Coincident Timing Task Research Articles

Body-part specificity for learning of multiple prior distributions in human coincidence timing

During timing tasks, the brain learns the statistical distribution of target intervals and integrates this prior knowledge with sensory inputs to optimise task performance. Daily events can have different temporal statistics (e.g., fastball/slowball in baseball batting), making it important to learn and retain multiple priors. However, the rules governing this process are not yet understood. Here, we demonstrate that the learning of multiple prior distributions in a coincidence timing task is characterised by body-part specificity. In our experiments, two prior distributions (short and long intervals) were imposed on participants. When using only one body part for timing responses, regardless of the priors, participants learned a single prior by generalising over the two distributions. However, when the two priors were assigned to different body parts, participants concurrently learned the two independent priors. Moreover, body-part specific prior acquisition was faster when the priors were assigned to anatomically distant body parts (e.g., hand/foot) than when they were assigned to close body parts (e.g., index/middle fingers). This suggests that the body-part specific learning of priors is organised according to somatotopy.

Bilateral Transfer of Performance between Real and Non-Immersive Virtual Environments in Post-Stroke Individuals: A Cross-Sectional Study.

(1) Background: Post-stroke presents motor function deficits, and one interesting possibility for practicing skills is the concept of bilateral transfer. Additionally, there is evidence that the use of virtual reality is beneficial in improving upper limb function. We aimed to evaluate the transfer of motor performance of post-stroke and control groups in two different environments (real and virtual), as well as bilateral transfer, by changing the practice between paretic and non-paretic upper limbs. (2) Methods: We used a coincident timing task with a virtual (Kinect) or a real device (touch screen) in post-stroke and control groups; both groups practiced with bilateral transference. (3) Results: Were included 136 participants, 82 post-stroke and 54 controls. The control group presented better performance during most parts of the protocol; however, it was more evident when compared with the post-stroke paretic upper limb. We found bilateral transference mainly in Practice 2, with the paretic upper limb using the real interface method (touch screen), but only after Practice 1 with the virtual interface (Kinect), using the non-paretic upper limb. (4) Conclusions: The task with the greatest motor and cognitive demand (virtual-Kinect) provided transfer into the real interface, and bilateral transfer was observed in individuals post-stroke. However, this is more strongly observed when the virtual task was performed using the non-paretic upper limb first.

Motor learning of people with visual impairment in a non-immersive virtual reality coincident time task

Introduction: Virtual reality (VR) is used nowadays as an assessment and intervention tool in rehabilitation. One of the capabilities that can be assessed through VR is coincident timing, a perceptual-motor ability to execute a motor response in synchrony with an external stimulus. Visually impaired (VI) people need this synchronization of movements with external objects in their daily and leisure activities. Objective: To investigate the performance of VI individuals in a VR coincident timing task. Methods: Quantitative cross-sectional study with an interventional, quasi-experimental, descriptive, and explanatory nature. Sixty individuals participated in this study: 20 VI, 20 blindfolded and 20 non-VI, over 18 years of age. A semi-structured interview and a virtual coincident timing task were used. Results: VI individuals started the task with the worst performance (Absolute error = group VI 945ms x blindfolded group 591ms x control group 557ms), but they improved throughout the task, as well as all groups, reducing the number of errors (mean absolute error= 698ms to 408ms). Furthermore, all groups increased task speed (mean variable error= last acquisition block 408ms x immediate transfer 227ms x late transfer 247ms). Conclusion: It is concluded that VI individuals can develop motor learning from tasks in VR, showing the importance of taking advantage of these technological advances in this area, not only as a facilitator of task execution, but also as an instrument that enable rehabilitation programs to ensure functional improvements for real everyday tasks.

Disrupting Short-Term Memory Maintenance in Premotor Cortex Affects Serial Dependence in Visuomotor Integration.

