scholarly journals Reward and punishment enhance motor adaptation in stroke

2017 ◽  
Author(s):  
Graziella Quattrocchi ◽  
Richard Greenwood ◽  
John C Rothwell ◽  
Joseph M Galea ◽  
Sven Bestmann
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Motor Adaptation ◽  
Similar Degree ◽  
Stroke Patients ◽  
Neutral Group ◽  
Rehabilitation Outcomes ◽  
First Time ◽  
Adaptation Phase ◽  
Reward And Punishment

ABSTRACTThe effects of motor learning, such as motor adaptation, in stroke rehabilitation are often transient, thus mandating approaches that enhance the amount of learning and retention. Previously, we showed in young individuals that reward-and punishment-feedback have dissociable effects on motor adaptation, with punishment improving adaptation and reward enhancing retention. If these findings were able to generalise to stroke patients, they would provide a way to optimize motor learning in these patients. Therefore, we tested this in 45 chronic stroke patients allocated in three groups. Patients performed reaching movements with their paretic arm with a robotic manipulandum. After training (day 1), day 2 involved adapting to a novel force-field. During this adaptation phase, patients received performance-based feedback according to the group they were allocated: reward, punishment or no feedback (neutral). On day 3, patients readapted to the force-field but all groups now received neutral feedback. All patients adapted, with reward and punishment groups displaying greater adaptation and readaptation than the neutral group, irrespective of demographic, cognitive or functional differences. Remarkably, the reward and punishment groups adapted to similar degree as healthy controls. Finally, the reward group showed greater retention. This study provides, for the first time, evidence that reward and punishment can enhance motor adaptation in stroke patients. Further research on reinforcement-based motor learning regimes is warranted to translate these promising results into clinical practice and improve motor rehabilitation outcomes in stroke patients.

scholarly journals On the encoding capacity of human motor adaptation

2021 ◽  
Author(s):  
Seung-Yeon Kim ◽  
Jae-Woon Kwon ◽  
Jin-Min Kim ◽  
Frank Chong-Woo Park ◽  
Sang-Hoon Yeo
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Information Content ◽  
Motor Adaptation ◽  
Movement Speed ◽  
Limiting Factor ◽  
Information Encoding ◽  
Motor Primitives ◽  
Human Motor ◽  
Human Motor Adaptation

Primitive-based models of motor learning suggest that adaptation occurs by tuning the responses of motor primitives. Based on this idea, we consider motor learning as an information encoding procedure, that is, a procedure of encoding a motor skill into primitives. The capacity of encoding is determined by the number of recruited primitives, which depends on how many primitives are "visited" by the movement, and this leads to a rather counter-intuitive prediction that faster movement, where a larger number of motor primitives are involved, allows learning more complicated motor skills. Here we provide a set of experimental results that support this hypothesis. First, we show that learning occurs only with movement, i.e., only with non-zero encoding capacity. When participants were asked to counteract a rotating force applied to a robotic handle, they were unable to do so when maintaining a static posture but were able to adapt when making small circular movements. Our second experiment further investigated how adaptation is affected by movement speed. When adapting to a simple (low-information-content) force field, fast (high-capacity) movement did not have an advantage over slow (low-capacity) movement. However, for a complex (high-information-content) force field, the fast movement showed a significant advantage over slow movement. Our final experiment confirmed that the observed benefit of high-speed movement is only weakly affected by mechanical factors. Taken together, our results suggest that the encoding capacity is a genuine limiting factor of human motor adaptation.

scholarly journals No effects of cerebellar transcranial direct current stimulation on force field and visuomotor reach adaptation in young and healthy subjects

2019 ◽  
Vol 121 (6) ◽  
pp. 2112-2125 ◽  
Author(s):  
A. Mamlins ◽  
T. Hulst ◽  
O. Donchin ◽  
D. Timmann ◽  
J. Claassen
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Healthy Subjects ◽  
Motor Adaptation ◽  
Visuomotor Rotation ◽  
Direct Current Stimulation ◽  
Cerebellar Tdcs ◽  
Adaptation Task

