PSF has an adverse effect on the patient's quality of life, recovery, and mortality. Its impact on physical function and independence requires further investigation. There are a number of tools available to measure fatigue in neurological conditions. However, very few of them have been validated in stroke. Lastly, single-disciplinary management for PSF was rarely successful. In contrast, evidence suggests that approaches which incorporated both physical and psychological interventions may be beneficial. Further studies are urgently needed to gain a better understanding of the etiology of PSF, such that the development of better management strategies is possible.
Although intermixing different motor learning tasks via random schedules enhances long-term retention compared with "blocked" schedules, the mechanism underlying this contextual interference effect has been unclear. Furthermore, previous studies have reported inconclusive results in individuals poststroke. We instructed participants to learn to produce three grip force patterns in either random or blocked schedules and measured the contextual interference effect by long-term forgetting: the change in performance between immediate and 24-h posttests. Nondisabled participants exhibited the contextual interference effect: no forgetting in the random condition but forgetting in the blocked condition. Participants at least 3 mo poststroke exhibited no forgetting in the random condition but marginal forgetting in the blocked condition. However, in participants poststroke, the integrity of visuospatial working memory modulated long-term retention after blocked schedule training: participants with poor visuospatial working memory exhibited little forgetting at 24 h. These counterintuitive results were predicted by a computational model of motor memory that contains a common fast process and multiple slow processes, which are competitively updated by motor errors. In blocked schedules, the fast process quickly improved performance, therefore reducing error-driven update of the slow processes and thus poor long-term retention. In random schedules, interferences in the fast process led to slower change in performance, therefore increasing error-driven update of slow processes and thus good long-term retention. Increased forgetting rates in the fast process, as would be expected in individuals with visuospatial working memory deficits, led to small updates of the fast process during blocked schedules and thus better long-term retention. stroke; neurorehabilitation; motor learning; computational neuroscience DURING NEUROREHABILITATION after brain injury, but also in activities such as sports, technical training, and music, one must often learn, or relearn, multiple motor tasks within a given period. Intermixing the learning of different tasks via random schedules reduces performance during training but enhances long-term retention compared with blocked schedules, (e.g., Schmidt and Lee 1999;Shea and Morgan 1979;Tsuitsui et al. 1998). This phenomenon is known as the contextual interference (CI) effect.Despite close to a century of research (Pyle 1919), however, the mechanism underlying the CI effect are unclear. According to the "forgetting-reconstruction" hypothesis of the CI effect, short-term forgetting between successive presentations of the same task during random training requires the learner to "reconstruct the action plan at each presentation," resulting in stronger memory representations (Lee and Magill 1983;Lee et al. 1985). Recent computational models similarly suggest a crucial role of working memory in the CI effect. It has notably been proposed that motor adaptation occurs via simultaneous update of a fast proce...
Practicing a motor task under dual-task conditions can be beneficial to motor learning when the secondary task is difficult (Roche et al. in Percept Psychophys 69(4):513-522, 2007) or when it engages similar processes as the primary motor task (Hemond et al. in J Neurosci 30(2):650-654, 2010). The purpose of this pilot study was to determine which factor, difficulty level or engaged processes, of a secondary task is more critical in determining dual-task benefit. Participants practiced a discrete arm task in conjunction with an audio-vocal reaction time (RT) task. We presented two different RT tasks that differed in difficulty, simple versus choice (i.e., more difficult), at two different arm task phases that differed in engaged processes, preparation versus execution, resulting in four dual-task conditions. A simple RT task is thought to predominantly engage motor execution processes, therefore would engage similar processes as the arm movement task when it is presented during the execution phase, while a choice RT task is thought to engage planning processes and therefore would engage similar processes too when it is presented during the preparation phase. Enhanced motor learning was found in those who engaged similar process as the primary task during dual-tasking (i.e., choice RT presented during preparation and simple RT presented during execution). Moreover, those who showed enhanced learning also demonstrated high dual-task cost (poor RT task performance) during practice, indicating that both tasks were taxing the same resource pool possibly due to engaging similar cognitive processes. To further test the relation between dual-task cost and enhanced learning, we delayed the presentation timing of the choice RT task during the preparation phase and the simple RT task during the execution phase in two control experiments. Dual-task cost was reduced in these delayed timing conditions, and the enhanced learning effect was attenuated. Together, our preliminary findings suggest that it is the similarity hypothesis and not the difficulty hypothesis that mediates the enhanced motor learning under dual-task conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.