Human behavior is biased by past experience. For example, when intercepting a moving target, the speed of previous targets will bias responses in future trials. Neural mechanisms underlying this so-called serial dependence are still under debate. Here, we tested the hypothesis that the previous trial leaves a neural trace in brain regions associated with encoding task-relevant information in visual and/or motor regions. We reasoned that injecting noise by means of transcranial magnetic stimulation (TMS) over premotor and visual areas would degrade such memory traces and hence reduce serial dependence. To test this hypothesis, we applied bursts of TMS pulses to right visual motion processing region hV5/MT+ and to left dorsal premotor cortex (PMd) during intertrial intervals of a coincident timing task performed by twenty healthy human participants (15 female). Without TMS, participants presented a bias toward the speed of the previous trial when intercepting moving targets. TMS over PMd decreased serial dependence in comparison to the control Vertex stimulation, whereas TMS applied over hV5/MT+ did not. In addition, TMS seems to have specifically affected the memory trace that leads to serial dependence, as we found no evidence that participants' behavior worsened after applying TMS. These results provide causal evidence that an implicit short-term memory mechanism in premotor cortex keeps information from one trial to the next, and that this information is blended with current trial information so that it biases behavior in a visuomotor integration task with moving objects.SIGNIFICANCE STATEMENT Human perception and action are biased by the recent past. The origin of such serial bias is still not fully understood, but a few components seem to be fundamental for its emergence: the brain needs to keep previous trial information in short-term memory and blend it with incoming information. Here, we present evidence that a premotor area has a potential role in storing previous trial information in short-term memory in a visuomotor task and that this information is responsible for biasing ongoing behavior. These results corroborate the perspective that areas associated with processing information of a stimulus or task also participate in maintaining that information in short-term memory even when this information is no longer relevant for current behavior.

Temporal dynamics of implicit memory underlying serial dependence.

Serial dependence is the effect in which the immediately preceding trial influences participants' responses to the current stimulus. But for how long does this bias last in the absence of interference from other stimuli? Here, we had 20 healthy young adult participants (12 women) perform a coincident timing task using different inter-trial intervals to characterize the serial dependence effect as the time between trials increases. Our results show that serial dependence abruptly decreases from 0.1 s to 1 s inter-trial interval, but it remains pronounced after that for up to 8 s. In addition, participants' response variability slightly decreases over longer intervals. We discuss these results in light of recent models suggesting that serial dependence might rely on a short-term memory trace kept through changes in synaptic weights, which might explain its long duration and apparent stability over time.

Modulation of cerebellar brain inhibition during temporal adaptive learning in a coincident timing task.

In the present study, we examined the role of the cerebellum in temporal adaptive learning during a coincident timing task, i.e., a baseball-like hitting task involving a moving ball presented on a computer monitor. The subjects were required to change the timing of their responses based on imposed temporal perturbations. Using paired-pulse transcranial magnetic stimulation, we measured cerebellar brain inhibition (CBI) before, during, and after the temporal adaptive learning. Reductions in CBI only occurred during and after the temporal adaptive learning, regardless of the direction of the temporal perturbations. In addition, the changes in CBI were correlated with the magnitude of the adaptation. Here, we showed that the cerebellum is essential for learning about and controlling the timing of movements during temporal adaptation. Furthermore, changes in cerebellar-primary motor cortex connectivity occurred during temporal adaptation, as has been previously reported for spatial adaptation.

Motor learning through a non-immersive virtual task in people with limb-girdle muscular dystrophies

Introduction: Limb-girdle muscular dystrophies (LGMDs) are neuromuscular and genetic disorders that progress with weakness and damage of the proximal muscles, developing with loss of functionality. Virtual reality environments are suggested as an effective alternative for performance of daily life activities. However, there is no evidence in the literature on the use of virtual reality in this population. Objective: Assess motor performance through a motor learning protocol in a coincident timing task. Methods: 10 participants with LGMD and 10 healthy individuals were selected and included in the study to perform a non-immersive virtual reality task divided into three phases: acquisition (20 attempts), retention (5 attempts), and transfer (5 attempts, with speed increase). Results: It is observed that the accuracy of movement improves from the beginning to the end of the acquisition (p = 0.01); however, there is a marginal difference between the groups in block A1 (p = 0.089). Regarding the variability of touches, observed by the variable error, both groups improved performance in all phases. Conclusion: Even with lower performance than the control group at the beginning of the practice, individuals with LGMD showed the potential to optimize motor function during the practice of a non-immersive virtual reality activity and were able to match their performance with the control group after a few attempts.

EEG Analysis in Coincident Timing Task Towards Motor Rehabilitation.

The identification of specific components in EEG signals is often key when designing EEG-based brain-computer interfaces (BCIs), and a good understanding of the factors that elicit such components can be helpful when it comes to precise, energy-efficient and time-accurate actuation of exoskeletons. CNVs (Contingent Negative Variations), ERDs or ERSs (Event-Related Desynchronizations/Synchronizations) as well as ErrPs (Error-Related Potentials) are particularly important components can be identified during motor tasks and related to specific events in a Coincident Timing (CT) task. This work investigates offline EEG signals acquired during an upper limb CT task and analyzes the task protocol with the purpose of correlating the aforementioned EEG features to movement onset. CNVs and ERD/ERS were successfully identified after averaging multiple trials, and it was further concluded that complementary information about muscle activity (via EMG) as well as video tracking of arm movement play a critical role in the synchronization of EEG components with movement onset. The framework for EEG analysis presented in this paper allows for future development of a BCI on top of this CT task capable of assessing motor learning and actuating an exoskeleton to enable faster motor rehabilitation.

