Donovan Clifford H, Wong Scott A, Randolph Sienna H, Stark Rachel A, Gibb Robbin L, Gruber Aaron J
Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive West, Lethbridge, AB, T1K 6T5, Canada.
Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive West, Lethbridge, AB, T1K 6T5, Canada.
Behav Brain Res. 2018 Apr 16;342:62-69. doi: 10.1016/j.bbr.2018.01.018. Epub 2018 Feb 4.
Although male and female rats appear to perform differently in some tasks, a clear picture of sex differences in decision-making has yet to develop. This is in part due to significant variability arising from differences in strains and tasks. The aim of this study was to characterize the effects of sex on specific response elements in a reinforcement learning task so as to help identify potential explanations for this variability. We found that the primary difference between sexes was the propensity to approach feeders out of the task context. This extraneous feeder sampling affects choice on subsequent trials in both sexes by promoting a lose-shift response away from the last feeder sampled. Female rats, however, were more likely to engage in this extraneous feeder sampling, and therefore exhibited a greater rate of this effect. Once trials following extraneous sampling were removed, there were no significant sex differences in any of the tested measures. These data suggest that feeder approach outside of the task context, which is often not recorded, could produce a confound in sex-based differences of reinforcement sensitivity in some tasks.
尽管雄性和雌性大鼠在某些任务中的表现似乎有所不同，但决策过程中的性别差异尚未有清晰的定论。部分原因在于品系和任务差异导致的显著变异性。本研究的目的是刻画性别对强化学习任务中特定反应要素的影响，以帮助找出这种变异性的潜在解释。我们发现，两性之间的主要差异在于在任务情境之外接近喂食器的倾向。这种无关的喂食器采样通过促使远离最后采样的喂食器产生损失转移反应，影响两性后续试验中的选择。然而，雌性大鼠更有可能进行这种无关的喂食器采样，因此这种效应的发生率更高。一旦去除无关采样后的试验，在任何测试指标中都没有显著的性别差异。这些数据表明，任务情境之外的喂食器接近行为（通常未被记录）可能会在某些任务中强化敏感性的性别差异方面产生混淆。
