3-14 The Biological Basis Of Language (Part 2)

Front 1

Objective

Describe the symptoms of Broca's and Wernicke's aphasia.

Back 1

See study guide.

Front 2

Objective

Find at least three ways that a dyslexic and non-dyslexic brain tend to differ.

Back 2

Dyslexia is a specific impairment of reading in a person with adequate vision and adequate skills in other academic areas. Here are three differences that have been notes in the brains of dyslexic and non-dyslexic individuals:

1. People with dyslexia are more likely to have a bilaterally symmetrical cerebral cortex, whereas in other people, the planum temporale and certain other areas are larger in the left hemisphere.
2. In some people with dyslexia, certain language-related areas are actually larger in the right hemisphere.
3. Dyslexics also show signs of weak connections among several brain areas, such that activity in one part of the left cerebral cortex tends to be uncorrelated with activity in other areas of the left cortex, unlike the pattern for normal readers.

Front 3

Objective

Discuss three hypotheses about the cause of dyslexia.

Back 3

1. Visual Impairment: This theory has fallen out of favor because most people with dyslexia show normal, or close to normal, visual abilities.

2. Hearing Impairment: The brains of dyslexics show less-than-normal levels of activation in response to speech sounds, especially consonants. However, it is possible to have dyslexia without a hearing impairment.

3. Problems Connecting Vision to Sound: In one study, dyslexics performed normally at watching nonsense words flashed on the screen and saying whether they were the same or different (e.g. brap-brap (same), sond-snod (different)). They were also equal to normals at listening to two nonsense words and saying whether they were the same. They were impaired only when they had to look at a nonsense word on the screen and then say whether it was the same as a nonsense word they heard. Other evidence indicate that the act of reading, which strongly activates areas of the left temporal and parietal cortex for most people, only weakly activates them in people with dyslexia. These areas are believed to be important for linking visual and auditory information.

4. Differences in Attention: Suppose a dot flashes on the left or right part of a screen, and it is your task to identify the location. Sometimes a circle flashes off and on just 100 milliseconds before the dot. If it flashes in the same location as the circle, it improves the performance of most people but not those with dyslexia. Evidently, they do not shift attention in the same way as other people, and reading requires shifting attention from one word to the next.

Front 4

aphasia

Back 4

Severe language impairment

Front 5

Broca's area

Back 5

Portion of the human left frontal lobe associated with certain aspects of language, especially language production

Front 6

Broca's aphasia

Back 6

Condition marked by loss of fluent speech and impaired use and understanding of prepositions, word endings, and other grammatical devices

Front 7

Wernicke's area

Back 7

Portion of the human left temporal lobe associated with language comprehension

Front 8

Wernicke's aphasia

Back 8

Condition marked by poor language comprehension and great difficulty remembering the names of objects

Front 9

anomia

Back 9

Difficulty recalling the names of objects

Front 10

dyslexia

Back 10

Specific reading difficulty in a person with adequate vision and at least average skills in other academic areas