Nightmares: Who has Them and Why?

How often do you have nightmares? What are your nightmares about? Have you ever wondered if your cat or dog and other animals have scary dreams too? A study from Nature, summarized in the Science Magazine has just established that even rats, the smallest of rodents, apparently have nightmares in the same way humans do.

The idea that rats have enough mental capacity to dream may seem ridiculous, but scientific experiments by Gabrielle Girardeau, Ingrid Inema, and György Buzsáki, scientists from the Neuroscience department at New York University, have proved that rats do indeed experience dreams.  The experiments these scientists used were quite ingenious. When the rats were awake, the scientists sent them through a maze. After reaching a certain point in the maze, they blasted compressed air from a keyboard into the rat’s face. This is the equivalent of a human being suddenly blasted with air from a leaf blower: a technically harmless, but pretty uncomfortable (and I must insist, rude) prank.

After this, the scientists let the rats sleep, and through deep brain stimulation (a practice where you put receivers directly into an organism’s brain to record its activity), they recorded the pattern of neural activity in the rats’ brains. They found that the activity corresponded to the rats’ mental map of the maze. Even more significantly, they saw a marked increase in the rat brains’ fear center, amygdala, whenever the rats remembered the scary air puff. This was the first time such an association was found in the rat brains, and it strongly suggested that the rats were mentally experiencing the maze as they slept. Still, as the article emphasizes, “Whether rats actually experience this phenomenon as fear in the context of a dream is impossible to know without asking them, however.”

One does not need to communicate with rats to observe the implications of this finding, however. This study was the first time scientists observed activity in the amygdala, the brain’s emotion-production center, during the process of dreaming. This leads to the predictable, but still exciting find that real emotions are activated and felt during dreams, adding more proof to the belief that while dreams are… well, dreams, the brain actually treats them like real memories. According to Nightmares and the Brain by Harvard Medical School, dreams are “recent autobiographical episodes that become woven with past memories to create a new memory that can be referenced later.” hey are basically a continuation of the thoughts people experience throughout the day. But since the sleeping brain is much more disorganized than the awake brain, they merge with other random thoughts and images. This slew of different thoughts and images creates a memory that is entirely new.

Nightmares are a specific subset of what we call dreams. They are essentially bad dreams, but there are some interesting patterns in whom they victimize and how often. Children are much more likely to experience them, according to Nightmares and the Brain, since they are more vulnerable than adults. Nightmares do often reflect anxiety and trauma especially when these emotions are strong. But there are surprising causes for bad dreams too; according to Psychology Today: even having a snack right before bed can trigger them (since you are increasing your body’s metabolism right before a time when you are supposed to be resting) and having an irregular sleep schedule (because you increasing your own stress).

There are some patterns in the content of dreams and nightmares, as observed by Valley Sleep Center, and they are expected, but serious. Normal dreams often concern falling, flying, failing a test, appearing without clothes in public, or losing money. Nightmares often concern themselves with the feeling of helplessness, the feeling of being caught in something you cannot control. Among the imagined events are natural disasters (tornadoes, hurricanes, and the like), being in danger and unable to move away, and being trapped or alone. All of these are very serious effects, and are often associated with PTSD. However, it is important not to unnecessarily pathologize nightmares either: it is perfectly normal for our brains to stress overtime over something or replay some notable incident, pleasant or not. Remember, even rats had bad dreams after a scary experience in the day, and this did not make them abnormal.

Apart from the fact that they are a random assortment of fleeting thoughts during the day, and may contain fears that we feel during daytime, dreams may not have any particular symbolism or meaning. They can  have serious effects, taking the classic halloween nightmare story to a much more frightening and dangerous level. Whether you approach them from a biological perspective, or a psychological one, they are very interesting mental processes that are even to this day, not fully understood. The brain is a complex and fascinating organ, and it’s sleeping activity is as intriguing as it’s conscious ones, if not more. Discoveries like rats’ nightmares will continue to advance our understanding of our own brains and how they create our dreams and thoughts.