Tradition
Aphasia
Overview
Aphasia, also known as dysphasia, is an impairment in a person's ability to comprehend or formulate language because of dysfunction in specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine, but aphasia due to stroke is estimated to be 0.1–0.4% in developed countries. Aphasia can also be the result of brain tumors, epilepsy, autoimmune neurological diseases like multiple sclerosis, infection of the brain, or neurodegenerative diseases like dementias.
To be diagnosed with aphasia, a person's ability to produce and/or comprehend written and/or spoken language must be significantly impaired. In the case of progressive aphasia, this impairment progresses slowly with time.
The difficulties of people with aphasia can range from occasional trouble finding words, to losing the ability to speak, read, or write; intelligence, however, is unaffected. Expressive language and receptive language can both be affected as well. Aphasia also affects visual language such as sign language. In contrast, the use of formulaic expressions in everyday communication is often preserved. For example, while a person with aphasia, particularly expressive aphasia (Broca's aphasia), may not be able to ask a loved one when their birthday is, they may still be able to sing "Happy Birthday". One prevalent deficit in all aphasias is anomia, in which the affected individual has difficulty finding the correct word.
With aphasia, one or more modes of communication in the brain have been damaged and are therefore functioning incorrectly. Aphasia is not caused by damage to the brain resulting in motor or sensory deficits, thus producing abnormal speech — that is, aphasia is not related to the mechanics of speech, but rather the individual's language cognition. However, it is possible for a person to have both problems, e.g. in the case of a hemorrhage damaging a large area of the brain. An individual's language abilities incorporate the socially shared set of rules, as well as the thought processes that go behind communication (as it affects both verbal and nonverbal language). Aphasia is not a result of other peripheral motor or sensory difficulty, such as paralysis affecting the speech muscles, or a general hearing impairment.
Neurodevelopmental forms of auditory processing disorder (APD) are differentiable from aphasia in that aphasia is by definition caused by acquired brain injury, but acquired epileptic aphasia has been viewed as a form of APD.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
In the original texts
Passages from public-domain books where Aphasia is discussed.
To illustrate: A patient afflicted with aphasia is brought to a physician. The fact that the trouble is aphasia may be quite evident. But what precisely is the form and seat of the aphasia? To the mind of the educated physician the problem will take on the disjunctive form: "This is either subcortical or cortical aphasia.
John Dewey, Studies in Logical Theory
names the idea; states what it is
One of the most instructive proofs of motor localization in the cortex is that furnished by the disease now called aphemia, or _motor Aphasia_. Motor aphasia is neither loss of voice nor paralysis of the tongue or lips. The patient's voice is as strong as ever, and all the innervations of his hypoglossal and facial nerves, except those necessary for speaking, may go on perfectly well. He can laugh and cry, and even…
William James, The Principles of Psychology, Volume 1
states what it is; names the idea
Nay, the evidence is still more extensive and conspicuous. What are the puny malformed children, seen in poverty-stricken districts, but children whose appetites for food and desires for warmth have not been adequately satisfied?
Herbert Spencer, The Data of Ethics
opens on it; names the idea
And, since we are concerned with what is called "thought," we must pay more attention than we otherwise should do to the private as opposed to the social use of language. Language profoundly affects our thoughts, and it is this aspect of language that is of most importance to us in our present inquiry. We are almost more concerned with the internal speech that is never uttered than we are with the things said out…
Bertrand Russell, The Analysis of Mind
states what it is
The use of our own language has led us to neglect it so far as to forget it altogether. Let us study children and we shall soon learn it afresh from them. Nurses can teach us this language; they understand all their nurslings say to them, they answer them, and keep up long conversations with them; and though they use words, these words are quite useless. It is not the hearing of the word, but its accompanying…
Jean-Jacques Rousseau, Emile
states what it is
Philosophers who discussed Aphasia
Related ideas
- Epilepsy
- Greek language
- Grammar
- Ancient Greek
- Neologism
- Language
- Functional magnetic resonance imaging
- Phoneme
- Papyrus
- Prefix
- Syntax
- Sign language
- Semantics
- Writing
- Brain
- Noun
- Broca's area
- Stroke
Place in the tradition
Part of Philosophy of mind.