scholarly journals Variance in exposed perturbations impairs retention of visuomotor adaptation

2017 ◽  
Vol 118 (5) ◽  
pp. 2745-2754 ◽  
Author(s):  
Cesar Augusto Canaveral ◽  
Frédéric Danion ◽  
Félix Berrigan ◽  
Pierre-Michel Bernier
Keyword(s):  
Visuomotor Adaptation ◽  
The Body ◽  
Forward Model ◽  
Success Rates ◽  
Visuomotor Rotation ◽  
Sensory Signals ◽  
Motor Commands ◽  
The Mean ◽  
Sensory Predictions ◽  
The Brain

Sensorimotor control requires an accurate estimate of the state of the body. The brain optimizes state estimation by combining sensory signals with predictions of the sensory consequences of motor commands using a forward model. Given that both sensory signals and predictions are uncertain (i.e., noisy), the brain optimally weights the relative reliance on each source of information during adaptation. In support, it is known that uncertainty in the sensory predictions influences the rate and generalization of visuomotor adaptation. We investigated whether uncertainty in the sensory predictions affects the retention of a new visuomotor relationship. This was done by exposing three separate groups to a visuomotor rotation whose mean was common at 15° counterclockwise but whose variance around the mean differed (i.e., SD of 0°, 3.2°, or 4.5°). Retention was assessed by measuring the persistence of the adapted behavior in a no-vision phase. Results revealed that mean reach direction late in adaptation was similar across groups, suggesting it depended mainly on the mean of exposed rotations and was robust to differences in variance. However, retention differed across groups, with higher levels of variance being associated with a more rapid reversion toward nonadapted behavior. A control experiment ruled out the possibility that differences in retention were accounted for by differences in success rates. Exposure to variable rotations may have increased the uncertainty in sensory predictions, making the adapted forward model more labile and susceptible to change or decay. NEW & NOTEWORTHY The brain predicts the sensory consequences of motor commands through a forward model. These predictions are subject to uncertainty. We use visuomotor adaptation and modulate uncertainty in the sensory predictions by manipulating the variance in exposed rotations. Results reveal that variance does not influence the final extent of adaptation but selectively impairs the retention of motor memories. These results suggest that a more uncertain forward model is more susceptible to change or decay.

scholarly journals The brain dynamics of architectural affordances during transition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zakaria Djebbara ◽  
Lars Brorson Fich ◽  
Klaus Gramann
Keyword(s):  
Occipital Cortex ◽  
The Body ◽  
Brain Dynamics ◽  
Alpha Band ◽  
Time Frequency ◽  
Posterior Cingulate ◽  
Sensory Signals ◽  
Event Related Desynchronization ◽  
The Brain ◽  
Attentional Mechanisms

AbstractAction is a medium of collecting sensory information about the environment, which in turn is shaped by architectural affordances. Affordances characterize the fit between the physical structure of the body and capacities for movement and interaction with the environment, thus relying on sensorimotor processes associated with exploring the surroundings. Central to sensorimotor brain dynamics, the attentional mechanisms directing the gating function of sensory signals share neuronal resources with motor-related processes necessary to inferring the external causes of sensory signals. Such a predictive coding approach suggests that sensorimotor dynamics are sensitive to architectural affordances that support or suppress specific kinds of actions for an individual. However, how architectural affordances relate to the attentional mechanisms underlying the gating function for sensory signals remains unknown. Here we demonstrate that event-related desynchronization of alpha-band oscillations in parieto-occipital and medio-temporal regions covary with the architectural affordances. Source-level time–frequency analysis of data recorded in a motor-priming Mobile Brain/Body Imaging experiment revealed strong event-related desynchronization of the alpha band to originate from the posterior cingulate complex, the parahippocampal region as well as the occipital cortex. Our results firstly contribute to the understanding of how the brain resolves architectural affordances relevant to behaviour. Second, our results indicate that the alpha-band originating from the occipital cortex and parahippocampal region covaries with the architectural affordances before participants interact with the environment, whereas during the interaction, the posterior cingulate cortex and motor areas dynamically reflect the affordable behaviour. We conclude that the sensorimotor dynamics reflect behaviour-relevant features in the designed environment.

