Comfortable synchronization of cyclic drawing movements with a metronome

Augmented Visual Feedback for Complex Motor Skill Acquisition: A Demonstration with Healthy Young Adults

Mirror therapy (MT) is a treatment for improving motor function after stroke. Video therapy (VT) training combines observation and imitation of video clips, and it has been used to conduct efficient occupational therapy. We sought to determine the effects of MT and VT on tool-use with healthy young adults. We assigned participants to three different training groups in which they used their non-dominant left hands to move a ball with chopsticks: (a) a self-paced MT group (N = 14), (b) an MT group who moved the ball while looking at the mirror image of the right hand with a sound cue (4-second intervals) (N = 12), and (c) a group who imitated a video demonstration (4-second intervals) (N = 13). The ball-moving time was significantly reduced after training in all three groups: MT group (p < .001), MT-R group (p = .010), and VT group (p = .014), but the video group showed significantly greater relative improvements in motion variability (p = .030) and object prediction (p = .008).We concluded that MT was as effective as VT in improving movement speed, but, with these healthy young adults, MT was less effective than VT in learning speed control or hand pre-shaping to refine task movements for tool use.

Using immersive virtual reality to remotely examine performance differences between dominant and non-dominant hands

Circle drawing may be a useful task to study upper-limb function in patient populations. However, previous studies rely on expensive and bulky robotics to measure performance. For clinics or hospitals with limited budgets and space, this may be unfeasible. Virtual reality (VR) provides a portable and low-cost tool with integrated motion capture. It offers potentially a more feasible medium by which to assess upper-limb motor function. Prior to use with patient populations, it is important to validate and test the capabilities of VR with healthy users. This study examined whether a VR-based circle drawing task, completed remotely using participant's own devices, could capture differences between movement kinematics of the dominant and non-dominant hands in healthy individuals. Participants (n = 47) traced the outline of a circle presented on their VR head-mounted displays with each hand, while the positions of the hand-held controllers were continuously recorded. Although there were no differences observed in the size or roundness of circles drawn with each hand, consistent with prior literature our results did show that the circles drawn with the dominant hand were completed faster than those with the non-dominant hand. This provides preliminary evidence that a VR-based circle drawing task may be a feasible method for detecting subtle differences in function in clinical populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10055-023-00794-z.

The challenge of being slow: Effects of tempo, laterality, and experience on dance movement consistency

In dance, music, or sports, reproducibility and consistency as well as bilateral dexterity/coordination of movement are crucial for motor control. Research into the biomechanics of movement consistency and variability is important for motor learning to achieve proficiency and maximize outcome reproduction and stability as well as to reduce the risk of injury. Thirty-six participants were instructed to perform a repetitive circular, ipsilateral motion of arms and legs at three different tempi, while being recorded with optical motion capture. Two velocity-based consistency measures were developed an overall measure of consistency and a laterality difference measure. Maintaining velocity consistency was more challenging at slower than at faster tempi, suggesting that slow movement could require more attentional focus and thus become more variable. Music experience resulted in higher consistency, especially on the subdominant body side, possibly due to extensive bilateral training. Outcomes could have potential implications for music instrument, dance, and sports practice and training.

A developmental study of the effect of music training on timed movements

When people clap to music, sing, play a musical instrument, or dance, they engage in temporal entrainment. We examined the effect of music training on the precision of temporal entrainment in 57 children aged 10–14 years (31 musicians, 26 non-musicians). Performance was examined for two tasks: self-paced finger tapping (discrete movements) and circle drawing (continuous movements). For each task, participants synchronized their movements with a steady pacing signal and then continued the movement at the same rate in the absence of the pacing signal. Analysis of movements during the continuation phase revealed that musicians were more accurate than non-musicians at finger tapping and, to a lesser extent, circle drawing. Performance on the finger-tapping task was positively associated with the number of years of formal music training, whereas performance on the circle-drawing task was positively associated with the age of participants. These results indicate that music training and maturation of the motor system reinforce distinct skills of timed movement.

Sensorimotor synchronization: a review of recent research (2006-2012)

Sensorimotor synchronization (SMS) is the coordination of rhythmic movement with an external rhythm, ranging from finger tapping in time with a metronome to musical ensemble performance. An earlier review (Repp, 2005) covered tapping studies; two additional reviews (Repp, 2006a, b) focused on music performance and on rate limits of SMS, respectively. The present article supplements and extends these earlier reviews by surveying more recent research in what appears to be a burgeoning field. The article comprises four parts, dealing with (1) conventional tapping studies, (2) other forms of moving in synchrony with external rhythms (including dance and nonhuman animals' synchronization abilities), (3) interpersonal synchronization (including musical ensemble performance), and (4) the neuroscience of SMS. It is evident that much new knowledge about SMS has been acquired in the last 7 years.

