Ricciardi Emiliano, Tozzi Leonardo, Leo Andrea, Pietrini Pietro
Laboratory of Clinical Biochemistry and Molecular Biology, University of Pisa, Pisa, Italy.
Multisens Res. 2014;27(3-4):247-62. doi: 10.1163/22134808-00002454.
Cross-modal responses in occipital areas appear to be essential for sensory processing in visually deprived subjects. However, it is yet unclear whether this functional recruitment might be dependent on the sensory channel conveying the information. In order to characterize brain areas showing task-independent, but sensory specific, cross-modal responses in blind individuals, we pooled together distinct brain functional studies in a single based meta-analysis according only to the modality conveying experimental stimuli (auditory or tactile). Our approach revealed a specific functional cortical segregation according to the sensory modality conveying the non-visual information, irrespectively from the cognitive features of the tasks. In particular, dorsal and posterior subregions of occipital and superior parietal cortex showed a higher cross-modal recruitment across tactile tasks in blind as compared to sighted individuals. On the other hand, auditory stimuli activated more medial and ventral clusters within early visual areas, the lingual and inferior temporal cortex. These findings suggest a modality-specific functional modification of cross-modal responses within different portions of the occipital cortex of blind individuals. Cross-modal recruitment can thus be specifically influenced by the intrinsic features of sensory information.
枕叶区域的跨模态反应似乎对视觉剥夺受试者的感觉处理至关重要。然而，这种功能募集是否可能依赖于传递信息的感觉通道仍不清楚。为了表征在盲人中显示出与任务无关但具有感觉特异性的跨模态反应的脑区，我们仅根据传递实验刺激的模态（听觉或触觉），将不同的脑功能研究汇总到一个基于单一的荟萃分析中。我们的方法揭示了根据传递非视觉信息的感觉模态而产生的特定功能皮质分离，与任务的认知特征无关。特别是，与视力正常的个体相比，盲人枕叶和顶上叶皮质的背侧和后亚区域在跨触觉任务中表现出更高的跨模态募集。另一方面，听觉刺激激活了早期视觉区域、舌回和颞下回内更多的内侧和腹侧簇。这些发现表明盲人枕叶皮质不同部分的跨模态反应存在模态特异性功能改变。因此，跨模态募集可能会受到感觉信息内在特征的特异性影响。
