Figure 1.

The continuous between structured experimental designs and unstructured ones, the impact of design decisions on some dimensions such as ecological validity and cognitive degrees of freedom are depicted. MoBI experiments could be carefully designed in order to be escalable, allowing (i) the exploration of brain/body dynamics emerging from structured and controlled conditions on robust findings [e.g., N2/P3 complex (Folstein and Van Petten, 2008)], (ii) testing previous results in semi-structured complex yet fairly controlled situations [e.g. (Malcolm et al., 2017)], (iii) pushing new hypothesis into complex unstructured settings, and (iv) returning back to a more structured settings if needed. Structured experimental designs are characterized by increasing internal validity at the cost of ecological validity. Left column shows a typical structured experimental setting, where a micro-version of a complex task can be implemented. Such a structured task could range from basic attentional deployment paradigm to a fully-fledged goal-kicking/catching simulator. Furthermore, this experiment could be implemented in both one-person or hyperscanning setups. Multi-modal data acquisition is very possible and highly encouraged in structured settings. Semi-structured experimental designs are characterized by providing some control over experimental variables and more behavioral/cognitive degrees of freedom through allowing more real-life behaviors at reduced ecological validity. Middle column depicts a semi-structured interactional setting where some aspects of natural cognition are preserved. As in real-life, the behavioral goal will be to score (in the case of the kicker) and to catch the ball (in the case of the goalkeeper). Even though multi-modal data acquisition still is a complex task, given the semi-structured nature of the design (e.g., trials, experimenter-controlled timings, etc.), data analysis and interpretation might be relatively straightforward. Finally, unstructured experimental designs are (almost) real-life situations where brain/body datasets are collected. In these setups macro-cognitive states unfold where participants have large behavioral/cognitive degrees of freedom at the possible cost of internal validity and interpretability of results. Right column depicts a natural unstructured interactional setting where collective time-pressured engaged decisions are made, in this case the common goal is to score. Considering these three levels as a natural continuum provides grounds for advancing the field. EEG depictions courtesy of ANT Neuro (The Netherlands).