Dreaming has always been a mystery to people. From the ancient Greeks to Sigmund Freud, everyone’s got a theory on the origin and function of dreams. But when it comes to the cold, hard facts, the science of dreams is a relatively new area of study.

However, a new research has found a so-called “hot zone” near the back of the brain that is always active during dreaming. Now, neuroscientists are able to identify when we are dreaming, which areas of the brain are involved, and describe how the signals in the brain can even predict what a person is dreaming about.

Colored sagittal MRI scans of the human brain. Changes in brain activity offer clues to what the dream is about. Photograph: Simon Frazer/SPL/Getty Images

Brain Region Associated With Dream-Like States

Neuroscientists from the University of Wisconsin-Madison studied the dream state of 46 people by hooking them up to EEG brain activity monitors while they slept. After waking up, they were asked whether they remember dreams. Whenever volunteers were able to describe their dreaming experience, researchers went back and reviewed the patterns recorded with an EEG. This method leads them to pinpoint what they called a “cortical hot zone”.

This hot zone is identified at the back of the brain where low-frequency activity slowed down and high-frequency activity picked up during the periods of dreaming. It turns out that we don’t just dream during the REM phase, as previously thought, but also during NREM phase.

Dr. Lampros Perogamvros said the posterior cortical ‘hot zone’ helps shape our perception of reality.

The next experiment involved sleeper’s report the content of their dreams. Researchers wanted to see the activity in areas of the brain that respond to specific stimulation, like seeing a face, or hearing speech. The results showed while sleeper’s dream included faces, there was an activity in a part of the brain used to recognize faces. In other words, neuroscientists are now able to recognize what you are dreaming about, at least in a rough sense.

They also tested whether observational EEG data could be used to predict whether a subject was dreaming. In 81 percent of the time, they successfully predicted the absence of dreaming, while its presence was successfully predicted 92 percent of the time.

Researchers said their findings could have broad implications for studying how drugs such as antidepressants or disorders such as sleep apnoea affect dreaming, learning, and memory.