The brain is as complicated as its mysterious dream function. And that doesn’t always show if it’s dreaming in a concrete way.
All that remains is just a signal now to tell if the person is dreaming and, therefore, in REM sleep.
Scientists at the University of California, Berkeley have detected a signal of brain activity, which distinguishes the dreaming phase from the waking state. The dream stage was once similar to that of a waking brain, which made it difficult to read using only electroencephalogram (EEG) data.
This study was published in the eLife Magazine.
What’s the noise?
EEG tests can show whether a person is awake, in deep sleep, or in REM sleep. However, detecting the dream stage in REM sleep is not enough and it takes a doctor’s observation to check for rapid eye movements and contraction of muscle tone.
We tend to have most of our dreams during the REM phase of sleep, while some can take place in NREM. However, EGG data can be confused due to noise in the brain, during REM and perceive the electrical activity as if the brain is awake.
It’s kind of the trick that the brain unwittingly uses to deceive us.
“There’s this substantive activity, which isn’t rhythmic, and we’ve neglected it for quite a long time,” said Jenna Lindner, lead author of the study. Sometimes it has been called noise, but it’s not noise.
It contains a lot of information, also about the underlying arousal level. This measure makes it possible to distinguish paradoxical sleep from waking state by looking only at the EEG.
Started with a comparison.
This study was done with the purpose of monitoring people under anesthesia during surgery, and to understand the differences in unconsciousness, between artificial sleep and natural sleep.
Anesthesia can have side effects. If we learn a bit about how they overlap, maybe the anesthesia distracts some sleep pathways, and we might be able to improve anesthesia in the long run.
Now it has been easier to monitor people during a coma and, make inferences about their states.
This could solve, for example, if someone was in a minimal state of consciousness, and not moving, and if he’s more alert than you think they are, stated Robert Knight, lead author of the study.