LAUSR

Some evidence suggests that testosterone can increase attentional orientation toward biologically relevant stimuli and increase sustained attention during goal-oriented behaviors. While rare irregular distractors often capture attention involuntarily and distract us away from the task at hand, we hypothesized that testosterone might (1) facilitate attentional orientation to novel distractors that are of potential behavioral relevance and (2) inhibit information processing of distractors that are irrelevant to the task. To test this hypothesis, we investigated the effects of testosterone on distractor processing in a novelty oddball task, during which infrequent target and distractor sounds were interspersed within a series of frequent non-target sounds. Using a double-blind, placebo-controlled within-participant design, we administered a single dose of either testosterone or placebo to 34 healthy male volunteers and compared their electroencephalographic responses to distractors. Increased amplitude of the early (260-310 ms) P3 component-which has been associated with phasic arousal and alertness triggered by novel stimuli-was observed in the testosterone session than in the placebo session. This early-P3 response mediated the effect of testosterone administration on target hit rate during the task. In addition, less α-oscillation suppression-which has been associated with the inhibition of task-irrelevant information processing-was observed in response to distractors later (538-757 ms) in the testosterone session than in the placebo session. These results suggest that testosterone facilitated phasic arousal to novel distractors during the early-latency stage, which might have influenced behavioral performance during the task. Furthermore, testosterone inhibited task-irrelevant information processing during the late-latency stage, which allowed better reorientation of attention back to the primary task. Our findings highlight the role of testosterone in distractor processing, and provide a theoretical basis for treating attention-related behavioral disorders with hormone therapies.