Is It Time to Rethink Motion Artifacts? Temporal Relationships between Electrodermal Activity and Body Movements in Real-Life Conditions

This work investigates the temporal dynamics between electro dermal activity (EDA) and gestures during real-life public speaking. Wrist movements and EDA were recorded from speakers during a high-stakes public speaking event. The extreme values theory, more typically used for detecting relatively rare events in financial markets or flood calculations, was adapted and combined with continuous wavelet transform to automatically detect significant temporal events from the derivatives of the movement and EDA time series. The literature describing motion artifacts in EDA predicts that detected movement events should precede or co-occur with EDA. In contrast, we also observed a second case in which EDA changes preceded movement (approximately 40% of cases). These results suggest that humans may move or gesture in response to affective changes, which has clear implications for anyone studying arousal and gesture ´in the wild.