Grounding spatial language in the motor system: Reciprocal interactions between spatial semantics and orienting.

Shifts of attention that are directed by spatial words are thought to be mediated by a spatial frame of reference. Previous studies have documented a selection cost when visual attention is directed along the left/right axis relative to the above/below axis due to the greater ambiguity of the horizontal endpoints. The present study investigated whether the horizontal endpoints may be more fully disambiguated when 'left/right' cues are first enacted by nondivisible, more discrete, modes of orienting such as directional motor responses. This issue was investigated using a repetition priming paradigm in which the effects of prior enactments were measured on the subsequent conceptual control of visual attention. The results of four experiments showed that grounding spatial language in the motor system can enhance the focus of visual attention by disambiguating the endpoints of the horizontal axis. In so doing, the present study extends previous research demonstrating that spatial concepts can influence the spatial distribution of attention by demonstrating that different modes of orienting can also influence the semantics of space. Implications for the premotor theory of attention and grounded theories of cognition are also discussed. [ABSTRACT FROM AUTHOR]