Partial acquisition and extinction of an avoidance response in two breeds of swine.
Richard L. Willham, G. G. Karas, D. C. Henderson
Journal of Comparative and Physiological Psychology, Vol. 57, No. 1, pp. 117-122, 1964
Abstract
60 acquisition trials were given 282 3-week-old swine; 80 of these were given an additional 30 acquisition trials. Of those given 60 trials, 98 were given 120 extinction trials. In the 3rd set of 10 acquisition trials, genetic differences within breeds were larger than in prior or subsequent sets. The variance for sets of 10 extinction trials averaged 1.7 times the maximum acquisition variance, yet genetic differences accounted for less of the total. Breed difference was largest during the early sets of acquisition trials and then gradually decreased until, during extinction, no significant difference was found.