Dictionary of Biological Psychology
Anomia is an acquired disorder of naming. Like most disorders, anomia is a matter of degree: that is, anomic patients rarely fail completely in naming, and their success is often significantly related to one or more factors, such as the familiarity of the object/ concept, the frequency of the word used to name it, the age at which the term was learned, the length and/or complexity of the word, and so on. PURE ANOMIA is a disorder limited to word retrieval, and can be distinguished from anomia attributable to other underlying causes, such as deficits in OBJECT RECOGNITION, semantic knowledge, phonological or articulatory processes (see SPEECH PERCEPTION; SPEECH PRODUCTION) and so forth. There are some documented cases of selective anomia for a particular class of names (for example, names of people, places or objects) or from a particular modality of presentation (for example, naming an object in response to seeing it, or touching it without seeing it, or being given a verbal description of it). Such category-specific or modality-specific anomias are however rare, with the majority of anomic patients having difficulties in naming under all of these conditions.
The symptoms of anomia are: a failure to find words; the use of a more general word (for instance place instead of kitchen); circumlocutions (such as a description of the meaning of the word rather than the name—for instance a chair becomes you sit on it); and a variety of errors. These errors are referred to as PARAPHASIAS and may take various forms. In VERBAL PARAPHASIA an incorrect word is substituted that is unrelated to the correct word; SEMANTIC PARAPHASIAS substitute a word related in meaning (for example dog named as cat), and PHONEMIC PARAPHASIAS occur when a word is mispronounced (for example boat as bat or broat). Subjects who make phonemic paraphasias often make several attempts at naming the word, suggesting that they recognize that the pronunciation is wrong. A mispronunciation that is not related to the target is called a NEOLOGISM (for example horse named as sprod). In connected speech which includes affixed words, such as dancing, rider, only the root morphemes (that is dance, ride) are neologized; the affixes ing and er are spared. Subjects who make numerous neologisms in speech are referred to as showing JARGON APHASIA.
Anomia is affected by the frequency of the word in the language, and the age at which the word is acquired.
Less common words, and those acquired later, are most vulnerable. This follows the pattern observed in normal subjects who are slower to name less common words and words that appear later in the vocabulary. Anomia can arise from a number of underlying causes. A pure anomia arises when a word in the LEXICON of spoken word forms is either damaged, or cannot be retrieved. SEMANTIC ANOMIA arises when there is a disorder of SEMANTIC MEMORY: semantic paraphasias are produced frequently, and particular semantic categories (such as fruit and vegetables, or proper names) may be affected.
PHONEMIC CUEING is a technique used to assist in the production of spoken words. The initial phoneme of the word is provided which may then prompt the word to be produced. The technique is successful in cases where the spoken lexical form is intact but cannot be retrieved. In cases of semantic anomia, the initial phoneme of a word related semantically to the target will sometimes evoke a semantic paraphasia (for example the initial phoneme /t/ will prompt the word tiger to a picture of a lion). Treatment with phonemic cueing, based on the subject’s knowledge of the initial letter of the word, have had most success. is most successful in cases of pure anomia. To date, methods using semantic cueing and computer generated phonemic cueing have had most success.
Reference
Ellis A.W. & Young A.W. (1996) Human Neuropsychology, Psychology Press: Hove UK.
ELAINE FUNNELL
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