Literature Review : Pengaruh Latihan Rom (Range Of Motion) Terhadap Peningkatan Kekuatan Otot Pada Pasien Stroke

2021 ◽  
Vol 1 ◽  
pp. 1407-1413
Author(s):  
Dwi Haryati ◽  
Nuniek Nizmah Fajriyah ◽  
Firman Faradisi
Keyword(s):  
Muscle Strength ◽  
Literature Review ◽  
Blood Vessel ◽  
Range Of Motion ◽  
Scientific Paper ◽  
The Body ◽  
Before And After ◽  
Motion Exercise ◽  
The Mean ◽  
The Brain

AbstractStroke is an acute neurocological disease caused by blood vessel disorders in the brain that occur suddenly and can cause symptoms according to areas in the brain that occur suddenly and can cause symptoms of paralysis, difficulty speaking, numbness of one side of the body and other disorders. ROM (Range of Motion) exercise is the maximum number of movements performed by the joints under normal conditions where a person moves each joint according to normal movements either actively or passively.The purpose of this scientific paper is to determine the effect of giving Range Of Motion (ROM) on increasing muscle strength in stroke patients.There is a difference in the mean (mean) before giving Range Of Motion therapy is 2.65 and after giving Range Of Motion is 3.62, there is an effect of giving Range Of Motion (ROM) therapy. Most of the respondents were male with a partial presentation (70%) and (30%) female, the age of the respondent in this study was >56 years old. Prior to ROM therapy, the degree of muscle strength was categorized as 0 to degree 2 and after ROM therapy, the degree of muscle strength was categorized as grade 2 to degree 4. The conclusion was that there was an increase in muscle strength before and after Range Of Motion (ROM) therapy. ROM therapy is effective for increasing muscle strength in stroke patients.Keywords: Muscle Strength, Range Of Motion (ROM), Stroke AbstrakStroke merupakan suatu penyait neurokologis akut yang disebabkan oleh gangguan pembulu darah otak yang terjadi secara mendadak dan dapat menimbulkan gejala yang sesuai dengan daerah di otak yang terserang terjadi secara tiba-tiba dan dapat menimbulkan gejala kelumpuhan, kesulitan bicara,mati rasa sebelah badan dan gangguan lainnya. Latihan ROM (Range of Motion) adalah jumlah maksimum gerakan yang yang dilakukan oleh sendi dalam keadaan normal dimana seseorang menggerakan masing-masing persendiannya sesuai gerakan normal baik secara aktif ataupun pasif. Tujuan karya tulis ilmiah ini adalah untuk mengetahui pengaruh pemberian Range Of Motion (ROM) Terhadap peningkatan kekuatan otot pada pasien stroke.Terdapat perbedaan rata-rata (mean) sebelum pemberian terapi Range Of Motion adalah 2,65 dan sesudah pemberian Range Of Motion adalah 3,62, terdapat pengaruh pemberian terapi Range Of Motion (ROM). Responden terbanyak berjenis kelamin laki-laki dengan presentasi sebagian (70%) dan (30%) perempuan, umur respoden pada penelitian ini berusia >56 tahun. Sebelum dilakukan terapi ROM derajat kekuatan otot termasuk katagori 0 hingga derajat 2 dan sesudah dilakukan terapi ROM derajat kekuatan otot termasuk kategori derajat 2 hingga derajat 4. Simpulan terdapat peningkatan kekuatan otot sebelum dan sesudah dilakukan terapi Range Of Motion (ROM). Terapi ROM efektif untuk meningkatkan kekuatan otot pada pasien stroke. Kata kunci : Kekuatan Otot, Range Of Motion (ROM), Stroke

scholarly journals Generalization via superposition: combined effects of mixed reference frame representations for explicit and implicit learning in a visuomotor adaptation task

