| Abstract: | The variability of anticipating a meal was investigated. Sprague-Dawley rats earned food by inspecting a food source during a 3-hr interval. Food was not available at other times. In Experiment 1, the meal started 3 or 7 hr after light offset in a 12-hr light-dark cycle. Experiment 2 was conducted in constant darkness with 14-, 22-, 22.5-, 24-, 25.5-, 26-, or 34-hr intermeal intervals. Inspections increased before the meal. Rats timed intervals in the circadian range (22–26 hr) with lower variability than that for intervals outside this range (3–14 and 34 hr). Higher precision in timing selected intervals violates the scalar property. Proximity to a circadian oscillator improves timing precision. Variability may be used to identify oscillators with noncircadian periods. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
