Visuomotor reconstruction of visual space.

The existence of an internal representation of visual space can be demonstrated by observing the ability to reconstruct different spatial locations in absence of visual object still indicating those positions. The characteristics of this spatial map were investigated in healthy human subjects instructed to point to different spatial positions previously indicated by a visual objects which disappeared. Pointings were made with different delays from the disappearance of the peripheral visual target and with different permanence time of it. The idea emerging from this study of the internal representation of visual space is that it is distorted, with the lower hemifield overestimated with respect to the upper one. Moreover, this map slowly deteriorates with time and its precision depends on the time during which the object can be observed.