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The Use of Open‐ and Closed‐Loop Control During Goal‐Directed Force Responses by Children with Heavy Prenatal Alcohol Exposure
Author(s) -
Simmons Roger W.,
Nguyen Tanya T.,
Thomas Jennifer D.,
Riley Edward P.
Publication year - 2015
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/acer.12827
Subject(s) - duration (music) , prenatal alcohol exposure , alcohol , turnover , physical medicine and rehabilitation , loop (graph theory) , control (management) , psychology , medicine , computer science , control theory (sociology) , physics , chemistry , mathematics , biochemistry , management , combinatorics , artificial intelligence , acoustics , economics
Background Many daily functional activities involve goal‐directed responses based on open‐loop and closed‐loop motor control, yet little is known about how children with heavy prenatal alcohol exposure organize and regulate these 2 types of control systems when completing a goal‐directed force response. Methods Children with ( n = 19) or without ( n = 23) heavy prenatal alcohol exposure were required to match a target force (25 and 50% of maximum voluntary force) in a specified target time (200, 800, and 2,000 ms). Target force and produced force were visually displayed on a computer monitor. The analog force–time record was parsed into 2 segments: the period beginning from force initiation to the first reversal in force was designated the open‐loop phase, and the remainder of the response was the closed‐loop phase. Results Compared to controls, alcohol‐exposed children produced a significantly shorter duration of open‐loop control, a higher open‐loop phase rate of force development, a shorter time to reach maximum force during the closed‐loop phase, and greater absolute target force error. Increasing target force magnitude did not differentially alter the performance of the clinical group. Conclusions The results indicate that alcohol‐exposed children experience deficits in completing goal‐directed force responses that likely stem from an alcohol‐related insult to the central nervous system. Therapeutic exercises should be designed to recalibrate internal timing systems and improve visuomotor integration.