IRCCS San Camillo Hospital, Venice, Italy.
Department of General Psychology, University of Padova, 35131, Padua, Italy.
Exp Brain Res. 2023 Aug;241(8):2179-2190. doi: 10.1007/s00221-023-06668-9. Epub 2023 Jul 21.
Emotional facial expressions provide cues for social interactions and emotional events can distort our sense of time. The present study investigates the effect of facial emotional stimuli of anger and sadness on time perception. Moreover, to investigate the causal role of the orbitofrontal cortex (OFC) in emotional recognition, we employed transcranial random noise stimulation (tRNS) over OFC and tested the effect on participants' emotional recognition as well as on time processing. Participants performed a timing task in which they were asked to categorize as "short" or "long" temporal intervals marked by images of people expressing anger, sad or neutral emotional facial expressions. In addition, they were asked to judge if the image presented was of a person expressing anger or sadness. The visual stimuli were facial emotional stimuli indicating anger or sadness with different degrees of intensity at high (80%), medium (60%) and low (40%) intensity, along with neutral emotional face stimuli. In the emotional recognition task, results showed that participants were faster and more accurate when emotional intensity was higher. Moreover, tRNS over OFC interfered with emotion recognition, which is in line with its proposed role in emotion recognition. In the timing task, participants overestimated the duration of angry facial expressions, although neither emotional intensity not OFC stimulation significantly modulated this effect. Conversely, as the emotional intensity increased, participants exhibited a greater tendency to overestimate the duration of sad faces in the sham condition. However, this tendency disappeared with tRNS. Taken together, our results are partially consistent with previous findings showing an overestimation effect of emotionally arousing stimuli, revealing the involvement of OFC in emotional distortions of time, which needs further investigation.
情绪面部表情为社交互动提供线索，而情绪事件会扭曲我们的时间感。本研究调查了愤怒和悲伤的面部情绪刺激对时间感知的影响。此外，为了研究眶额皮层（OFC）在情绪识别中的因果作用，我们采用经颅随机噪声刺激（tRNS）对 OFC 进行刺激，并测试其对参与者情绪识别以及时间处理的影响。参与者执行计时任务，要求他们将表达愤怒、悲伤或中性情绪的人脸图像标记为“短”或“长”时间间隔。此外，他们被要求判断呈现的图像是否为表达愤怒或悲伤的人。视觉刺激是具有不同强度（80%、60%和 40%）的愤怒或悲伤的面部情绪刺激，以及中性情绪面部刺激。在情绪识别任务中，结果表明，当情绪强度较高时，参与者的反应速度更快，准确性更高。此外，OFC 上的 tRNS 干扰了情绪识别，这与它在情绪识别中的预期作用一致。在计时任务中，参与者高估了愤怒面部表情的持续时间，尽管情绪强度和 OFC 刺激都没有显著调节这种影响。相反，随着情绪强度的增加，参与者在假刺激条件下表现出更大的倾向高估悲伤面孔的持续时间。然而，这种趋势在 tRNS 后消失了。总之，我们的结果部分与先前的发现一致，表明情绪唤起刺激的高估效应，揭示了 OFC 在时间的情绪扭曲中的参与，这需要进一步研究。
