Introduction to Psychology 10th Edition by Rod Plotnik,Haig Kouyoumdjian

Exercise 5

Consciousness during Coma
In this article, we'll describe two fascinating, tragic, and wellpublicized cases of people in comas. These cases represent two very different types of comas, yet pose the same fundamental question: Does this person experience consciousness?
We'll begin with the case of Terri Schiavo, a 27-year-old woman who suffered a heart attack that resulted in her losing consciousness. During the next 15 years, she never regained consciousness. She could still breathe without a respirator and at times even opened her eyes. Despite these abilities, however, Terri remained completely unaware of her surroundings.
Doctors describe Terri's condition as a persistent vegetative state, meaning she has severe brain damage to the cortex, resulting in long-term loss of cognitive function and awareness, but she retains basic physiological functions, such as breathing.
As a result of being in a vegetative state for more than a decade, Terri's brain severely deteriorated. All that remained was enough of a brain stem (includes midbrain, pons, and medulla) to keep certain basic life functions working (e.g., heart rate, breathing, arousal, visual and auditory reflexes). After she died, her autopsy showed she had massive and irreversible brain damage that shrunk her cortex. It's certain that Terri had been unconscious for a long time.
The second case is Jean-Dominique Bauby, a 43-year-old man who suffered a devastating stroke. It took him nearly three weeks to wake up, and when he did, he was almost completely paralyzed. He could only open and close his left eyelid.
Doctors describe Jean-Dominique's condition as a locked-in syndrome, meaning he remains completely conscious but is almost totally unable to move or speak. Jean-Dominique lived in a locked-in state for the final 15 months of his life. During this time, he learned to communicate with others by blinking his left eye. With his creativity and determination, as well as the help of an assistant, he dictated a best-selling book about his experience of being in a locked-in state: The Diving Bell and the Butterfly.
Although both Jean-Dominique and Terri lacked the ability to speak or communicate readily with others, Jean-Dominique retained full consciousness and Terri's level of consciousness was severely impaired. These cases raise the question of how doctors can determine the level of consciousness in people who cannot communicate.
The presence or absence of consciousness is typically measured through behavioral criteria, which is difficult and can lead to misdiagnosis. Past brain-imaging techniques used to assess consciousness had limitations, such as requiring patients to comprehend or carry out instructions. Very recently, transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) has been used to noninvasively measure the electrical response of the brain. TMS sends signals to activate the brain, and EEG records the brain's activity. This combined technique evaluates brain activity without requiring the active participation of patients. Therefore, it can be used to detect and track recovery in braininjured patients who are unable to understand, communicate, or move. The use of this combined technique may prevent patients who retain some level of consciousness but cannot communicate (such as Jean-Dominique) from being misdiagnosed as being in a vegetative state.
Midbrain
If a boxer is knocked unconscious, part of the reason lies in the midbrain.
The midbrain has a reward or pleasure center, which is stimulated by food, sex, money, music, attractive faces, and some drugs (cocaine); has areas for visual and auditory reflexes, such as automatically turning your head toward a noise; and contains the reticular formation, which arouses the forebrain so that it is ready to process information from the senses (Holroyd Coles, 2002).
If the reticular formation were seriously damaged-by a blow to the head, for example-a person would be unconscious and might go into a coma because the forebrain could not be aroused (Bleck, 2007).
Pons
If someone has a serious sleep disorder, it may involve the pons. In Latin, pons means "bridge," which suggests its function.
The pons functions as a bridge to transmit messages between the spinal cord and brain. The pons also makes the chemicals involved in sleep (Monti et al., 2008).
Medulla
If someone dies of a drug overdose, the cause of death probably involved the medulla.
The medulla, which is located at the top of the spinal cord, includes a group of cells that control vital reflexes, such as respiration, heart rate, and blood pressure. Large amounts of alcohol, heroin, or other depressant drugs suppress the functions of cells in the medulla and cause death by stopping breathing.
Question
What explains why Jean-Dominique had the thinking abilities required to write a book?