Human expressive movements: The boundary between health and disease from a contaminated perspective

Expressive movements represent forms of non-verbal communication by means of gestures, postures, and body expressions. They are a fundamental aspect of human communication, enriching and expanding the meaning of spoken words (Niedenthal, 2007). Expressive movements are a highly coordinated and creative form of motor behavior, generated by a common anatomical-functional substrate, particularly the Central Pattern Generators (CPGs) able to produce complex, rhythmic, innate patterns. The activity of CPGs is modulated by sensory input and signals from higher brain regions (Yuste et al., 2005), including the limbic system, which is involved in emotions processing. Participation in collective mystical-religious rituals and dance are powerful inducers of complex motor activities with high emotional impact. Notably, some brain diseases can result in uncontrolled actions and movements with high expressive contents. Epileptic seizures represent a well-known example. Depending on the cortical area involved, ictal motor manifestations may assume various and peculiar forms, sometimes resembling physiological, voluntary, human expressive movements, such as spitting, laughter, and dancing. Notably, expressive movements may also occur in functional neurological disorders (FND), such as Psychogenic Non-Epileptic Seizures (PNES) and a wide spectrum of other movements disorders. FND are characterized by changes in motor, sensory, or cognitive functioning and exhibit one or more deficit patterns primarily indicative of nervous system dysfunction. The interpretation of expressive movements either as pathological or cultural phenomena can vary depending on historical, socio-cultural, and individual context. This theme represents the main objective of this paper and it was discussed in a conference titled “Expressive Actions and Movements in Rite, Art and Illness” held in Reggio Calabria (Italy) in June 2023, featuring contributions from neurologists, psychiatrists, anthropologists, historians, archaeologists, and choreographers (see Supplementary material).