Timing the events of directional cueing.

To explore the role of temporal context on voluntary orienting of attention, we submitted healthy participants to a spatial cueing task in which cue-target stimulus onset asynchronies (SOAs) were organized according to two-dimensional parameters: range and central value. Three ranges of SOAs organized around two central SOA values were presented to six groups of participants. Results showed a complex pattern of responses in terms of spatial validity (faster responses to correctly cued target) and preparatory effect (faster responses to longer SOAs). Responses to validly and neutrally cued targets were affected by the increase in SOA duration if the difference between longer and shorter SOA was large. On the contrary, responses to invalidly cued targets did not vary according to SOA manipulations. The observed pattern of cueing effects does not fit in the typical description of spatial attention working as a mandatory disengaging-shifting-engaging routine. In contrast, results rather suggest a mechanism based on the interaction between context sensitive top-down processes and bottom-up attentional processes.