Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELL, 08097, L'Hospitalet de Llobregat, Barcelona, Spain; Dept. of Cognition, Development and Education Psychology, Campus Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08097, Spain.
Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELL, 08097, L'Hospitalet de Llobregat, Barcelona, Spain; Dept. of Cognition, Development and Education Psychology, Campus Bellvitge, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08097, Spain; Catalan Institution for Research and Advanced Studies (ICREA), 08010, Barcelona, Spain.
Neuroimage. 2017 Nov 15;162:23-31. doi: 10.1016/j.neuroimage.2017.08.054. Epub 2017 Aug 24.
Previous research assessing the presence of enhanced tactile skills in early-blind (EB) population obtained conflicting results. Most of the studies relied on behavioral measures with which different mechanisms leading to the same outcome go unnoticed. Moreover, the scarce electrophysiological research that has been conducted focused exclusively on the processing of microgeometric properties. To clarify the extent of superior tactile abilities in EBs using high-density multichannel electrophysiological recordings, the present study compared the electrophysiological correlates of EBs and sighted controls (CON) in two tactile discrimination tasks that targeted microgeometric (texture) and macrogeometric (shape) properties. After a restricted exploration (haptic glance), participants judged whether a touched stimulus corresponded to an expected stimulus whose name had been previously presented aurally. In the texture discrimination task, differences between groups emerged at ∼75 ms (early perceptual processing stages) whereas we found no between-group differences during shape discrimination. Furthermore, for the first time, we were able to determine the latency at which EBs started to discriminate micro- (EB: 170 ms; CON: 230 ms) and macrogeometric (EB: 250 ms; CON: 270 ms) properties. Altogether, the results suggest different electrophysiological signatures during texture (but not shape) discrimination in EBs, possibly due to cortical reorganization in occipital areas and their increased connectivity with S1.
先前评估早期失明（EB）人群中增强触觉技能存在的研究得出了相互矛盾的结果。大多数研究依赖于行为测量，而这些测量方法忽略了导致相同结果的不同机制。此外，进行的为数不多的电生理研究仅专注于微几何属性的处理。为了使用高密度多通道电生理记录来阐明 EB 中卓越触觉能力的程度，本研究在两个触觉辨别任务中比较了 EB 和视力正常对照组（CON）的电生理相关性，这两个任务针对微几何（纹理）和宏观几何（形状）属性。在受限的探索（触觉扫视）之后，参与者判断触摸刺激是否与先前听觉呈现的预期刺激相对应。在纹理辨别任务中，组间差异出现在约 75ms（早期感知处理阶段），而在形状辨别过程中，我们没有发现组间差异。此外，我们首次能够确定 EB 开始辨别微观（EB：170ms；CON：230ms）和宏观几何属性（EB：250ms；CON：270ms）的潜伏期。总的来说，结果表明在 EB 中进行纹理（而非形状）辨别时存在不同的电生理特征，这可能是由于枕叶区域的皮质重组及其与 S1 的连接增加所致。