Previous studies have shown that cerebellar transcranial direct current stimulation (tDCS) leads to faster adaptation of arm reaching movements to visuomotor rotation and force field perturbations in healthy subjects. The first aim of the present study was to confirm a stimulation-dependent effect on motor adaptation. Second, we investigated whether tDCS effects differ depending on onset, that is, before or at the beginning of the adaptation phase. A total of 120 healthy and right-handed subjects (60 women, mean age 23.2 ± SD 2.7 yr, range 18–31 yr) were tested. Subjects moved a cursor with a manipulandum to one of eight targets presented on a vertically orientated screen. Three baseline blocks were followed by one adaptation block and three washout blocks. Sixty subjects did a force field adaptation task (FF), and 60 subjects did a visuomotor adaptation task (VM). Equal numbers of subjects received anodal, cathodal, or sham cerebellar tDCS beginning either in the third baseline block or at the start of the adaptation block. In FF and VM, tDCS and the onset of tDCS did not show a significant effect on motor adaptation (all P values >0.05). We were unable to support previous findings of modulatory cerebellar tDCS effects in reaching adaptation tasks in healthy subjects. Prior to possible application in patients with cerebellar disease, future experiments are needed to determine which tDCS and task parameters lead to robust tDCS effects. NEW & NOTEWORTHY Transcranial direct current stimulation (tDCS) is a promising tool to improve motor learning. We investigated whether cerebellar tDCS improves motor learning in force field and visuomotor tasks in healthy subjects and what influence the onset of stimulation has. We did not find stimulation effects of tDCS or an effect of onset of stimulation. A reevaluation of cerebellar tDCS in healthy subjects and at the end of the clinical potential in cerebellar patients is demanded.

scholarly journals Feedback adaptation to unpredictable force fields in 250ms

2019 ◽  
Author(s):  
Frédéric Crevecoeur ◽  
James Mathew ◽  
Marie Bastin ◽  
Philippe Lefevre
Keyword(s):  
Nervous System ◽  
Motor Learning ◽  
Force Field ◽  
Recent Work ◽  
Muscle Activity ◽  
Force Fields ◽  
Control Strategies ◽  
Motor Adaptation ◽  
Classical Studies ◽  
Learning And Adaptation

AbstractMotor learning and adaptation are important functions of the nervous system. Classical studies have characterized how humans adapt to changes in the environment during tasks such as reaching, and have documented improvements in behavior across movements. Yet little is known about how quickly the nervous system adapts to such disturbances. In particular, recent work has suggested that adaptation could be sufficiently fast to alter the control strategies of an ongoing movement. To further address the possibility that learning occurred within a single movement, we designed a series of human reaching experiments to extract in muscles recordings the latency of feedback adaptation. Our results confirmed that participants adapted their feedback responses to unanticipated force fields applied randomly. In addition, our analyses revealed that the feedback response was specifically and finely tuned to the ongoing perturbation not only across trials with the same force field, but also across different kinds of force fields. Finally, changes in muscle activity consistent with feedback adaptation occurred in about 250ms following reach onset. We submit this estimate as the latency of motor adaptation in the nervous system.

scholarly journals Identifying the neural representation of fast and slow states in force field adaptation via fMRI

2019 ◽  
Author(s):  
Andria J. Farrens ◽  
Fabrizio Sergi
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Motor Adaptation ◽  
Neural Representation ◽  
Control Processes ◽  
Behavioral Studies ◽  
Motor Learning And Control ◽  
Force Field Adaptation ◽  
The Brain ◽  
Slow Learning

AbstractNeurorehabilitation is centered on motor learning and control processes, however our understanding of how the brain learns to control movements is still limited. Motor adaptation is a rapid form of motor learning that is amenable to study in the laboratory setting. Behavioral studies of motor adaptation have coupled clever task design with computational modeling to study the control processes that underlie motor adaptation. These studies provide evidence of fast and slow learning states in the brain that combine to control neuromotor adaptation.Currently, the neural representation of these states remains unclear, especially for adaptation to changes in task dynamics, commonly studied using force fields imposed by a robotic device. Our group has developed the MR-Softwrist, a robot capable of executing dynamic adaptation tasks during functional magnetic resonance imaging (fMRI) that can be used to localize these networks in the brain.We simulated an fMRI experiment to determine if signal arising from a switching force field adaptation task can localize the neural representations of fast and slow learning states in the brain. Our results show that our task produces reliable behavioral estimates of fast and slow learning states, and distinctly measurable fMRI activations associated with each state under realistic levels of behavioral and measurement noise. Execution of this protocol with the MR-Softwrist will extend our knowledge of how the brain learns to control movement.

