Neuringer A, Huntley R W
Department of Psychology, Reed College, Portland, OR 97202.
Physiol Behav. 1992 Jan;51(1):145-9. doi: 10.1016/0031-9384(92)90216-o.
Operant variability was compared in four groups of Long-Evans rats (young males, young females, mature males and mature females) under two different conditions. Under VAR contingencies, where response variability was required for reinforcement, a sequence of four responses on left (L) and right (R) levers had to differ from each of the preceding four sequences. If LLLL, LRLL, RRRR, and RRLL had just occurred, then a RLRL sequence, for example, would be reinforced in the next trial, but LRLL would not. Sequence variability was compared to that under YOKE contingencies, where reinforcement was provided whether or not the rats varied their responses. We found that young rats behaved more variably than mature rats, this effect most pronounced under the YOKE contingencies, where variability was not required. On the other hand, variability was not related to gender under either VAR or YOKE conditions. Thirdly, all groups were sensitive to the schedule contingencies, behaving more variably under VAR than under YOKE. Thus age and schedule requirements influenced operant variability, but gender did not.
在两种不同条件下，对四组朗-埃文斯大鼠（年轻雄性、年轻雌性、成熟雄性和成熟雌性）的操作性变异性进行了比较。在可变比率（VAR）条件下，强化需要反应变异性，左右杠杆上的四个反应序列必须与之前的四个序列中的每一个都不同。例如，如果刚刚出现了LLLL、LRLL、RRRR和RRLL，那么在下一次试验中，RLRL序列将得到强化，但LRLL不会。将序列变异性与在匹配控制（YOKE）条件下的变异性进行了比较，在该条件下，无论大鼠是否改变其反应都会给予强化。我们发现，年轻大鼠比成熟大鼠表现出更多的变异性，这种效应在不需要变异性的YOKE条件下最为明显。另一方面，在VAR或YOKE条件下，变异性与性别无关。第三，所有组都对强化程序敏感，在VAR条件下比在YOKE条件下表现出更多的变异性。因此，年龄和强化程序要求影响操作性变异性，但性别不影响。
