Tag Archives: locked-in syndrome

Can the Clinical Diagnosis of Disorders of Consciousness Avoid Behaviorism?

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The “standard approach” in clinical neurology has been accused of suffering from an implicit “behaviorist epistemology” because disorders of consciousness are typically diagnosed on the basis of a lack of behavior. All the gold standard diagnostic assessment programs such as the JFK-Coma Recovery Scale are behavioral in nature insofar as they are expressly looking for behavior or the lack of behavior, either motor behavior or verbal behavior. If the behavior occurs appropriately in response to the command or stimulus then they get points that accumulate towards “normal” consciousness. If no behavior is observable in response to the cue then they don’t get points and are said to have a “disorder of consciousness”.

The problem with this approach is both conceptual and empirical. Conceptually, there is no necessary link between behavior and consciousness because unless you are Gilbert Ryle or Wittgenstein you don’t want to define consciousness in terms of behavior. That is, we don’t want to define “pain” as simply the behavior of your limbs whenever your cells are damaged, or the disposition to say “ouch”. The reason we don’t want to do this is because pain is supposed to be a feeling, painfulness, not a behavior.

Empirically, we know of many cases where behavior and consciousness can be decoupled such as in the total locked-in state where someone’s mind is more-or-less normal but they are completely paralyzed, looking for all intents and purposes like someone in a deep coma or vegetative state yet retaining normal brain function. From the outside they would fail these behavioral assessment techniques yet from the inside have full consciousness. Furthermore we know that in some cases of general anesthesia there can be a complete lack of motor response to stimulation while the person maintains their conscious awareness.

Another problem with the behaviorist epistemology of clinical diagnosis is that the standard assessment scales require a certain level of human expertise in making the diagnostic judgment. Although for most scales there is high inter-rater reliability it nevertheless ultimately comes down to a fallible human making a judgment about someone’s consciousness on the basis of subtle differences between “random” and “meaningful” behavior. A random behavior is just that: a random, reflexive movement that signifies no higher purpose or goal. But if I ask someone to squeeze my hand and they squeeze it, this is a meaningful sign because it suggests that they can listen to language and translate a verbal command to a willed response. But what if the verbal command to squeeze just triggers an unconscious response to squeeze? Sure, it’s possible. No one should rule it out. But what if they do it 5 times in a row? Or what if I say “don’t squeeze my hand” and they don’t squeeze it? Now we are getting into what clinicians call “unambiguous signs of consciousness” because the behavior is expressive of a meaningful purpose and shows what they call “contingency”, which is just another way of saying “appropriate”.

But what does it mean for a behavior to really be meaningful? Just that there is a goal-structure behind it? Or that it is willed? Again, we don’t want to define “meaning” or “appropriateness” in terms of outward behavior because when you are sleepwalking your behavior is goal-structured yet you are not conscious. Or consider the case of automatic writing. In automatic writing one of your hands is capable of having a written conversation and writing meaningful linguistic statements without “you” being in control at all. So clearly there is a possible dissociation between “meaningful” behavior and consciousness. All we can say is that for normal people in normal circumstances meaningful behavior is a good indicator of normal consciousness. But notice how vacuous that statement is. It tells us nothing about the hard cases. 

So in a nutshell the diagnosis of disorders of consciousness has an inescapable element of human subjectivity in it. Which is precisely why researchers are trying to move to brain-based diagnostic tools such as fMRI or EEG, which are supposed to be more “objective” because they skip right over the question of meaningful behavior and look at the “source” of the behavior: the brain itself. But I want to argue such measures can never bypass the subjectivity of diagnosis without going full behaviorist. The reason why brain-based measures of disorders of consciousness are behaviorist is simply because you are looking at the behavior of neurons. You can’t see the “feelings” of neurons from a brain scanner anymore than you can see the “feeling” of pain from watching someone’s limb move. Looking at the brain does not grant you special powers to see consciousness more directly. It is still an indirect measure of consciousness and it will always require the human judgment of the clinician to say “Ok, this brain activity is going to count as a measure towards “normal” consciousness”. It might be slightly more objective but it will never be any less subjective unless you want to define normal consciousness in terms of neural behavior. But how is that any different from standard behaviorism? The only difference is that we are relying on the assumption that neural behavior is the substrate of consciousness. This might be true from a metaphysical perspective. But it’s no help in the epistemology of diagnosis because as an outside observer you don’t see the consciousness. You just see the squishy brain or some representation on a computer screen. I believe there is a circularity here that cannot be escaped but I won’t go into it here (I talk about it in this post).

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What It’s Like to Be Locked-In, part 3 – The Willingness to Understand

I had not regressed to infancy, yet, owing to my immobility, the nursing staff tended to treat me as an infant. Does anyone stop to ask a newborn whether he is comfortably installed in his or her bassinet? Nothing is worse than being taken for a baby when you are in your thirties.

I therefore tended to divide all human beings into two categories: those who were willing to understand me and…everyone else.

~Philippe Vigand, Only the Eyes Say Yes, p. 25

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What It’s Like To Be Locked-In, part 2

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I am absolutely paralyzed. Only my heart continues to beat and my lungs to breathe. The physical sensations — heat, cold, pain –are also very much with me. And my senses — sight, touch, hearing — are intact.

But as for movement, none. None whatsoever. It is as though my body were encased in cement, except for my head. I am no longer able to lift a finger, even to make the simplest gesture, such as scratching my ear. And though I understand, I cannot speak. I am like a well-preserved mummy, minus the bandages. I have even lost the newborn’s capacity to swallow.

My brain? It functions exactly as before!

In America, this rare condition is called locked-in syndrome. The description is apt enough, with the difference that the walls of this prison have large windows without any bars, through which all the sounds of life can enter. Those felled by locked-in syndrome rarely survive.

Philippe Vigand, Only the Eyes Say Yes: A Love Story, p. 4

 

[Note: this is the second installment of what I am planning to be an on-going series of posts on the phenomenology of locked-in patients as told through their own words.]

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What It’s Like to Be Locked-In

Jean-Dominique-Bauby

I need to feel strongly, to love and to admire, just as desperately as I need to breathe. A letter from a friend, a Balthus painting on a postcard, a page of Saint-Simon, give meaning to the passing hours. But to keep my mind sharp, to avoid descending into resigned indifference, I maintain a level of resentment and anger, neither too much nor too little, just as a pressure cooker has a safety valve to keep it from exploding.

-Jean-Dominique Bauby, The Diving Bell and the Butterfly, p. 52

As I mentioned in this post my latest research project involves the measurement of consciousness in patients with brain damage, including the rare case of Locked-in Syndrome. I recently finished reading Bauby’s memoir about being in the locked-in state, The Diving Bell and the Butterfly where Bauby takes you inside what he called his “diving bell”, submerged in the depths of his useless body peering out at the world through the tiny window of his left eye. The memoir is nothing less than riveting, a powerful demonstration of the indefatigable human will.

Bauby dictated the entire book to an assistant with only the use of his left eye. The assistant would read off letters in the alphabet in a pre-established series arranged by frequency in the French language and Bauby would blink when the assistant spoke the correct letter; then they would start from the beginning for the next letter, and so on. You can imagine how laborious this would be. Yet the book reads beautifully, revealing an active, curious, intelligent mind trapped inside a bodily shell.

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