Adipokines as Potential Biomarkers in the Neurorehabilitation of Obese Stroke Patients

2020 ◽  
Vol 17 (4) ◽  
pp. 437-445
Author(s):  
Irene Ciancarelli ◽  
Giovanni Morone ◽  
Marco Iosa ◽  
Stefano Paolucci ◽  
Loris Pignolo ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Functional Recovery ◽  
Functional Independence Measure ◽  
Functional Independence ◽  
Enzyme Linked Immunosorbent Assay ◽  
Stroke Patients ◽  
Rehabilitation Outcomes ◽  
Before And After ◽  
Forward Stepwise ◽  
Clinical Measures

Background: Limited studies concern the influence of obesity-induced dysregulation of adipokines in functional recovery after stroke neurorehabilitation. Objective: To investigate the relationship between serum leptin, resistin, and adiponectin and functional recovery before and after neurorehabilitation of obese stroke patients. The adipokine potential significance as prognostic markers of rehabilitation outcomes was also verified. Methods: Twenty obese post-acute stroke patients before and after neurorehabilitation and thirteen obese volunteers without-stroke, as controls, were examined. Adipokines were determined by commercially available enzyme-linked immunosorbent assay (ELISA) kits. Functional deficits were assessed before and after neurorehabilitation with the Barthel Index (BI), modified Rankin Scale (mRS), and Functional Independence Measure (FIM). Results: Compared to controls, higher leptin and resistin values and lower adiponectin values were observed in stroke patients before neurorehabilitation and no correlations were found between adipokines and clinical outcome measures. Neurorehabilitation was associated with improved scores of BI, mRS, and FIM. After neurorehabilitation, decreased values of Body Mass Index (BMI) and resistin together increased adiponectin were detected in stroke patients, while leptin decreased but not statistically. Comparing adipokine values assessed before neurorehabilitation with the outcome measures after neurorehabilitation, correlations were observed for leptin with BI-score, mRS-score, and FIM-score. No other adipokine levels nor BMI assessed before neurorehabilitation correlated with the clinical measures after neurorehabilitation. The forward stepwise regression analysis identified leptin as prognostic factor for BI, mRS, and FIM. Conclusions: Our data show the effectiveness of neurorehabilitation in modulating adipokines levels and suggest that leptin could assume the significance of biomarker of functional recovery.

scholarly journals Explicit motor sequence learning after stroke: a neuropsychological study

2021 ◽  
Author(s):  
Cristina Russo ◽  
Laura Veronelli ◽  
Carlotta Casati ◽  
Alessia Monti ◽  
Laura Perucca ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Motor Learning ◽  
Upper Limb ◽  
Motor Recovery ◽  
Finger Tapping ◽  
Control Group ◽  
Stroke Severity ◽  
Motor Sequence ◽  
Stroke Patients ◽  
Motor Practice

