New paradigms and tests for evaluating and remediating visuospatial deficits in children.

This review suggests several hypotheses about the cognitive developmental mechanisms involved in the motor deficits of children with cerebral palsy. We suggest a new theory that visuospatial deficits involving the manipulation of multiple spatial reference frames are crucial components of the disorder in spatial orientation, manipulation, locomotion, navigation, and even social interactions. We review basic knowledge about the brain networks involved in spatial memory and cognition. We then present several potential paradigms for studying specific deficits. We consider first the use of vestibular signals for egocentric spatial orientation in children and the 'locomotor trajectory paradigm' for studying gaze anticipation and perceptual components of walking. We then describe new paradigms for studying egocentric and allocentric strategies in spatial tasks: the 'virtual path length', the 'virtual palace' and the 'virtual star maze'. We also consider paradigms involving the use of other persons and perspective change from a first person's to a third person's viewpoint as reference in spatial tasks or social interactions: the 'designation' paradigm, the 'harlequin', and the 'tightrope walker'. Finally, we briefly present a new experimental set up involving a 'virtual carpet', which follows previous studies of cognitive strategies for generating locomotor trajectories using the 'magic carpet' and which will allow a large variety of studies involving executive functions and inhibition of the first-appearing strategies during development. Several of these new paradigms could be used for remediation.