The time course of alerting effect over orienting in the attention network test.

In the present experiment we used a version of the attention network test (ANT) similar to that of Callejas et al. (Exp Brain Res 167:27-37, 2005) to assess the Posner's attention networks (alerting, orienting and conflict), and their interactions. We observed shorter reaction times with alerting tone than with no alerting tone trials (the alerting effect); with cued than with uncued trials (the orienting effect); and with congruent than with incongruent trials (the conflict effect). These results replicate previous findings with the ANT. We also manipulated cue-target interval at five stimulus onset asynchrony (SOA) values (100, 300, 500, 800, and 1,200 ms) to trace the alerting network influence over the orienting network. The SOA manipulation showed that cuing effects peaked at 300 ms SOA irrespective of whether an alerting tone was present or not, and the alerting tone improved the cuing effect equally for 100-500 SOAs, but it did not at the longest 800-1,200 ms SOAs. These results suggest that alerting improves rather than accelerates orienting effects, a result that agrees with data from neuropsychological rehabilitation of parietal patients with spatial bias.