Behavioral recovery on a spatial variant of the Konorski test following prefrontal damage in dogs

Two groups of naive dogs were trained on a spatial variant of the Konorski Test, in which pairs of successively presented auditory location cues were differentiated in a conditioning procedure. Instrumental leg flexion to positive stimuli was reinforced by food. Combinations of four different location cues were used as compound conditioned stimuli (CS). In group AA a positive CS involved two identical, successively presented location cues, Sx-Sx, separated by an interval of 5 s, whereas the negative CS was formed by two different successive location, cues, Sx-Sy, with the same intercomponent interval. In group AB positive and negative combinations of location cues were reversed: Sx-Sy combinations were positive, while Sx-Sx were negative. Solving the task required a comparison of the second CS component with the memory trace left by the first component of CS. The two groups did not differ in reaching the preoperative criterion, but the response time was significantly shorter in the AA group. Prefrontal proreal lesion produced a significant but transient impairment of performance in both groups. The third group, trained on a simple differentiation task with single location cues, was completely unimpaired.