What are the mechanisms that mediate the experience of time in humans and other animals? Killeen and Fetterman (1988) argued that animals base temporal judgments on behaviors elicited by periodic reinforcements, and that the frequency of reinforcement determines the speed of a pacemaker whose pulses instigate transitions from one behavior to another. This research will evaluate the adequacy of that Behavioral Theory of timing, and will compare its predictions against those of an information- processing theory of animal timing (Scalar Expectancy Theory). Behavioral Theory predicts a correlation between temporal judgments and ongoing behavior, and thus Dr. Fetterman will observe animals as they time the duration of events. Temporal judgments should be better predicted by the ongoing behavior than by the time elapsed. Dr. Fetterman will also disrupt ongoing behavior, which should produce a decrease in the accuracy of timing. Other experiments concern the statistical properties of the pacemaker and the relation between the speed of the pacemaker, arousal, and ensuing temporal judgments. Behavioral Theory holds that a given interval of time is always evaluated relative to the prevailing level of arousal; changes in arousal should cause changes in the perceived duration of events. Several experiments will incorporate manipulations that should alter level of arousal (e.g., by changing rate of reinforcement), and thus should perturb the animal's sense of time. These findings may be related to the human literature on disturbances in biorhythmicity and to disorders that involve a distortion of time perspective.
