Subspace-based predictive control of Parkinson’s disease: A model-based study

2021 ◽  
Author(s):  
Mahboubeh Ahmadipour ◽  
Mojtaba Barkhordari-Yazdi ◽  
Saeid R. Seydnejad
2001 ◽  
Vol 7 (6) ◽  
pp. 710-727 ◽  
Author(s):  
W. TODD MADDOX ◽  
J. VINCENT FILOTEO

The contribution of the striatum to category learning was examined by having patients with Parkinson's disease (PD) and matched controls solve categorization problems in which the optimal rule was linear or nonlinear using the perceptual categorization task. Traditional accuracy-based analyses, as well as quantitative model-based analyses were performed. Unlike accuracy-based analyses, the model-based analyses allow one to quantify and separate the effects of categorization rule learning from variability in the trial-by-trial application of the participant's rule. When the categorization rule was linear, PD patients showed no accuracy, categorization rule learning, or rule application variability deficits. Categorization accuracy for the PD patients was associated with their performance on a test believed to be sensitive to frontal lobe functioning. In contrast, when the categorization rule was nonlinear, the PD patients showed accuracy, categorization rule learning, and rule application variability deficits. Furthermore, categorization accuracy was not associated with performance on the test of frontal lobe functioning. Implications for neuropsychological theories of categorization learning are discussed. (JINS, 2001, 7, 710–727.)


2020 ◽  
Author(s):  
Zahra Rahmati ◽  
Saeed Behzadipour ◽  
Alfred C. Schouten ◽  
Ghorban Taghizadeh ◽  
Keikhosrow Firoozbakhsh

Abstract Background: Balance training improves postural control in Parkinson’s disease (PD). However, a systematic approach for the development of individualized, optimal training programs is still lacking, as the learning dynamics of the postural control in PD, over a training program are poorly understood. Objectives: We investigated the learning dynamics of the postural control in PD, during a balance-training program, in terms of the clinical, posturographic, and novel model-based measures. Methods: Twenty patients with PD participated in a balance-training program, 3 days a week, for 6 weeks. Clinical tests assessed functional balance and mobility pre-training, mid-training, and post-training. Center-of-pressure (COP) was recorded at four time-points during the training (pre-, week 2, week 4, and post-training). COP was used to calculate the sway measures and to identify the parameters of a patient-specific postural control model, at each time-point. The posturographic and model-based measures constituted the two sets of stability- and flexibility-related measures. Results: Mobility- and flexibility-related measures showed a continuous improvement during the balance-training program. In particular, mobility improved at mid-training and continued to improve to the end of the training, whereas flexibility-related measures reached significance only at the end. The progression in the balance- and stability-related measures was characterized by early improvements over the first three to four weeks of training, and reached a plateau for the rest of the training. Conclusions: The progression in balance and postural stability is achieved earlier and susceptible to plateau out, while mobility and flexibility continues to improve during the balance training.


2020 ◽  
Author(s):  
Zahra Rahmati ◽  
Saeed Behzadipour ◽  
Alfred C. Schouten ◽  
Ghorban Taghizadeh ◽  
Keikhosrow Firoozbakhsh

Abstract Background: Balance training improves postural control in Parkinson’s disease (PD). However, a systematic approach for the development of individualized, optimal training programs is still lacking, as the learning dynamics of the postural control in PD, over a training program are poorly understood.Methods: We explored the learning dynamics of the postural control in PD, during a balance-training program, in terms of the clinical, posturographic, and model-based measures. Twenty patients with PD participated in a balance-training program, 3 days a week, for 6 weeks. Clinical tests assessed functional balance and mobility pre-training, mid-training, and post-training. Center-of-pressure (COP) was recorded at four time-points during the training (pre-, week 2, week 4, and post-training). COP was used to calculate the sway measures and to identify the parameters of a patient-specific postural control model, at each time-point (stability and flexibility degree). The posturographic and model-based measures constituted the two sets of stability- and flexibility-related measures.Results: Mobility- and flexibility-related measures showed a continuous improvement during the balance-training program. In particular, mobility improved at mid-training and continued to improve to the end of the training, whereas flexibility-related measures reached significance only at the end. The progression in the balance- and stability-related measures was characterized by early improvements over the first three to four weeks of training, and reached a plateau for the rest of the training. Conclusions: The progression in balance and postural stability is achieved earlier and susceptible to plateau out, while mobility and flexibility continues to improve during balance training.


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