Cerebral Networks of Speech Motor Control: fMRI Data
H. Ackermann, K. Mathiak, I. Hertrich,
W. Grodd, A. Riecker
Departments of Neurology and Neuroradiology,
University of Tübingen
5th International Conference onSpeech Motor ControlNijmegen, June 7 – 10, 2006
Cerebral Organization of Speech Motor Control: The Beginnings
Petersen et al. 1988, 1989 (PET study)but see Sidtis et al. 1999
Cerebral Organization of ….
Petersen et al. 1988, 1989, Posner & Raichle 21999
supplementary motor area (SMA)BL sensorimotor cortex LH insular cortexBL medial cerebellum
Wise et al. 1999: left anterior insula engaged in „articulatory planning“ (Dronkers 1996, but see Hillis et al. 2002)
P Indefrey, WJM Levelt. The spatial and temporal signatures of word production components. Cognition 2004;92:101-144
review of 82 imaging studies on word production
cerebral correlates / time course of the following successive stages of speech production:
lexical selection, phonological code retrieval, syllabification, self-monitoring, phonetic / articulatory processes (Levelt, Roelofs & Meyer 1999)
Indefrey & Levelt 2004
Cerebral Network of Phonetic /
Articulatory Processes
12 areas pertaining to the central-motor system:
R/L ventral motor and sensory regions, R dorsal motor region, R SMA, R/L cerebellum, R/L thalamus, R midbrain
5 areas not pertaining to the central-motor system,
e.g., orbitofrontal and occipitotemporal regions
Indefrey & Levelt 2004
Syllable Rate Control: fMRI Experiment I
figure
Riecker et al. 2005
normal subjects, overt (aloud) syllable repetitions (“pa”), 2.0 / 2.5 / 3.0 / 4.0 / 5.0 / 6.0 Hz, applied via earphones
Experiment I: Signal Analysis
1. Parametric approach:
1.1. hemodynamic main effects across all
repetition rates versus baseline
1.2. positive linear, negative linear andnonlinear rate / response
functions Büchel & Friston 1996,
1998
2. Connectivity analyses based upon time series of hemodynamic activation
Experiment I: Signal Analysis
1. Parametric approach:
1.1. hemodynamic main effects across all
repetition rates versus baseline
1.2. positive linear, negative linear andnonlinear rate / response
functions Büchel & Friston 1996,
1998
2. Connectivity analyses based upon time series of hemodynamic activation
Overt Syllable Repetitions IMain Effects
normal subjects
Riecker et al. 2005
Guenther et al. 2006
Experiment I: Signal Analysis
1. Parametric approach:
1.1. hemodynamic main effects across all
repetition rates versus baseline
1.2. positive linear, negative linear andnonlinear rate / response
functions Büchel & Friston 1996,
1998
2. Connectivity analyses based upon time series of hemodynamic activation
Overt Syllable Repetitions IIRate / Response Functions
Riecker et al. 2005
Overt Syllable Repetitions IIIGroup Averages
Riecker et al. 2005normal subjects
Insel links
0
2
4
6
1 2 3 4 5 6
Caudatum links
0
2
4
6
1 2 3 4 5 6
Putamen / Pallidum
0
2
4
6
1 2 3 4 5 6
Thalamus
0
2
4
6
1 2 3 4 5 6
JJ Sidtis, SC Strother, DA Rottenberg. Predicting performance from functional imaging data: Methods matter. NeuroImage 2003;20:615-624
question: can functional imaging data predict performance?
task: syllable repetitions as fast as possible
syllable rate = (- 3.55 * right caudate) + (2.51 * left inferior frontal) + 5.60
more efficient organization at higher rates (p.c.)
