To achieve our moment-to-moment goals, we must often keep information temporarily in mind. Yet, this working memory (WM) may compete with demands for our attention in the environment. Attentional and WM functions are thought to operate by similar underlying principles, and they often engage overlapping fronto-parietal brain regions. In a recent fMRI study, bilateral parietal cortex BOLD activity displayed an interaction between WM and visual attention dual-task demands. However, prior studies also suggest that left and right parietal cortices make unique contributions to WM and attentional functions. Moreover, behavioral performance often shows no interaction between concurrent WM and attentional demands. Thus, the scope of reciprocity between WM and attentional functions, as well as the specific contribution that parietal cortex makes to these functions, remain unresolved. Here, we took a causal approach, targeting brain regions that are implicated in shared processing between WM and visual attention, to better characterize how those regions contribute to behavior. We first examined whether behavioral indices of WM and visual search differentially correlate with left and right parietal dual-task BOLD responses. Then, we delivered TMS over fMRI-guided left and right parietal sites during dual-task WM-visual search performance. Only right-parietal TMS influenced visual search behavior, but the stimulation either helped or harmed search depending on the current WM load. Therefore, whereas the left and right parietal contributions were distinct here, attentional and WM functions were codependent. Right parietal cortex seems to hold a privileged role in visual search behavior, consistent with prior findings, but the current results reveal that behavior may be sensitive to the interaction between visual search and WM load only when normal parietal activity is perturbed. The parietal response to heightened WM and attentional demands may therefore serve to protect against dual-task interference.

中文翻译：

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半球特定顶叶对工作记忆和注意力相互作用的贡献。

为了实现我们的即时目标，我们必须经常暂时记住信息。然而，这种工作记忆（WM）可能会与我们在环境中的注意力需求竞争。注意力和 WM 功能被认为是通过相似的基本原理运作的，并且它们经常涉及重叠的额顶叶大脑区域。在最近的 fMRI 研究中，双侧顶叶皮层 BOLD 活动显示了 WM 和视觉注意双重任务需求之间的相互作用。然而，先前的研究还表明，左右顶叶皮质对 WM 和注意力功能做出了独特的贡献。此外，行为表现通常显示并发 WM 和注意力需求之间没有相互作用。因此，WM 和注意力功能之间的互惠范围，以及顶叶皮层对这些功能的具体贡献仍未解决。在这里，我们采用了因果方法，针对与 WM 和视觉注意力之间的共享处理有关的大脑区域，以更好地描述这些区域对行为的贡献。我们首先检查了 WM 和视觉搜索的行为指数是否与左右顶叶双任务 BOLD 反应存在差异相关性。然后，我们在双任务 WM 视觉搜索性能期间在 fMRI 引导的左右顶叶部位提供 TMS。只有右顶叶 TMS 影响了视觉搜索行为，但根据当前的 WM 负载，刺激要么帮助要么损害搜索。因此，虽然左右顶叶的贡献在这里是不同的，但注意力和 WM 功能是相互依赖的。右顶叶皮层似乎在视觉搜索行为中扮演着特殊的角色，这与之前的研究结果一致，但目前的结果表明，只有当正常的顶叶活动受到干扰时，行为才可能对视觉搜索和 WM 负载之间的相互作用敏感。因此，顶叶对提高的 WM 和注意力需求的反应可能有助于防止双重任务干扰。