A research team led by neurologist Nicholas Schiff has recently published a brain scanning study on two patients who may show evidence of an internal mental life, despite being in a coma-like “minimally conscious state”.
MCS usually occurs after severe brain damage and is a condition where patients seem to be unconscious, but show intermittent awareness of the self or the environment, although they are not able to communicate or maintain this awareness for pronlonged periods of time.
It is thought to be ‘less severe’ than coma, where patients are entirely unresposive, or persistent vegetative state, where patients are unconscious but may show simple automatic functions such as the sleep-wake cycle or eye-tracking.
Schiff’s study found that an area of the temporal lobe, known to be involved in language comprehension, was activated when the two unconscious patients were played recordings of a friend or relative recounting a familiar event.
These responses were remarkably similar to the responses recorded from healthy participants used as controls. This surprised the researchers, who expected far less brain activity in the MCS patients.
One further result they describe as “haunting” was finding activity in the patients’ occipital lobe. The researchers speculate that activity in these areas may reflect memories and mental images triggered by the recordings and the sound of their family member’s voice.
Little is known about the functioning of the brain during these coma-like or miminally conscious states, and medical science is often surprised by the recovery of function even after prolonged periods of unconsciousness.
Terry Wallis, the subject of a recent Channel 4 documentary, regained consciousness after a record 19 years in a coma.
Link to abstract of Schiff study.
Link to news story about the study from Yahoo News.
Link to information on Terry Wallis, his recovery and the documentary about him (“The Man Who Slept for 19 Years”).