Cerebral Networks of Speech Motor Control: fMRI Data

1
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 on Speech Motor
Control Nijmegen, June 7 10, 2006
2
Cerebral Organization of Speech Motor Control
The Beginnings

Petersen et al. 1988, 1989 (PET study) but see
Sidtis et al. 1999
3
Cerebral Organization of .

supplementary motor area (SMA) BL sensorimotor
cortex LH insular cortex BL medial cerebellum
Petersen et al. 1988, 1989, Posner Raichle
21999
Wise et al. 1999 left anterior insula engaged in
articulatory planning (Dronkers 1996, but see
Hillis et al. 2002)
4

• P Indefrey, WJM Levelt. The spatial and temporal
  signatures of word production components.
  Cognition 200492101-144
• 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)

5
Indefrey Levelt 2004
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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
7

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
8
Experiment I Signal Analysis
1. Parametric approach 1.1. hemodynamic
main effects across all repetition
rates versus baseline 1.2. positive linear,
negative linear and nonlinear rate / response
functions Büchel Friston 1996, 1998
2. Connectivity analyses based upon time
series of hemodynamic activation
9
Experiment I Signal Analysis
1. Parametric approach 1.1. hemodynamic
main effects across all repetition
rates versus baseline 1.2. positive linear,
negative linear and nonlinear rate / response
functions Büchel Friston 1996, 1998
2. Connectivity analyses based upon time
series of hemodynamic activation
10
Overt Syllable Repetitions I Main Effects
normal subjects
Riecker et al. 2005
11
Guenther et al. 2006
12
Experiment I Signal Analysis
1. Parametric approach 1.1. hemodynamic
main effects across all repetition
rates versus baseline 1.2. positive linear,
negative linear and nonlinear rate / response
functions Büchel Friston 1996, 1998
2. Connectivity analyses based upon time
series of hemodynamic activation
13
Overt Syllable Repetitions II Rate / Response
Functions
Riecker et al. 2005
14
Overt Syllable Repetitions III Group Averages
normal subjects
Riecker et al. 2005
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• JJ Sidtis, SC Strother, DA Rottenberg. Predicting
  performance from functional imaging data Methods
  matter. NeuroImage 200320615-624
• 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.)

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• 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

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Overt Syllable Repetitions III Group Averages
normal subjects
Riecker et al. 2005
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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
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Covert Syllable Repetitions R/R-F
Wildgruber et al. 2001
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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, 11-47 Review
Ackermann, Mathiak, Ivry. Temporal organization
of internal speech ... Behav Cogn Neurosci Rev
2004314-22
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Overt Syllable Repetitions III Group Averages
normal subjects
Riecker et al. 2005
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Finger Tapping Tasks Rate / Response Functions
normal subjects
Riecker et al. 2003
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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 (gt 3 Hz) fMRI threshold
effect at about 3 Hz
for a review see Ackermann Hertrich 2000,
Ackermann et al. 2004
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Cerebellar Functions
25
Experiment I Signal Analysis
1. Parametric approach 1.1. hemodynamic
main effects across all repetition
rates versus baseline 1.2. positive linear,
negative linear and nonlinear rate / response
functions Büchel Friston 1996, 1998
2. Connectivity analyses based upon time
series of hemodynamic activation
26
Time course of hemodynamic activation
Riecker et al. 2005
27
Two Cerebral Networks of Speech Motor Control
???
effect size
bold lines very high correlations (gt0.9)
thin lines high correlations (0.75-0.9)
time (s)
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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

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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

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Covert Syllable Repetitions R/R-F
Wildgruber et al. 2001
LC -21, -60, -24 / RC 24, -57, -24
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Guenther et al. 2006 DIVA model
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Two Cerebral Networks of Speech Motor Control
???
effect size
anterior insula / speech production Ackermann
Riecker 2004
33

• 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
34

• 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
35

• 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
36
Part 1 Rate / Response Functions
of Hemodynamic Activation
effect size
Part 2 Time Course of Hemodynamic Activation
time (s)
37
Participants
NEUROLOGY

• Dirk Wildgruber
• Axel Riecker
• Ingo Hertrich
• Klaus Mathiak
• Hermann Ackermann

NEURORADIOLOGY
Michael Erb Uwe Klose Wolfgang Grodd