Ch 7

Question 1

MRI Morphometry
Note …… in the sylvian fossa of the stutterer

Answer 1

Extra gyri

Question 2

Gene locations

Answer 2

All stutterers: chr 9
Persistent only: chr 15
Males only: chr. 7
Females only: chr. 21

Question 3

What might be transmitted?

Answer 3

Structural anomalies
Biochemical pathways
Brain processing
Motor skills
Temperament

Question 4

Cerebral dominance Theory

Answer 4

Proposed stuttering was caused by a lack of cerebral dominance

Left and right hemispheres compete for control of speech movements

Asynchrony of neural impulses from both sides of the brain disrupts speech fluency

Question 5

Auditory perceptual theory

Answer 5

1. Stuttering was caused by defective auditory feedback
2. The speaker expects to hear own speech sound earlier than their auditory system feeds it back
3. The speaker waits (prolongs) or repeats trying to correct the delay

Question 6

Brainstem reflexes: disorder of movement theory

Answer 6

Proposed stutterers have reduced tolerance for a range of oral movements

If the range is exceeded, brainstem reflex management is upset

Afferent and efferent signals of speech muscles conflict > so stuttering occurs

Question 7

DIVA (Directions into Velocities of Articulators)

Answer 7

Stuttering is due to a disorder of sensorimotor speech control

PWS have unreliable feedforward systems; they rely excessively on controlling speech via feedback

Fluency is disrupted by attempts to adjust speech movements after commands have been issued