Dravida Swethasri, Noah J Adam, Zhang Xian, Hirsch Joy
Interdepartmental Neuroscience Program, Yale School of Medicine, New Haven, CT, United States.
Brain Function Laboratory, Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States.
Front Hum Neurosci. 2020 Jun 3;14:201. doi: 10.3389/fnhum.2020.00201. eCollection 2020.
Eye-to-eye contact is a spontaneous behavior between interacting partners that occurs naturally during social interactions. However, individuals differ with respect to eye gaze behaviors such as frequency of eye-to-eye contacts, and these variations may reflect underlying differences in social behavior in the population. While the use of eye signaling to indicate a shared object of attention in joint attention tasks has been well-studied, the effects of the natural variation in establishing eye contact during joint attention have not been isolated. Here, we investigate this question using a novel two-person joint attention task. Participants were not instructed regarding the use of eye contacts; thus all mutual eye contact events between interacting partners that occurred during the joint attention task were spontaneous and varied with respect to frequency. We predicted that joint attention systems would be modulated by differences in the social behavior across participant pairs, which could be measured by the frequency of eye contact behavior. We used functional near-infrared spectroscopy (fNIRS) hyperscanning and eye-tracking to measure the neural signals associated with joint attention in interacting dyads and to record the number of eye contact events between them. Participants engaged in a social joint attention task in which real partners used eye gaze to direct each other's attention to specific targets. Findings were compared to a non-social joint attention task in which an LED cue directed both partners' attention to the same target. The social joint attention condition showed greater activity in right temporoparietal junction than the non-social condition, replicating prior joint attention results. Eye-contact frequency modulated the joint attention activity, revealing bilateral activity in social and high level visual areas associated with partners who made more eye contact. Additionally, when the number of mutual eye contact events was used to classify each pair as either "high eye contact" or "low eye contact" dyads, cross-brain coherence analysis revealed greater coherence between high eye contact dyads than low eye contact dyads in these same areas. Together, findings suggest that variation in social behavior as measured by eye contact modulates activity in a subunit of the network associated with joint attention.
目光对视是互动伙伴之间的一种自发行为，在社交互动中自然发生。然而，个体在目光注视行为方面存在差异，例如目光对视的频率，这些差异可能反映了人群中社交行为的潜在差异。虽然在联合注意任务中使用眼神信号来指示共同关注的对象已经得到了充分研究，但在联合注意过程中建立眼神接触的自然变化所产生的影响尚未被单独分离出来。在这里，我们使用一种新颖的两人联合注意任务来研究这个问题。参与者没有被告知关于目光接触的使用；因此，在联合注意任务期间互动伙伴之间发生的所有相互目光接触事件都是自发的，并且在频率上有所不同。我们预测，联合注意系统会受到参与者对之间社交行为差异的调节，这种差异可以通过目光接触行为的频率来衡量。我们使用功能性近红外光谱（fNIRS）超扫描和眼动追踪来测量与互动二元组中的联合注意相关的神经信号，并记录他们之间的目光接触事件数量。参与者参与了一项社交联合注意任务，其中真实的伙伴使用目光注视将彼此的注意力引导到特定目标上。研究结果与一项非社交联合注意任务进行了比较，在该任务中，一个LED提示将两个伙伴的注意力引导到同一个目标上。社交联合注意条件下右侧颞顶联合区的活动比非社交条件下更活跃，重复了先前的联合注意结果。目光接触频率调节了联合注意活动，揭示了与进行更多目光接触的伙伴相关的社交和高级视觉区域的双侧活动。此外，当使用相互目光接触事件的数量将每对分为“高目光接触”或“低目光接触”二元组时，跨脑相干分析显示，在这些相同区域中，高目光接触二元组之间的相干性比低目光接触二元组更大。总之，研究结果表明，通过目光接触测量的社交行为差异会调节与联合注意相关的网络子单元中的活动。
