Control of avoidance response patterning by time-correlated stimuli was studied in rhesus monkeys. At several shock-shock = response-shock intervals, the intervals were divided into 8, 4, or 2 time segments by correlating, respectively, 1, 2, or 4 discrete lights of an eight-light display with each successive segment. A further condition examined response patterning when the avoidance interval was not segmented: all eight lights of the display were lit throughout the interval. Reversal of the order in which the lights were lit in sequence was also examined. Generally, increasing the number of lights lit at one time (decreasing the number of signalled time segments) increased response rates and shifted interresponse time distributions to the left. When the lights were lit one at a time, signalling eight discrete time segments of the interval, response rates were consistently low.