Gesture imitation in musicians and non-musicians

The assessment of presence and performance in an AR environment for motor imitation learning: A case-study on violinists

The acquisition of advanced gestures is a challenge in various domains of proficient sensorimotor performance. For example, orchestral violinists must move in sync with the lead violinist's gestures. To help train these gestures, an educational music play-back system was developed using a HoloLens 2 simulated AR environment and an avatar representation of the lead violinist. This study aimed to investigate the impact of using a 2D or 3D representation of the lead violinist's avatar on students' learning experience in the AR environment. To assess the learning outcome, the study employed a longitudinal experiment design, in which eleven participants practiced two pieces of music in four trials, evenly spaced over a month. Participants were asked to mimic the avatar's gestures as closely as possible when it came to using the bow, including bowing, articulations, and dynamics. The study compared the similarities between the avatar's gestures and those of the participants at the biomechanical level, using motion capture measurements, as well as the smoothness of the participants' movements. Additionally, presence and perceived difficulty were assessed using questionnaires. The results suggest that using a 3D representation of the avatar leads to better gesture resemblance and a higher experience of presence compared to a 2D representation. The 2D representation, however, showed a learning effect, but this was not observed in the 3D condition. The findings suggest that the 3D condition benefits from stereoscopic information that enhances spatial cognition, making it more effective in relation to sensorimotor performance. Overall, the 3D condition had a greater impact on performance than on learning. This work concludes with recommendations for future efforts directed towards AR-based advanced gesture training to address the challenges related to measurement methodology and participants' feedback on the AR application.

The prevalence of the Val66Met polymorphism in musicians: Possible evidence for compensatory neuroplasticity from a pilot study

The study compared the prevalence of the Val66Met Brain-derived Neurotrophic Factor single nucleotide polymorphism (rs6265) in a sample of musicians (N = 50) to an ethnically matched general population sample from the 1000 Human Genome Project (N = 424). Met-carriers of the polymorphism (Val/Met and Met/Met genotypes) are typically present in 25–30% of the general population and have associated deficits in motor learning and plasticity. Many studies have assessed the benefits of long-term music training for neuroplasticity and motor learning. This study takes a unique genetic approach investigating if the prevalence of the Val66Met BDNF polymorphism, which negatively affects motor learning, is significantly different in musicians from the general population. Our genotype and allele frequency analyses revealed that the distribution of the Val66Met polymorphism was not significantly different in musicians versus the general population (p = 0.6447 for genotype analysis and p = 0.8513 allele analysis). In the Musician sample (N = 50), the prevalence of the Val/Met genotype was 40% and the prevalence of the Met/Met genotype was 2%. In the 1000 Human Genome Project subset (N = 424), the prevalence of Val/Met was 33.25% and the Met/Met genotype prevalence was 4%. Therefore, musicians do exist with the Val66Met polymorphism and the characteristics of long-term music training may compensate for genetic predisposition to motor learning deficits. Since the polymorphism has significant implications for stroke rehabilitation, future studies may consider the implications of the polymorphism in music-based interventions such as Neurologic Music Therapy.

Delayed feedback embedded in perception-action coordination cycles results in anticipation behavior during synchronized rhythmic action: A dynamical systems approach

Dancing and playing music require people to coordinate actions with auditory rhythms. In laboratory perception-action coordination tasks, people are asked to synchronize taps with a metronome. When synchronizing with a metronome, people tend to anticipate stimulus onsets, tapping slightly before the stimulus. The anticipation tendency increases with longer stimulus periods of up to 3500ms, but is less pronounced in trained individuals like musicians compared to non-musicians. Furthermore, external factors influence the timing of tapping. These factors include the presence of auditory feedback from one’s own taps, the presence of a partner performing coordinated joint tapping, and transmission latencies (TLs) between coordinating partners. Phenomena like the anticipation tendency can be explained by delay-coupled systems, which may be inherent to the sensorimotor system during perception-action coordination. Here we tested whether a dynamical systems model based on this hypothesis reproduces observed patterns of human synchronization. We simulated behavior with a model consisting of an oscillator receiving its own delayed activity as input. Three simulation experiments were conducted using previously-published behavioral data from 1) simple tapping, 2) two-person alternating beat-tapping, and 3) two-person alternating rhythm-clapping in the presence of a range of constant auditory TLs. In Experiment 1, our model replicated the larger anticipation observed for longer stimulus intervals and adjusting the amplitude of the delayed feedback reproduced the difference between musicians and non-musicians. In Experiment 2, by connecting two models we replicated the smaller anticipation observed in human joint tapping with bi-directional auditory feedback compared to joint tapping without feedback. In Experiment 3, we varied TLs between two models alternately receiving signals from one another. Results showed reciprocal lags at points of alternation, consistent with behavioral patterns. Overall, our model explains various anticipatory behaviors, and has potential to inform theories of adaptive human synchronization.

