The “sensory recruitment hypothesis” posits an essential role of sensory cortices in working memory, beyond the well-accepted frontoparietal areas. Yet, this hypothesis has recently been challenged. In the present study, participants performed a delayed orientation recall task while high-spatial-resolution 3 T functional magnetic resonance imaging (fMRI) signals were measured in posterior cortices. A multivariate inverted encoding model approach was used to decode remembered orientations based on blood oxygen level-dependent fMRI signals from visual cortices during the delay period. We found that not only did activity in the contralateral primary visual cortex (V1) retain high-fidelity representations of the visual stimuli, but activity in the ipsilateral V1 also contained such orientation tuning. Moreover, although the encoded tuning was faded in the contralateral V1 during the late delay period, tuning information in the ipsilateral V1 remained sustained. Furthermore, the ipsilateral representation was presented in secondary visual cortex (V2) as well, but not in other higher-level visual areas. These results thus supported the sensory recruitment hypothesis and extended it to the ipsilateral sensory areas, which indicated the distributed involvement of visual areas in visual working memory.

中文翻译：

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重新审视感官募集：同侧 V1 参与视觉工作记忆

“感觉募集假说”假设感觉皮层在工作记忆中的重要作用，超出了广为接受的额顶叶区域。然而，这一假设最近受到了挑战。在本研究中，参与者执行延迟定向回忆任务，同时在后皮质测量高空间分辨率 3 T 功能磁共振成像 (fMRI) 信号。在延迟期间，基于来自视觉皮层的血氧水平依赖性 fMRI 信号，使用多元反向编码模型方法对记忆的方向进行解码。我们发现，不仅对侧初级视觉皮层 (V1) 中的活动保留了视觉刺激的高保真表示，而且同侧 V1 中的活动也包含这种方向调整。而且，尽管编码调谐在延迟后期对侧 V1 中消失，但同侧 V1 中的调谐信息保持持续。此外，同侧表示也出现在次级视觉皮层（V2）中，但不在其他更高级别的视觉区域中。因此，这些结果支持感觉募集假设并将其扩展到同侧感觉区域，这表明视觉区域在视觉工作记忆中的分布参与。