The effect of Parkinson’s disease on the control of multi-segmental coordination

Bertram, Christopher P.; Lemay, Martin; Stelmach, George E.

doi:10.1016/j.bandc.2004.08.014

Cited by 33 publications

(13 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was found that the subjects significantly decreased peak arm velocity and spent more time for arm deceleration when reaching for an uncovered cup compared to those parameters observed when the subjects reached for a covered cup (Bertram et al 2005). Hence, in full agreement with the model of state estimation bias, significant safety margin is also induced by an increase in error cost asymmetry, while the amount of uncertainty about hand position with respect to the target object remains the same.…”

Section: State Estimation Bias Reflected As Safety Marginsupporting

confidence: 73%

State estimation bias induced by optimization under uncertainty and error cost asymmetry is likely reflected in perception

Shimansky

2011

Biol Cybern

View full text Add to dashboard Cite

It is well known from numerous studies that perception can be significantly affected by intended action in many everyday situations, indicating that perception and related decision-making is not a simple, one-way sequence, but a complex iterative cognitive process. However, the underlying functional mechanisms are yet unclear. Based on an optimality approach, a quantitative computational model of one such mechanism has been developed in this study. It is assumed in the model that significant uncertainty about task-related parameters of the environment results in parameter estimation errors and an optimal control system should minimize the cost of such errors in terms of the optimality criterion. It is demonstrated that, if the cost of a parameter estimation error is significantly asymmetrical with respect to error direction, the tendency to minimize error cost creates a systematic deviation of the optimal parameter estimate from its maximum likelihood value. Consequently, optimization of parameter estimate and optimization of control action cannot be performed separately from each other under parameter uncertainty combined with asymmetry of estimation error cost, thus making the certainty equivalence principle non-applicable under those conditions. A hypothesis that not only the action, but also perception itself is biased by the above deviation of parameter estimate is supported by ample experimental evidence. The results provide important insights into the cognitive mechanisms of interaction between sensory perception and planning an action under realistic conditions. Implications for understanding related functional mechanisms of optimal control in the CNS are discussed.

show abstract

Section: State Estimation Bias Reflected As Safety Marginsupporting

confidence: 73%

State estimation bias induced by optimization under uncertainty and error cost asymmetry is likely reflected in perception

Shimansky

2011

Biol Cybern

View full text Add to dashboard Cite

show abstract

“…Research suggests that extensor muscles are more impaired than flexor muscles for people with PD (Robichaud, Pfann, Comella, Brandabur, & Corcos, 2004), so using hip flexors to elevate the trunk might be easier than trying to push the trunk to an erect position from side lying using elbow extensors. Also, despite research indicating that people with PD have difficulty simultaneously performing two separate tasks or coordinating movements of the trunk with an extremity (Bertram, Lemay, & Stelmach, 2005;Seidler et al, 2001;Suri, Albani, & Glattfelder, 1998), other studies (Almeida, Wishart, & Lee, 2002;Stelmach & Worringham, 1988) reported no difference between people with PD and controls when performing the same task bilaterally simultaneously. Therefore, it may be easier for people with PD to coordinate bilateral simultaneous trunk and hip flexion than to coordinate the asymmetric Phys Occup Ther Geriatr Downloaded from informahealthcare.com by QUT Queensland University of Tech on 11/01/14…”

Section: Discussionmentioning

confidence: 96%

How People with Parkinson's Disease Get Out of Bed

Mount

Cianci

Weiman

et al. 2009

Physical & Occupational Therapy In Geriatrics

View full text Add to dashboard Cite

Background and Purpose. Difficulty with bed mobility is reported by 66% of people with Parkinson's disease (PD). Our purpose was to describe movement patterns (MPs) used by individuals with PD for rising from the bed and the influence of physical therapy (PT) on these patterns. Subjects. Thirty-nine subjects, ages between 45 and 89, Hoehn and Yahr levels I-IV, participated. Methods. Subjects were videotaped rising from bed five times. MPs were categorized for each body part. Subjects' reports of previous bed mobility training was documented. Results. The most common MPs were "come to sit" for the axial region, "multipush" for the near arm, "double-push" for the far arm, and "synchronous" for the legs. People with PD are significantly more likely to lift their legs synchronously and significantly less likely to use the "roll off" strategy than older adults without PD. Nine (23%) subjects had been taught the "lateral roll." Only three actually used it, and none of those three used it for every trial. Discussion and Conclusion. Further

show abstract

“…A number of studies on PD patients have reported impaired motor coordination in early PD, with some of the changes reflecting more general signs such as bradykinesia and tremor (Bertram et al 2005; Fradet et al 2009; Brown and Almeida 2011). One of the main goals of our line of research has been to introduce an objective, quantitative method for measuring impaired motor coordination.…”

Section: Discussionmentioning

confidence: 99%

Prehension synergies and hand function in early-stage Parkinson’s disease

Park

Lewis

et al. 2014

Exp Brain Res

View full text Add to dashboard Cite

We explored the multi-digit synergies and hand performance in object manipulations and pressing tasks in patients with early-stage Parkinson’s disease (PD) and healthy controls. Synergies were defined as inter-trials co-variation patterns among forces/moments produced by individual digits that stabilized a resultant mechanical variable. The subjects performed three main tasks: Pressing (steady-state force production followed by a force pulse into the target), prehension (manipulation of a hand-held instrumented handle imitating the action of taking a sip from a glass), and functional object manipulation (moving a glass with water as quickly and accurately as possible along a chain of targets). The PD patients were slower compared to controls in all three tasks. Patients showed smaller synergy indices in the pressing and prehension tasks. In the prehension tasks, patients showed elevated grip force at steady states with smaller grip force modulation during the handle motion. PD patients showed smaller feed-forward synergy adjustments in preparation to the quick action in the pressing and (to a smaller degree) prehension tasks. Synergy indices correlated with the time index of performance in the functional glass-with-water task, whereas none of the indices correlated with the Unified PD Rating Scale part III – motor scores (UPDRS- III). We interpret the results as pointing at an important role of subcortical structures in motor synergies and their feed-forward adjustments to action.

show abstract

The effect of Parkinson’s disease on the control of multi-segmental coordination

Cited by 33 publications

References 7 publications

State estimation bias induced by optimization under uncertainty and error cost asymmetry is likely reflected in perception

State estimation bias induced by optimization under uncertainty and error cost asymmetry is likely reflected in perception

How People with Parkinson's Disease Get Out of Bed

Prehension synergies and hand function in early-stage Parkinson’s disease

Contact Info

Product

Resources

About