Wernike´s
Wernicke's area is one of the two
parts of the cerebral cortex linked since the
late nineteenth century to speech (the other is Broca's area). It is involved in
the understanding of written and spoken language. It is traditionally
considered to consist of the posterior section of the superior
temporal gyrus in the dominant cerebral hemisphere(which is
the left hemisphere in about 97% of people).
Wernicke and aphasia
Wernicke's area is named after Carl Wernicke, a German neurologist and psychiatrist who, in 1874, hypothesized
a link between the left posterior section of the superior temporal gyrus and
the reflexive mimicking of words and their syllables that associated the
sensory and motor images of spoken words. He did this on the basis of the
location of brain
injuries that caused aphasia. Receptive aphasia in which such abilities
are preserved is also known as Wernicke's aphasia. In this condition
there is a major impairment of language comprehension, while speech retains a
natural-sounding rhythm and a relatively normal syntax. Language as a result is
largely meaningless (a condition sometimes called fluent or jargon aphasia).
While neuroimaging and lesion evidence generally support the idea that
malfunction of or damage to Wernicke's area is common in people with receptive
aphasia, this is not always so. Some people may use the right hemisphere for
language, and isolated damage of Wernicke's area cortex (sparing white matter
and other areas) may not cause severe receptive aphasia. Even when patients
with Wernicke's area lesions have comprehension deficits, these are usually not
restricted to language processing alone. For example, one study found that
patients with posterior lesions also had trouble understanding nonverbal sounds
like animal and machine noises. In fact, for Wernicke's area, the impairments
in nonverbal sounds were statistically stronger than for verbal sounds.
Right homologous area
Research using Transcranial magnetic stimulation suggests that the
area corresponding to the Wernicke’s area in the non-dominant cerebral
hemisphere has a role in processing and resolution of subordinate meanings of
ambiguous words—such as (‘‘river’’) when given the ambiguous word (‘‘bank’’).
In contrast, the Wernicke's area in the dominant hemisphere processes dominant
word meanings (‘‘teller’’ given ‘‘bank’’).
No comments:
Post a Comment