Force field adaptation does not alter space representation.

Prism adaptation is a well-known model to study sensorimotor adaptive processes. It has been shown that following prism exposure, after-effects are not only restricted to the sensorimotor level but extend as well to spatial cognition. The main purpose of the present study was to investigate in healthy individuals whether expansion to spatial cognition is restricted to adaptive processes peculiar to prism adaptation or whether it occurs as well following other forms of adaptive process such as adaptation to a novel dynamic environment during pointing movements. Representational after-effects were assessed by the perceptual line bisection task before and after adaptation to a leftward or a rightward force field. The main results showed that adaptation developed at sensorimotor level but did not influence space representation. Our results have therefore a strong methodological impact for prospective investigations focusing on sensorimotor plasticity while sparing space cognition. These methodological considerations will be particulary relevant when addressing sensorimotor plasticity in patients with specific representational feature to preserve. The discussion highlights the differences between prism and dynamic adaptation that could explain the lack of after-effect on space representation following force field adaptation.