Endocrine Abstracts

Introduction: It appears recently that the lack of physical activity might not be a factor for obesity but rather a consequence of perceptual-motor difficulties (D’Hondt et al. 2011). Perception and action are two intertwined processes: perception is a means to action and action is a means to perception. Not being able to perceive correctly visual or auditory information would alter someone’s movement kinematics of any given task. The key question is how do these different senses interact in situations that rely on the tight coupling between perception and action? To which extend obesity modifies the sensory motor integration and the movement output?

Methods: 88 participants (44 Obese and 44 matched-control) sat on a chair equipped with a wrist pendulum that moves in the sagittal plane. The pendulum had a potentiometer built-in that records the angular wrist movement. For one of the experimental conditions, an oscillating visual stimulus was displayed on the screen. Another experimental condition consisted of an auditory signal oscillating between the right and left ears of the participants. The task was to synchronise the pendulum with either or both sensory modalities.

Results: The key findings from the repeated-measures ANOVAs revealed a strong reduction of the movement accuracy of the obese participants. For all sensory modalities, patients struggled to synchronise their action with the stimuli (P<0.05). To make an analogy with a dance performance, one can imagine someone dancing off the beat of the music. The movement variability of the obese patients was also higher than the control group (P<0.05).

Conclusion: This perceptual problem reduces the motor control of obese patients revealing even more encompassed difficulties. The identification of the origin of the perceptual problem will allow us to address the problem to its source and eventually to break the vicious circle of a deficient perception and action coupling.