Task measurements
Positions of participants' hands in 3D space were recorded for 120 s in each experimental condition, at a sampling rate of 50 Hz. Instantaneous velocities were calculated as the difference between consecutive position measurements for each participant. To eliminate jitter, a 100 ms Gaussian sliding window was applied to the calculated velocities (Figure 
The calculated CVV enabled identifying synchronized motion, calculated with the measure We used linear mixed effects (LME) models using the R language, as suggested by Baayen et al. (