Schoenberg Hannah L, Sola Emily X, Seyller Ellen, Kelberman Michael, Toufexis Donna J
Department of Psychological Science, University of Vermont.
Department of Cellular and Molecular Biology, University of Vermont.
Behav Neurosci. 2019 Feb;133(1):110-120. doi: 10.1037/bne0000282. Epub 2018 Oct 25.
Habitual behavior can be advantageous by increasing the availability of cognitive resources for use in other tasks. However, habitual behaviors are problematic when they are coopted to prolong the maladaptive responding present in several psychopathologies such as substance abuse, dysregulated fear responding in posttraumatic stress disorder, and obsessive-compulsive disorder. Although sex differences exist in the occurrence or progression of these psychopathologies, there are no studies that compare the development of habitual behavior systematically in male and female animals. In the present study, male and female rats were identically trained on a variable interval 30-s (VI 30-s) schedule of reinforcement to nose-poke for sucrose pellet reinforcers. Subsequently, the sucrose was devalued in one half of the animals by pairing its presentation with injections of lithium chloride (LiCl) to induce nausea, thus conditioning a taste aversion. Habitual behavior was operationalized as continued operant responding in an extinction test following devaluation of the sucrose reinforcer. Successful devaluation was confirmed with both a consumption and reacquisition test. Given identical training to 240 sucrose pellets, female rats demonstrate habitual behavior whereas male rats remain goal-directed. Additionally, females are habitual after 200 or 160 reinforcers earned on a VI 30-s schedule, but remain goal-directed at 120 and 80 reinforcers on this schedule. These data suggest that behavioral flexibility may be compromised in female rats compared to males due to accelerated habit formation in females. These results are important because sex differences are present in several psychopathologies, which may be related to differences in the development of habitual behavior. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
习惯性行为通过增加可用于其他任务的认知资源的可用性而具有优势。然而，当习惯性行为被用于延长几种精神病理学中存在的适应不良反应时，就会出现问题，比如药物滥用、创伤后应激障碍中失调的恐惧反应以及强迫症。尽管这些精神病理学的发生或发展存在性别差异，但尚无研究系统比较雄性和雌性动物习惯性行为的发展情况。在本研究中，对雄性和雌性大鼠进行相同的训练，采用可变间隔30秒（VI 30-s）强化程序，让它们通过戳鼻子来获取蔗糖颗粒强化物。随后，在一半的动物中，通过将蔗糖呈现与注射氯化锂（LiCl）配对以诱发恶心，从而使蔗糖价值降低，以此来建立味觉厌恶。在蔗糖强化物价值降低后的消退测试中，持续的操作性反应被定义为习惯性行为。通过消耗和重新习得测试确认了成功的价值降低。在接受相同的240颗蔗糖颗粒训练后，雌性大鼠表现出习惯性行为，而雄性大鼠仍保持目标导向性。此外，在VI 30-s程序中获得200或160次强化后，雌性大鼠会变得习惯性，但在此程序中获得120和80次强化时，它们仍保持目标导向性。这些数据表明，与雄性大鼠相比，雌性大鼠的行为灵活性可能会受到损害，因为雌性大鼠的习惯形成更快。这些结果很重要，因为在几种精神病理学中存在性别差异，这可能与习惯性行为发展的差异有关。（PsycINFO数据库记录（c）2019美国心理学会，保留所有权利）