AbstractMotor learning interacts with and shapes experience-dependent cerebral plasticity. In stroke patients with paresis of the upper limb, motor recovery was proposed to reflect a process of re-learning the lost/impaired skill, which interacts with rehabilitation. However, to what extent stroke patients with hemiparesis may retain the ability of learning with their affected limb remains an unsolved issue, that was addressed by this study. Nineteen patients, with a cerebrovascular lesion affecting the right or the left hemisphere, underwent an explicit motor learning task (finger tapping task, FTT), which was performed with the paretic hand. Eighteen age-matched healthy participants served as controls. Motor performance was assessed during the learning phase (i.e., online learning), as well as immediately at the end of practice, and after 90 min and 24 h (i.e., retention). Results show that overall, as compared to the control group, stroke patients, regardless of the side (left/right) of the hemispheric lesion, do not show a reliable practice-dependent improvement; consequently, no retention could be detected in the long-term (after 90 min and 24 h). The motor learning impairment was associated with subcortical damage, predominantly affecting the basal ganglia; conversely, it was not associated with age, time elapsed from stroke, severity of upper-limb motor and sensory deficits, and the general neurological condition. This evidence expands our understanding regarding the potential of post-stroke motor recovery through motor practice, suggesting a potential key role of basal ganglia, not only in implicit motor learning as previously pointed out, but also in explicit finger tapping motor tasks.

Abstract P670: Obesity and Mortality After the First Ischemic Stroke: Is Obesity Paradox Real?

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Durgesh Chaudhary ◽  
Ayesha Khan ◽  
Mudit Gupta ◽  
Yirui Hu ◽  
Jiang Li ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Proportional Hazards Model ◽  
Obesity Paradox ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Obese Patients ◽  
Stroke Patients ◽  
Stroke Event ◽  
One Year ◽  
First Time

Introduction: Obesity is an established risk factor for ischemic stroke but the association of increased body mass index (BMI) with survival after ischemic stroke remains controversial. Many studies have shown that increased BMI has a “protective” effect on survival after stroke while other studies have debunked the obesity paradox. This study aimed at examining the relationship between BMI and all-cause mortality at one year in first-time ischemic stroke patients using data extracted from different resources including electronic health records. Methods: We analyzed consecutive ischemic stroke patients captured in the Geisinger NeuroScience Ischemic Stroke (GNSIS) database. Survival in first-time ischemic stroke patients was analyzed using Kaplan-Meier estimator, stratified by different BMI categories. The predictors of mortality at one-year were assessed using a multivariate Cox proportional hazards model. Results: Among 6,703 first-time adult ischemic stroke patients, mean age was 70.2 ±13.5 years and 52% were men. Of these patients, 24% patients were non-overweight (BMI < 25), 34% were overweight (BMI 25-29.9) and 41% were obese (BMI ≥ 30). One-year survival probability was significantly higher in overweight patients (87%, 95% CI: [85.6 - 88.4], p<0.001) and obese patients (89.5%, 95% CI: [88.4 - 90.7], p<0.001) compared to non-overweight patients (78.1%, 95% CI: [76.0 - 80.1]). In multivariate analysis, one-year mortality was significantly lower in overweight and obese patients (overweight patients- HR = 0.61 [95% CI, 0.52 - 0.72]; obese patients- HR = 0.56 [95% CI, 0.48 - 0.67]). Other significant predictors of one-year mortality were age at the ischemic stroke event (HR = 1.04 [95% CI, 1.03 - 1.04]), history of neoplasm (HR = 1.59 [95% CI, 1.38 - 1.85]), atrial fibrillation or flutter (HR = 1.26 [95% CI, 1.09 - 1.46]), heart failure (HR = 1.68 [95% CI, 1.42 - 1.98]), diabetes mellitus (HR = 1.27 [95% CI, 1.1 - 1.47]), rheumatic disease (HR = 1.37 [95% CI, 1.05 - 1.78]) and myocardial infarction ((HR = 1.23 [95% CI, 1.02 - 1.48]). Conclusion: Our results support the obesity paradox in ischemic stroke patients as shown by a significantly decreased hazard ratio for one-year mortality among overweight and obese patients in comparison to non-overweight patients.

scholarly journals Transcranial Color Coded Duplex Sonography Findings in Stroke Patients Undergoing Rehabilitation: An Observational Study

2022 ◽  
Author(s):  
Srikant Venkatakrishnan ◽  
Meeka Khanna ◽  
Anupam Gupta
Keyword(s):  
Clinical Outcome ◽  
Duplex Sonography ◽  
Modified Rankin Scale ◽  
Mean Flow ◽  
Stroke Patients ◽  
Symmetric Flow ◽  
Rehabilitation Outcomes ◽  
Outcome Scores ◽  
Color Coded Duplex Sonography ◽  
Flow Velocities

