Olfactory hormonal signals for human behavior: can you smell ovulation and pregnancy?

在这项功能性磁共振成像（fMRI）研究中，我们将采用转化研究方法来研究女性化学信号是否可以介导人类的性可用性和生育能力。在动物界，根据女性体臭成功检测排卵和怀孕为择偶提供了进化优势。在人类中，可以假设性选择以类似的方式受到影响，如果男性和女性可以从女性的体臭中识别出她们是排卵还是怀孕，并相应地调整她们的行为。这项功能磁共振成像研究将调查排卵期和怀孕期女性的体味是否对异性恋男性和异性恋（排卵期和怀孕期）女性有直接影响。为此，两个功能磁共振成像实验与视觉刺激将进行调查的基本影响，体臭的评价照片的妇女的脸，并确定是否增加水平的唤醒引起的视觉色情刺激调制体臭和是否评价色情照片的妇女被改变。此外，在评估照片的同时，还将研究暴露于身体气味时的潜在大脑活动。在一项针对异性恋男性的初步研究中，结果表明，性可获得性的检测激活了男性大脑中与面部处理和奖励/动机相关的区域，而怀孕的感知激活了负责同情和亲社会行为的区域。因此，可以得出结论，这种通过体臭感知女性生殖状态的进化机制可能会使男性更加关注排卵期的女性。在拟议的研究中，这些结果将被复制和验证，包括异性恋妇女和扩展的功能磁共振成像范式的性唤起。

In this functional magnetic resonance imaging (fMRI) study, we will apply a translational research approach to investigate whether female chemical signals can mediate sexual availability and fertility in humans. In the animal kingdom, the successful detection of ovulation and pregnancy based on female body odor provides an evolutionary advantage in mate choice. In humans, it could be assumed that sexual selection is influenced in a similar way if men but also women could recognize from the body odor of the females whether they are ovulating or pregnant and could adapt their behavior accordingly. The proposed fMRI study will investigate whether the body odors of ovulating and pregnant women have a direct influence on heterosexual men and heterosexual (ovulating and menstruating) women. To this end, two fMRI experiments with visual stimuli will be conducted to investigate the basal effect of body odors on the evaluation of photographs of women's faces and to determine whether an increased level of arousal provoked by visual erotic stimuli is modulated by body odors and whether the evaluation of erotic photographs of women is altered. In addition, the underlying brain activity during exposure to body odors will be investigated while simultaneously assessing the photographs.In a pilot study conducted with heterosexual men, the results suggest that the detection of sexual availability activates the male brain regions associated with facial processing and rewarding/motivation, while the perception of pregnancy activates a region responsible for empathy and prosocial behavior. Thus, it can be concluded that this evolutionary mechanism of perceiving a woman's reproductive status through the body odor likely biases men toward paying more attention to ovulating women. In the proposed study, these results will be replicated and validated by including heterosexual women and the extended fMRI paradigm for sexual arousal.