Disruption Of Discrimination Research Articles

The effects of individual cross-fostering on the development of intrasexual kin discrimination in male laboratory mice, Mus musculus L

The relative importance of experience of self and littermates' cues in the development of the discrimination of unfamiliar same-sex kin by male mice was investigated by individually cross-fostering single pups between unrelated litters. The results suggested that learning the cues of familiar littermates (whether these animals were genetic relatives or not) was an important influence on discrimination by juveniles. The cues of self may also be learned and influence discrimination by juveniles. However, in contrast to previous studies, cross-fostered mice increased rather than decreased their performance of investigatory behaviours towards relatives. It may be that some degree of perceived similarity between the cues of self and those of familiar littermates is important for the development of the patterns of discrimination reported previously. Subject animals did not show any evidence for discrimination when adult. Cohabitation with non-kin until adult appeared to disrupt the ability to recognize, or motivation to discriminate, on the basis of perceived kinship. The results also suggested that a mouse carrying the cues of unrelated animal(s) may be misidentified as kin by these animals' relatives. The effects of recognition cue transfer within subject litters appeared to be stronger in adult test pairings, and this may be a factor involved in the disruption of discrimination by adult subject animals.

Alleyway paper flooring as a locus of nondifferential components of reward and nonreward odors

The locus of discriminable differences in conspecific odors arising from rewarded (R) and nonrewarded (N) trials administered to rats in a straight alleyway was examined by collecting the paper flooring from the alleyway after a squad of donor rats had received R or N. Paper flooring was also collected after a different squad of donors, with no history of alleyway R and N, merely walked on the paper. Different test rats were trained to discriminate between one of these kinds of alleyway paper and clean paper, and then each test rat was successively shifted through two more discriminations involving each of the other kinds of alleyway paper and clean paper. Results indicate that all of the alleyway papers retained olfactory components, which were discriminable from clean paper, and that interchanging the kinds of alleyway paper produced little disruption of discrimination. Implications for the volatility and nondifferential nature of components captured on the paper are discussed.