2019 ◽  
Vol 121 (5) ◽  
pp. 1953-1966 ◽  
Author(s):  
Eugene Poh ◽  
Jordan A. Taylor
Keyword(s):  
Implicit Learning ◽  
Reference Frame ◽  
Reference Frames ◽  
Visuomotor Adaptation ◽  
Visuomotor Rotation ◽  
Mixed Representation ◽  
Multiple Processes ◽  
Implicit Motor ◽  
The Individual ◽  
The Brain

Studies on generalization of learned visuomotor perturbations have generally focused on whether learning is coded in extrinsic or intrinsic reference frames. This dichotomy, however, is challenged by recent findings showing that learning is represented in a mixed reference frame. Overlooked in this framework is how learning appears to consist of multiple processes, such as explicit reaiming and implicit motor adaptation. Therefore, the proposed mixed representation may simply reflect the superposition of explicit and implicit generalization functions, each represented in different reference frames. Here we characterized the individual generalization functions of explicit and implicit learning in relative isolation to determine whether their combination could predict the overall generalization function when both processes are in operation. We modified the form of feedback in a visuomotor rotation task in an attempt to isolate explicit and implicit learning and tested generalization across new limb postures to dissociate the extrinsic/intrinsic representations. We found that the amplitude of explicit generalization was reduced with postural change and was only marginally shifted, resembling an extrinsic representation. In contrast, implicit generalization maintained its amplitude but was significantly shifted, resembling a mixed representation. A linear combination of individual explicit and implicit generalization functions accounted for nearly 85% of the variance associated with the generalization function in a typical visuomotor rotation task, where both processes are in operation. This suggests that each form of learning results from a mixed representation with distinct extrinsic and intrinsic contributions and the combination of these features shapes the generalization pattern observed at novel limb postures. NEW & NOTEWORTHY Generalization following learning in visuomotor adaptation tasks can reflect how the brain represents what it learns. In this study, we isolated explicit and implicit forms of learning and showed that they are derived from a mixed reference frame representation with distinct extrinsic and intrinsic contributions. Furthermore, we showed that the overall generalization pattern at novel workspaces is due to the superposition of independent generalization effects developed by explicit and implicit learning processes.

scholarly journals Mini-review: The Role of the Cerebellum in Visuomotor Adaptation

2021 ◽  
Author(s):  
Elinor Tzvi ◽  
Sebastian Loens ◽  
Opher Donchin
Keyword(s):  
Premotor Cortex ◽  
Motor Program ◽  
Visuomotor Adaptation ◽  
Prediction Errors ◽  
Visuomotor Rotation ◽  
Non Invasive ◽  
Behavioral Studies ◽  
Sensory Prediction ◽  
The Brain

AbstractThe incredible capability of the brain to quickly alter performance in response to ever-changing environment is rooted in the process of adaptation. The core aspect of adaptation is to fit an existing motor program to altered conditions. Adaptation to a visuomotor rotation or an external force has been well established as tools to study the mechanisms underlying sensorimotor adaptation. In this mini-review, we summarize recent findings from the field of visuomotor adaptation. We focus on the idea that the cerebellum plays a central role in the process of visuomotor adaptation and that interactions with cortical structures, in particular, the premotor cortex and the parietal cortex, may be crucial for this process. To this end, we cover a range of methodologies used in the literature that link cerebellar functions and visuomotor adaptation; behavioral studies in cerebellar lesion patients, neuroimaging and non-invasive stimulation approaches. The mini-review is organized as follows: first, we provide evidence that sensory prediction errors (SPE) in visuomotor adaptation rely on the cerebellum based on behavioral studies in cerebellar patients. Second, we summarize structural and functional imaging studies that provide insight into spatial localization as well as visuomotor adaptation dynamics in the cerebellum. Third, we discuss premotor — cerebellar interactions and how these may underlie visuomotor adaptation. And finally, we provide evidence from transcranial direct current and magnetic stimulation studies that link cerebellar activity, beyond correlational relationships, to visuomotor adaptation .

scholarly journals Comparison of the Position Sense of the Knee Joint in PatientsWith Multiple Sclerosis and Healthy Controls

