In a recent podcast, “Michael Egnor on Whether People in Comas Can Think,” Robert J. Marks discusses with neurosurgeon Michael Egnor a difficult question many of us have had to ask: Am I heard? Or am I just doing this for myself? What can recent research tell us? A partial transcript follows. [Audio of the full interview can be found here.]
Can you still think in a coma?
Robert J. Marks (right): If you’re in a coma, can you still think? What does neuroscience say?
Michael Egnor: First, people usually take “coma” to mean that a peron has no meaningful interaction with their environment. And there is a condition called persistent vegetative state which is thought to be the deepest level of coma. It’s not brain death because brain death means actual death. But it’s the closest thing there is to brain death. It’s a state in which it’s been assumed that a person has absolutely no subjective experience. There is no first-person experience; you don’t dream, you don’t feel anything, you don’t think anything. You’re just not really there.
Robert J. Marks: But I assume there’s still brain activity going on, right?
Michael Egnor: Yes, people in a persistent vegetative state can breathe, they can control their heart rate, things like that. But basically, they’ve been thought of as a vegetable, that is, as a human body without a mind, and that’s been the assumption for persistent vegetative state.
Note: The following 2003 definition captures the general assumption Dr. Egnor describes: persistent vegetative state a condition of profound nonresponsiveness in the wakeful state caused by brain damage at whatever level and characterized by a nonfunctioning cerebral cortex, the absence of any discernible adaptive response to the external environment, akinesia, mutism, and inability to signal; the electroencephalogram may be isoelectric or show abnormal activity. Vegetative states raise ethical questions regarding appropriate care, use of resources, and allowing a patient to die.- Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved April 14 2020 via The Medical Dictionary
Persistent vegetative state (PVS), vegetative state (q.v.) of prolonged duration (defined in different sources as duration of longer than 1 month, 1 year, or 2 years); usually permanent. – Farlex Partner Medical Dictionary © Farlex 2012
Michael Egnor (left): So the question one can ask is, is there any evidence that a person in the deepest level of coma has any awareness of what’s going on around them? And that question was first addressed rigorously by a neuroscientist named Adrian Owen at Cambridge in England back about fifteen years ago.
The research of Adrian Owen on comas
Michael Egnor: Owen took a woman who was in a persistent vegetative state — she’d been in a car accident and had severe brain damage, and she’d been in this state for several years — and he put her in an MRI machine and did what’s called a functional MRI test. A functional MRI test looks at changes in blood flow in the brain that we believe correspond to activation of parts of the brain. So you can kind of tell what’s going on inside the brain during the time they’re in the machine.
So he put her in the machine and he put headphones on her and he asked her to think about things. Now remember, she’s a woman who, supposedly, is the deepest level of coma, just a hair above brain dead. And he said, “Imagine you’re walking across the room.” “Imagine you’re playing tennis.” “Think of things.” And he found activation in her brain. Even though she had massive brain damage, there were patterns of activation.
So he then took fifteen normal volunteers, put them in the machine, and asked them the same questions. And her patterns of activation were identical to theirs. So he said, well, to a first approximation, it looks like she can think just like they can think.
But, he said, you know, maybe the activation that we are seeing in the brain isn’t because she understands. Maybe it’s just the brain’s reaction to sound. Maybe it doesn’t necessarily mean that you understand, maybe just the noise from the headphones is causing this activation. So he scrambled the words so, instead of saying, “Imagine walking across a room” he would say “across walking imagine room your”. So it made no sense. And the activation went away in her brain and in the volunteers’.
So he showed that the only time she had activation in her brain was when what was asked of her made sense. And her activation was completely indistinguishable from the activation of completely conscious people. So he concluded that she was able to understand and think about things that he was asking her to understand and think about, even though she was in the deepest level of coma.
His research has been repeated by a number of other laboratories on many, many patients with persistent vegetative state. And about forty percent of people in persistent vegetative state show high levels of intellectual functioning even in deep coma.
There are ways of conversing with people in deep coma where you can, for example, look at the activation state representing Yes and the activation state representing No and you can ask them questions. You know, “Are you lonely?” “Do you wish your mother were here?” “Would you like something to eat?”, stuff like that, and they can answer you, with these brain states.
In addition, some people can do mathematics in a coma. You can ask them “Is the square root of 25, 6?” and they do a No. And “Is it 5?” and they do a Yes. So there can be very high levels — not in all patients that we have found — but in many patients, forty percent, at least — of mental function in profoundly damaged brains. To the point where the medical profession has actually added a category to this list of ways you can be in a coma, and this is called minimally conscious state. So patients who have evidence of intellectual functioning in deep coma are called “minimally conscious,” although, frankly, they’re not really minimally conscious, they’re quite conscious.
Minimally conscious state: A severe alteration in consciousness that does not meet the diagnostic criteria for either coma or a persistent vegetative state, in which patients respond to some sounds and unpleasant stimuli and have a sleep-wake cycle but do not attend to their environment consistently.
Segen’s Medical Dictionary. (2011). Retrieved April 15, 2020
Michael Egnor: What this research shows us — apart from the fact that people who we previously thought were in deep coma are aware of what is going on around them — would have relevance, for example, to the Terry Schiavo issue. That happened about fifteen years ago, where this woman in Florida — who was in a persistent vegetative state from a lack of oxygen to her brain — was starved to death by her husband, supposedly according to what her wishes would be, because it was assumed that she had no consciousness at all.
And this would suggest that there is at least a chance that she was very much aware of what was happening to her, which is what her family said, what her parents said. So it suggests that we should treat people in coma with a lot of respect and a lot of consideration and — what I think ought to be the presumption — that they are aware and we should treat them that way.
Note: At one time, the acronym GORK (God Only Really Knows) was sometimes applied to people in a persistent vegetative state. – The Urban Dictionary, 2003. Prior to such technologies as functional magnetic resonance imaging (fMRI), there was no clear way to be sure.
Michael Egnor: But anyway, what this research suggests is that there is a disconnect between mental states and brain states. That is, you can have massive brain damage and still have surprisingly high levels of mental function. Which at least suggests — it’s indirect evidence but it is evidence — that some aspects of mental function, and particularly intellectual functioning, don’t necessarily have a basis in the brain. Maybe that functioning transcends the brain.
Note: Adrian Owen is the author of Into the Gray Zone (2017), in which he describes his relationships with and efforts to research people trapped in persistent vegetative states. From an author interview we learn “He got his start in exploring what he called “the Gray Zone” when a former partner of his had a brain aneurysm which turned her into a mental vegetable. This started him on the decades-long journey of exploring a mental area that is between full awareness and total lack of awareness — the so-called “Gray Zone” — using the brain scanning technology.”