Why does listening to music (Olivers & Niewenhius, 2005), being in a positive mood (Olivers & Niewenhius, 2006), employing a relaxation strategy (Smilek et al, 2006) or being distracted by task-irrelevant events (Arend et al, 2006) improve performance on attentionally demanding tasks? These effects have sometimes been attributed to the benefits of positive affect on cognitive performance and at other times to the benefits of dividing attention in tasks where participants tend to overemphasize slow executive processes when rapid automatic processes will do.
What has been overlooked in these discussions is that a participant's emotional state is determined by at least two separable dimensions: one corresponding to whether the state is pleasant or aversive (affect) and another that concerns the level of activation (arousal).
Here we examine the influence of each of these dimensions on performance in a standard attentional blink task. Four emotional states were induced using a music mood induction technique combined with autobiographical memory (Eich & Macauley, 2000): calm (positive, low arousal), happy (positive, high arousal), sad (negative, low arousal), anxious (negative, low arousal).
The results showed that the attentional blink was reduced in the low arousal states relative to the high arousal states. However, this main effect interacted with affect, such that the attentional blink was most severe when participants were highly aroused and negative (anxious) and least severe when they were less aroused (sad). Participants in a positive mood had an intermediate blink that did not differ with arousal (calm, happy).
These results imply (1) that the influence of emotions on attentional control cannot be assessed without taking both affect (positive-negative) and arousal (low, high) into account, and (2) that the influence of “distraction” on attentionally demanding tasks cannot be evaluated without considering the emotional consequences of the distractions.