An ecological study protocol for the multimodal investigation of the neurophysiological underpinnings of dyadic joint action

Abstract

A novel multimodal experimental setup and dyadic study protocol were designed to investigate the neurophysiological underpinnings of joint action through the synchronous acquisition of EEG, ECG, EMG, respiration and kinematic data from two individuals engaged in ecologic and naturalistic cooperative and competitive joint actions involving face-to-face real-time and real-space coordinated full body movements. Such studies are still missing because of difficulties encountered in recording reliable neurophysiological signals during gross body movements, in synchronizing multiple devices, and in defining suitable study protocols. The multimodal experimental setup includes the synchronous recording of EEG, ECG, EMG, respiration and kinematic signals of both individuals via two EEG amplifiers and a motion capture system that are synchronized via a single-board microcomputer and custom Python scripts. EEG is recorded using new dry sports electrode caps. The novel study protocol is designed to best exploit the multimodal data acquisitions. Table tennis is the dyadic motor task: it allows naturalistic and face-to-face interpersonal interactions, free in-time and in-space full body movement coordination, cooperative and competitive joint actions, and two task difficulty levels to mimic changing external conditions. Recording conditions—including minimum table tennis rally duration, sampling rate of kinematic data, total duration of neurophysiological recordings—were defined according to the requirements of a multilevel analytical approach including a neural level (hyperbrain functional connectivity, Graph Theoretical measures and Microstate analysis), a cognitive-behavioral level (integrated analysis of neural and kinematic data), and a social level (extending Network Physiology to neurophysiological data recorded from two interacting individuals). Four practical tests for table tennis skills were defined to select the study population, permitting to skill-match the dyad members and to form two groups of higher and lower skilled dyads to explore the influence of skill level on joint action performance. Psychometric instruments are included to assess personality traits and support interpretation of results. Studying joint action with our proposed protocol can advance the understanding of the neurophysiological mechanisms sustaining daily life joint actions and could help defining systems to predict cooperative or competitive behaviors before being overtly expressed, particularly useful in real-life contexts where social behavior is a main feature.

An Analytical Approach for Naturalistic Cooperative and Competitive EEG-Hyperscanning Data: A Proof-of-Concept Study

“…EEG-hyperscanning acquisitions were performed according to our recently published table tennis protocol, that permits implementing both cooperation and competition within the same experimental framework [44]. Within this framework, the members of a dyad were asked to either exchange the ball as they do before a match (cooperation condition) or play table tennis like in a conventional match (competition condition).…”

“…Participants were allowed to take short breaks between sessions. The higher number of competitive sessions (double than for the cooperative condition) is justified by the relatively lower number of rallies with a duration sufficient for the subsequent analysis, as described in detail in our study protocol [44].…”

“…We recently proposed a novel study protocol including free full-body movements, to meet the recommendations of social neuroscience. We selected table tennis as the joint action task, as it permits implementation of a naturalistic experimental setting and can be played in both cooperative and competitive mode [44]. Notably, table tennis is a turnbased dyadic task that extends the variability of action frequency to both competition and cooperation.…”

“…The pipeline was designed to quantify the global intra-and inter-brain dynamics sustaining these two modes of the same turn-based joint action, hence contributing to filling a gap in the investigation of the neural mechanisms underpinning turn-based joint actions during real-world unconstrained cooperation and competition. To test the effectiveness of our pipeline, we performed a proofof-concept EEG-hyperscanning study on two dyads according to our recently published table tennis study protocol [44]. Herein, we present the proposed analytical pipeline and the case study and compare our initial results with the literature.…”

Simultaneous Dry and Gel-Based High-Density Electroencephalography Recordings

“…Thus, it is important to test the performance of the dry electrodes in direct comparison with the gold standard electrodes. In addition to mechanical, electrical, and chemical characterizations of both types of electrodes [ 10 , 15 , 19 ], comparisons in studies with human volunteers are important to assess electrode performance under realistic conditions and for distinct applications like laboratory settings in research [ 1 , 2 , 3 , 4 , 5 , 11 , 12 , 13 , 18 ] and clinical diagnostics [ 6 ], emergency applications [ 20 , 21 ], brain–computer interfacing [ 22 , 23 ], home settings [ 16 ], or mobile recordings in, for example, sports and movement sciences [ 24 , 25 ]. Each of these applications poses specific requirements for the sensors and sensor applicators, but across all of them, ensuring objective comparison metrics, reproducibility, and minimizing the impact of not sensor-related influences and parameters are key aspects during study design.…”