Muscular effort coding in action representation in ballet dancers and controls: Electrophysiological evidence

Abstract

Dancers and controls were shown technical ballet gestures during EEG recording.• Effortful and effortless movements were compared. • Effortful steps elicited a larger P300 and parietal LP (late positivity) in dancers.• Visuomotor regions were more active in dancers than controls in LP time window. • Expertise was required for an automatic and more refined coding of muscular effort. A R T I C L E I N F O A B S T R A C TThe present electrophysiological (EEG) study investigated the neural correlates of perceiving effortful vs. effortless movements belonging to a specific repertoire (ballet). Previous evidence has shown an increased heart and respiratory rate during the observation and imagination of human actions that require a great muscular effort. In addition, TMS (transcranial magnetic stimulation) and EEG studies have evidenced a greater musclespecific cortical excitability and an increase in late event-related potentials during the observation of effortful actions. In this investigation, fifteen professional female ballet dancers and 15 controls with no experience whatsoever with dance, gymnastics, or martial arts were recruited. They were shown 326 short videos displaying a male dancer performing standard ballet steps that could be either effortful or relatively effortless. Participants were instructed to observe each clip and imagine themselves physically executing the same movement. Importantly, they were blinded to the stimuli properties. The observation of effortful compared with effortless movements resulted in a larger P300 over frontal sites in dancers only, likely because of their visuomotor expertise with the specific steps. Moreover, an enhanced Late Positivity was identified over posterior sites in response to effortful stimuli in both groups, possibly reflecting the processing of larger quantities of visual kinematic information. The source reconstruction swLORETA performed on the Late Positivity component showed greater engagement of frontoparietal regions in dancers, while task-related frontal and occipitotemporal visual regions were more active in controls. It, therefore, appears that, in dancers, effort information was encoded in a more refined manner during action observation and in the absence of explicit instruction. Acquired motor knowledge seems to result in visuomotor resonance processes, which, in turn, underlies enhanced action representation of the observed movements.

The Effect of Expertise on Kinesthetic Motor Imagery of Complex Actions

“…If KMI requires the engagement of visuomotor processes, ballet dancers should be able to recall sensorimotor representations due to their extensive training (larger AN). They were also expected to encode effort information during movement observation (Orlandi et al, 2020), consistent with previous evidence on professional musicians (vs. controls; Pau et al, 2013). In contrast, MI of effortful (vs. effortless) movements would result in enhanced cognitive demands (larger AN) in controls lacking in specific motor expertise with ballet, due to increased effortrelated kinematic information (Proverbio et al, 2009).…”

“…Since the partial functional overlap between the neural substrates that underlie MI and motor planning (Hardwick et al, 2017;Jeannerod, 1994;2001), we interpreted the present findings consistent with Pau's study. In a previous paper (Orlandi et al, 2020), we reported evidence of increased frontoparietal activity (larger frontal P300 and parietal Late Positivity components) during the observation of the effortful (vs. effortless) dance movements (used in the present study) in ballet dancers (vs. controls). It is, therefore, possible that effort information has been efficiently processed by dancers while observing the actions, resulting in reduced cognitive demands (smaller AN to effortful vs. effortless movements)…”

The Neuroscience of Dance: A Systematic Review of the Present State of Research and Suggestions for Future Work

“…In (Orlandi et al, 2020b), when dancers and non-dancer controls observed "effortful" ballet steps: both groups had a greater late positivity effect in posterior regions than when they observed and "effortless" ones; frontoparietal regions were more engaged in dancers and occipitotemporal regions were more engaged in controls. A larger P300 was observed in the frontal regions of dancers when they observed effortful movements than in the controls.…”

“…Many components of the neuroscience of dance observation appear to be affected by dance training, including corticospinal excitability (Jola et al, 2012), and brain wave activity (Di Nota et al, 2017;Orgs et al, 2008;Poikonen et al, 2018aPoikonen et al, , 2018b. Dancers also appear to have faster processing and subsequent recognition of dance, with enhanced visuo-motor resonance processes, and refined action processing (Orlandi and Proverbio, 2019;Orlandi et al, 2017Orlandi et al, , 2020b.…”

Extension of Dancer’s Legs: Increasing Angles Show Motion

“…Cortical activation levels might indicate amount of depicted motion perceivers report, and impressions of the perceived position of stationary objects ( Pinna and Brelstaff, 2000 ; Pavan et al, 2011 ). A cortical AON or action observation network is thought to be triggered by static images and might be related to the observer’s own skills ( Orlandi et al, 2020b ).…”