单项选择题

Studies of children’s acquisition of language suggest that the faculty of language includes an inborn knowledge of the formal principles of language structure, a knowledge that depends on generically determined portions of (usually) that left cerebral hemisphere. Although it is well established that the left hemisphere is specialized for language, one cannot say that language is "located" in this or that part of the hemisphere. What is known is that language disorders are the results of lesions in the left hemisphere. Disorders of language resulting from damage to the brain are called aphasias.
The anterior portion of the "language area" is termed Broca’s area. Lesions in this area interfere with the motor and articulatory aspects of language. Speech is slow, labored, grammatically incorrect, and telegraphic; in extreme cases, it may be impossible to carry out. Writing is likewise severely impaired. Comprehension of the spoken or written word, however, may be unimpaired or, nearly so. (It is interesting to note that under emotional stress, a patient with Broca’s aphasia may be temporarily fluent. )Because Broca’s area is close to the motor cortex, if the former is damaged, the latter is often damaged simultaneously. Hence, such patients often suffer form weakness or paralysis of the right side of the body. Similar lesions in the right hemisphere will cause a left--sided weakness of paralysis but will have no effect on language.
Damage to the posterior portion of the "language area," especially to Wernick’s area, results in a loss of comprehension of the spoken word and often of the written word. The patient’s native language is now like a foreign language. In addition, the patient’s speech is rapid and well--articulated, but without meaning. Writing is defective, and words that are heard cannot be repeated, although hearing itself is completely normal. Similar lesions in the right hemisphere usually have no effect on language.
Injuries to the "language area" in children result in severe aphasias, but the development of language mechanism in the right hemisphere can often compensate for them to an extraordinary degree. This potential function of the right hemisphere is probably normally/ suppressed by the left hemisphere. In adults, aphasias from similar lesions are often permanent.
It can be inferred that the author bases his description on ______.