Department of Neurology, University Hospital Düsseldorf, Düsseldorf, Germany.
Hum Brain Mapp. 2012 Apr;33(4):812-23. doi: 10.1002/hbm.21258. Epub 2011 Apr 11.
Emblematic (or symbolic) gestures allow individuals to convey a variety of thoughts and emotions ranging from approval to hostility. The use of such gestures involves the execution of a codified motor act by the addresser and its perception and decoding by the addressee. To examine underlying common and distinct neural correlates, we used fMRI tasks in which subjects viewed video clips of emblematic one-hand gestures. They were asked to (1) take the perspective of the addresser and imagine executing the gestures ("expression" condition), and to (2) take the perspective of the addressee and imagine being confronted with the gestures ("reception" condition). Common areas of activation were found in inferior frontal, medial frontal, and posterior temporal cortices with left-hemispheric predominance as well as in the cerebellum. The distinction between regions specifically involved in the expression or reception condition partly resembled the dorsal and ventral stream dichotomy of visual processing with junctions in inferior frontal and medial prefrontal cortices. Imagery of gesture expression involved the dorsal visual stream as well as higher-order motor areas. In contrast, gesture reception encompassed regions related to semantic processing, and medial prefrontal areas known to be involved in the process of understanding the intentions of others. In conclusion, our results provide evidence for a dissociation in representations of emblematic gesture processing between addresser and addressee in addition to shared components in language-related areas.
象征性（或符号性）手势可以让个体传达从赞成到敌对等各种不同的思想和情感。此类手势的使用涉及发讯者执行编码运动行为，以及收讯者对其进行感知和解码。为了研究潜在的共同和独特的神经关联，我们使用 fMRI 任务，让受试者观看象征性单手手势的视频片段。他们被要求（1）从发讯者的角度想象执行手势（“表达”条件），和（2）从收讯者的角度想象面对手势（“接收”条件）。在额下回、额内侧回和颞后皮质中发现了共同激活区域，并且左侧半球占优势，同时也在小脑中发现了共同激活区域。专门参与表达或接收条件的区域之间的区别部分类似于视觉处理的背侧和腹侧流二分法，其交界处位于额下回和额前皮质中。手势表达的意象涉及到背侧视觉流以及更高阶的运动区域。相比之下，手势接收包括与语义处理相关的区域，以及已知涉及理解他人意图的额前内侧区域。总之，我们的研究结果为在发讯者和收讯者之间的象征性手势处理的代表之间提供了一种分离的证据，除了语言相关区域中的共享成分。
