Slide 16 of 29

One aspect of the stimulus that influenced the PRC was stimulus duration. These are data were taken from a single male on the same evening using stimuli having different numbers of pulses. For the long duration, 14-pulse stimulus the PRC showed a typical type 0 resetting. Note, however, that the phase shifts for stimuli presented early in the male’s period are not zero but are delayed by about 25% of the male’s period. In other words the male lengthened his period by about 25%. For the 8-pulse stimulus the male had a type 1 PRC, whereas there was little or no phase shift for a 1-pulse stimulus no matter what phase the stimulus was presented.