Rate Control / Basal Ganglia:
Brown 2003: Oscillatory nature of human basal
ganglia activity
Logigian et al. 1991: Tremor oscillations may pace
repetitive voluntary motor behaviour (finger
flexion / extension, oral diadochokinesis)
Possible control mechanism of syllable
repetitions: adjustment of inherent basal ganglia
oscillations to the pacing signal
Overt Syllable Repetitions IIIGroup Averages
Riecker et al. 2005
Cerebellum z=-24
0
2
4
6
1 2 3 4 5 6
Cerebellum z=-57
0
2
4
6
1 2 3 4 5 6
normal subjects
Syllable Rate Control: fMRI Experiment II
Hypothesis: differential contribution of basal ganglia and cerebellum to syllable rate control
Task: covert (silent) syllable repetitions, 2.5 / 4.0 / 5.5 Hz,
paced via earphones
Design: block design (8 blocks, R/A, 10 meas)
Analysis: categorical and parametric (rate and time effects) analysis using SPM99
Wildgruber et al. 2001
Covert Syllable Repetitions: R/R-F
Wildgruber et al. 2001
Syllable Rate in Dysarthric SubjectsAcoustic Analyses
Ackermann et al. 1995
Review: Hertrich, Ackermann. Acoustic analysis of durational ... In: Lebrun Y (ed). From the Brain to the Mouth. Dordrecht 1997, 11-47Review: Ackermann, Mathiak, Ivry. Temporal organization of „internal speech” ... Behav Cogn Neurosci Rev 2004;3:14-22
Overt Syllable Repetitions IIIGroup Averages
Riecker et al. 2005normal subjects
Insel links
0
2
4
6
1 2 3 4 5 6
Caudatum links
0
2
4
6
1 2 3 4 5 6
Putamen / Pallidum
0
2
4
6
1 2 3 4 5 6
Thalamus
0
2
4
6
1 2 3 4 5 6
Finger Tapping TasksRate / Response Functions
Riecker et al. 2003normal subjects
Summary Part 1: Cerebral Rate Control
Convergence of clinical-behavioural findings and
functional imaging data:
Striatum: normal speaking rate / hastening
phenomenon - negative fMRI rate / response
functions
Cerebellum: reduced syllable rate (> 3 Hz) –
fMRI threshold effect at about 3 Hz
for a review see Ackermann & Hertrich 2000, Ackermann et al. 2004
Cerebellar Functions
Experiment I: Signal Analysis
1. Parametric approach:
1.1. hemodynamic main effects across all
repetition rates versus baseline
1.2. positive linear, negative linear andnonlinear rate / response
functions Büchel & Friston 1996,
1998
2. Connectivity analyses based upon time series of hemodynamic activation
Time course of
hemodynamic
activation
Riecker et al. 2005
time (s)
effectsize
Two Cerebral Networks of Speech Motor Control ???
bold lines: very high correlations (>0.9)
thin lines: high correlations (0.75-0.9)
Syllable Rate Control: fMRI Experiment II
Hypothesis: differential contribution of basal ganglia and cerebellum to syllable rate control
Task: covert (silent) syllable repetitions, 2.5 / 4.0 / 5.5 Hz,
paced via earphones
Design: block design (8 blocks, R/A, 10 meas)
Analysis: categorical and parametric (rate and time effects) analysis using SPM99
Wildgruber et al. 2001
Covert production of fluent speech (highly overlearned word strings): Wildgruber et al. 1996, Ackermann et al. 1998, Riecker et al. 2000
Inner / Silent / Covert Speech
internal speech = “prearticulatory, but otherwise fully parsed speech code” (Levelt 1989)
“close functional equivalence between motor imagery and motor preparation” (Jeannerod 1994)
inner speech = “window” into articulatory planning processes (preceding movement execution)
but: Sokolov 1968, 1972
Covert Syllable Repetitions: R/R-F
Wildgruber et al. 2001LC: -21, -60, -24 / RC: 24, -57, -24
Guenther et al. 2006: DIVA model
effectsize
Two Cerebral Networks of Speech Motor Control ???
anterior insula / speech production: Ackermann & Riecker 2004
Hemodynamic activation of intrasylvian cortex
in association with
anticipation / application of painful stimuli,
spider phobia (sensitive to therapy),
swallowing & tactile stimulation of the tongue,
stress urinary incontinence (sensitive to therapy),
high-intensity emotional facial expressions,
aesthetic judgments of beauty,
olfactory functions.
NeuroImage, vol 29, no 1, January 1, 2006
Speech and Anterior Insula
Insular cortex part of the cerebral representation of the autonomic nervous system, e.g., cardiac functions or respiration, e.g., Harper et al. 2005
pre-setting of laryngeal and respiratory muscles
However, no insular activation during whistling, Dresel et al. 2005
for a review see Ackermann & Riecker 2004
Hemodynamic activation of intrasylvian cortex
in association with
anticipation / application of painful stimuli,
spider phobia (sensitive to therapy),
swallowing & tactile stimulation of the tongue,
stress urinary incontinence (sensitive to therapy),
high-intensity emotional facial expressions,
aesthetic judgments of beauty,
olfactory functions.
NeuroImage, vol 29, no 1, January 1, 2006
time (s)
effectsize
Insel links
0
2
4
6
1 2 3 4 5 6
Caudatum links
0
2
4
6
1 2 3 4 5 6
Putamen / Pallidum
0
2
4
6
1 2 3 4 5 6
Thalamus
0
2
4
6
1 2 3 4 5 6
Part 1: Rate / Response Functions ofHemodynamicActivation
Part 2:Time Course of Hemodynamic Activation
NEUROLOGIE Dirk Wildgruber
Axel RieckerIngo Hertrich Klaus Mathiak
Hermann Ackermann
Michael Erb Uwe Klose
Wolfgang Grodd
NEUROLOGY
NEURORADIOLOGY
Participants
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