improvements in technology, we now have a greater appreciation for the importance of dreaming.

The health effects of not only dreaming, but sleep in general, are so extensive that sleep disorders are an especially devastating class of illness. One of the more well-known sleep disorders is somnambulism or sleep walking. Individuals who sleep walk perform a variety of different activities while their brain is in deep NREM sleep. For most people, episodes are harmless and treatable. Insomnia is another common sleep disorder that affects as many as one in nine people. There are multiple triggers of insomnia with many patients turning to sleeping pills for treatment. However, cognitive behavioral therapy and improving sleep hygiene practices are much safer and recommended as treatment over sleeping pills. Finally, Dr. Walker covers one of the more devastating sleep disorders, narcolepsy. Narcolepsy patients suffer from a range of crippling symptoms including extensive daytime sleepiness and cataplexy. Cataplectic attacks are triggered by strong emotions, forcing those who suffer from cataplexy to try and avoid emotional extremes. There are currently very limited treatment options for narcoleptic patients, but researchers are working to develop more effective drugs.

Andi DeRogatis is a graduate student at UC Davis in the animal biology graduate group. She is currently studying how the avian immune system is influenced by the process of molt. She loves all things birds and is passionate about getting others excited about birds as well! You can follow her on Twitter @AndiDerogatis.

Lindsey Mooney is a graduate student in the UC Davis Psychology Department. You can follow her on Twitter @Linz_Mooney.

For more content from the UC Davis science communication group "Science Says", follow us on Twitter @SciSays.