Hypnosis and anesthesia can also teach us a great deal about consciousness. Just as under anesthesia, the connections between certain brain areas are less active under hypnosis. And finally, we are curious to understand what near-death experiences can tell us about consciousness. What does it mean that some people feel they are leaving their bodies, whereas others suddenly feel elated?
Two different networks seem to play a role: the external, or sensory, network and the internal self-consciousness network. The former is important for the perception of all sensory stimuli.
To hear, we need not only ears and the auditory cortex but also this external network, which probably exists in each hemisphere of the brain—in the outermost layer of the prefrontal cortex as well as farther back, in the parietal-temporal lobes. Our internal consciousness network, on the other hand, has to do with our imagination—that is, our internal voice.
This network is located deep within the cingulate cortex and in the precuneus. For us to be conscious of our thoughts, this network must exchange information with the thalamus.
The brain is so heavily damaged that neither of the networks functions correctly anymore. This malfunction can occur as a result of serious injury, a brain hemorrhage, cardiac arrest or a heart attack.
At most, a coma lasts for a few days or weeks. This does not, however, mean that a person is conscious. Most patients who awaken from a coma soon recuperate. But a minority will succumb to brain death; a brain that is dead is completely destroyed and cannot recover.
But some patients who are not brain-dead will never recover either. For that we use the Glasgow Coma Scale. If we pinch their hand, they will move it away. But these signs of consciousness are not always evident, nor do we see them in every patient. A patient who awakens from a coma may also develop a so-called locked-in syndrome, being completely conscious but paralyzed and unable to communicate, except through eye blinks.
So the difference between unresponsiveness, minimal consciousness and locked-in would seem to be hard to determine. If there is no response to commands, sounds or pain stimuli, this does not necessarily mean that the patient is unconscious. Family members are often quicker than physicians to recognize whether a patient exhibits consciousness. How do you determine whether they are conscious? If the motor cortex is activated, we know that the patient heard and understood and therefore is conscious.
With different brain scanners, I can find out where brain damage is located and which connections are still intact. This information tells family members what the chances of recovery are.
If the results show that there is no hope whatsoever, we then discuss difficult topics with the family, such as end-of-life options. Occasionally we see much more brain activity than anticipated, and then we can initiate treatment aimed at rehabilitation. He was a very important patient for us: as far as anyone could tell, he had been left completely unresponsive for 23 years after a car accident.
But in the mids we placed him in a brain scanner and saw clear signs of consciousness. It is possible that he experienced emotions over all those years. He was the first of our patients who was given a different diagnosis after such a long time. We subsequently conducted a study in several Belgian rehab centers and found that 30 to 40 percent of unresponsive patients may exhibit signs of consciousness.
Yes, but his facilitator was the only person who seemed able to understand and translate his minimal hand signals. Over time, the person may start to gradually regain consciousness and become more aware. Some people will wake up after a few weeks, while others may go into a vegetative state or minimally conscious state. Patients can exhibit different levels of unconsciousness and unresponsiveness depending on which brain regions have been damaged and how much or how little of the brain is functioning.
In some instances, coma may be deliberately induced using pharmaceutical agents in order to preserve higher brain functions following brain trauma, or to save the patient from extreme pain during healing of injuries or diseases. All of these factors will influence the path through treatment and recovery, which is detailed below. Initial treatment will depend on the cause of the coma and will be directed at preventing further damage to the brain.
In the short term, a person will normally be looked after in an intensive care unit ICU. If the patient is having difficulty breathing, they may be placed on a respirator while the underlying cause is treated. If there is an underlying illness, or poisoning, then treatment will be directed at the underlying cause. Intravenous fluids or blood and other supportive care must be provided as needed. For example, this could involve providing adequate nutrition, and preventing infection e.
In the longer term, healthcare staff will give supportive treatment on a hospital ward. A person in a coma may become restless, requiring care to prevent them from hurting themselves or attempting to pull on tubes or dressings.
In these instances, medicine may be given to calm the patient. Side rails on the bed should be kept up to prevent the patient from falling. While not empirically validated, families have reported benefits from arousal regimes, such as those implemented by Dr Ted Freeman eg Coma Arousal Therapy. The therapy involves family members taking the patient through a regimen of controlled auditory, visual and physical stimulation for up to six hours a day, every day.
So there is no electrical test or scanning test that will tell you definitively that this person is aware or not aware. So has that person extracted some meaning from what is happening?
If I pinch anybody, if I pinch you, you would withdraw your hand — among other things. They were aware that somebody, me, was causing them pain and they thought how can they remove it. So in the end, saying somebody is vegetative means that you have determined that nothing that they do requires them to have formulated a goal, formulated an idea, or understood the meaning of what is happening around them.
And that does come down to commonsense, in a way. You have to decide that. Because people in the vegetative state will respond to noise - by startle or jump, will respond to pain — by moving away, often will have some spontaneous movement, their eyes will move all over the place, they might yawn, sometimes they might stretch or they might move their arms. The question of whether someone in the vegetative state can feel pain is interesting and difficult to answer.
I personally believe that they are not aware of pain. And of course we talk about it — we say they feel pain and withdraw. But they respond to it. Fern does not think her partner feels pain.
From eyes watching and looking at another body, that body is suffering. So it might look like, every time he goes through these. The body is going through something, but he is not in that body, he does not feel it. He does not feel any of it. Fern describes how her partner did appear to be suffering before he was given ongoing long-term pain relief. Since he has been administered pain relief she has noticed that he appears more relaxed and not in pain. He was on, as and when paracetamol [laughs].
And I can see it, because he just relaxes. That dystonic arm thing — he come down. The breathing, it regulates. And now the thing is, you can do the SATS level, and it still may be done at ninety, or eighty-nine or whatever. The sweat, the panic, you know, we had him sat up and he was just not coping.
He was puffing, he was puffing, he was gurgling. The heart rate was shot up, do you know, it was uncomfortable.
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