Neurosciences Graduate Program, University of California, San Diego, San Diego, United States.
Department of Machine Learning, Carnegie Mellon University, Pittsburgh, United States.
Elife. 2022 May 6;11:e75688. doi: 10.7554/eLife.75688.
Working memory provides flexible storage of information in service of upcoming behavioral goals. Some models propose specific fixed loci and mechanisms for the storage of visual information in working memory, such as sustained spiking in parietal and prefrontal cortex during working memory maintenance. An alternative view is that information can be remembered in a flexible format that best suits current behavioral goals. For example, remembered visual information might be stored in sensory areas for easier comparison to future sensory inputs, or might be re-coded into a more abstract action-oriented format and stored in motor areas. Here, we tested this hypothesis using a visuo-spatial working memory task where the required behavioral response was either known or unknown during the memory delay period. Using functional magnetic resonance imaging (fMRI) and multivariate decoding, we found that there was less information about remembered spatial position in early visual and parietal regions when the required response was known versus unknown. Furthermore, a representation of the planned motor action emerged in primary somatosensory, primary motor, and premotor cortex during the same task condition where spatial information was reduced in early visual cortex. These results suggest that the neural networks supporting working memory can be strategically reconfigured depending on specific behavioral requirements during a canonical visual working memory paradigm.
工作记忆为即将到来的行为目标提供了灵活的信息存储。一些模型提出了特定的固定位置和机制来存储工作记忆中的视觉信息，例如在工作记忆维持期间顶叶和前额叶皮层中的持续尖峰。另一种观点认为，信息可以以最适合当前行为目标的灵活格式进行记忆。例如，被记住的视觉信息可以存储在感觉区域中，以便更容易与未来的感觉输入进行比较，或者可以重新编码为更抽象的面向动作的格式并存储在运动区域中。在这里，我们使用视空间工作记忆任务来检验这一假设，在该任务中，在记忆延迟期间，所需的行为反应是已知的还是未知的。使用功能磁共振成像（fMRI）和多元解码，我们发现当所需的反应是已知的还是未知的时，早期视觉和顶叶区域中关于记忆空间位置的信息较少。此外，在同一任务条件下，主要体感、主要运动和前运动皮层中出现了对计划运动动作的表示，而在早期视觉皮层中，空间信息减少了。这些结果表明，支持工作记忆的神经网络可以根据经典视觉工作记忆范式期间的特定行为要求进行策略性地重新配置。
