title: Gnawing and retrieval of inedible objects by Norway rats: Motivational interactions and habituatory effects.
abstract: The relation between gnawing and retrieval of inedible, partible objects (wooden blocks) by domestic Norway rats (Rattus norvegicus Berkenhout) was examined by manipulating the tendency to gnaw and testing subsequent retrieval. Experiments 1 and 2 established that rats gnaw wooden blocks but do not ingest them even during food deprivation, and that gnawing declines (habituates) over days for most rats. In Experiment 3, food deprivation produced a decrease in retrieval of blocks that was reversed under subsequent ad lib conditions. This result was confirmed in Experiment 4, which also demonstrated concommitant changes in gnawing and object retrieval as well as effects on component responses of the retrieval sequence. In Experiment 5, continuous exposure to blocks sufficient to reduce gnawing to a low level led to a decline in retrieval of these objects that was not reversed by discontinuing exposure. These results are consistent with the incentive-motivational account of retrieval preferences developed in earlier work, and some inferences are made about the kinds of processes that could mediate the effects of deprivation and habituation.
authors.affiliation: Department of Computer Science, University of New Hampshire, Durham NH 03824, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wallace