Psychology Department and Milan Center for Neuroscience, University of Milano-Bicocca, Milano, Italy.
Psychology Department and Milan Center for Neuroscience, University of Milano-Bicocca, Milano, Italy; IRCCS Istituto Ortopedico Galeazzi, Milano, Italy.
Neuropsychologia. 2023 Mar 12;181:108492. doi: 10.1016/j.neuropsychologia.2023.108492. Epub 2023 Feb 1.
Interpersonal synchronization is fundamental for motor coordination during social interactions. Discerning emergent (entrainment) from planned synchronization represents a non-trivial issue in visually bonded individuals acting together, as well as assessing whether inter-individual differences, e.g., in autistic traits, modulate both types of synchronization. In a visuomotor finger-tapping task, two participants replicated a target tempo either synchronizing ('joint' condition) or not ('non-interactive' condition, 'non-int') with each other. One participant was exposed ('induced') to tempo aftereffect (a medium tempo seems faster or slower after exposure to slower or faster inducing tempi), but not the other participant ('not induced'); thus they had different timing perceptions of the same target. We assessed to what degree emergent and/or planned synchronization affected dyads by analyzing inter-tap-intervals, synchronization indexes, and cross-correlation coefficients. Results revealed a 'tempo aftereffect contagion': inter-tap-intervals of both induced and not-induced participants showed aftereffect in both the joint and non-int conditions. Moreover, aftereffects did not correlate across conditions suggesting they might be due to (at least in part) different processes, but the propensity for tempo aftereffect contagion correlated with individuals' autistic traits only in the non-int condition. Finally, participants co-adjusted their tapping more in the joint condition than in the non-int one, as confirmed by higher synchronization indexes and the mutual adaptation pattern of cross-correlation coefficients. Altogether, these results show the subtle interplay between emergent and planned interpersonal synchronization mechanisms that act on a millisecond timescale independently from synching or not with the partner.
人际同步对于社交互动中的运动协调至关重要。在视觉上相互作用的个体中，辨别出新兴的（同步）和计划的同步是一个复杂的问题，同时还需要评估个体间差异（例如自闭症特征）是否会调节这两种类型的同步。在一个视觉运动手指敲击任务中，两个参与者复制目标节奏，要么相互同步（“联合”条件），要么不相互同步（“非交互”条件，“非交互非诱导”条件，“non-int”）。一个参与者暴露于（“诱导”）节拍后效（在暴露于较慢或较快的诱导节拍后，中等节拍似乎更快或更慢），而另一个参与者没有暴露（“未诱导”）；因此，他们对相同的目标有不同的时间感知。我们通过分析两个参与者之间的每个敲击之间的间隔、同步指数和互相关系数，来评估新兴的和/或计划的同步对双人组合的影响程度。结果显示出了“节拍后效传染”：诱导和未诱导的参与者的每个敲击之间的间隔在联合和非交互条件下都显示出了后效。此外，后效在不同条件下不相关，这表明它们可能至少部分是由不同的过程引起的，但在非交互条件下，节拍后效传染的倾向仅与个体的自闭症特征相关。最后，参与者在联合条件下比在非交互条件下更协调他们的敲击，这可以通过更高的同步指数和互相关系数的相互适应模式来确认。总之，这些结果显示了新兴的和计划的人际同步机制之间的微妙相互作用，这些机制在毫秒级独立于与伙伴同步或不同步的情况下发挥作用。
