TY - JOUR
T1 - Control and prediction components of movement planning in stuttering versus nonstuttering adults
AU - Daliri, Ayoub
AU - Prokopenko, Roman A.
AU - Flanagan, J. Randall
AU - Max, Ludo
N1 - Publisher Copyright:
© American Speech-Language-Hearing Association.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Purpose: Stuttering individuals show speech and nonspeech sensorimotor deficiencies. To perform accurate movements, the sensorimotor system needs to generate appropriate control signals and correctly predict their sensory consequences. Using a reaching task, we examined the integrity of these control and prediction components separately for movements unrelated to the speech motor system.Method: Nine stuttering and 9 nonstuttering adults made fast reaching movements to visual targets while sliding an object under the index finger. To quantify control, we determined initial direction error and end point error. To quantify prediction, we calculated the correlation between vertical and horizontal forces applied to the object—an index of how well vertical force (preventing slip) anticipated direction-dependent variations in horizontal force (moving the object).Results: Directional and end point error were significantly larger for the stuttering group. Both groups performed similarly in scaling vertical force with horizontal force.Conclusions: The stuttering group’s reduced reaching accuracy suggests limitations in generating control signals for voluntary movements, even for nonorofacial effectors. Typical scaling of vertical force with horizontal force suggests an intact ability to predict the consequences of planned control signals. Stuttering may be associated with generalized deficiencies in planning control signals rather than predicting the consequences of those signals.
AB - Purpose: Stuttering individuals show speech and nonspeech sensorimotor deficiencies. To perform accurate movements, the sensorimotor system needs to generate appropriate control signals and correctly predict their sensory consequences. Using a reaching task, we examined the integrity of these control and prediction components separately for movements unrelated to the speech motor system.Method: Nine stuttering and 9 nonstuttering adults made fast reaching movements to visual targets while sliding an object under the index finger. To quantify control, we determined initial direction error and end point error. To quantify prediction, we calculated the correlation between vertical and horizontal forces applied to the object—an index of how well vertical force (preventing slip) anticipated direction-dependent variations in horizontal force (moving the object).Results: Directional and end point error were significantly larger for the stuttering group. Both groups performed similarly in scaling vertical force with horizontal force.Conclusions: The stuttering group’s reduced reaching accuracy suggests limitations in generating control signals for voluntary movements, even for nonorofacial effectors. Typical scaling of vertical force with horizontal force suggests an intact ability to predict the consequences of planned control signals. Stuttering may be associated with generalized deficiencies in planning control signals rather than predicting the consequences of those signals.
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U2 - 10.1044/2014_JSLHR-S-13-0333
DO - 10.1044/2014_JSLHR-S-13-0333
M3 - Article
C2 - 25203459
AN - SCOPUS:84918806887
SN - 1092-4388
VL - 57
SP - 2131
EP - 2141
JO - Journal of Speech, Language, and Hearing Research
JF - Journal of Speech, Language, and Hearing Research
IS - 6
ER -