Moderation of Caffeine's Cognitive Effects by Menstrual Cycle Phase

总的来说，这个项目的主要目的是研究咖啡因如何影响大脑活动，从而影响整个月经周期的行为。这样做的原因有三点。首先，大脑活动和任务表现在月经周期中会发生变化。其次，咖啡因也会通过刺激作用改变大脑活动和任务表现，或者让我们“振作起来”的能力。然而，我们不知道咖啡因对大脑的影响是否会改变（是好是坏）我们在月经周期中看到的大脑活动的一些变化，尽管事实上大约88%的加拿大人经常摄入咖啡因。最后，或许也是最重要的一点，我们不知道咖啡因在月经周期的不同阶段如何影响大脑的一个原因是，在药物研究中，女性一直被忽视。对娱乐性药物的研究，对医疗药物（如治疗艾滋病毒或癌症的药物）的研究，以及对咖啡因和尼古丁等常见药物的研究都是如此。女性被排除在这类研究之外的一个主要原因是，药物的效果可能（如果不是可能的话）会根据月经周期的不同阶段而变化，而在这些不同的阶段对女性进行测试既耗时又昂贵。因此，这些研究中的许多只测试和报告了药物对男性的影响。这是有问题的，因为这些结果通常被推广到整个人类，尽管我们通常只有男性的数据，或者当我们有女性的数据时，要么没有考虑月经期，要么只测试了一个阶段。咖啡因当然也是如此；不仅很少有研究关注咖啡因是如何影响大脑的，而且几乎没有研究研究这些影响在女性的月经周期中是如何变化的。因此，本项目的一个主要目标是填补这方面的文献空白。除此之外，我们希望这将是我们实验室研究项目的开始，以记录整个月经周期中精神活性物质对大脑的影响，从而使女性更容易被纳入未来的研究。该项目将在“自然周期”的妇女中进行，也就是说，她们的月经周期不受药物激素的影响，在月经、卵泡和黄体周期阶段。然而，鉴于以激素为基础的避孕措施（如避孕药）的普及，我们也将在目前使用激素避孕方法的妇女中进行这些测试。在项目结束时，我们希望不仅能更好地了解咖啡因是如何影响我们大脑的工作方式的，而且还能开始了解月经周期和咖啡因等药物是如何共同影响大脑功能的。

Overall, the main purpose of this project is to examine how caffeine affects brain activity and, therefore, behavior across the course of the menstrual cycle. The reasons for doing so are threefold. Firstly, brain activity and performance on tasks changes across the menstrual cycle. Secondly, caffeine also changes brain activity and performance on tasks through its stimulating effects, or its ability to make us ‘perk up’. We don’t know, however, if the effects of caffeine on the brain work to alter (for better or worse) some of the changes in brain activity we see across the menstrual cycle, despite the fact that about 88% of the Canadian population regularly consumes caffeine. Finally, and perhaps most importantly, one of the reasons why we don’t know how caffeine affects the brain at different points of the menstrual cycle is because in drug studies, women have historically been ignored as participants. This is true of studies looking at recreational drugs, studies looking at medical drugs (such as those to treat HIV or cancer), and studies looking at common drugs like caffeine and nicotine. One major reason why women have been excluded from this type of research is because of the possibility (if not likelihood) that the effects of the drug will change depending on the menstrual cycle phase and it is time consuming and expensive to test women across these different phases. As such, many of these studies have only tested and reported the effects of drugs on men. This is problematic because the results are often generalized to humans as a whole, despite the fact that we often only have data on men, or when we do have data on women either menstrual phase isn’t accounted for or only one phase is tested. This is certainly true of caffeine; not only is there very little research looking at how caffeine affects the brain, there is virtually no research examining how these effects change in women across their cycle. Therefore, one major goal of this project is to fill this gap in the literature. Beyond this, we hope this will be the beginning of a program of research in our lab to document the effects of psychoactive substances on the brain across the menstrual cycle to make it easier for women to be included in future studies. This project will be conducted in women who are ‘naturally-cycling’, which is to say their menstrual cycle is not affected by hormones from medications, in the menstrual, follicular and luteal phases of their cycle. However, given the popularity of hormone-based birth control (such as the birth control pill), we will also perform these tests in women currently using a hormonal birth control method. At the end of the project, we hope to not only better understand how caffeine affects the way our brains work, but to also begin our understanding of how the menstrual cycle and drugs like caffeine work together to affect or brain's ability to function.