Self And The Phenomenon Of Life: A Biologist Examines Life From Molecules To Humanity

Self and Conscious Experience 175

“9x6” b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity

is the cardio-respiratory function. Reflexes are present but there is no
purposeful movement. The eyes may open spontaneously, though the
patient shows no intention to communicate. With tube feeding, a “vege-
tative” patient may survive for years. (The distinction between minimally
conscious state and persistent vegetative state is not clear-cut and can be
a source of controversy.) Brain death is a condition in which the EEG
is flat and the patient cannot be aroused. In brain death cranial nerve
reflexes are absent but spinal nerve reflexes may be retained. Cardiovas-
cular function and general metabolism are retained whereas respiration
has to be artificially maintained. The loss of consciousness in brain death
is irreversible as the neurons in the brain undergo necrosis (cell death).
Locked-in syndrome is a condition in which the patient is conscious but
unable to communicate except for minimal muscle twitching such as eye
blinking. It can easily be confused with loss of consciousness.

8.5.3 Recurrent and episodic

Epilepsy is a group of neurological disorders typically characterized by
recurrent, sudden but transient loss of consciousness (with or without mus-
cular jerking), accompanied by an EEG picture of bursts of excessive
electrical activities. One type of epilepsy, called temporal lobe epilepsy
(the pathology being in the temporal lobe), manifests a state of altered
consciousness, during which time the patient may engage in simple activ-
ities of which he subsequently has no recollection. For example, during
the epileptic attack (seizure), the patient may pace aimlessly inside a
room without bumping into any of the furniture. He may open his eyes
but engages in no purposeful act, and does not respond to other people
in the room. Because of bizarre behavior, temporal lobe epilepsy is also
known as psychomotor seizure. Sleepwalking is a sleep disorder in which
the patient suddenly gets up and wanders in the room for a few minutes
while still in sleep. The patient looks confused and will have no recall
of the incident. Narcolepsy is a pathologic condition in which a per-
son is afflicted with repeated, episodic attacks of irresistible sleepiness.