The Picower Institute for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA.
The Picower Institute for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA; Department of Psychology, Stockholm University, 106 91 Stockholm, Sweden.
Neuron. 2021 Mar 17;109(6):1055-1066.e4. doi: 10.1016/j.neuron.2021.01.016. Epub 2021 Feb 8.
Visual working memory (WM) storage is largely independent between the left and right visual hemifields/cerebral hemispheres, yet somehow WM feels seamless. We studied how WM is integrated across hemifields by recording neural activity bilaterally from lateral prefrontal cortex. An instructed saccade during the WM delay shifted the remembered location from one hemifield to the other. Before the shift, spike rates and oscillatory power showed clear signatures of memory laterality. After the shift, the lateralization inverted, consistent with transfer of the memory trace from one hemisphere to the other. Transferred traces initially used different neural ensembles from feedforward-induced ones, but they converged at the end of the delay. Around the time of transfer, synchrony between the two prefrontal hemispheres peaked in theta and beta frequencies, with a directionality consistent with memory trace transfer. This illustrates how dynamics between the two cortical hemispheres can stitch together WM traces across visual hemifields.
视觉工作记忆 (WM) 存储在很大程度上是独立于左右视觉半视野/大脑半球的，但 WM 却感觉是无缝的。我们通过从外侧前额叶皮层双侧记录神经活动来研究 WM 是如何在半视野之间整合的。在 WM 延迟期间进行的指令性扫视将记忆位置从一个半视野转移到另一个半视野。在转移之前，尖峰率和振荡功率显示出明显的记忆偏侧性特征。转移后，偏侧性发生反转，与记忆痕迹从一个半球转移到另一个半球一致。转移的痕迹最初使用来自前馈诱导的不同神经集合，但在延迟结束时它们会聚。在转移前后，两个前额叶半球之间的同步在 theta 和 beta 频率达到峰值，其方向性与记忆痕迹转移一致。这说明了两个大脑半球之间的动力学如何将 WM 痕迹缝合在一起跨越视觉半视野。
