Spatial cognition and motor development: a study of children with spina bifida

The purpose of this study was to examine the relation between motor development and spatial cognition. The sample was 20 children with Spina bifida (M age: 11.4 yr., SD = 1.7) and 20 healthy children as controls (M age: 11.8, SD = 1.8 yr.). An experimental assessment of motor development in spatial cognition in a simulated virtual maze by school-age children is lacking. In this study children with Spina bifida, who were impaired in walking since birth, completed four visuospatial tasks in a small-scale space (Mental Rotation, Water-Level Task, Embedded Figures Test, Visual Short-term Memory Test), and a spatial behaviour and knowledge task in a virtual maze. These children showed poorer performance than children in the control group on most measures. The results are discussed with respect to theoretical implications and further research.     

Actuality and possibility: On the complementarity of two registers in the bodily constitution of experience

The purpose of this paper is to demonstrate the usefulness of the concept of possibility, and not merely that of actuality, for an inquiry into the bodily constitution of experience. The paper will study how the possibilities of action that may (or may not) be available to the subject help to shape the meaning attributed to perceived objects and to the situation occupied by the subject within her environment. This view will be supported by reference to empirical evidence provided by recent and current research on the perceptual estimation of distances and the effects brought about by the use of a tool on the organisation of our perceived immediate space.

PERCEPTION OF MOTION AND CHANGING FORM: A study of visual perception from continuous transformations of a solid angle of light at the eye

It is shown how geometrically changing projections of objects which move and/or change their shape carry no specific information about form and three-dimensional motion. How, then, does the visual apparatus produce specific percepts from such non-specific changing stimuli? By applying an analogue computer technique, changing projections of artificial objects are generated on a CRT screen. These projections are fed into the eye by means of an optical device where they form a continuously changing solid angle of homogeneous light. The main conclusion is that it is a principle of perceptual three-dimensionality which gives specificity to the percepts. Preliminary statements of principles for prediction of perceived motion in depth from a given change in proximal stimulus are presented.