A PRELIMINARY-STUDY OF THE RELATIONSHIP BETWEEN DISCRIMINATION REVERSAL-LEARNING AND PERFORMANCE-TASKS IN YEARLING AND 2-YEAR-OLD HORSES

A study was conducted to determine the relationship between discrimina tion reversal learning and performance tasks in horses. Ten yearling a nd seven 2-year-old mares and geldings of Arabian (n = 4), Quarter Hor se (n = 9), and Thoroughbred (n = 4) breeding were given a two-choice discrimination task in which either a black or a white bucket containe d a food reward for ten trials per day during 19 test days. The spatia l position of the buckets was Varied on a random schedule. The rewarde d bucket color was reversed each time a subject met criterion of eight correct choices per day for 2 consecutive days, Discrimination revers al testing was followed by 6 days of performance tasks: three crossing a wooden bridge and three jumping an obstacle to reach food and consp ecifics, within a maximum allotted time of 15 min day(-1). Total rever sals attained by the horses were low (x = 1.5 +/- 0.9). All subjects d id attain at least one reversal, and six had two or more reversals. No differences (P > .05) were detected between ages or sexes, nor among breeds in discrimination reversal learning or performance test measure ments. However, there was a trend towards a breed difference (P less t han or equal to 0.09) in the mean number of correct responses to the f irst reversal criterion. Correlations between reversal learning result s and performance task results were extremely low, indicating that the discrimination reversal learning test was not useful for predicting s uccess at these performance tasks. Results from the two performance ta sks also showed little correlation (r = 0.04, P < 0.91), indicating th at horses might not use the same approach when solving the problem of crossing these two obstacles. The overall poor performance of the hors es on the discrimination reversal task suggests horses may have diffic ulty reversing previously learned tasks. (C) 1997 Elsevier Science B.V .