Visual discrimination learning of group-housed goats at an automated learning device
Abstract. A general purpose computer system for behavioral conditioning experiments, the "Fields-Monitor", was developed and has been in use for several years. The set-up allows flexible stimulus presentations and rewards for different kinds of learning behavior in animals. It enables training and testing of animals even under group housing conditions which prevent the social isolation and possible distorting influences resulting from the experimenter or from the time of the day (the test animals visit the learning device whenever they want). Thus, it eliminates most of the stress factors known to decrease learning success. Using this device, 160 dwarf goats were trained for visual discrimination of four stimulus patterns (simple geometric figures, Roman letters) presented simultaneously. One of these patterns was rewarded with a small portion of water after each correct choice. A comparison of mean learning curves in the three consecutive tests showed that in the second and third test successful learning started earlier and reached a higher level (70–80% correct choices as early as the 5–6th Test Day) than in Test 1 (about 60% correct choices at the 10th Test Day). The coefficient of variation of average learning success for 10 days was 28.4, 18.7, 16.8 % in Test 1–3 respectively, indicating great differences between the animals. All animals could use the learning equipment voluntarily over several weeks, without any social deprivation.