Individuals in a minimally conscious state are capable of dreaming
A new study in the August issue of Brain concludes that some patients do dream while in a minimally conscious state and are therefore likely to still have a form of consciousness about themselves and the external world. (The three stages of unconsciousness are coma, vegetative state and minimally conscious state.)
The researchers compared electrical brain activity using EEG’s in patients who were considered to be in a vegetative state and in an minimally conscious state.
Electrical activity differed little between sleep and wakefulness in patients in a vegetative state, but the sleep of patients in a minimally conscious state was similar to that of normal sleep in a healthy person, the investigators found.
During sleep, the patients in a minimally conscious state had changes in "slow wave" activity in the front of the brain considered important for learning and brain plasticity. They also had non-rapid eye movement, slow wave sleep and rapid eye movement, which is associated with dreaming.
The researchers concluded that that their results indicate that individuals in the minimally conscious state do have a form of consciousness about themselves as well as the outside world.