2019 ◽  
Author(s):  
Saina Aliabadi ◽  
Roya Khanmohammadi ◽  
Gholamrezareza Olyaei ◽  
Nastaran Ghotbi ◽  
Saeed Talebian ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Nervous System ◽  
Knee Joint ◽  
Healthy Subjects ◽  
Position Sense ◽  
The Body ◽  
Control Group ◽  
The Central Nervous System ◽  
The Mean ◽  
The Brain

Introduction: Position sense, one of the most accurate senses in the body, makes everyone aware of the state of the body in space. This sense is an essential ability in maintaining physical health and avoiding injury. Deficits in position sense cause balance impairments in people with mild Multiple Sclerosis (MS). Position sense requires instant and coordinated communication between the central nervous system and peripheral nervous system, while in patients with MS, communication between the brain and other parts of the body is disrupted. This study aims to compare the position sense of knee joint in people with MS and healthy subjects. Materials and Methods: Ten healthy subjects with the Mean±SD age of 27.6±3.71 years and 10 persons with MS disease and the Mean±SD age of 31.40±3.50 years participated in this study. For evaluating their position sense of knee joint, they flexed their knees (from 90 to 45 degrees) four times, and then a software calculated their repositioning errors. Results: No significant changes in repositioning errors (constant, variable, absolute) were observed in MS patients, and the control group (P˃0.05). Conclusion: The results indicate that mild MS disease cannot disturb the position sense of knee joint.

scholarly journals Forward modelling the rubber hand: illusion of ownership modifies motor-sensory predictions by the brain

2016 ◽  
Vol 3 (8) ◽  
pp. 160407 ◽  
Author(s):  
Laura Aymerich-Franch ◽  
Damien Petit ◽  
Abderrahmane Kheddar ◽  
Gowrishankar Ganesh
Keyword(s):  
Haptic Perception ◽  
Forward Model ◽  
Rubber Hand Illusion ◽  
Body Parts ◽  
Rubber Hand ◽  
Self And Other ◽  
Sensory Predictions ◽  
Motor Actions ◽  
The Brain ◽  
Real Hand

The question of how we attribute observed body parts as our own, and the consequences of this attribution on our sensory-motor processes, is fundamental to understand how our brain distinguishes between self and other. Previous studies have identified interactions between the illusion of ownership, and multi-sensory integration and cross-sensory predictions by the brain. Here we show that illusory ownership additionally modifies the motor-sensory predictions by the brain. In our preliminary experiments, we observed a new numbness illusion following the classical rubber-hand illusion (RHI); brushing only the rubber hand after induction of the RHI results in illusory numbness in one's real hand. Previous studies have shown that self-generated actions (like tickling) are attenuated by motor-sensory predictions by the so-called forward model . Motivated by this finding, here we examined whether the numbness illusion after the RHI is different when the rubber hand is brushed oneself, compared with when the brushing is performed by another. We observed that, all other conditions remaining the same, haptic perception in the real hand was lower (numbness higher) during self-generated brushing. Our result suggests that RHI reorganizes the forward model, such that we predict haptic consequences of self-generated motor actions on the rubber hand.

scholarly journals Comparative morphometry of the brainstem of the male and female Helmeted Guinea Fowl (Numida meleagris)

2018 ◽  
Vol 51 (3) ◽  
pp. 121-124
Author(s):  
Mohammed Adam ◽  
Barth Izuchukwu Onyeanusi ◽  
Joseph Olusegun Hambolu ◽  
Suleiman Folorunsho Ambali ◽  
Chikera Samuel Ibe
Keyword(s):  
Medulla Oblongata ◽  
Guinea Fowl ◽  
The Body ◽  
Base Line ◽  
Male And Female ◽  
Numida Meleagris ◽  
Body Weights ◽  
The Mean ◽  
The Difference ◽  
The Brain

Abstract The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

scholarly journals Sensory prediction errors, not performance errors, update memories in visuomotor adaptation

