Postural control tasks in an emotional context

Abstract

Basic postural control tasks always take place in an environmental context. Environmental parameters such as optic flow, changes in support surface, and integrity of reflex loops, have been widely studied to unravel the postural control mechanisms. My research focuses on environmental parameters that have clear survival value, namely emotions. Within psychological theory, emotions serve an evolutionary purpose, and prepare the organism for adaptive physiological, cognitive, and behavioral responses. Numerous studies have found markers of these emotion responses in the way humans organize and coordinate their movements (manual, facial, postural, etc.). My own research has focused on two basic postural control tasks, namely quiet standing, and gait initiation in a particular direction. Analysis of center-of-pressure displacements during a brief emotional episode has revealed postural adjustments that are specific to emotion. Key parameters are reductions in postural sway (resembling ‘freezing’ when fearful), and tendencies to move forward (with pleasant stimuli) and backward (with unpleasant stimuli). My experimental work has also revealed that these postural responses are modulated by the duration of an emotion event, and by the arousal level experienced. Most of my studies have been conducted using healthy participants, but some of the above effects seem to be amplified in certain psychiatric conditions.