Temporal specificity of the initial adaptive response in motor adaptation

Wilsaan Joiner, Gary C. Sing, Maurice A. Smith

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Repeated exposure to a novel physical environment eventually leads to a mature adaptive response whereby feedforward changes in motor output mirror both the amplitude and temporal structure of the environmental perturbations. However, adaptive responses at the earliest stages of learning have been found to be not only smaller, but systematically less specific in their temporal structure compared to later stages of learning. This observation has spawned a lively debate as to whether the temporal structure of the initial adaptive response is, in fact, stereotyped and non-specific. To settle this debate, we directly measured the adaptive responses to velocity-dependent and position-dependent force-field perturbations (vFFs and pFFs) at the earliest possible stage of motor learning in humans–after just a single-movement exposure. In line with previous work, we found these earliest stage adaptive responses to be more similar than the perturbations that induced them. However, the single-trial adaptive responses for vFF and pFF perturbations were clearly distinct, and the disparity between them reflected the difference between the temporal structure of the perturbations that drove them. Critically, we observed these differences between single-trial adaptive responses when vFF and pFF perturbations were randomly intermingled from one trial to the next within the same block, indicating perturbation response specificity at the single trial level. These findings demonstrate that the initial adaptive responses to physical perturbations are not stereotyped. Instead, the neural plasticity in sensorimotor areas is sensitive to the temporal structure of a movement perturbation even at the earliest stage in learning. This insight has direct implications for the development of computational models of early-stage motor adaptation and the evolution of this adaptive response with continued training.

Original languageEnglish (US)
Article numbere1005438
JournalPLoS Computational Biology
Volume13
Issue number7
DOIs
StatePublished - Jul 1 2017
Externally publishedYes

Fingerprint

Specificity
learning
perturbation
Perturbation
Learning
Plasticity
Mirrors
Neuronal Plasticity
Dependent
Force Field
Feedforward
plasticity
Computational Model
Mirror
Distinct
trial
Line
Output
Demonstrate

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Modeling and Simulation
  • Ecology
  • Molecular Biology
  • Genetics
  • Cellular and Molecular Neuroscience
  • Computational Theory and Mathematics

Cite this

Temporal specificity of the initial adaptive response in motor adaptation. / Joiner, Wilsaan; Sing, Gary C.; Smith, Maurice A.

In: PLoS Computational Biology, Vol. 13, No. 7, e1005438, 01.07.2017.

Research output: Contribution to journalArticle

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