Abstract Background Transcranial color-coded duplex sonography (TCCD) provides information on intracranial blood flow status in stroke patients and can predict rehabilitation outcomes. Objective This study aimed to assess middle cerebral artery (MCA) parameters using TCCD in MCA territory stroke patients admitted for rehabilitation and correlate with clinical outcome measures. Material and Methods Patients aged 18 to 65 years with a first MCA territory stroke, within 6 months of onset were recruited. The clinical outcome scales and TCCD parameters were assessed at both admission and discharge. The scales used were the Scandinavian stroke scale (SSS), Barthel Index (BI), modified Rankin Scale (mRS), Fugl–Meyer upper extremity scale (FMA-UE), modified motor assessment scale (mMAS) scores. TCCD parameters measured were MCA peak systolic, end diastolic, mean flow velocities (MFV), and index of symmetry (SI) and were correlated with clinical scores. Results Fourteen patients were recruited with median age of 56.5 years, median duration of stroke was 42.5 days. Mean flow velocities of affected and unaffected MCA were 46.2 and 50.7 cm/s, respectively. Flow velocities and SI did not change between the two assessments. There was significant improvement in clinical outcome scores at discharge. Significant correlation was observed for patient group with SI > 0.9 at admission with FMA-UE, SSS, and BI scores at discharge (p < 0.05). Conclusion Flow velocity parameters did not change during in-patient rehabilitation. Patients with symmetric flow at admission had improved clinical outcomes measure scores at discharge. Thus SI can predict rehabilitation outcomes in stroke survivors.

scholarly journals Exposure to auditory feedback delay while speaking induces perceptual habituation but does not mitigate the disruptive effect of delay on speech auditory-motor learning

2020 ◽  
Author(s):  
Douglas M. Shiller ◽  
Takashi Mitsuya ◽  
Ludo Max
Keyword(s):  
Motor Learning ◽  
Visual Feedback ◽  
Auditory Feedback ◽  
Detrimental Effect ◽  
Negative Impact ◽  
Motor Adaptation ◽  
List Type ◽  
Disruptive Effect ◽  
Feedback Delay ◽  
Spectral Perturbation

ABSTRACTPerceiving the sensory consequences of our actions with a delay alters the interpretation of these afferent signals and impacts motor learning. For reaching movements, delayed visual feedback of hand position reduces the rate and extent of visuomotor adaptation, but substantial adaptation still occurs. Moreover, the detrimental effect of visual feedback delay on reach motor learning—selectively affecting its implicit component—can be mitigated by prior habituation to the delay. Auditory-motor learning for speech has been reported to be more sensitive to feedback delay, and it remains unknown whether habituation to auditory delay reduces its negative impact on learning. We investigated whether 30 minutes of exposure to auditory delay during speaking (a) affects the subjective perception of delay, and (b) mitigates its disruptive effect on speech auditory-motor learning. During a speech adaptation task with real-time perturbation of vowel spectral properties, participants heard this frequency-shifted feedback with no delay, 75 ms delay, or 115 ms delay. In the delay groups, 50% of participants had been exposed to the delay throughout a preceding 30-minute block of speaking whereas the remaining participants completed this block without delay. Although habituation minimized awareness of the delay, no improvement in adaptation to the spectral perturbation was observed. Thus, short-term habituation to auditory feedback delays is not effective in reducing the negative impact of delay on speech auditory-motor adaptation. Combined with previous findings, the strong negative effect of delay and the absence of an influence of delay awareness suggest the involvement of predominantly implicit learning mechanisms in speech.HIGHLIGHTSSpeech auditory-motor adaptation to a spectral perturbation was reduced by ~50% when feedback was delayed by 75 or 115 ms.Thirty minutes of prior delay exposure without perturbation effectively reduced participants’ awareness of the delay.However, habituation was ineffective in remediating the detrimental effect of delay on speech auditory-motor adaptation.The dissociation of delay awareness and adaptation suggests that speech auditory-motor learning is mostly implicit.

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