TMS-Adaptation Reveals Abstract Letter Selectivity in the Left Posterior Parietal Cortex
TMS-Adaptation Reveals Abstract Letter Selectivity in the Left Posterior Parietal Cortex
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DOI：
10.1093/cercor/bhn249
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发表时间：
2009-10-01
期刊：
影响因子：
3.7
通讯作者：
Silvanto, Juha
中科院分区：
文献类型：
--
作者：
Cattaneo, Zaira;Rota, Federica;Silvanto, Juha
左后顶叶皮层（PPC）的激活与独立于视觉形式的字母编码有关。在这里，我们使用经颅磁刺激（TMS）的适应，以调查是否这种抽象的字母选择性发挥因果关系的作用，在字母处理。在应用TMS之前，使用视觉适应来操纵调谐到不同字母的神经元的初始激活状态，之后受试者对与适应字母不同的情况下呈现的字母执行检测任务。适应后，TMS适用于左PPC促进检测的适应字母，而它没有影响检测nonadapted字母。在右侧PPC上应用TMS对两种类型的字母都没有显着影响。适应和左PPC TMS的影响之间的这种相互作用表明，适应调制在左PPC的神经活动，从而表明在该地区的抽象字母的选择性。重要的是，由于适应的字母和目标字母在不同的情况下，这一发现表明，左PPC在字母处理独立的视觉形式的因果关系的作用。
Activation of the left posterior parietal cortex (PPC) has been associated with the encoding of letters independent of visual form. Here we used transcranial magnetic stimulation (TMS)-adaptation to investigate whether this abstract letter selectivity plays a causal role in letter processing. Visual adaptation was used to manipulate the initial activation state of neurons tuned to different letters prior to the application of TMS, after which subjects performed a detection task on letters that were presented in a different case from the adapting letter. After adaptation, TMS applied over the left PPC facilitated the detection of the adapted letter, whereas it had no impact on the detection of nonadapted letters. TMS applied over the right PPC had no significant effect on either type of letter. This interaction between adaptation and the effects of left PPC TMS demonstrates that adaptation modulated neural activity in the left PPC and thus demonstrates abstract letter selectivity in this region. Importantly, as the adapted letter and the target letters were presented in different cases, this finding demonstrates that the left PPC plays a causal role in letter processing independent of visual form.