Determining how, cognition and emotion interact is pivotal to an understanding of human behavior and its disorders. Available data suggest that changes in emotional reactivity and behavior associated with drinking are intertwined with alcohol's effects on cognitive processing. In the study reported here, we demonstrated that alcohol dampens anticipatory fear and response inhibition in human participants not by directly suppressing subcortical emotion centers, as posited by traditional tension-reduction theories, but instead by impairing cognitive-processing capacity. During intoxication, reductions in fear response (assessed via startle potentiation) occurred only under dual-stimulus conditions, and coincided with reduced attentional processing of threat cues as evidenced by brain response (assessed via P3 event-related potentials). The results are consistent with higher cortical mediation of alcohol 's effects on fear, and illustrate more broadly how disruption of a cognitive process can lead to alterations in emotional reactivity and adaptive behavior.