An Investigation of Collateral Wood-Chewing as a Time-Mediational Device

Abstract

10 albino rats were divided into 2 groups and were exposed to a DRL-18-sec. schedule. For one group a block of wood was present for the first 40 days while for the second group no wood was present. Subjects with wood available initially showed more reinforced barpresses primarily due to long interresponse time responses (27+ sec.) and large amounts of collateral wood chewing. After 28 days the two groups were receiving essentially the same number of reinforcements. After 40 days the conditions of wood availability were reversed. The animals with wood now available did not engage in collateral wood chewing, and there was no apparent difference in the performance of the two groups. The results question the hypothesis that collateral activities serve as time-mediational devices.