Effect of experimental setting on learning and performance of Auditory Delayed Matching-to-Sample task in dogs.

Twelve dogs were trained in a new task for auditory recognition memory: auditory Delayed Matching-to-Sample (DMS). The animals were tested in two experimental settings using approach (Setting 1) or bar-press (Setting 2) responses. At the early stages of training, the learning took more trials in Setting 2, which was caused by different instrumental response and/or different relationship among manipulanda, stimuli, and reward in these two settings. The performance of the final task did not differ between settings and showed a gradual decline with extended delays. No differences were found in responding patterns or in dynamics of learning. Therefore, we conclude that the auditory DMS, trained in either setting, offers a valuable and reliable tool for studies of neural substrate of auditory recognition memory. The detailed analyses of the dogs' behaviour will allow to evaluate the subtle effects of experimental manipulations in future experiments, and for many reasons the data obtained from these two settings may be combined in further analyses.