Bernstein Center for Computational Neuroscience, Charité Universitätsmedizin, 10115 Berlin, Germany.
J Neurosci. 2012 Sep 19;32(38):12983-9. doi: 10.1523/JNEUROSCI.0184-12.2012.
How content is stored in the human brain during visual short-term memory (VSTM) is still an open question. Different theories postulate storage of remembered stimuli in prefrontal, parietal, or visual areas. Aiming at a distinction between these theories, we investigated the content-specificity of BOLD signals from various brain regions during a VSTM task using multivariate pattern classification. To participate in memory maintenance, candidate regions would need to have information about the different contents held in memory. We identified two brain regions where local patterns of fMRI signals represented the remembered content. Apart from the previously established storage in visual areas, we also discovered an area in the posterior parietal cortex where activity patterns allowed us to decode the specific stimuli held in memory. Our results demonstrate that storage in VSTM extends beyond visual areas, but no frontal regions were found. Thus, while frontal and parietal areas typically coactivate during VSTM, maintenance of content in the frontoparietal network might be limited to parietal cortex.
在视觉短期记忆（VSTM）期间，信息是如何存储在人脑中的，这仍然是一个悬而未决的问题。不同的理论假设，记忆中的刺激存储在前额叶、顶叶或视觉区域中。为了区分这些理论，我们使用多元模式分类，研究了在 VSTM 任务期间来自不同大脑区域的 BOLD 信号的内容特异性。为了参与记忆维持，候选区域需要具有关于记忆中不同内容的信息。我们确定了两个大脑区域，其中 fMRI 信号的局部模式代表了记忆中的内容。除了先前在视觉区域中发现的存储之外，我们还发现了顶叶后皮质中的一个区域，其活动模式使我们能够解码记忆中存储的特定刺激。我们的结果表明，VSTM 的存储不仅限于视觉区域，但是没有发现额叶区域。因此，虽然在 VSTM 期间，额顶叶区域通常会共同激活，但在额顶叶网络中维持内容可能仅限于顶叶皮层。
