Ferchmin P A, Bennett E L
J Comp Physiol Psychol. 1975 Jan;88(1):360-7. doi: 10.1037/h0076175.
To test the relative effectiveness of direct vs. indirect interaction with an enriched environment, some rats were housed in groups of 12 in large enriched condition (EC) cages while littermate "observer" (OC) rats were placed singly in small wire-mesh cages within EC. A third group was housed singly in an impoverished condition (IC) where stimulation was minimal. After 30 days, the animals were killed and the brains dissected. In both experiments the usual pattern of EC-IC differences in brain weights appeared, whereas OC showed no significant differences from IC. On measures of exploratory behavior taken during the last 2 days of the second experiment, IC fell significantly below EC, and OC was somewhat below IC. Thus EC differen from both IC and OC in brain and in behavior. Active contact with an enriched environment appears necessary for development of EC effects.
为了测试与丰富环境直接互动和间接互动的相对有效性，一些大鼠被12只一组饲养在大型丰富条件（EC）笼中，而同窝的“观察”（OC）大鼠则单独放置在EC内的小铁丝笼中。第三组单独饲养在贫乏条件（IC）下，那里的刺激最少。30天后，处死动物并解剖大脑。在两个实验中，都出现了大脑重量上常见的EC - IC差异模式，而OC与IC没有显著差异。在第二个实验的最后两天进行的探索行为测量中，IC显著低于EC，而OC略低于IC。因此，EC在大脑和行为方面与IC和OC都不同。与丰富环境的积极接触似乎是产生EC效应所必需的。
