scholarly journals Signatures of motor output variability across a spectrum of neurological disorders reveal severity levels and unexpected ties

2015 ◽  
Vol 15 (12) ◽  
pp. 641
Author(s):  
Elizabeth Torres
Keyword(s):  
Neurological Disorders ◽  
Motor Output ◽  
Output Variability ◽  
Motor Output Variability ◽  
Severity Levels

Different Neural Adjustments Improve Endpoint Accuracy With Practice in Young and Old Adults

2007 ◽  
Vol 97 (5) ◽  
pp. 3340-3350 ◽  
Author(s):  
Evangelos A. Christou ◽  
Brach Poston ◽  
Joel A. Enoka ◽  
Roger M. Enoka
Keyword(s):  
Young Adults ◽  
Motor Output ◽  
Peak Force ◽  
Absolute Difference ◽  
Antagonist Muscle ◽  
Old Adults ◽  
Time To Peak ◽  
Output Variability ◽  
Motor Output Variability ◽  
Target Force

The purpose of the study was to determine the practice-induced adjustments in the motor-output variability and the agonist–antagonist activity that accompanied improvements in endpoint accuracy of goal-directed isometric contractions in young and old adults. Young and old adults performed 100 trials that involved accurately matching the peak of a force trajectory (25% maximum) to a target force in 150 ms. Endpoint accuracy was quantified as the absolute difference between the target and the peak force and time-to-peak force. Motor-output variability was expressed as the SDs of the force trajectory, peak force, and time-to-peak force. The force and time errors differed between the two groups initially, but after 35 practice trials the errors were similar for the two groups. Reductions in force endpoint error were predicted by decreases in the variability of the force trajectory for both groups, adaptations in the agonist (first dorsal interosseus) and antagonist (second palmar interosseus) EMG for young adults, and adaptations only for the agonist EMG for old adults. Reductions in time endpoint error were predicted by increases in the SD of time-to-peak force and a longer delay to the peak EMG of the antagonist muscle for young adults, but by decreases in the SDs of time-to-peak force and force trajectory and a shorter delay to the peak EMG of the antagonist muscle for the old adults. The findings indicate that the neural adjustments underlying the improvement in endpoint accuracy with practice differed for young and old adults.

scholarly journals Response to “Motor Output Variability Impairs Driving Ability in Older Adults”

2017 ◽  
Vol 73 (2) ◽  
pp. 267-268
Author(s):  
Arne Stinchcombe ◽  
Anne Dickerson ◽  
Bruce Weaver ◽  
Michel Bédard
Keyword(s):  
Older Adults ◽  
Motor Output ◽  
Driving Ability ◽  
Output Variability ◽  
Motor Output Variability

scholarly journals What Is the Contribution of Ia-Afference for Regulating Motor Output Variability during Standing?

2017 ◽  
Vol 11 ◽  
Author(s):  
Niklas König ◽  
Matteo G. Ferraro ◽  
Heiner Baur ◽  
William R. Taylor ◽  
Navrag B. Singh
Keyword(s):  
Motor Output ◽  
Output Variability ◽  
Motor Output Variability

Age-associated differences in motor output variability and coordination during the simultaneous dorsiflexion of both feet

2017 ◽  
Vol 34 (2) ◽  
pp. 96-101 ◽  
Author(s):  
Amanda Marchini ◽  
Rafael Pereira ◽  
Wellington Pedroso ◽  
Evangelos Christou ◽  
Osmar Pinto Neto
Keyword(s):  
Motor Output ◽  
Output Variability ◽  
Motor Output Variability

scholarly journals Motor Output Variability Impairs Driving Ability in Older Adults: Reply to Stinchcombe, Dickerson, Weaver, and Bedard

2017 ◽  
Vol 73 (2) ◽  
pp. 269-270
Author(s):  
Evangelos Christou ◽  
Basma Yacoubi ◽  
Changki Kim ◽  
Hwasil Moon ◽  
Tanya Onushko ◽  
...  
Keyword(s):  
Older Adults ◽  
Motor Output ◽  
Driving Ability ◽  
Output Variability ◽  
Motor Output Variability

Speed/accuracy relations: The kinetic–kinematic link and predictions for rapid timing tasks

1997 ◽  
Vol 20 (2) ◽  
pp. 304-304
Author(s):  
Les G. Carlton ◽  
Yeou-Teh Liu
Keyword(s):  
Motor Output ◽  
Motor Tasks ◽  
Output Variability ◽  
Movement Error ◽  
Motor Output Variability ◽  
Model Predictions ◽  
Speed Accuracy

Recent accounts of the speed/accuracy relation for motor tasks have focused on the concept of motor output variability. We outline the advantages of this approach and the limitation of Plamondon's model in explaining movement error. We also examine and present complimentary data for rapid timing tasks. While these tasks do not meet the presented assumptions, the data still fit the model predictions.

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