Pupillary response as a measure of individuals' sexual interest in specific other individuals

瞳孔大小的增加似乎表明了观察者对其他人的性兴趣。这种瞳孔反应在20世纪60年代首次被发现，通过拍摄观察者的眼睛，同时观看露骨的性材料，然后在静态视频帧中手动测量他们的瞳孔大小。然而，直到最近，这种影响在心理学文献中基本上没有被注意到，当时最初的发现被现代眼球跟踪设备复制。在过去的几年里，对这一现象的研究加快了步伐，揭示了瞳孔对性兴趣图像的反应反映了观察者的性取向，类似于生殖器的唤醒，可以区分被观察者的性别和年龄，在分析方案中是一致的，并提供了基于潜伏期(即反应时间)的性兴趣测量的同时有效性。与这些基于潜伏期的方法相比，瞳孔反应似乎拥有一个关键的优势，因为这些方法可以被参与者操纵。相比之下，瞳孔反应与自主神经系统的激活有关，潜在地不受有意识控制的影响。这使得瞳孔反应在性认知研究中成为一种有价值的无偏见评估手段。鉴于有证据表明，瞳孔反应也预示着观察者自我报告的对儿童性骚扰的兴趣，这表明应用环境(例如，法医心理学中对恋童癖性犯罪者的治疗监测)具有很大的潜力。然而，这种反应可靠地测量性兴趣的条件一直存在激烈辩论，许多证据一直相互矛盾。例如，有一些证据表明这种反应不受性刺激的显性影响，而另一些证据则表明，瞳孔反应和性非显性刺激之间的关系是复杂的，充其量是适度的。虽然这种效应在男性观察者中一直存在(例如，在观察女性时，异性恋男性的瞳孔会放大)，但在女性观察者中通常不存在。然而，有有限的证据表明，在排卵期间有恋人照片的女性会引发这种情绪，但男性通常不会，这暗示与情感唤起有关，而不是与性唤起有关。这些问题的解决对于促进瞳孔反应理论和性兴趣的研究具有重要意义。我们需要知道这些措施是否真的反映了性兴趣，或者它们是否是出于对其他人的情感驱动。同样，我们需要确定这些措施是否对个人对特定他人的性兴趣敏感。解决这些问题将说明已观察到的男性和女性在瞳孔反应方面的差异(即，从这一措施中，男性的性兴趣一直很明显，但女性的性兴趣并不明显)，这在其他已被更广泛研究的性兴趣衡量标准中也很明显，并将直接为理论提供依据。反过来，这项研究对法医实践具有相关性，在商业领域，基于延迟的措施已经在使用。如果自主的瞳孔反应确实反映了性兴趣，在个体层面上是强大的，而且它在男性和女性之间的差异得到了更充分的理解，那么这可能会为应用环境提供比目前可用的更合适的衡量标准。此外，由于针对儿童的性犯罪最常由家庭成员实施，因此，寻求在评估中分离出性和情感因素的贡献的研究是重要的。因此，这项研究的目的是确定对于个别观察者来说，瞳孔反应是否能有力地指示性兴趣；男性和女性之间的差异是否反映了对其他人的普遍性兴趣或对特定人的兴趣；以及瞳孔反应是否反映了性兴趣或对其他人的影响。

Increases in pupil size seem to indicate observers' sexual interest in other people. This pupillary response was first discovered in the 1960s, by filming observers' eyes whilst viewing sexually explicit material before manually measuring their pupil size in still video frames. Until recently, however, this effect remained largely unnoticed in the psychological literature, when the original findings were replicated with modern eye-tracking equipment. In the last few years, the study of this phenomenon has gathered pace, revealing that pupillary responses to sexually interesting images reflect observers' sexual orientation similarly to genital arousal, can discriminate the sex and age of a viewed person, are consistent across analysis protocols, and provide concurrent validity with latency-based (i.e. reaction time) measures of sexual interest. Pupillary responses appear to hold a key advantage over these latency-based methods, which are open to manipulation by participants. In contrast, pupillary response is linked to activation of the autonomic nervous system and is potentially impervious to conscious control. This makes pupillary response a valuable measure for unbiased assessment in the study of sexual cognition. In light of evidence that pupillary responses also predict observers' self-reported interest in child molestation, this indicates strong potential for applied settings (e.g., for treatment monitoring of paedophilic sexual offenders in forensic psychology).However, the conditions under which this response reliably measures sexual interest have been heavily debated and much evidence has been contradictory. For example, there is some evidence that this response is unaffected by the sexually explicitness of stimuli, while others have suggested that the relationship between pupillary responses and sexually non-explicit stimuli is complicated and at best modest. And whereas this effect is consistently observed in male observers (e.g., with pupil dilation in straight men during the viewing of women), it is typically absent in female observers. There is, however, limited evidence that it can be elicited in women with photographs of their romantic partners during ovulation, but not men generally, hinting at links to affect rather than sexual arousal. Resolving these issues is of clear importance to advance theory of pupillary responses and the study of sexual interest. We need to know whether these measures truly reflect sexual interest, or whether they are driven by affect for other people. Similarly, we need to establish whether these measures are sensitive to individuals' sexual interest in a specific other. Resolving these issues will speak to the differences that have been observed between men and women in pupillary response (i.e. with men's but not women's sexual interest consistently apparent from this measure), which are also evident in other measures of sexual interest that have been studied more widely, and will directly inform theory. In turn, this research has relevance for forensic practice, commercial where latency-based measures are already in use. If autonomic pupillary responses indeed reflect sexual interest, are robust at the level of the individual, and its differences across men and women are more fully understood, then this is likely to provide a much more appropriate measure for applied settings than those currently available. Moreover, since sexual offences against children are most frequently committed by family members, research that seeks to isolate the contributions of sexual and affective components in assessment is important. The aims of this research are therefore to determine whether pupillary response can robustly indicate sexual interest for individual observers; whether differences between men and women reflect general sexual interest in other people or interest in specific people; and whether pupillary responses reflect sexual interest or affect for other people.