Kleinmans Maren, Bilkey David K
Department of Psychology.
Behav Neurosci. 2018 Dec;132(6):520-525. doi: 10.1037/bne0000275. Epub 2018 Oct 8.
One of the cognitive symptoms observed in schizophrenia is decreased flexibility in several tasks, including reversal learning. Reversal learning has previously been tested in rats following maternal immune activation (MIA), a risk factor for schizophrenia, with varying results. Whereas some previous studies have shown that MIA rats are slower to learn a reversal, others have reported more rapid learning compared with controls. Several of these latter studies have, however, used a T-maze task with aversive, negative reinforcement as a motivating factor. Because most human studies use positive reinforcement in reversal tasks, here we tested whether reinforcement valence might be a critical factor. We ran male MIA and control rats in a T-maze reversal procedure that was very similar to previous studies except that positive, appetitive reinforcement was used for motivation. The results showed that MIA animals performed similarly to controls during training, but in contrast to the previous, aversively motivated T-maze studies, slower reversal learning was observed. These results show that MIA animals are impaired in reversal learning under conditions of positive reinforcement, consistent with the effects observed in individuals with schizophrenia. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
精神分裂症患者中观察到的认知症状之一是在包括逆向学习在内的多项任务中灵活性下降。逆向学习此前已在母体免疫激活（MIA）后的大鼠身上进行测试，MIA是精神分裂症的一个风险因素，结果各不相同。虽然此前一些研究表明MIA大鼠学习逆向任务的速度较慢，但其他研究报告称与对照组相比学习速度更快。然而，这些后期研究中有几项使用了以厌恶、负强化作为激励因素的T迷宫任务。由于大多数人类研究在逆向任务中使用正强化，因此我们在此测试了强化效价是否可能是一个关键因素。我们让雄性MIA大鼠和对照大鼠进行T迷宫逆向程序，该程序与之前的研究非常相似，只是使用正性、奖赏性强化作为激励。结果表明，MIA动物在训练期间的表现与对照组相似，但与之前以厌恶为动机的T迷宫研究不同，观察到其逆向学习较慢。这些结果表明，MIA动物在正强化条件下的逆向学习受损，这与在精神分裂症患者中观察到的效应一致。（PsycINFO数据库记录（c）2018美国心理学会，保留所有权利）
