Aphasias

Question 1

Broca’s Aphasia

Answer 1

• Non-fluent and agrammatic, slowed syntax
• Grammatical deficit, repetitive and expressive processing, effects on retrieval ability
• Global parsing failures: trouble with gap-filling
• Trace-Deletion Hypothesis –> evidence does not support, because Broca’s aphasia does not only have trouble with sentences involving movement

Question 2

Wernicke’s Aphasia

Answer 2

• Fluent, but largely meaningless speech
• Difficulty comprehending spoken and written input
• Deficit in process that maps concepts to sounds

Question 3

Lateralization

Answer 3

Speech production and comprehension is lateralized to the left hemisphere of the brain ––> 95% of right-handed people, 70% of left-handed people

Question 4

Equipotentiality Theory

Answer 4

• Intellectual abilities (including language) are the result of mass action

Question 5

Localizationist Theory

Answer 5

• Specific parts of the brain perform different functions
• Broca’s and Wernicke’s areas: non-fluent and fluent aphasia
• Posterior areas store “remembered images” of sound and images & anterior areas store “impressions of action”

Question 6

WLG Model

Answer 6

Areas of the Brain:
- Wernicke’s area: stores sound and meaning
- Arcuate fasciculus (AF): transmits information from Wernicke’s area to Broca’s area
- Broca’s area: sequences words, generates grammatical form, stores motor plans for speech output
Additional:
- Posterior and anterior subsystems function independently –> causes comprehension and production to disassociate
- Damage to posterior: problems with sound and meaning
- Damage to anterior: problems with syntax and production
- Damage to AF: problems repeating what you hear (Conduction Aphasia)

Question 7

Weaknesses of the WGL Model

Answer 7

• Does not accurately describe brain areas in language processing (e.g. damage restricted to Broca’s area = short-lasting speech problems)
• Neurological disagreement on where Wernicke’s area is –> multifocal and diffuse regions can cause fluent aphasia
• Other brain areas in language comprehension: basal ganglia (Broca’s aphasia occurs when damage to Broca’s are + basal ganglia; not just Broca’s area)
• No correlation between lesion location and symptoms: damage outside of Broca’s, Wernicke’s, and AF can cause same symptoms

Question 8

Resource Restriction Hypothesis

Answer 8

• Building syntactic structure: assigning meanings to structured representations requires resources