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Mental processes remain intact in the brains of vegetative patients.

Updated: May 29, 2022

Studying the "Study of Consciousness" (Stanislas Duanne) can further deepen your understanding of coaching theory.

I am studying to add a unique flavour to "unconscious rewriting".


This series of blog posts are my study notes. This time, the theme that follows the unconscious and conscious

I will write a "sign of consciousness".


 

A paper published in the medical journal The New England Journal of Medicine proves that brain imaging can establish communication pathways with vegetative patients.


The experiments featured in the treatise are elementary.


Let's reexamine Owen's imaginary task.

  • Five of the 54 patients with impaired consciousness developed unique brain activity when instructed to imagine playing tennis or patrolling the room.

  • Four were in a vegetative state, and one of them had a second fMRI session.

  • Then I asked personal questions such as "Do you have siblings?"

  • At that time, the author Martin Monty and his colleagues instructed the following and asked them to answer by purely mental means.

  • "Imagine playing tennis if the answer is yes, or patrolling your room if no.

  • And start your imagination when you hear the word "answer" and stop when you hear the word (relax). "This clever strategy worked brilliantly.

  • For five of the six questions, one of the two previously identified brain networks showed apparent activity.

  • The experimenter himself did not know the correct answer, but when comparing brain activity with the information provided by the patient's family, all five questions were in line.



A series of mental processes should remain intact in the patient's brain.


  1. He understands the question, derives the correct answer, and holds it in working memory for a few minutes before scanning. This phenomenon means that language comprehension, long-term memory, and working memory function correctly.

  2. He deliberately follows the experimenter's instructions, who arbitrarily associated "yes" with tennis and "no" with room patrols.

  3. He followed the instructions correctly and flexibly changed his reaction through the following five scans. This execution attention and task switching ability indicate that the central execution system (a cognitive system that processes information) is maintained.


There is little evidence, and a rigorous statistician might have wanted to answer at least 20 questions instead of 5, but we can say that this patient still has consciousness and will.


In this way, the patient's brain flexibly conveys information via arbitrary modules.


This finding by itself shows that his Global Neuronal Workspace is intact.


Despite this awareness, there can be cases where a thorough examination overlooks that fact.


The news spread immediately through the media when Owen's work was published.

Unfortunately, some journalists have drawn stupid conclusions, such as "Patients in a coma are conscious."


Journalist misunderstandings are causing extra problems everywhere.


As a fact, it is not well known how many such patients are.

Because tests using brain imaging are almost undoubtedly conscious if positive results are obtained, they also cause hearing loss, speech impairment, low arousal, and attention. There are many cases where you are conscious but do not pass the test for various reasons, including lack of ability to maintain.


All responding patients had brain trauma.

In contrast, patients who lost consciousness due to severe stroke or lack of oxygen did not show the ability to perform tasks.


Perhaps their brains, like Teri Shybo, suffered extensive and radically irreparable damage to neurons in the cortex.


The "miracle" of discovering unharmed consciousness in vegetative patients occurs in only a few cases, and a pro-life debate calls for it to be used to provide unlimited medical support to all comatose patients. However, there is a great deal of difficulty in deploying.


Thirty of the 31 minimally conscious patients did not pass the test.

However, in clinical tests, all of these patients occasionally showed signs of the presence of will and awareness.


There are still two problems.

  1. A diagnosis of "minimum state of consciousness" does not necessarily mean that the patient has utterly ordinary consciousness.

  2. Owen's imaginative task can underestimate consciousness.


Due to these problems, no test will be devised to ensure the existence of consciousness in one shot.


It is essential to devise several such tests and see if any of them can establish patient awareness and communication.


Unfortunately, fMRI is a complex and expensive device, so it is not well suited. Because they usually only scan once or twice.


As Adrian Owen points out, "It's a shame that we can't continue supporting patients and their families daily while establishing communication channels with patients."


Even Owen's second patient, who showed clear signs of spontaneous reaction, could only be tested once before returning to the prison of confinement.


Some research teams are rushing to develop brain/computer interfaces using simple electroencephalography (EEG) techniques.

EEG is an inexpensive technology that only requires amplification of the electrical signal input from the surface of the head and can be used daily in clinical practice.


However, it is complicated for EEG to track a patient's image of playing tennis or patrolling the room.


In addition, many engineers are keenly interested in the challenge of connecting a computer to the brain, and more advanced systems are being developed.


Most of them are based on visual gaze and attention. Many patients are not good at the act. Still, there are also advances in decoding auditory attention and motor imagery techniques.


The gaming industry has entered this field by developing even lighter wireless recording devices.

Surgery has also made it possible to implant electrodes directly into the cortex of paralyzed patients.


Quadriplegic patients can manipulate the robot arm with their hearts with such a device.

The day may come when we can embed such devices in the linguistic domain and use speech synthesis to translate what the patient wants into actual speech.


"Twenty years later, we will be able to see patients with quadriplegia and locked-in syndrome who control their wheelchairs daily."

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