Lucid dreaming is a scientifically proven phenomenon in which it is possible to be conscious during REM sleep and to exert voluntary control over one's actions, with brain activity comparable to that of the waking state.

noli's read

Matthew Walker, a neuroscientist recognized for his work on sleep, draws here on solid research validating the existence of lucid dreaming. Pioneering studies, notably those using predefined ocular signals to communicate from within the dream (LaBerge et al., RCT/Case studies), have confirmed that dreamers can signal their lucidity while still in the REM phase. It is scientifically accurate that brain imaging shows activation of the prefrontal cortex—a zone associated with self-awareness—which is normally not very active during standard sleep. The idea that the brain 'executes' movements in the dream, such as clenching a fist, is corroborated by evidence showing activation of the corresponding motor areas of the brain (Dresler et al., neuroimaging). What is sometimes interpreted as 'total control' remains nuanced in research, however: while the consciousness is real, the degree of control over the dream scenario remains variable according to the individual and training. It is not an unlimited ability, but a distinct and documented neurophysiological state.

the sources

No named source held this one up — that absence is part of the verdict.