Prospective organization of neonatal arm movements: A motor foundation of embodied agency, disrupted in premature birth

Abstract

Prospective motor control moves the body into the future, from where one is to where one wants to be. It is a hallmark of intentionality. But its origin in development is uncertain. In this study, we tested whether or not the arm movements of newborn infants were prospectively controlled. We measured the spatiotemporal organization of 480 full-term neonatal arm movements and 384 arm movements of prematurely born infants at-risk for neurodevelopmental disorder. We found 75% of healthy term-birth neonatal movements and 68% of prematurely born infant movements conformed to the τG-coupling model of prospective sensorimotor control. Prospective coupling values were significantly reduced in the latter (p =.010, r =.087). In both cases prospectively controlled movements were tightly organized by fixed-duration units with a base duration of 218 ms and additional temporal units of 145 ms. Yet distances remained constant. Thus, we demonstrate for the first time a precise prospective spatiotemporal organization of neonatal arm movements and demonstrate that at-risk infants exhibit reduced sensorimotor control. Prospective motor control is a hallmark of primary sensorimotor intentionality and gives a strong embodied foundation to conscious motor agency.