Institute of Brain and Psychological Sciences, Sichuan Normal University, 610068, Chengdu, People's Republic of China.
Research Center of Brain and Cognitive Neuroscience, Liaoning Normal University, Dalian, People's Republic of China.
Psychopharmacology (Berl). 2021 Jul;238(7):2021-2029. doi: 10.1007/s00213-021-05828-5. Epub 2021 Mar 22.
Perceiving accurately that others are looking away from us (averted gaze) is as important, for social interactions, as perceiving that others are looking at us (direct gaze). However, previous studies have revealed that when the deflection angle of averted gaze is small, individuals tend to falsely perceive it as direct gaze. Oxytocin (OXT) has been shown to increase orientation to the eye region. Therefore, a critical question is whether and how OXT would facilitate the perception of ambiguous averted gaze.
The present study aimed to measure the effects of OXT on the performance of males and females in distinguishing ambiguous averted gaze from direct gaze of different emotional faces.
In a double-blind placebo-controlled crossover experiment, 48 participants were presented successively two emotional faces with direct gaze (defined as 0, indicating the center of the eye) or averted gaze (defined as ±4, indicating the corner of the eye; +4 means that the iris moves 4 steps to the right; and -4 means that the iris moves 4 steps to the left) following intranasal oxytocin or placebo treatment and asked to make judgments on whether or not the two faces were the same in terms of identity. The interference effect of gaze direction was calculated by subtracting the mean accuracy and reaction time in the congruent gaze condition from those in the incongruent gaze condition. The logic of the measurement was if intranasal OXT would facilitate the detection of ambiguous averted gaze, we would observe a larger interference effect in the gaze incongruent condition compared with the gaze congruent condition, leading to longer RT or/and lower accuracy for identification judgment in the gaze incongruent condition.
While there were no OXT effects in accuracy, we found a significant interaction between treatment, sex, and gaze congruency in reaction times. That is, following OXT as compared to placebo, women displayed stronger interference of gaze direction, whereas in men no significant difference was observed. Besides, this interaction did not vary across different emotional expressions.
Our findings provide the first evidence for sex-dependent effects of OXT on the perception of ambiguous averted gaze. Given potential therapeutic applications of OXT to patients with developmental and psychiatric disorders, who are characterized as atypical in encoding gaze features, the findings suggest that rather different treatment outcomes could be anticipated in males and females.
准确感知他人避开我们的目光（回避目光）与感知他人注视我们的目光（注视目光）一样重要，因为这对于社交互动很重要。然而，之前的研究表明，当回避目光的偏转角较小时，个体往往会错误地将其感知为注视目光。催产素（OXT）已被证明可以增加对眼部区域的关注。因此，一个关键问题是 OXT 是否以及如何促进对模糊回避目光的感知。
本研究旨在测量 OXT 对男性和女性在区分具有不同情绪的直接和模糊回避目光的能力上的影响。
在一项双盲安慰剂对照交叉实验中，48 名参与者先后接受了两种具有直接注视（定义为 0，指示眼睛中心）或回避注视（定义为±4，指示眼角；+4 表示虹膜向右移动 4 步；-4 表示虹膜向左移动 4 步）的情绪面孔，之后接受鼻内催产素或安慰剂治疗，并被要求判断这两个面孔在身份上是否相同。通过从一致注视条件的平均准确性和反应时间中减去不一致注视条件的平均准确性和反应时间来计算注视方向的干扰效应。测量的逻辑是，如果鼻内 OXT 有助于检测模糊的回避目光，那么我们将观察到在不一致注视条件下比在一致注视条件下更大的干扰效应，从而导致在不一致注视条件下的识别判断中反应时间更长或/和准确性更低。
虽然在准确性上没有观察到 OXT 的影响，但我们发现在反应时间上存在治疗、性别和注视一致性之间的显著交互作用。也就是说，与安慰剂相比，女性在接受 OXT 后表现出更强的注视方向干扰，而男性则没有观察到显著差异。此外，这种相互作用在不同的情绪表达中没有变化。
我们的发现为 OXT 对模糊回避目光感知的性别依赖性影响提供了首个证据。鉴于 OXT 在治疗发育和精神障碍患者方面具有潜在的应用，这些患者在编码注视特征方面表现出非典型性，研究结果表明，在男性和女性中可能会预期到不同的治疗效果。
