Deparment of Neuroscience and Imaging, G. d'Annunzio University Chieti-Pescara, Chieti, Italy.
J Cogn Neurosci. 2011 Jul;23(7):1808-22. doi: 10.1162/jocn.2010.21551. Epub 2010 Jul 28.
Previous studies suggested that the observation of other individuals' somatosensory experiences also activates brain circuits processing one's own somatosensory experiences. However, it is unclear whether cortical regions involved with the elementary stages of touch processing are also involved in the automatic coding of the affective consequences of observed touch and to which extent they show overlapping activation for somatosensory experiences of self and others. In order to investigate these issues, in the present fMRI study, healthy participants either experienced touch or watched videos depicting other individuals' inanimate and animate/social touch experiences. Essentially, a distinction can be made between exteroceptive and interoceptive components of touch processing, involved with physical stimulus characteristics and internal feeling states, respectively. Consistent with this distinction, a specific negative modulation was found in the posterior insula by the mere visual perception of other individuals' social or affective cutaneous experiences, compared to neutral inanimate touch. On the other hand, activation in secondary somatosensory and posterior superior temporal regions, strongest for the most intense stimuli, seemed more dependent on the observed physical stimulus characteristics. In contrast to the detected vicarious activation in somatosensory regions, opposite activation patterns for the experience (positive modulation) and observation (negative modulation) of touch suggest that the posterior insula does not reflect a shared representation of self and others' experiences. Embedded in a distributed network of brain regions underpinning a sense of the bodily self, the posterior insula rather appears to differentiate between self and other conditions when affective experiences are implicated.
先前的研究表明，观察他人的躯体感觉体验也会激活处理自身躯体感觉体验的大脑回路。然而，尚不清楚参与触摸加工基本阶段的皮质区域是否也参与了观察到的触摸的情感后果的自动编码，以及它们在多大程度上对自身和他人的躯体感觉体验表现出重叠的激活。为了研究这些问题，在本 fMRI 研究中，健康参与者要么体验触摸，要么观看视频描述其他个体的无生命和有生命/社会触摸体验。从本质上讲，可以区分触摸加工的外感受和内感受成分，分别涉及物理刺激特征和内部感觉状态。与这种区分一致，与中性无生命的触摸相比，仅仅通过视觉感知他人的社会或情感皮肤体验，在后脑岛中发现了特定的负调制。另一方面，在次级体感和后上颞叶区域的激活，对于最强烈的刺激最强，似乎更依赖于观察到的物理刺激特征。与躯体感觉区域中检测到的替代性激活相反，触摸体验（正调制）和观察（负调制）的相反激活模式表明，后脑岛并不反映自身和他人体验的共同表示。在后脑岛嵌入一个支持身体自我感的大脑区域的分布式网络中，当涉及到情感体验时，它似乎会在自我和他人条件之间进行区分。
