We all have dreams when we sleep (when we are in the REM phase). In this dream world, we have our dream bodies which we can interact with in the dream environment. We can touch, hear, see, taste, and smell things around us in the dream world.
It's striking that we can recreate such vivid bodily experiences in a state when our physical body is completely unresponsive.
The question is: can we manipulate dream content? You may have heard of lucid dreaming where the dreamer is aware that he is in a dream, and therefore he can control what happens in his dream. But this experiment is different. This one relies on electric current.
Recently, a study aimed to investigate whether the sensorimotor cortex underlies the generation of movement and bodily experiences in dreaming. The authors used a method called transcranial direct current stimulation (tDCS) to inhibit activity of the sensorimotor cortex during REM sleep, and observe the effect on bodily sensation and movement in dreams.
Two blind judges also carried out a content analysis of the dream reports and scored whether the report contained any movement of the dream-self, and what type of movements occurred— either single action, repetitive action, or passive movement. For instance, “diving” was classed a single action; “riding a bike downhill” as a passive movement; “writing something” as a repetitive action. A total of 50 dreams were analysed.
Overall the results support that using electrical stimulation to inhibit sensorimotor cortex activity specifically decreases presence of repetitive actions in REM sleep dreams. This provides novel evidence that the sensorimotor cortex is causal in the generation of dream movement.
Head over to Psychology Today for more details of the study.
(Image Credit: CreativeHexenkueche/ Pixabay)