Kujala T, Alho K, Kekoni J, Hämäläinen H, Reinikainen K, Salonen O, Standertskjöld-Nordenstam C G, Näätänen R
Department of Psychology, University of Helsinki, Finland.
Exp Brain Res. 1995;104(3):519-26. doi: 10.1007/BF00231986.
Previous event-related potential (ERP) studies have suggested a possible participation of the visual cortex of the blind in auditory processing. In the present study, somatosensory and auditory ERPs of blind and sighted subjects were recorded when subjects were instructed to attend to stimuli of one modality and to ignore those of the other. Both modalities were stimulated with frequent ("standard") and infrequent ("deviant") stimuli, which differed from one another in their spatial locus of origin. In the sighted, deviant stimuli of the attended modality elicited N2 type of deflections (auditory N2b and somatosensory N250) over the lateral scalp areas. In contrast, in the blind, these ERP components were centroposteriorly distributed, suggesting an involvement of posterior brain areas in auditory and somatosensory stimulus discrimination. In addition, the mismatch negativity, elicited by deviant auditory stimuli even when the somatosensory stimuli were attended, was larger in the blind than in the sighted. This appears to indicate enhanced automatic processing of auditory stimulus changes in the blind. Thus, the present data suggest several compensatory changes in both auditory and somatosensory modalities after the onset of early visual deprivation.
以往的事件相关电位（ERP）研究表明，盲人的视觉皮层可能参与听觉加工。在本研究中，当要求盲人和视力正常的受试者关注一种感觉模态的刺激并忽略另一种感觉模态的刺激时，记录了他们的体感和听觉ERP。两种感觉模态均用频繁出现的（“标准”）和不频繁出现的（“偏差”）刺激进行刺激，这两种刺激在空间起源位置上彼此不同。在视力正常的人中，被关注感觉模态的偏差刺激在头皮外侧区域诱发N2类型的偏转（听觉N2b和体感N250）。相比之下，在盲人中，这些ERP成分分布于中央后区，表明后脑区域参与了听觉和体感刺激辨别。此外，即使在关注体感刺激时，由偏差听觉刺激诱发的失匹配负波在盲人中也比视力正常的人更大。这似乎表明盲人对听觉刺激变化的自动加工增强。因此，目前的数据表明，早期视觉剥夺发生后，听觉和体感模态均出现了一些代偿性变化。
