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Titolo:
Intermittency in the visual control of force in Parkinson's disease
Autore:
Vaillancourt, DE; Slifkin, AB; Newell, KM;
Indirizzi:
Penn State Univ, Dept Kinesiol, University Pk, PA 16802 USA Penn State Univ University Pk PA USA 16802 l, University Pk, PA 16802 USA Penn State Univ, Dept Biobehav Hlth, University Pk, PA 16802 USA Penn State Univ University Pk PA USA 16802 h, University Pk, PA 16802 USA Penn State Univ, Gerontol Ctr, University Pk, PA 16802 USA Penn State Univ University Pk PA USA 16802 r, University Pk, PA 16802 USA CNRS, Marseille, France CNRS Marseille FranceCNRS, Marseille, France Univ Mediterranee, Marseille, France Univ Mediterranee Marseille FranceUniv Mediterranee, Marseille, France
Titolo Testata:
EXPERIMENTAL BRAIN RESEARCH
fascicolo: 1, volume: 138, anno: 2001,
pagine: 118 - 127
SICI:
0014-4819(200105)138:1<118:IITVCO>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOVEMENT CONTROL; MOTOR CONTROL; 40 HZ; TREMOR; VARIABILITY; INFORMATION; FEEDBACK; TRACKING; BRADYKINESIA; RESPONSES;
Keywords:
vision; force; Parkinson's disease; feedback;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Vaillancourt, DE Penn State Univ, Dept Kinesiol, 266 Recreat Bldg, University Pk, PA 16802 USA Penn State Univ 266 Recreat Bldg University Pk PA USA 16802
Citazione:
D.E. Vaillancourt et al., "Intermittency in the visual control of force in Parkinson's disease", EXP BRAIN R, 138(1), 2001, pp. 118-127

Abstract

Studies on the variability of motor output in Parkinson's disease have found contrasting results depending on the speed-accuracy constraints of the task. The first goal of this study was to determine if Parkinson's disease subjects are more variable than control subjects. The second goal of the study was to examine the limitations on visual and motor processing that contribute to the changes in force variability in Parkinson's disease. Eight mild to moderate Parkinson's disease (age: 68-80 years) and eight matched control (age: 68-80 years) subjects maintained a constant level of force at 25%of their maximum voluntary contraction with their index finger and thumb (grip precision task) for 20 s while online visual feedback of the total force was viewed on a computer monitor. During the force task, subjects received visual feedback at varying frequencies. The sampled visual feedback levels were presented at intervals as slow as every 5 s to as fast as every 0.04 s (0.2, 0.4, 0.8, 1.6, 3.2, 6.4, 12.8, 25.6 Hz). Force variability decreased over sampled visual feedback according to hyperbolic decay functions. The minimal visual processing time for both the Parkinson's disease and control subjects was approximately 160 ms. Motor output corrections were generated in both groups at a frequency of I Hz over a wide range of sampled visual feedback levels. However, the amplitude of the 1-2 Hz visuo-motor corrective process was amplified ill Parkinson's disease, and this related to increases in force-output variability. The findings suggest that the basal ganglia are important for adjusting the amplitude of motor output at 1-2 Hz during visuo-motor feedback control.

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Documento generato il 30/03/20 alle ore 19:44:34