Self in motion: sensorimotor and cognitive mechanisms in gait agency

Acting in our environment and experiencing ourselves as conscious agents are fundamental aspects of human selfhood. While large advances have been made with respect to understanding human sensorimotor control from an engineering approach, knowledge about its interaction with cognition and the conscious experience of movement (agency) is still sparse, especially for locomotion. We investigated these relationships by using life-size visual feedback of participants' ongoing locomotion, thereby extending agency research previously limited to goal-directed upper limb movements to continuous movements of the entire body. By introducing temporal delays and cognitive loading we were able to demonstrate distinct effects of bottom-up visuomotor conflicts as well as top-down cognitive loading on the conscious experience of locomotion (gait agency) and gait movements. While gait agency depended on the spatial and temporal congruency of the avatar feedback, gait movements were solely driven by its temporal characteristics as participants nonconsciously attempted to synchronize their gait with their avatar's gait. Furthermore, gait synchronization was suppressed by cognitive loading across all tested delays, whereas gait agency was only affected for selective temporal delays that depended on the participant's step cycle. Extending data from upper limb agency and auditory gait agency, our results are compatible with effector-independent and supramodal control of agency; they show that both mechanisms are dissociated from automated sensorimotor control and that cognitive loading further enhances this dissociation.

Timing continuous or discontinuous movements across effectors specified by different pacing modalities and intervals

Sensorimotor synchronization is hypothesized to arise through two different processes, associated with continuous or discontinuous rhythmic movements. This study investigated synchronization of continuous and discontinuous movements to different pacing signals (auditory or visual), pacing interval (500, 650, 800, 950 ms) and across effectors (non-dominant vs. non-dominant hand). The results showed that mean and variability of asynchronization errors were consistently smaller for discontinuous movements compared to continuous movements. Furthermore, both movement types were timed more accurately with auditory pacing compared to visual pacing and were more accurate with the dominant hand. Shortening the pacing interval also improved sensorimotor synchronization accuracy in both continuous and discontinuous movements. These results show the dependency of temporal control of movements on the nature of the motor task, the type and rate of extrinsic sensory information as well as the efficiency of the motor actuators for sensory integration.

Quantifying phase correction in sensorimotor synchronization: empirical comparison of three paradigms

Tapping in synchrony with a metronome requires phase error correction, a process often described by a single-parameter autoregressive model. The parameter (α) is a measure of sensorimotor coupling strength. This study compares α estimates obtained from three experimental paradigms: synchronization with (1) a perfectly regular metronome (RM), (2) a perturbed metronome containing phase shifts (PS), and (3) an "adaptively timed" metronome (AT). Musically trained participants performed in each paradigm at four tempi, with baseline interval durations ranging from 400 to 1300 ms. Two estimation methods were applied to each data set. Results showed that all α estimates increased with interval duration. However, the PS paradigm yielded much larger α values than did the AT paradigm, with those from the RM paradigm falling in between. Positional analysis of the PS data revealed that α increased immediately following a phase shift and then decreased sharply. Unexpectedly, all PS α estimates were uncorrelated with the RM and AT estimates, which were strongly correlated. These results suggest that abruptly perturbed sequences engage a different mechanism of phase correction than do regular or continuously modulated sequences.

Temporal evolution of the phase correction response in synchronization of taps with perturbed two-interval rhythms

Human sensorimotor synchronization is flexible but subject to temporal constraints. Previous research has shown that musicians tend to lose synchrony with target tones in an isochronous sequence when the sequence rate exceeds 8-10 Hz, presumably because phase correction ceases to function. The present study investigated directly the time required for an immediate phase correction response (PCR). Musicians tapped in synchrony with cyclic two-interval (short-long) rhythms, using the two hands in alternation. Perturbations were applied to the long interval, and the compensatory shift of the next tap (the PCR) was measured following the short interval, whose duration was varied from 100 to 300 ms. The PCR was found to increase gradually within this range, being nearly absent at 100 ms. Similar results were obtained when participants tapped only with the second tone in each rhythmic group, which confirms that the PCR is based on the preceding tone rather than on the preceding tap-tone asynchrony, and also when the second tone was omitted in the pacing sequence, which indicates that the PCR occurs automatically even when there is no synchronization target for the critical tap. These results extend earlier findings regarding rate limits of synchronization and also provide further support for an event-based phase resetting account of the PCR.