Our previous work defended that the motor theory is modulated by task load, claiming that motoric participation in phonological processing plays a changing and complementary role with the “auditory part” of the phonological processing system from perception to production: the LIFG being increasingly relevant and the LSTG, decreasingly relevant. We previously targeted the LIFG with tDCS and observed behavioural and functional connectivity patterns which were consistent with our model. Here we investigated whether neurostimulation of the LSTG with the same tasks would reverse the profile of functional connectivity responses previously obtained for the LIFG. With a within-subject design, we administered categorical perception, lexical decision and word naming tasks in three sessions (under cathodal, anodal and sham). This range of tasks was considered to be decreasingly relevant for the LSTG. The network we focused on consisted of the dorsal stream (LIFG and LSTG) and its right homologues (right inferior frontal gyrus and right superior temporal gyrus). Functional connectivity was analysed with partial correlations. C-tDCS LSTG inhibition and A-tDCS LSTG excitation should have a positive relationship with the relevance of the task to the target (task load). C-tDCS was expected to trigger compensation by other nodes in conditions of low task load, evidenced by a higher count of significant connections than in higher task load conditions or under A-tDCS. Overall, results met predictions. For example, C-tDCS in conditions of lower task load, such as with the word naming task, triggered the highest count of significant connections, suggesting compensation by other nodes.

我们以前的工作辩称，运动理论受任务负荷的调节，声称运动参与语音处理与语音处理系统的“听觉部分”从感知到生产都起着变化和互补的作用：LIFG越来越重要， LSTG，相关性逐渐降低。我们之前曾以tDCS为目标锁定LIFG，并观察了与我们的模型一致的行为和功能连接模式。在这里，我们研究了用相同的任务对LSTG进行神经刺激是否会逆转先前为LIFG获得的功能连接性反应。通过主题内设计，我们分三部分（在阴极，阳极和假条件下）管理了类别感知，词汇决策和单词命名任务。该任务范围与LSTG的相关性逐渐降低。我们关注的网络由背流（LIFG和LSTG）及其右同源物（右下额回和右上颞回）组成。使用部分相关性分析功能连接性。C-tDCS LSTG抑制和A-tDCS LSTG激发应与任务与目标的相关性（任务负载）成正相关。预计C-tDCS在低任务负载的情况下会触发其他节点的补偿，这是由比较高任务负载条件或A-tDCS更高的重要连接数所证明的。总体而言，结果符合预期。例如，在任务负载较低的情况下（例如单词命名任务），C-tDCS触发了最高数量的有效连接，