During social interactions, humans tend to imitate one another involuntarily. To investigate the neurocognitive mechanisms driving this tendency, researchers often employ stimulus-response compatibility (SRC) tasks to assess the influence that action observation has on action execution. This is referred to as automatic imitation (AI). The stimuli used frequently in SRC procedures to elicit AI often confound action-related with other nonsocial influences on behaviour; however, in response to the rotated hand-action stimuli employed increasingly, AI partly reflects unspecific up-right/down-left biases in stimulus-response mapping. Despite an emerging awareness of this confounding orthogonal spatial-compatibility effect, psychological and neuroscientific research into social behaviour continues to employ these stimuli to investigate AI. To increase recognition of this methodological issue, the present study measured the systematic influence of orthogonal spatial effects on behavioural and neurophysiological measures of AI acquired with rotated hand-action stimuli in SRC tasks. In Experiment 1, behavioural data from a large sample revealed that complex orthogonal spatial effects exert an influence on AI over and above any topographical similarity between observed and executed actions. Experiment 2 reproduced this finding in a more systematic, within-subject design, and high-density electroencephalography revealed that electrocortical expressions of AI elicited also are modulated by orthogonal spatial compatibility. Finally, source localisations identified a collection of cortical areas sensitive to this spatial confound, including nodes of the multiple-demand and semantic-control networks. These results indicate that AI measured on SRC procedures with the rotated hand stimuli used commonly might reflect neurocognitive mechanisms associated with spatial associations rather than imitative tendencies.

在社交互动中，人类倾向于不自觉地相互模仿。为了研究驱动这种趋势的神经认知机制，研究人员经常使用刺激反应相容性 (SRC) 任务来评估动作观察对动作执行的影响。这被称为自动模仿 (AI)。在 SRC 程序中经常使用的刺激来引发 AI 经常混淆与其他非社会行为相关的行为影响；然而，为了响应越来越多地使用的旋转手部动作刺激，人工智能部分地反映了刺激-反应映射中的非特定的右上/左下偏差。尽管人们逐渐意识到这种令人困惑的正交空间相容性效应，但对社会行为的心理学和神经科学研究继续使用这些刺激来研究人工智能。为了提高对这一方法论问题的认识，本研究测量了正交空间效应对 SRC 任务中通过旋转手部动作刺激获得的 AI 的行为和神经生理学测量的系统影响。在实验 1 中，来自大样本的行为数据表明，复杂的正交空间效应对 AI 的影响超过了观察到的和执行的动作之间的任何地形相似性。实验 2 以更系统的、受试者内的设计重现了这一发现，高密度脑电图显示，诱发的 AI 的皮层电表达也受正交空间兼容性的调节。最后，源定位确定了一系列对这种空间混淆敏感的皮质区域，包括多需求和语义控制网络的节点。这些结果表明，在 SRC 程序上测量的人工智能可能反映了与空间关联相关的神经认知机制，而不是模仿倾向。