Motivational artifact in standard food-deprivation schedules

    loading  Checking for direct PDF access through Ovid


5 albino rats (adjusted percentage: AP) held at 80% of normal body weight of 25 Ss maintained on ad-lib. food and water (criterion) were compared with 5 Ss maintained at 80% of their individual predeprivation weight (fixed percentage: FP) and 5 Ss fed for 30 min. every 24 hr. (fixed interval: FI). Predictions based on an assumed artifact due to failure to account for normal body growth under FP and FI were confirmed. Lever-press rates under a VI-2-min. reinforcement schedule gradually increased under FP and FI as body weight (percentage of criterion Ss) decreased, whereas AP Ss maintained constant-response rates. Interchanging AP and FP deprivation schedules resulted in response rates consistent with weight levels assumed under new schedules. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

    loading  Loading Related Articles