The effects of endogenous and exogenous spatial cueing in a sustained attention task

The decrease in sustained attention performance over time has been ascribed to the involvement of attentional top–down processes. However, to our knowledge, this hypothesis has never been experimentally tested. In order to differentiate the respective involvement of endogenous and exogenous spatial attention processes in the decrement of sustained attention performance over time, we devised a new experimental paradigm, which is a combination of the X-Type Continuous Performance Task (Rosvold et al. 1956) and the Spatial Cueing paradigm (Posner 1980). This task implies both attentional orienting and sustained attention processes. Two experiments were then conducted, one with exogenous cueing, and the other with endogenous cueing. We expected performance in the endogenous experimental condition to be more vulnerable to deterioration. Indeed, we observed a RT increase over time in the endogenous cueing task, but no effect with exogenous cueing. The observed effects are consistent with an endogenous control on sustained attention.