About Kai Schreiber Expertise Mostly questions specific to vision science and eye movements, with some expertise in general neuroscience and cognitive science. Strongest background in mathematical theory, modelling and the theory of perception, but I will try to answer anything that comes my way.
Experience Postdoc in Vision/Oculomotor research.
Organizations UC Berkeley
Publications Journal of Vision, Nature, IEEE Transactions on Biomedical Enginerring
Education/Credentials Dipl Phys (Universtität Tübingen), PhD (Physiology, Univeristy of Toronto), Graduate Program in Neuroscience (University of Toronto)
Expert: Kai Schreiber Date: 6/18/2007 Subject: vegetative state
Question Hi Dr Schreiber,
When people talk about vegetative state, does that mean that the person who is in such state does not feel or suffer from anything because he has no consciousness? Does this expression has anything to do with the fact that plants do not have one either and are therefore incapable of thinking or suffering?
Thank you and all the best.
Answer Dear Jack,
the short answer to that is that yes, the oft quoted vegetative state refers to the lack of consciousness and inner life that we commonly associate with plants (though some folk who talk to and play Mozart to their flowers would probably disagree with that). It is meant to capture this lack of responsiveness to input, and the lack of output and action, in a simple image that is immediately accessible, and I suppose it achieves that goal.
That having been said, we do not know really what is going on in the mind of a person in such a state. There is recent evidence from fmri studies, showing that the patterns of brain activation seemed very similar between normal subjects and people in a vegetative state, when they were read similar stories. This might be an automatic response, not associated with consciousness, or it might mean they are truly locked in, unable to respond or move, but fully aware - a frightening thought. Though it is generally also true that patients with disabilities and restrictions usually cope much better than people without those restrictions would imagine, it is hard not to be terrified by the thought of being entirely unable to act, yet fully aware.
Currently, with our lack of understanding of how consciousness arises, and what exactly is wrong with people in a coma, there can be no definite answer to the underlying question. My personal opinion is that there probably exists a continuum of consciousness and responsiveness, from fully awake, over automatic behaviour, sleep, unconsciousness down to coma and death, and that people in so called vegetative states can fall onto quite a range on this spectrum.
