Lateralized perception: the role of attention in spatial relation processing.

Any spatial situation can be approached either categorically - the window is to my left - or coordinately - the glass is 20cm away from the bottle. Since the first description of the distinction between categorical and coordinate spatial relation processing, it has often been shown that they are processed by at least partially different underlying mechanisms, mainly located in the left and right hemisphere, respectively. A number of recent studies have suggested that spatial attention plays a particularly important part in the perception of space: categorical processing benefits from a local focus of attention, and coordinate processing profits from a global focus of attention. This suggests that the lateralization pattern is modified by the concurrent size of the attentional focus, and is consequently more dynamic than previously thought. Therefore, a thorough revision of earlier theories on spatial relation processing is in order. In this review, we present a new model on lateralization of spatial relation processing that explicitly describes the role of spatial attention.