76 undergraduates participated in 2 experiments to determine (1) whether differential allocation of processing capacity would predict greater capacity allocation during the reinforced CS (CS+) than during the nonreinforced CS (CS-) and (2) whether there are systematic temporal changes in capacity allocation during the CS–UCS interval. A 7.0-sec delay paradigm was used to establish responses to a visual CS+. Electrodermal responses were the primary measures of autonomic classical conditioning. Allocation of processing capacity was measured by monitoring performance on a secondary RT task. The auditory secondary-task RT signal was presented before and 300, 500, 3,500, 6,500, and 7,500 msec following CS onset. The RT signal was also presented following properly and improperly cued shock UCSs. Results demonstrate that cognitive processing capacity is allocated differentially to CS+ and CS- and that capacity allocation changed systematically during the CS–UCS interval, exhibiting a peak at 300 msec following CS+ onset.