Physiology · Central Nervous System

Aphasia and speech physiology

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Definition

  • Aphasia (dysphasia) is loss or impairment of production and/or comprehension of spoken or written language due to an acquired lesion of the brain.
  • Language and speech areas (the "language zone") lie in association cortex around the Sylvian fissure (perisylvian areas).

Language and Speech Areas of the Brain

Receptive and executive language areas

Area

Wernicke's area (area 22)

Type
Receptive
Location
Superior temporal lobe (parieto-temporo-occipital association cortex)
Function
Comprehension, recognition and construction of spoken language

Angular gyrus (area 39, Dejerine's area)

Type
Receptive
Location
Inferior parietal lobule, anterior to the visual receptive area
Function
Perception of written language

Areas 41 and 42

Type
Receptive
Location
Association cortex
Function
Processing of spoken language

Broca's area (areas 44 and 45)

Type
Executive (motor)
Location
Frontal lobe, prefrontal association cortex adjacent to motor cortex
Function
Motor programming of speech; regulates muscles of lips, tongue, pharynx, larynx

Exner writing area

Type
Executive (motor)
Location
Posterior frontal lobe
Function
Expresses visually perceived words in writing