Paulesu E, Harrison J, Baron-Cohen S, Watson J D, Goldstein L, Heather J, Frackowiak R S, Frith C D
MRC Cyclotron Unit, Hammersmith Hospital, London, UK.
Brain. 1995 Jun;118 ( Pt 3):661-76. doi: 10.1093/brain/118.3.661.
In a small proportion of the normal population, stimulation in one modality can lead to perceptual experience in another, a phenomenon known as synaesthesia. In the most common form of synaesthesia, hearing a word can result in the experience of colour. We have used the technique of PET, which detects brain activity as changes of regional cerebral blood flow (rCBF), to study the physiology of colour-word synaesthesia in a group of six synaesthete women. During rCBF measurements synaesthetes and six controls were blindfolded and were presented with spoken words or pure tones. Auditory word, but not tone, stimulation triggered synaesthesia in synaesthetes. In both groups word stimulation compared with tone stimulation activated the classical language areas of the perisylvian regions. In synaesthetes, a number of additional visual associative areas, including the posterior inferior temporal cortex and the parieto-occipital junctions, were activated. The former has been implicated in the integration of colour with shape and in verbal tasks which require attention to visual features of objects to which words refer. Synaesthetes also showed activations in the right prefrontal cortex, insula and superior temporal gyrus. By contrast, no significant activity was detected in relatively lower visual areas, including areas V1, V2 and V4. These results suggest that colour-word synaesthesia may result from the activity of brain areas concerned with language and visual feature integration. In the case of colour-word synaesthesia, conscious visual experience appears to occur without activation of the primary visual cortex.
在一小部分正常人群中，一种感觉模态的刺激可引发另一种感觉模态的感知体验，这种现象被称为联觉。在最常见的联觉形式中，听到一个单词会引发颜色体验。我们使用正电子发射断层扫描（PET）技术，该技术通过检测局部脑血流量（rCBF）的变化来检测脑活动，对一组六名女性联觉者进行了颜色 - 单词联觉的生理学研究。在测量rCBF期间，联觉者和六名对照者被蒙上眼睛，并听取口语单词或纯音。听觉单词刺激而非音调刺激在联觉者中引发了联觉。在两组中，与音调刺激相比，单词刺激激活了颞叶周围区域的经典语言区域。在联觉者中，包括颞叶后下部皮质和顶枕交界处在内的一些额外的视觉联想区域被激活。前者与颜色和形状的整合以及在需要关注单词所指物体视觉特征的语言任务中有关。联觉者在右侧前额叶皮质、脑岛和颞上回也表现出激活。相比之下，在包括V1、V2和V4区域在内的相对较低级视觉区域未检测到明显活动。这些结果表明，颜色 - 单词联觉可能源于与语言和视觉特征整合相关的脑区活动。在颜色 - 单词联觉的情况下，有意识的视觉体验似乎在初级视觉皮层未被激活的情况下发生。
