Judgment Bias in Lister Hooded Rats

Subjects were 16 male Lister Hooded rats (Charles River, Margate, UK). Two rats did not complete judgement bias (JB) testing due to poor performance in training; they did not reach the progression criterion at the discrimination stage of training (see: Jones et al. (2018)^{25 (link)}). The rats were housed in stable pairs in cages measuring 560x340x190mm and kept under a 12-h reverse light cycle, with lights off at 7am and on at 7pm. Two cardboard tubes and an aspen block were provided as enrichment and subjects had ad libitum access to food (LabDiet) and water. This research received ethical approval from the Animal Welfare and Ethical Review Body at the University of Bristol (UIN: UB/16/004) and adhered to ASAB/ABS guidelines for the use of animals in research. Subjects were rehomed as pet rats on completion of the experiment.