Humans can construct rich subjective experience even when no information is available in the external world. Here, we investigated the neural representation of purely internally generated stimulus-like information during visual working memory. Participants performed delayed recall of oriented gratings embedded in noise with varying contrast during fMRI scanning. Their trialwise behavioral responses provided an estimate of their mental representation of the to-be-reported orientation. We used multivariate inverted encoding models to reconstruct the neural representations of orientation in reference to the response. We found that response orientation could be successfully reconstructed from activity in early visual cortex, even on 0% contrast trials when no orientation information was actually presented, suggesting the existence of a purely internally generated neural code in early visual cortex. In addition, cross-generalization and multidimensional scaling analyses demonstrated that information derived from internal sources was represented differently from typical working memory representations, which receive influences from both external and internal sources. Similar results were also observed in intraparietal sulcus, with slightly different cross-generalization patterns. These results suggest a potential mechanism for how externally driven and internally generated information is maintained in working memory.

即使外部世界没有信息，人类也可以构建丰富的主观体验。在这里，我们研究了视觉工作记忆期间纯粹内部生成的类刺激信息的神经表征。在功能磁共振成像扫描过程中，参与者对嵌入噪声中具有不同对比度的定向光栅进行延迟回忆。他们的试验性行为反应提供了他们对待报告取向的心理表征的估计。我们使用多元反向编码模型来重建参考响应的方向的神经表示。我们发现，即使在实际没有呈现方向信息的 0% 对比试验中，也可以根据早期视觉皮层的活动成功重建反应方向，这表明早期视觉皮层中存在纯粹内部生成的神经代码。此外，交叉概括和多维尺度分析表明，从内部来源获得的信息的表示方式与典型的工作记忆表示方式不同，后者受到外部和内部来源的影响。在顶内沟中也观察到类似的结果，但交叉概括模式略有不同。这些结果提出了如何在工作记忆中维护外部驱动和内部生成的信息的潜在机制。