The Brain Without Behavior

Julia Lewis
Professor Grobstein
2/24/09

The Brain Without Behavior

This paper is about exploring the relationship between the human brain and behavior.  To that end, I would like to explore the nervous system and behavior of paralyzed patients.  Paralysis is a condition in which portions of the body receive decreased or no direction from the nervous system. 

Locked-in syndrome is an extreme form of paralysis.  Locked-in syndrome results when nerves are either distressed or destroyed.  The brain is no longer capable of communicating with either sensory or motor neurons.  The brain can not initiate, stop, or otherwise control nervous system function below the place of injury.  In this case, paralysis is less the absence of movement and more the lack of control of movement.  The extent of the paralysis is determined by the position along the spinal cord at which the nerves are damaged. (1,2)

Locked-in patients are unable to control a majority of the common input/output functions of the nervous system.  Their nervous system may receive an input or stimulus to a sensory neuron and respond with an appropriate output by means of a motor neuron.  If their finger is pinched, then it will withdraw. (3) However, the patient as a conscious agent can only observe the behavior of their own body.  The upper part of the nervous system is unable to communicate with the lower part of the nervous system.  There are two autonomous nervous systems present in the same body.  A damaged nervous system is capable of performing some functions normally or indistinguishably from a single unified nervous system.  Such phenomenon complicates the model that the brain is equivalent to behavior.  There is not a one-to-one ratio between the brain and behavior. 

Initially the case of locked-in syndrome struck me as a challenge to professor Grobstein’s assertion that the brain is equivalent to behavior.  There is virtually no behavior available for observation in a person with locked-in syndrome.  The absence of behavior might be taken to indicate the absence of brain function, yet biological, medical, and personal evidence (presented later) disagree. (4) Instead, if we assume that the presence of a functional brain in a locked-in patient, then there is some sort of associated behavior.  Perhaps locked-in syndrome requires a new method of indentifying and interpreting behavior?  A special sensitivity on the part of caregivers? 

Arriving at the diagnosis of locked-in syndrome requires a variety of observations about the patient.  Imaging studies of the brain by either contrast computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) to visualize any abnormalities.  Electroencephalography (EEG) results indicate normal sleep-wake patterns. (1) The patient may also be asked to communicate by blinking coded eye movements.  Locked-in syndrome has been misdiagnosed as persistent vegetative state historically.  The two conditions have similar presentations, the most significant difference being the relative cognitive abilities.  Patients in a persistent vegetative state are not conscious and have no measurable higher brain function. (2) Locked-in syndrome is diagnosed by using current biological and medical understanding of the brain.  I wonder how will our perception of this illness and other severe brain injuries change as our scientific understandings change? (6)

Language and communication possibilities for a patient with locked-in syndrome are limited.  In most cases, the patient is only able to blink their eye, at best; they are capable of generating some sound with their vocal cords.  Thus speaking and conversation in the conventional sense are impossible. (1) All available methods of communication require painstaking precision, special training for the correspondent, and significant amounts of time.  Most strategies make use of the patient’s ability to signal by blinking their eye.  When the alphabet is read out, the patient may blink their eye to indicate the desired letter.  This strategy allows the painstaking construction of words, phrases, and sentences.  Jean-Dominique Bauby dictated his memoirs in the way. (5)

Observations from the outside provide only a superficial description of locked-in syndrome, an account from the inside, a patient experiencing such paralysis can add depth to our understanding.  In the form of a memoir, Jean-Dominique Bauby offers a beautiful picture of his life after suffering a severe brain stem stroke.  He writes in the first person singular, asserting that he is related to any other author or person.  Pushing back against a strong sense of societal marginalization, he forces his reader to see the “broken-winged birds, voiceless parrots, ravens of doom, who have made [their] nest in a dead-end corridor of the neurology department.” (5, p 32).  His prose is poetic combining precision, powerful imagery, and exquisite creativity. 

Bauby’s book is episodic in nature consisting of chapters that describe particular experiences and impressions of life in the hospital or his fantasies.  The contrast between his flights of fancy and paralyzed physical form are reminiscent of the idea that in the absence of stimulus, the brain generates its own stimulus. (3) This situation may not be so severe as to warrant such measures on the part of his nervous system though. (7) Another potential interpretation is accessible by comparing Bauby’s work with Emily Dickinson’s poem about the brain.  In the first stanza she writes,
“The Brain - is wider than the Sky -
For - put them side by side -
The one the other will contain
With ease - and You - beside-“

I think that Bauby agrees ardently with Dickinson that the human brain is capable of encompassing all else. (7) Thus his brain is sufficient for his fantastic travels.  What is clear from reading Bauby’s work is that the storytelling component of his brain is highly developed and functional.  
Bauby’s memoirs are a strong argument for his humanity.  The quality of his intellectual work indicates that his cognitive capacities have not been diminished by the damage to his nervous system.  In an extension of Emily Dickinson’s claim about the capacity of the brain, I would argue that Bauby’s brain is sufficient to contain not only his consciousness, but his behavior as well.  


1.)    http://content.nejm.org/cgi/content/full/330/22/1572
2.)    /bb/neuro/neuro04/web1/shamdounia.html#6
3.)    /exchange/courses/bio202/s09/notes
4.)    /bb/neuro/neuro02/web1/gimperato.html
5.)    Bauby, Jean-Dominique, The Diving Bell and the Butterfly. Trans. Jeremy Leggatt New York: Vintage International 1997
6.)    http://www.merck.com/mmpe/sec16/ch212/ch212c.html
7.)    /bb/neuro/neuro07/index.html#starting