Are the unconscious actually conscious?
Minimally conscious patients are an unusually phenomena, falling at one end of the conscious spectrum.
The conscious spectrum (PVS = permeant vegetative state, MCS = minimally conscious state). Credit: Google images
Recently, the minimally conscious state has appeared in the media spotlight with the accident of Formula 1 legend Michael Schumacher, who was classified as a minimally conscious patient during his rehabilitation. But in the psychology world these patients really came into light when researchers studying a 23 year old female minimally conscious patient ‘confirmed beyond any doubt that a she was consciously aware of herself and her surroundings’ (Owen et al., 2006, p.1402), a horrifying concept.
In a minimally conscious state, patients demonstrate periods of wakefulness – but not in the way the laymen would consider being ‘awake’. Wakefulness for minimally conscious patients refers to their EEG consisting of alpha waves interspersed with beta waves. Beta waves, irregular low frequency waves, indicate a very alert, and attentive state of mind – how you are when you are reading this blog. Alpha waves are what occur when you are falling asleep, they are small amplitude with high frequency. They indicate a relaxed, calm and non thinking state. These patients, many of whom are unable to communicate due to severe injuries, demonstrate these periods of ‘alert’ EEG.
Furthermore, minimally conscious patients also demonstrate a level of awareness regarding their environment, being able to respond to stimulation, albeit inconsistently. Commonly, these patients will ‘respond’ to a familiar voice previously known to them, such as their mother or husband. It was understood that these patients demonstrated some form of consciousness, but it was assumed that minimally conscious patients couldn’t really ‘comprehend’ the world- they were not ‘thinking’ and ‘processing’ the way you or I do. It is significantly easier for the families of these patients to believe that their loved one isn’t aware they are in this state. To know that your loved one is periodically able to realise you are there, think and process how they are is a gut wrenching feeling.
But this one patient suggests that perhaps these patients are aware, and to a degree significantly more than we could imagine.
Owen and colleagues in 2006 were exploring information processing in minimally conscious patients, hoping to determine how information processing eventuates as conscious experience. Their patients was a 23 year old female who had been a car crash, consequently with traumatic brain injury. She first demonstrated that her speech-specific brain regions activated and ‘responded’ to spoken sentences. Subsequently, the researchers established she was ‘comprehending’ their sentences and placed her in an fMRI.
From here things started to get a little sci-fi.
She was asked to perform two mental imagery tasks. Playing tennis, a sport she was highly involved with before her accident, and walking through her home. The two tasks had known, distinguishable patterns of activation in specific regions of the brain.
Astonishingly, her neural responses when performing the two tasks were indistinguishable to healthy controls, and furthermore her cooperation on the task demonstrated a clear intention on her behalf. Her intention to perform the activity, and crucially that their brain activity was consistent with a healthy person, lead the researchers to conclude that perhaps minimally conscious patients may demonstrate a higher level of consciousness than previously thought. It seems that these patients demonstrate a rich tapestry of mental life and are consciously experiencing the world, even if it is only through their mind.
As you can imagine, the results of their research were mind blowing to not only those in their field, but especially to those with loved ones in a minimally conscious state.
Now, somehow, we must find a way to allow these patients to communicate through their thoughts so we can truly understand the mental life of a minimally conscious patient.
Their original paper: Owen, A. M., Coleman, M. R., Boly, M., Davis, M. H., Laureys, S., & Pickard, J. D. (2006). Detecting awareness in the vegetative state. Science, 313(5792), 1402-1402.
Interview with Owens: http://www.theguardian.com/science/neurophilosophy/2011/sep/02/detecting-covert-consciousness-vegetative-state