Field of view affects reaching, not grasping

It has been observed that wearing goggles that restrict the field of view ( FOV) causes familiar objects to appear both smaller and nearer. To investig ate this further, we examined the effect of a range of field sizes (4 degre es, 8 degrees, 16 degrees, 32 degrees and 64 degrees) on estimates of objec t distance and object size used to control reaching and grasping movements of binocular observers. No visual or haptic feedback was available during t he experiment. It was found that, as the FOV was decreased, the distance re ached by subjects also decreased, whereas the size of their grasp was unaff ected. In a second experiment, we compared reaching and grasping responses under binocular and monocular conditions for 8 degrees and 64 degrees field sizes and show that the effects of FOV do not result from the progressive loss of binocular information. We conclude that reducing the FOV produces s ubstantial and dissociable effects on reaching and grasping behaviour and t hat field size must be taken into account in any context where visuo-motor performance is important.