Spatial representations in number processing--evidence from a pointing task

This study investigated cognitive interactions between visuo-motor processing and numerical cognition. In a pointing task healthy participants moved their hand to a left or right target, depending on the parity of small or large digits (1, 2, 8, or 9) shown at central fixation. Movement execution was faster when left-responses were made to small digits and right-responses to large digits. These results extend the SNARC effect (spatial-numerical association of response codes) to manual pointing and support the notion of a spatially oriented mental number line.