McCabe Ciara, Rolls Edmund T, Bilderbeck Amy, McGlone Francis
University of Oxford, Department of Experimental Psychology, South Parks Road, Oxford OX1 3UD, UK.
Soc Cogn Affect Neurosci. 2008 Jun;3(2):97-108. doi: 10.1093/scan/nsn005. Epub 2008 Mar 19.
We show that the affective experience of touch and the sight of touch can be modulated by cognition, and investigate in an fMRI study where top-down cognitive modulations of bottom-up somatosensory and visual processing of touch and its affective value occur in the human brain. The cognitive modulation was produced by word labels, 'Rich moisturizing cream' or 'Basic cream', while cream was being applied to the forearm, or was seen being applied to a forearm. The subjective pleasantness and richness were modulated by the word labels, as were the fMRI activations to touch in parietal cortex area 7, the insula and ventral striatum. The cognitive labels influenced the activations to the sight of touch and also the correlations with pleasantness in the pregenual cingulate/orbitofrontal cortex and ventral striatum. Further evidence of how the orbitofrontal cortex is involved in affective aspects of touch was that touch to the forearm [which has C fiber Touch (CT) afferents sensitive to light touch] compared with touch to the glabrous skin of the hand (which does not) revealed activation in the mid-orbitofrontal cortex. This is of interest as previous studies have suggested that the CT system is important in affiliative caress-like touch between individuals.
我们发现，触觉的情感体验以及对触摸的视觉感受可受到认知的调节，并通过一项功能磁共振成像（fMRI）研究来探究在人类大脑中，自下而上的触觉体感和视觉处理及其情感价值的自上而下的认知调节发生在何处。认知调节由文字标签“滋润保湿霜”或“基础霜”产生，在面霜涂抹于前臂时，或在看到面霜被涂抹于前臂时。主观愉悦感和丰富感受到文字标签的调节，顶叶皮质7区、脑岛和腹侧纹状体对触摸的fMRI激活也受到调节。认知标签影响了对触摸视觉的激活，以及与前扣带回/眶额皮质和腹侧纹状体中愉悦感的相关性。眶额皮质参与触觉情感方面的进一步证据是，与对手掌无毛皮肤的触摸（其对轻触不敏感）相比，对前臂的触摸（其有对轻触敏感的C纤维触觉（CT）传入神经）在眶额皮质中部显示出激活。这一点很有意思，因为之前的研究表明，CT系统在个体间类似亲昵抚摸的触摸中很重要。