Elbow movement estimation based on EMG with NARX Neural Networks.

The use of the electrical activity from the muscles may provide a natural way to control exoskeletons or other robotic devices seamlessly. The major challenges to achieve this goal are human motor redundancy and surface electromyography (sEMG) variability. The goal of this work is to find a feature extraction and classification procedures to estimate accurately elbow angular trajectory by means of a NARX Neural Network. The processing time-step should be small enough to make it feasible its further use for online control of an exoskeleton. In order to do so we analysed the Biceps and Triceps Brachii data from an elbow flexo-extension Coincident Timing task performed in the horizontal plane. The sEMG data was pre-processed and its energy was divided in five frequency intervals that were fed to a Nonlinear Auto Regressive with Exogenous inputs (NARX) Neural Network. The estimated angular trajectory was compared with the measured one showing a high correlation between them and a RMSE error maximum of 7 degrees. The procedure presented here shows a reasonably good estimation that, after training, allows real-time implementation. In addition, the results are encouraging to include more complex tasks including the shoulder joint.

Baseball Players' Eye Movements and Higher Coincident-Timing Task Performance.

Previous studies have reported that baseball players have higher than average visual information processing abilities and outstanding motor control. The speed and position of the baseball and the batter are constantly changing, leading skilled players to acquire highly accurate visual information processing and decision-making. This study sought to clarify how movement of the eyes is associated with baseball players’ higher coincident-timing task performance. We recruited 15 right-handed baseball players and 15 age-matched track and field athletes. On a computer-based coincident-timing task, we instructed participants to stop a computer image of a moving target by pressing a button at a designated point. We presented bidirectional moving targets with various velocities, presented in a random order. The targets’ moving angular velocity varied between 100, 83, 71, 63, 56, 50, and 46 deg/s. We conducted 168 repetitions (42 reps × 4 sets) of this coincident-timing task and measured participants’ eye movements during the task using Pupil Centre Corneal Reflection. Mixed-design analysis of variance results revealed participant group effects in favor of baseball players for timing absolute error and low absolute error, as predicted from prior visual processing and decision-making research with baseball players. However, in contrast to prior research, we found significantly shorter smooth-pursuit onset latency in elite baseball players, and there were no significant group differences for saccade onset and offset latencies. This may be explained by the difference in our research paradigm with mobile targets randomly presented at various velocities from the left and right. Our data showed baseball players’ higher than normal simultaneous timing execution for making decisions and movements based on visual information, even under laboratory conditions with randomly moving mobile targets.

Visual Strategy during Coincident Timing Tasks for a Moving Target

Visual Strategy during Coincident Timing Tasks for a Moving Target

Motor learning and transfer between real and virtual environments in young people with autism spectrum disorder: A prospective randomized cross over controlled trial.

Autism spectrum disorder (ASD) is associated with persistent deficits in social communication and social interaction, including impaired multisensory integration, which might negatively impact cognitive and motor skill performance, and hence negatively affect learning of tasks. Considering that tasks in virtual environment may provide an engaging tool as adjuncts to conventional therapies, we set out to compare motor performance between young people with ASD and a typically developing (TD) control group that underwent coincident timing tasks based on Kinect (no physical contact) and on Keyboard (with physical contact) environments. Using a randomized repeated cross-over controlled trial design, 50 young people with ASD and 50 with TD, matched by age and sex were divided into subgroups of 25 people that performed the two first phases of the study (acquisition and retention) on the same device-real or virtual-and then switched to the other device to repeat acquisition and retention phases and finally switched on to a touch screen (transfer phase). Results showed that practice in the virtual task was more difficult (producing more errors), but led to a better performance in the subsequent practice in the real task, with more pronounced improvement in the ASD as compared to the TD group. It can be concluded that the ASD group managed to transfer the practice from a virtual to a real environment, indicating that virtual methods may enhance learning of motor and cognitive skills. A need for further exploration of its effect across a number of tasks and activities is warranted. Autism Res 2020, 13: 307-319. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Individuals with autism spectrum disorder are known to have difficulties with learning motor tasks. Considering that performing motor tasks in virtual environment may be an engaging tool as adjuncts to conventional therapies, we aimed to estimate performance in tasks regardless of physical touch. Results showed that participants had more difficulty using the non-touch task; however, virtual training improved performance on the physical (real) task. This result indicates that virtual methods could be a promising therapeutic approach for the ASD population.

