Final answer:
Aphasia is the term for impaired or absent comprehension or communication abilities in speech, writing, or signs due to lesions in the dominant cerebral hemisphere. It includes conditions like expressive aphasia, receptive aphasia, and conduction aphasia, depending on the area of the brain that is damaged.
Step-by-step explanation:
The condition described as impaired or absent comprehension or production of, or communication by, speech, writing, or signs, due to an acquired lesion of the dominant cerebral hemisphere is termed aphasia. Aphasia can occur from damage to areas of the brain that are vital for language processing, such as Broca's or Wernicke's areas, and the white matter connections between them. Patients with aphasia may present with varying symptoms depending on the type of aphasia they have, which is typically named after the structures that are damaged. For instance, expressive aphasia, often associated with damage to Broca's area, results in the loss of the ability to produce language. Conversely, receptive aphasia involves a loss in the ability to understand language, whether spoken or written, and can occur from damage to Wernicke's area. Conduction aphasia, involves a disruption in the ability to connect the comprehension and production of speech. Damage to the right hemisphere of the brain can also affect language use, though these deficits are not classified as aphasia, but may result in difficulties with the figurative or nonverbal aspects of speech.