2018 ◽  
Author(s):  
Kangwoo Lee ◽  
Youngmin Oh ◽  
Jun Izawa ◽  
Nicolas Schweighofer
Keyword(s):  
Visuomotor Adaptation ◽  
Motor Memory ◽  
Prediction Errors ◽  
Visuomotor Rotation ◽  
Main Target ◽  
Memory Decay ◽  
Performance Errors ◽  
Sensory Predictions ◽  
Sensory Prediction

AbstractSensory prediction errors are thought to update memories in motor 1 adaptation, but the role of performance errors is largely unknown. To dissociate these errors, we manipulated visual feedback during fast shooting movements under visuomotor rotation. Participants were instructed to strategically correct for performance errors by shooting to a neighboring target in one of four conditions: following the movement onset, the main target, the neighboring target, both targets, or none of the targets disappeared. Participants in all conditions experienced a drift away from the main target following the strategy. In conditions where the main target was shown, participants often tried to minimize performance errors caused by the drift by generating corrective movements. However, despite differences in performance during adaptation between conditions, memory decay in a delayed washout block was indistinguishable between conditions. Our results thus suggest that, in visuomotor adaptation, sensory predictions errors, but not performance errors, update the slow, temporally stable, component of motor memory.

scholarly journals Comparative morphometry of the brainstem of the male and female Helmeted Guinea Fowl (Numida meleagris)

2018 ◽  
Vol 51 (3) ◽  
pp. 121-124
Author(s):  
Mohammed Adam ◽  
Barth Izuchukwu Onyeanusi ◽  
Joseph Olusegun Hambolu ◽  
Suleiman Folorunsho Ambali ◽  
Chikera Samuel Ibe
Keyword(s):  
Medulla Oblongata ◽  
Guinea Fowl ◽  
The Body ◽  
Base Line ◽  
Male And Female ◽  
Numida Meleagris ◽  
Body Weights ◽  
The Mean ◽  
The Difference ◽  
The Brain

Abstract The aim of this study was to obtain base-line morphometric data on the whole brain and brainstem in the adult male and female helmeted guinea fowl (Numida meleagris), and compare the result in the two sexes. Brain samples of seventy adult helmeted guinea fowls, comprising 35 males and 35 females, intended for slaughter, were extracted for the study. The body weights for both male and female helmeted guinea fowls were 1247 ± 5.51 g and 1230 ± 4.85 g, respectively. The mean brain weights were 3.39 ± 0.02 g and 3.47 ± 0.18 g for male and female, respectively, and the difference in the values was not significant (P > 0.05). The lengths of the brain and medulla oblongata, as well as the lengths of the midbrain and mesencephalic tectum, did not differ between the two sexes. Neither the mean weights nor lengths of the pons differed between the two sexes. In conclusion, the results of this study showed that there was no sex dimorphism observed in the morphometry of the midbrain, medulla oblongata and pons in the helmeted guinea fowl.

Experience-Dependent Modulation of Rubber Hand Illusion in Badminton Players

2021 ◽  
pp. 1-9
Author(s):  
Masanori Sakamoto ◽  
Hirotoshi Ifuku
Keyword(s):  
The Body ◽  
Neural Representation ◽  
Rubber Hand Illusion ◽  
Short Term ◽  
Rubber Hand ◽  
Sensory Signals ◽  
Visuotactile Integration ◽  
The Brain ◽  
Plastic Modification

Badminton players have a plastic modification of their arm representation in the brain due to the prolonged use of their racket. However, it is not known whether their arm representation can be altered through short-term visuotactile integration. The neural representation of the body is easily altered when multiple sensory signals are integrated in the brain. One of the most popular experimental paradigms for investigating this phenomenon is the “rubber hand illusion.” This study was designed to investigate the effect of prolonged use of a racket on the modulation of arm representation during the rubber hand illusion in badminton players. When badminton players hold the racket, their badminton experience in years is negatively correlated with the magnitude of the rubber hand illusion. This finding suggests that tool embodiment obtained by the prolonged use of the badminton racket is less likely to be disturbed when holding the racket.

Sign in / Sign up

Export Citation Format

Share Document