When navigating a busy sidewalk, people coordinate their behavior in an orderly manner. Other activities require people to carefully synchronize periodic actions, as in a group rowing or marching. When individuals tap in synchrony with a metronome, their taps tend to anticipate the metronome. Experiments have revealed that factors like musical expertise, the presence of a synchronizing partner, auditory feedback, and the sound travel time, all systematically affect the tendency to anticipate. While researchers have hypothesized a number of potential mechanisms for such anticipatory behavior, none have successfully accounted for all of the effects. Previous research on coupled physical systems has shown that when one system receives input from a second system, plus its own delayed signal as input, this causes system 1 to anticipate system 2. We hypothesize that the tendency to anticipate is the result of delayed communication between neurons. Our work demonstrates the ability of delay-coupled physical systems to capture human anticipation and the effect of external factors in the anticipation tendency. Our model supports the theory that delayed communication within the nervous system is crucial to understanding anticipatory coordinative behavior.

Differential Effects of Transcranial Direct Current Stimulation (tDCS) Depending on Previous Musical Training

Previous studies have shown that transcranial direct current stimulation (tDCS) facilitates motor performance, but individual differences such as baseline performance seem to influence this effect. Accordingly, musicians offer an inter-individual differences model due to anatomical and functional variances displayed among the motor cortex regions. The aim of the present work was to study if the baseline motor skill predicts whether tDCS can enhance motor learning. For that objective, we administered anodal (n = 20) or sham (n = 20) tDCS on the right primary motor cortex region of 40 right-handed healthy participants, who were divided into four groups: musicians (tDCS/sham) and non-musicians (tDCS/sham). We measured the skill index (SI) presented in the sequential finger-tapping task (SEQTAP) at baseline, during three 20 min/2 mA stimulation sessions, and in follow-up tests after 20 min and 8 days. Depending on the normality of the data distribution, statistical differences were estimated by ANOVA and Bonferroni post hoc test or Kruskal-Wallis and U Mann-Whitney. Results showed that musicians scored higher in baseline performance than non-musicians. The non-musicians who received tDCS scored higher than the sham group in the first and second stimulation session. This effect was extended to the 20 min and 8 days follow-up test. In musicians, there was no effect of tDCS. The present method seems to be suitable for the achievement of positive and consolidated tDCS effects on motor learning in inexperienced participants, but not in musicians. These data may have an implication for the rehabilitation of motor impairments, contributing to more individualized stimulation protocols.

Frequency-specific genetic influence on inferior parietal lobule activation commonly observed during action observation and execution

Brain activity relating to recognition of action varies among subjects. These differences have been hypothesised to originate from genetic and environmental factors although the extent of their effect remains unclear. Effects of these factors on brain activity during action recognition were evaluated by comparing magnetoencephalography (MEG) signals in twins. MEG signals of 20 pairs of elderly monozygotic twins and 11 pairs of elderly dizygotic twins were recorded while they observed finger movements and copied them. Beamformer and group statistical analyses were performed to evaluate spatiotemporal differences in cortical activities. Significant event-related desynchronisation (ERD) of the β band (13–25 Hz) at the left inferior parietal lobule (IPL) was observed for both action observation and execution. Moreover, β-band ERD at the left IPL during action observation was significantly better correlated among monozygotic twins compared to unrelated pairs (Z-test, p = 0.027). β-band ERD heritability at the left IPL was 67% in an ACE model. These results demonstrate that β-band ERD at the IPL, which is commonly observed during action recognition and execution, is affected by genetic rather than environmental factors. The effect of genetic factors on the cortical activity of action recognition may depend on anatomical location and frequency characteristics.