Analysis of motor performance in individuals with cerebral palsy using a non-immersive virtual reality task - a pilot study.

PurposeTo evaluate the performance improvement of individuals with hemiparesis cerebral palsy (CP) using a virtual task.Participants and methodsTwenty individuals were selected and distributed into two groups. The experimental group (CP group) comprised ten individuals with a medical diagnosis of CP, and ten individuals with typical development (sex- and age-matched) composed the control group (TD group). Both groups followed the same intervention protocol, which included a virtual coincident timing task: the participants performed upper limb movements in front of a computer’s webcam and interacted with the task with the aim of virtually intercepting spheres that fell in four rows following the rhythm of a pre-selected song during an 8-minute period. To verify the influence on a real task, pre- and posttests were performed in a similar task, but with physical contact (using the spacebar on the keyboard of a computer). To analyze the data, we evaluated the variable, constant, and absolute errors during the task and in the pre- and posttests.ResultsThe results showed that there was an improvement in performance between the pre- and posttests; that is, after practicing the task in an environment without physical contact, there was a performance improvement in posttests in the real task, but only for the CP group. Moreover, there were significant differences in precision and accuracy between the two groups, with worse performance in the CP group.ConclusionIndividuals with CP presented better performance in the real task after practice in a virtual reality task, albeit with worse performance compared with individuals with TD. This is an interesting result that supports the possible use of virtual tasks for the rehabilitation of individuals with CP.

An object-tracking model that combines position and speed explains spatial and temporal responses in a timing task.

Many tasks require synchronizing our actions with particular moments along the path of moving targets. However, it is controversial whether we base these actions on spatial or temporal information, and whether using either can enhance our performance. We addressed these questions with a coincidence timing task. A target varying in speed and motion duration approached a goal. Participants stopped the target and were rewarded according to its proximity to the goal. Results showed larger reward for responses temporally (rather than spatially) equidistant to the goal across speeds, and this pattern was promoted by longer motion durations. We used a Kalman filter to simulate time and space-based responses, where modeled speed uncertainty depended on motion duration and positional uncertainty on target speed. The comparison between simulated and observed responses revealed that a single position-tracking mechanism could account for both spatial and temporal patterns, providing a unified computational explanation.

Motor learning in post stroke subjects: the effects of practice conditions on the temporal synchronization

Abstract AIMS The aim of this study was to investigate the effects of practice schedule on the motor learning of a synchronization timing task in post-stroke subjects. Subjects and METHODS Seventeen post-stroke individuals were assigned to the experimental group and for the control group were selected seventeen healthy individuals. At the acquisition phase, all participants performed 30 trials of a coincident timing task. Nine individuals from each group practiced constantly and eight from each group practiced randomly, with speed changes in the task. Subsequent phases included: 1) immediate transfer test and 2) long term transfer test after 3 days. Data were analyzed in relation to absolute, variable, and constant errors to assess the performance concerning accuracy, consistence, and direction of responses, respectively. RESULTS All groups increased their accuracy through the practice and were able to adapt it in different speeds. The stroke subjects were more variable in their motor responses. There was no effect of the practice schedule on motor learning, regardless the presence or absence of the neurologic damage. CONCLUSION Post stroke individuals were able to learn a synchronizing task and the capacity of adapt their performance after speed perturbation was preserved. There was no effect of the practice schedule on motor learning.

Improved Learning a Coincident Timing Task With a Predictable Resisting Force.

The present study analyzes the learning in a coincident timing task with force perturbation. We aimed to verify whether a predictable load (constant spring) applied to hand movements could facilitate learning and, thus, performance improvement with respect to movements without any external load and an unpredictable load to perform a coincident timing task with a few number of repetitions (n = 28) under acquisition and transfer phases. The results showed that the group with a predictable load had a significant better performance with lower percentage of errors and smaller time variance in the acquisition and transfer phase. The groups with no load and unpredictable load had a similar performance in the transfer phase. It can be concluded that adding a predictable force to the coincident timing task results in performance improvement. Therefore, learning to reach a target at a correct time could be improved with the application of predictable external loads.

