Marc Leman’s research while affiliated with Ghent University and other places

Humans exhibit a strong tendency to synchronize movements with each other, with visualperspective potentially influencing interpersonal synchronization. By manipulating the visualscenes of participants engaged in a joint finger-tapping task, we examined the effects of 1stand 2nd person visual perspectives on their coordination dynamics. We hypothesized thatperceiving the partner's movements from their 1st person perspective would enhancespontaneous interpersonal synchronization, potentially mediated by the embodiment of thepartner's hand. We observed significant differences in attractor dynamics across visualperspectives. Specifically, participants in 1st person coupling were unable to maintain de-coupled trajectories as effectively as in 2nd person coupling. Our findings suggest that visualperspective influences coordination dynamics in dyadic interactions, engaging error-correction mechanisms in individual brains as they integrate the partner's hand into theirbody representation. Our results have the potential to inform the development ofapplications for motor training and rehabilitation.

Researchers have widely studied peripersonal space (the space within reach) in the last 20 years with a focus on its plasticity following the use of tools and, more recently, social interactions. Ensemble music is a sophisticated joint action that is typically explored in its temporal rather than spatial dimensions, even within embodied approaches. We, therefore, devised a new paradigm in which two musicians could perform a jazz standard either in a cooperative (correct harmony) or uncooperative (incorrect harmony) condition, under the hypothesis that their peripersonal spaces are modulated by the interaction. We exploited a well-established audio-tactile integration task as a proxy for such a space. After the performances, we measured reaction times to tactile stimuli on the subjects’ right hand and auditory stimuli delivered at two different distances, (next to the subject and next to the partner). Considering previous literature’s evidence that integration of two different stimuli (e.g. a tactile and an auditory stimulus) is faster in near space compared to far space, we predicted that a cooperative interaction would have extended the peripersonal space of the musicians towards their partner, facilitating reaction times to bimodal stimuli in both spaces. Surprisingly, we obtained complementary results in terms of an increase of reaction times to tactile-auditory near stimuli, but only following the uncooperative condition. We interpret this finding as a suppression of the subject’s peripersonal space or as a withdrawal from the uncooperative partner. Subjective reports and correlations between these reports and reaction times comply with that interpretation. Finally, we determined an overall better multisensory integration competence in musicians compared to non-musicians tested in the same task.

For decades, modal analysis has been a tool to gain insights in the vibrational and acoustical behavior of music instruments. This study provides a critical comparison of various experimental modal analysis approaches with the violin as a case study. Both contact and non-contact excitation and different acquisition approaches are considered. The influence of different boundary conditions (clamped, supported, free/free) on the vibrational response of the violin is investigated. The response is analyzed to extract relevant modal parameters (frequency, damping and mode shape) within the frequency range of 0–1000 Hz. The performance of the different approaches is evaluated in terms of (i) signature vibration modes, (ii) experimental reproducibility, (iii) contact requirement and (iv) cost of required equipment. Two optimal approaches are proposed for performing modal analysis on violins: a contact method for use in the violinmaker’s practice, and a non-contact method for use with fragile instruments.

Co-regulated timing in a music ensemble rests on the human capacity to coordinate actions in time. Here we explore the hypothesis that humans predict timing constancy in coordinated actions, in view of timing their own actions in line with the others. An algorithm (BListener) is presented that predicts timing constancy, using Bayesian inference about incoming timing data from the music ensemble. The algorithm is then applied to a timing analysis of real data, first, to a choir consisting of four singers, then, to a dataset containing performances of duet singers. Global features of timing constancy, such as fluctuation and stability, correlate with human subjective estimates of the music ensembles’ quality and associated experienced agency. In future work, BListener could serve as component in an artificial musician that plays along with human musicians in a music ensemble.

We argue that current cultural developments, driven by innovative technology, call for a reconsideration of the role of humanities as a field of study in which art and science is tightly integrated. This integration would allow the humanities to develop a proactive power such that it can (co-)steer the innovative developments of the techno-culture. Integrated art-science research may be realized in contexts where human expressive interaction with multimedia is investigated. Research outcomes from this domain may offer opportunities for humanities to contribute to cultural developments. Given the context of interactive multimedia, we offer a theoretical framework based on art-science research concerning: (1) human interaction, (2) interaction systems, and (3) cultural and societal interaction outcomes. The goal of the framework is to contribute to a new ambition for the humanities, one in which knowledge about culture, on top of being reflective, critical, and descriptive, has an intrinsic power to contribute to innovative techno-cultural developments.

For centuries, wood, and more specifically spruce, has been the material of choice for violin top plates. Lately, carbon fiber instruments have entered the market. Some studies show that composite materials have potential advantages for making instruments [Damodaran, Lessard, and Babu, Acoust. Aust. 43, 117–122 (2015)]. However, no studies exist that evaluate violins made of different composite materials as judged by listeners. For this study, six prototype violins, differing only by the material of the top plate, were manufactured in a controlled laboratory setting. The six prototype violins were judged by experienced listeners in two double-blind experiments. In contrast to popular opinion that violins made from carbon have or lack a specific sound quality, the study provides insights in the diverse sounds and timbres violins from fiber-reinforced polymers can create. It allows an investigation of the links between the perception and the variations in material properties of the soundboards. Additionally, as neither players nor listeners are acquainted with these instruments, these results provide an interesting view on what type of qualities of violin-like sounds are preferred by listeners.

For centuries, wood, and more specifically spruce, has been the material of choice for violin top plates. Lately, carbon fiber instruments have entered the market. Some studies show that composite materials have potential advantages for making instruments [Damodaran, Lessard, and Babu, Acoust. Aust. 43, 117–122 (2015)]. However, no studies exist that evaluate violins made of different composite materials as judged by listeners. For this study, six prototype violins, differing only by the material of the top plate, were manufactured in a controlled laboratory setting. The six prototype violins were judged by experienced listeners in two double-blind experiments. In contrast to popular opinion that violins made from carbon have or lack a specific sound quality, the study provides insights in the diverse sounds and timbres violins from fiber-reinforced polymers can create. It allows an investigation of the links between the perception and the variations in material properties of the soundboards. Additionally, as neither players nor listeners are acquainted with these instruments, these results provide an interesting view on what type of qualities of violin-like sounds are preferred by listeners.

A method is presented for detecting changes in the axial peak tibial acceleration while adapting to self-discovered lower-impact running. Ten runners with high peak tibial acceleration were equipped with a wearable auditory biofeedback system. They ran on an athletic track without and with real-time auditory biofeedback at the instructed speed of 3.2 m·s-1. Because inter-subject variation may underline the importance of individualized retraining, a change-point analysis was used for each subject. The tuned change-point application detected major and subtle changes in the time series. No changes were found in the no-biofeedback condition. In the biofeedback condition, a first change in the axial peak tibial acceleration occurred on average after 309 running gait cycles (3'40"). The major change was a mean reduction of 2.45 g which occurred after 699 running gait cycles (8'04") in this group. The time needed to achieve the major reduction varied considerably between subjects. Because of the individualized approach to gait retraining and its relatively quick response due to a strong sensorimotor coupling, we want to highlight the potential of a stand-alone biofeedback system that provides real-time, continuous, and auditory feedback in response to the axial peak tibial acceleration for lower-impact running.