Laboratory for Language and Cognitive Neuroscience, San Diego State University, 6495 Alvarado Road, San Diego, CA 92120, USA.
Neuroimage. 2010 Jan 1;49(1):994-1005. doi: 10.1016/j.neuroimage.2009.08.001. Epub 2009 Aug 11.
Deaf signers have extensive experience using their hands to communicate. Using fMRI, we examined the neural systems engaged during the perception of manual communication in 14 deaf signers and 14 hearing non-signers. Participants passively viewed blocked video clips of pantomimes (e.g., peeling an imaginary banana) and action verbs in American Sign Language (ASL) that were rated as meaningless by non-signers (e.g., TO-DANCE). In contrast to visual fixation, pantomimes strongly activated fronto-parietal regions (the mirror neuron system, MNS) in hearing non-signers, but only bilateral middle temporal regions in deaf signers. When contrasted with ASL verbs, pantomimes selectively engaged inferior and superior parietal regions in hearing non-signers, but right superior temporal cortex in deaf signers. The perception of ASL verbs recruited similar regions as pantomimes for deaf signers, with some evidence of greater involvement of left inferior frontal gyrus for ASL verbs. Functional connectivity analyses with left hemisphere seed voxels (ventral premotor, inferior parietal lobule, fusiform gyrus) revealed robust connectivity with the MNS for the hearing non-signers. Deaf signers exhibited functional connectivity with the right hemisphere that was not observed for the hearing group for the fusiform gyrus seed voxel. We suggest that life-long experience with manual communication, and/or auditory deprivation, may alter regional connectivity and brain activation when viewing pantomimes. We conclude that the lack of activation within the MNS for deaf signers does not support an account of human communication that depends upon automatic sensorimotor resonance between perception and action.
聋人手语使用者在使用手部进行交流方面有着丰富的经验。我们使用 fMRI 技术，对 14 名聋人手语使用者和 14 名听力正常的非手语使用者在感知手语交流时所涉及的神经系统进行了研究。参与者被动观看了手拍影片（例如，剥一个想象中的香蕉）和美国手语（ASL）中的动作动词的视频片段，这些动作动词被非手语使用者评为无意义（例如，TO-DANCE）。与视觉注视相比，手拍影片在手语使用者中强烈激活了额顶区域（镜像神经元系统，MNS），但在聋人手语使用者中仅激活了双侧颞中区域。当与 ASL 动词进行对比时，手拍影片在手语使用者中选择性地激活了下顶叶和上顶叶区域，但在聋人手语使用者中仅激活了右侧颞上叶。聋人手语使用者对手语动词的感知与手拍影片类似，也有证据表明，聋人手语使用者对 ASL 动词的左额下回的参与度更高。使用左侧半球种子体素（腹侧运动前皮质、下顶叶、梭状回）进行的功能连接分析显示，听力正常的非手语使用者的 MNS 具有很强的连接性。聋人手语使用者表现出与右侧半球的功能连接，而听力组的梭状回种子体素则没有观察到这种连接。我们认为，终生的手语交流经验和/或听觉剥夺可能会改变对手拍影片进行观察时的区域连接和大脑激活。我们得出的结论是，聋人手语使用者 MNS 内缺乏激活并不能支持一种依赖于感知和动作之间自动感觉运动共鸣的人类交流解释。
