ABSTRACT
Interval timing procedures with extensive associative learning requirements are not useful as mutant screens because they are too long and labor-intensive. Temporal variables have well established effects on the rate of habituation: the longer the interstimulus interval, the slower the habituation. The behavioral criteria for isolating interval timing mutants are important for minimizing the false positive and false negative errors in the identification of interval timing mutants. Notice that even if the mechanisms of learning and timing are independent, screening for loss of interval timing mutations can result in misidentification of learning mutants as timing mutants. The neurotransmitter dopamine is suggested in the timing of temporal intervals in the seconds-to-minutes range because a disruption or imbalance of dopaminergic activity alters the perception of temporal intervals. Accuracy of timing refers to the coincidence of the average subjective estimates of duration with the actual duration of timed intervals.
