Discrimination Learning 145 Discrimination Learning in Rats

Previous research has indicated that rats use various conceptual classes to select the correct stimulus when presented with a discrimination task. Four male hood rats were required to discriminate hetween pairs of triangles or circles that varied in size. The rats were tested in a T-maze where they underwent three phases. The training phase involved presentations of either circles or triangles that required the rats to select the correct stimulus for a reinforcer. The testing phase involved the presentation of a random probe trial where the pair of untrained shapes was presented. A post-testing phase assessed the rats' capability to select the correct stimulus when presented with the pair of untrained shapes. A one-way within-suhjects ANOVA found that the rats selected the correct stimulus ahove chance level, F(19,57) = 2.85, p < 0.05, and two Chi Square Goodness of Fit Tests found that the rats ' performance on probe trials was above chance, (1, N=4) = 22.5, p< 0.05, and that the rats performance in the post-testing phase was above chance, (1, N=4) =4.5, p< 0.05. A multitude of research has been devoted to the assessment of whether or not animals make use of conceptual classes that have been previously assumed to be distinctly human. It has been suggested that animals employ various perceptual and relational classes to function and learn about their surrounding environment (Wasserman et al., 2008). Perceptual classes have heen defined by Wasserman et al. (2008) as the process wherein one sorts a variety of stimuli into certain categories based upon physical characteristics. Relational classes are described as the grouping of stimuli based on similarities or differences (Wasserman et al., 2008)