Biological bases of human musicality

Music is a universal language, present in all human societies. It pervades the lives of most human beings and can recall memories and feelings of the past, can exert positive effects on our mood, can be strongly evocative and ignite intense emotions, and can establish or strengthen social bonds. In this review, we summarize the research and recent progress on the origins and neural substrates of human musicality as well as the changes in brain plasticity elicited by listening or performing music. Indeed, music improves performance in a number of cognitive tasks and may have beneficial effects on diseased brains. The emerging picture begins to unravel how and why particular brain circuits are affected by music. Numerous studies show that music affects emotions and mood, as it is strongly associated with the brain's reward system. We can therefore assume that an in-depth study of the relationship between music and the brain may help to shed light on how the mind works and how the emotions arise and may improve the methods of music-based rehabilitation for people with neurological disorders. However, many facets of the mind-music connection still remain to be explored and enlightened.

Sensorimotor integration is enhanced in dancers and musicians

Studying individuals with specialized training, such as dancers and musicians, provides an opportunity to investigate how intensive practice of sensorimotor skills affects behavioural performance across various domains. While several studies have found that musicians have improved motor, perceptual and sensorimotor integration skills compared to untrained controls, fewer studies have examined the effect of dance training on such skills. Moreover, no study has specifically compared the effects of dance versus music training on perceptual or sensorimotor performance. To this aim, in the present study, expert dancers, expert musicians and untrained controls were tested on a range of perceptual and sensorimotor tasks designed to discriminate performance profiles across groups. Dancers performed better than musicians and controls on a dance imitation task (involving whole-body movement), but musicians performed better than dancers and controls on a musical melody discrimination task as well as on a rhythm synchronization task (involving finger tapping). These results indicate that long-term intensive dance and music training are associated with distinct enhancements in sensorimotor skills. This novel work advances knowledge of the effects of long-term dance versus music training and has potential applications in therapies for motor disorders.

The effect of musical practice on gesture/sound pairing

Learning to play a musical instrument is a demanding process requiring years of intense practice. Dramatic changes in brain connectivity, volume, and functionality have been shown in skilled musicians. It is thought that music learning involves the formation of novel audio visuomotor associations, but not much is known about the gradual acquisition of this ability. In the present study, we investigated whether formal music training enhances audiovisual multisensory processing. To this end, pupils at different stages of education were examined based on the hypothesis that the strength of audio/visuomotor associations would be augmented as a function of the number of years of conservatory study (expertise). The study participants were violin and clarinet students of pre-academic and academic levels and of different chronological ages, ages of acquisition, and academic levels. A violinist and a clarinetist each played the same score, and each participant viewed the video corresponding to his or her instrument. Pitch, intensity, rhythm, and sound duration were matched across instruments. In half of the trials, the soundtrack did not match (in pitch) the corresponding musical gestures. Data analysis indicated a correlation between the number of years of formal training (expertise) and the ability to detect an audiomotor incongruence in music performance (relative to the musical instrument practiced), thus suggesting a direct correlation between knowing how to play and perceptual sensitivity.

Effect of mindfulness meditation on brain-computer interface performance

Electroencephalogram based brain-computer interfaces (BCIs) enable stroke and motor neuron disease patients to communicate and control devices. Mindfulness meditation has been claimed to enhance metacognitive regulation. The current study explores whether mindfulness meditation training can thus improve the performance of BCI users. To eliminate the possibility of expectation of improvement influencing the results, we introduced a music training condition. A norming study found that both meditation and music interventions elicited clear expectations for improvement on the BCI task, with the strength of expectation being closely matched. In the main 12 week intervention study, seventy-six healthy volunteers were randomly assigned to three groups: a meditation training group; a music training group; and a no treatment control group. The mindfulness meditation training group obtained a significantly higher BCI accuracy compared to both the music training and no-treatment control groups after the intervention, indicating effects of meditation above and beyond expectancy effects.