Journal article
Anticipatory postural adjustments under simple and choice reaction time conditions
Brain research, Vol.924(2), pp.184-197
2002
DOI: 10.1016/S0006-8993(01)03233-4
PMID: 11750904
Abstract
Two different schemes of the central organization of anticipatory postural adjustments (APAs) have been proposed: one of them assumes that postural and focal components of an action are results of a single control process (single-process hypothesis) while the other one suggests that these two components result from two relatively independent control processes (dual-process hypothesis). To distinguish between the two hypotheses, we investigated changes in the relative timing of the postural and focal components under self-paced, simple reaction time (SRT) and choice reaction conditions (CRT). Standing subjects performed one of four small arm movements resulting in a standard postural perturbation (dropping a load). APAs were quantified as changes in the background muscle activity as well as shifts of the center of pressure. APAs occurred at a larger delay prior to the focal movement under the self-paced condition than under the SRT condition. Under the CRT condition, actual RTs were longer than under SRT, but APAs were more similar to those under self-paced conditions. A negative correlation between the reaction time and APA onset was found. The findings demonstrate that the focal and APA components of an action can be decoupled, thus supporting the dual-process hypothesis. Changes in APAs with action suggest a possibility of modifications of a function that transforms two parallel control signals into a single command to the focal and postural muscles, based on postural requirements and behavioral constraints.
Details
- Title: Subtitle
- Anticipatory postural adjustments under simple and choice reaction time conditions
- Creators
- Harm Slijper - Department of Kinesiology, Rec. Hall-267L, The Pennsylvania State University, University Park, PA 16802, USAMark L Latash - Department of Kinesiology, Rec. Hall-267L, The Pennsylvania State University, University Park, PA 16802, USAJ.Toby Mordkoff - Department of Psychology, The Pennsylvania State University, University Park, PA 16802, USA
- Resource Type
- Journal article
- Publication Details
- Brain research, Vol.924(2), pp.184-197
- DOI
- 10.1016/S0006-8993(01)03233-4
- PMID
- 11750904
- NLM abbreviation
- Brain Res
- ISSN
- 0006-8993
- eISSN
- 1872-6240
- Publisher
- Elsevier B.V
- Language
- English
- Date published
- 2002
- Academic Unit
- Psychological and Brain Sciences
- Record Identifier
- 9984001102302771
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