ABSTRACT
Human beings are active and social agents. They need to process spatial information in order to act accurately on objects in the surroundings and to interact appropriately with conspecifics. Although spatial perception is an inherent component of adaptive behaviours, it does not emerge as an innate ability. Instead, spatial perception develops through the active exploration of the environment during the very first period of life. In absence of early motor exploration of the environment and associated experience of sensory changes, spatial perception remains immature. Supporting this view, the pioneering work by Held and Hein on animals convincingly demonstrated that when a kitten receives visual stimulation and is allowed to walk during its first weeks of life, it remains nevertheless blind to visuo-spatial information if it cannot contingently experiment walking and seeing the consequence of walking. Its behaviour appears like that of a blind kitten colliding with obstacles, stumbling in hollows and falling in cliffs (Held & Hein, 1963). Likewise, Fine et al. (2003) showed more recently that a person recovering sight after a long period of blindness due to early damage of the eye cornea perceives visual shape and motion but fails to detect objects’ volume and 3-D surfaces (see also Gandhi, Ganesh, & Sinha, 2014). Similarly, newly sighted subjects did not exhibit immediate capacity to transfer information from the tactile to the visual domain (Held et al., 2011). These observations agree well with theories of perception that have long since defended the idea that the experience of spatiality proceeds from processing sensory information in reference to the possibilities of action (Berkeley, 1709; Husserl, 1907; Merleau-Ponty, 1945). According to the philosopher and mathematician Poincaré (1902),
[W]hen we say that we localize such an object in such a point in space, what does this mean? This simply means that we represent the movements that
are necessary to reach that object. . . . When I say that we represent these movements, I mean only that we represent the muscular sensations which accompany them and which have no geometrical character, which therefore do not imply the pre-existence of the concept of space.