Motor learning from virtual reality to natural environments in individuals with Duchenne muscular dystrophy

Purpose: To examine whether performance improvements in the virtual environment generalize to the natural environment. Study design: we had 64 individuals, 32 of which were individuals with DMD and 32 were typically developing individuals. Methods: The groups practiced two coincidence timing tasks. In the more tangible button-press task, the individuals were required to ‘intercept’ a falling virtual object at the moment it reached the interception point by pressing a key on the computer. In the more abstract task, they were instructed to ‘intercept’ the virtual object by making a hand movement in a virtual environment using a webcam. Results and Conclusions: For individuals with DMD, conducting a coincidence timing task in a virtual environment facilitated transfer to the real environment. However, we emphasize that a task practiced in a virtual environment should have higher rates of difficulties than a task practiced in a real environment.IMPLICATIONS FOR REHABILITATIONVirtual environments can be used to promote improved performance in ?real-world? environments.Virtual environments offer the opportunity to create paradigms similar ?real-life? tasks, however task complexity and difficulty levels can be manipulated, graded and enhanced to increase likelihood of success in transfer of learning and performance.Individuals with DMD, in particular, showed immediate performance benefits after using virtual reality

Biomechanical procedure to assess sleep restriction on motor control and learning.

The analysis of sleep quality during long periods and its impact on motor control and learning performance are crucial aspects for human health. The aim of this study is to analyze effects of chronic sleep restriction on motor performance. It is intended to establish motor control indicators in sleep quality analysis. A wearable actigraphy that records accelerometry, ambient light, and body temperature was used to monitor the sleep habits of 12 healthy subjects for two weeks before performing motor control and learning tests. The day of the motor test, the subjects filled two questionnaires about the quality of sleep (Pittsburgh Sleep Quality Index - PSQI) and sleepiness (Epworth Sleepiness Scale - ESS). Afterwards they performed a coincident timing task that consisted of hitting a virtual target falling on the screen with the hand. An elbow flexion in the horizontal plane had to be performed on the correct time to reach the real target on a table at the same time as the virtual target on the screen. The subjects performed three sets of acquisition and transfer blocks of the coincident timing task. The subjects were clustered in two groups based on the PSQI and ESS scores. Actigraphy and motor control parameters (L5, correct responses, time variance) were compared between groups and experimental sets. The group with better sleep parameters did show a constant performance across blocks of task acquisition while the bad sleeper group improved from the first to the second acquisition block. Despite of this improvement, their performance is not better than the one of the good sleepers group. Although the number of subjects is low and it should be increased, these results indicate that the subjects with better sleep converged rapidly to a high level of performance, while the worse sleepers needed more trials to learn the task and their performance was not superior to the other group.

Effects of the task complexity on the performance of a Coincidence Timing Task of people with Down syndrome

With the present study, we aimed to investigate the task complexity effects on the performance of a coincidence timing task in individuals with Down syndrome. The experimental group was consisted by 26 subjects with Down syndrome, 20 years old (± 5), and classified as mild or moderate in International Classification of Functioning and Health. Each participant in the experimental group was matched by in function of gender and age with a participant in a control group without Down syndrome. Both groups performed a coincident timing task, in which the participant had different levels of structural and functional complexity. Performance measure was derived from the consistency (absolute error), accuracy (variable error) and direction of response (constant error). Individuals with Down syndrome presented spatiotemporal organization impairments related to the difficulty in dealing with motor demand in order to interact with the perceptive demand. They also experienced difficulty in adapt to task complexity, causing performance error in the task. Individuals with Down syndrome have deficits in perceptive and space-time organization, and this phenomenon may be explained by the difficulty in integrating perceptive stimulus to motor actions with a high number of elements involved.

Temporal-Comparative Feedback Affects Motor Learning

In this experiment, we investigated the motivational effects of feedback on motor learning observing the impact of temporal-comparison feedback on the learning of a coincident timing task. Two groups of participants, a positive (PTC) and a negative temporal-comparison group (NTC), received veridical feedback about their accuracy scores after every other practice trial (50%). In addition, after each block of 10 trials, the PTC group was given bogus feedback suggesting that their average performance was better than it was in the previous block, while the NTC group received bogus feedback suggesting that their average performance was worse than it was in the previous block. A retention test was performed one day after the practice phase, without feedback, to observe learning effects. In addition, after the practice phase and before the retention test, all participants filled out questionnaires to report their self-efficacy levels. The results demonstrate that temporal-comparison feedback affects the learning of motor skills. Participants of the PTC group showed greater timing accuracy and reported higher self-efficacy levels than the NTC group on the retention test. The findings further support the important motivational role of feedback for motor learning.