Adjunctive behavior in humans on a food delivery schedule

Adjunctive behavior as indexed by increased activity has been shown previously in adult humans who were performing cognitive tasks or playing games of chance on a fixed interval schedule. In the present experiment with eating as the schedule controlled behavior, the amount of movement unrelated to eating was measured for eight subjects under three conditions. Movement scores were significantly higher when food was available either ad lib or on a FI 60 food delivery schedule than when food was not available. Data showed that with ad lib food, subjects operated on a self imposed schedule. These results establish the first direct comparison between animal and human adjunctive behaviors.