Aphasiology is the study of
linguistic problems usually resulting from
brain damage, as a result of a
stroke or progressive illness including the various types of
dementia. It is also the name of a
scientific journal covering the area. These specific language deficits, termed
aphasias, may be defined as impairments of language production or comprehension that cannot be attributed to trivial causes such as
deafness or oral
paralysis. A number of aphasias have been described, but two are best known:
Expressive aphasia (Broca's aphasia) and
Receptive aphasia (Wernicke's or sensory aphasia).