Neurodevelopmental Contributions to Stuttering Flashcards
Inferior Frontal Gyrus
Anterior: Wired to primary auditory cortex
-Sound meaning (VENTRAL STREAM)
Posterior: Wired to vPMC, pSTG, IPC
- Sound encoding
- Syllabification
- Articulatory codes
Ventral Premotor Cortex
Motor Cortex
Sensory Cortex
Ventral Premotor: Mapping speech sounds to motor commands (DORSAL stream)
Motor: executing motor movements
-sends signals to lungs, voice, tongue, lips & jaw
Auditory areas
Primary Auditory Cortex:
-1st cortical processing of speech sounds (part of STG)
Posterior STG:
- Secondary processing of speech sounds
- **Division of sound features and meaning (temporoparietal junction)
BG
Cerebellum
BG - voluntary motor control
- procedural learning
- action selection
- inhibitory influence on cortex
Cerebellum
- motor control
- coordination, precision and timing of movements
- motor learning & sensorimotor adaptation
Structure Brain Imaging
Measurement Tools:
- sMRI
- dMRI
- flash MRI
Analysis Tools
- volume
- density
- thickness
- folding pattern
- diffusion properties (FA)
- structural connectivity (tractography)
Functional Brain Imaging
Measurement Tools:
- fMRI
- MEG
- EEG
- fNIRS
Analysis Tools
- BOLD changes
- Functional connectivity
s/dMRI Summary of Differences
L posterior IFG
- altered development of grey matter (kids less, adults more) - delay in devt then in pruning
- reduced connectivity of white matter wiring
fMRI: adults who stutter
- no studies for kids
- increased motor activity in brain,
- decreased activity in sound perception (auditory)
MEG: adults & childern
Adults: different pattern of latencies in speech induced suppression, timing of brain signals was different
Children: same amplitude, timing of speech signals different
EEG: children
- lower accuracy on rhyming judgement
- reduced amplitude of EEG signal
- inefficient phonological rehersal and target anticipation for rhyming
fNIRS: both
differences in CWS brains from preschool age (no L hemi bias for phoneme monitoring or R hemi bias for prosody monitoring)
White Matter
Tracts from Broca’s (BA44) don’t extend as far back in adults, they have less functional connectivity from premotor area (BA 6)to auditory and motor areas
DIVA Model
theoretical model of speech that is fully specified both mathematically and neurally.
- most detailed/thorough
- accounts for variety of speech production phenomena
GODIVA
more complex DIVA including subcortical structures
-attempt to model basal ganglia loop and its role in speech sequence learning
