Brain, Vol. 123, No. 6, 1184-1202,
June 2000
© 2000 Oxford University Press
Single word reading in developmental stutterers and fluent speakers
1 Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland and 2 Department of Neurology, Heinrich-Heine-University, Düsseldorf, Germany
Correspondence to:
Riitta Salmelin, Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, PO Box 2200, FIN-02015 HUT, Finland E-mail: riitta{at}neuro.hut.fi
Ten fluent speakers and nine developmental stutterers read isolated nouns aloud in a delayed reading paradigm. Cortical activation sequences were mapped with a whole-head magnetoencephalography system. The stutterers were mostly fluent in this task. Although the overt performance was essentially identical in the two groups, the cortical activation patterns showed clear differences, both in the evoked responses, time-locked to word presentation and mouth movement onset, and in task-related suppression of 20-Hz oscillations. Within the first 400 ms after seeing the word, processing in fluent speakers advanced from the left inferior frontal cortex (articulatory programming) to the left lateral central sulcus and dorsal premotor cortex (motor preparation). This sequence was reversed in the stutterers, who showed an early left motor cortex activation followed by a delayed left inferior frontal signal. Stutterers thus appeared to initiate motor programmes before preparation of the articulatory code. During speech production, the right motor/premotor cortex generated consistent evoked activation in fluent speakers but was silent in stutterers. On the other hand, suppression of motor cortical 20-Hz rhythm, reflecting task-related neuronal processing, occurred bilaterally in both groups. Moreover, the suppression was right-hemisphere dominant in stutterers, as opposed to left-hemisphere dominant in fluent speakers. Accordingly, the right frontal cortex of stutterers was highly active during speech production but did not generate synchronous time-locked responses. The speech-related 20-Hz suppression concentrated in the mouth area in fluent speakers, but was evident in both the hand and mouth areas in stutterers. These findings may reflect imprecise functional connectivity within the right frontal cortex and incomplete segregation between the adjacent hand and mouth motor representations in stutterers during speech production. A network including the left inferior frontal cortex and the right motor/premotor cortex, likely to be relevant in merging linguistic and affective prosody with articulation during fluent speech, thus appears to be partly dysfunctional in developmental stutterers.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. L. Ludlow, J. Hoit, R. Kent, L. O. Ramig, R. Shrivastav, E. Strand, K. Yorkston, and C. M. Sapienza Translating Principles of Neural Plasticity Into Research on Speech Motor Control Recovery and Rehabilitation J Speech Lang Hear Res, February 1, 2008; 51(1): S240 - S258. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Saarinen, H. Laaksonen, T. Parviainen, and R. Salmelin Motor Cortex Dynamics in Visuomotor Production of Speech and Non-speech Mouth Movements Cereb Cortex, February 1, 2006; 16(2): 212 - 222. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Corbera, M.-J. Corral, C. Escera, and M. A. Idiazabal Abnormal speech sound representation in persistent developmental stuttering Neurology, October 25, 2005; 65(8): 1246 - 1252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. G. Vossler, A. M. Haltiner, S. K. Schepp, P. A. Friel, L. M. Caylor, J. D. Morgan, and M. J. Doherty Ictal stuttering: A sign suggestive of psychogenic nonepileptic seizures Neurology, August 10, 2004; 63(3): 516 - 519. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. T. Devlin, P. M. Matthews, and M. F. S. Rushworth Semantic Processing in the Left Inferior Prefrontal Cortex: A Combined Functional Magnetic Resonance Imaging and Transcranial Magnetic Stimulation Study J. Cogn. Neurosci., January 1, 2003; 15(1): 71 - 84. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. H. Perkins and D. B. Rosenfield Anomalous anatomy of speech-language areas in adults with persistent developmental stuttering Neurology, January 22, 2002; 58(2): 332 - 334. [Full Text] [PDF]
|
|
|
|
 |
|
 C. L. Ludlow Stuttering: dysfunction in a complex and dynamic system Brain, October 1, 2000; 123(10): 1983 - 1984. [Full Text] [PDF]
|
|