Objective: According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks--alerting, orienting, and executive attention. An important question is whether the experience of emotion differentially influences the efficiency of these networks. Method: This study examines 180 participants were randomly assigned to a happy, sad, or control condition and undertook a modified version of the Attention Network Test. Results: The results showed no effect of happiness or sadness on alerting, orienting, or executive attention. However, sad participants showed reduced intrinsic alertness. Conclusion: This suggests that sadness reduces general alertness rather than impairing the efficiency of specific attention networks. (Contains 2 notes, 2 tables, and 1 figure.)