Kamiński Jan, Sullivan Shannon, Chung Jeffrey M, Ross Ian B, Mamelak Adam N, Rutishauser Ueli
Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, California, USA.
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA.
Nat Neurosci. 2017 Apr;20(4):590-601. doi: 10.1038/nn.4509. Epub 2017 Feb 20.
Persistent neural activity is a putative mechanism for the maintenance of working memories. Persistent activity relies on the activity of a distributed network of areas, but the differential contribution of each area remains unclear. We recorded single neurons in the human medial frontal cortex and medial temporal lobe while subjects held up to three items in memory. We found persistently active neurons in both areas. Persistent activity of hippocampal and amygdala neurons was stimulus-specific, formed stable attractors and was predictive of memory content. Medial frontal cortex persistent activity, on the other hand, was modulated by memory load and task set but was not stimulus-specific. Trial-by-trial variability in persistent activity in both areas was related to memory strength, because it predicted the speed and accuracy by which stimuli were remembered. This work reveals, in humans, direct evidence for a distributed network of persistently active neurons supporting working memory maintenance.
持续性神经活动是维持工作记忆的一种假定机制。持续性活动依赖于一个分布式脑区网络的活动，但每个脑区的不同贡献仍不清楚。我们在人类内侧前额叶皮层和内侧颞叶记录单个神经元活动，同时让受试者记忆多达三个项目。我们在这两个脑区都发现了持续活跃的神经元。海马体和杏仁核神经元的持续性活动具有刺激特异性，形成稳定吸引子并能预测记忆内容。另一方面，内侧前额叶皮层的持续性活动受记忆负荷和任务集调节，但不具有刺激特异性。两个脑区持续性活动的逐次试验变异性与记忆强度相关，因为它能预测刺激被记住的速度和准确性。这项研究在人类中揭示了支持工作记忆维持的持续性活跃神经元分布式网络的直接证据。
