Department of Physiology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan.
J Neurosci. 2014 Apr 16;34(16):5621-6. doi: 10.1523/JNEUROSCI.0295-14.2014.
Spatial working memory is one of the most studied cognitive functions, serving as a model system to decipher computational principles of the brain. Although neuronal mechanisms for remembering a single location have been well elucidated, little is known about memory for multiple locations. Here, we examined the activities of prefrontal neurons during monkeys remembered positions of one or two visual cue(s). When the two cues were presented across the left and right visual fields, neurons exhibited a comparable response to the activity for the preferred cue presented alone. When the two cues were presented within the same hemifield, neurons exhibited an intermediate response between those to the individual cues. Subsequent computer simulations predicted a lower signal-to-noise ratio in the latter condition, which was further verified by behavioral experiments. Considering the separation of contralateral and ipsilateral visual processing, the lateral inhibition in local circuits might implicitly determine different neuronal computations and memory capacities for bilateral and unilateral displays.
空间工作记忆是研究最多的认知功能之一，可作为破译大脑计算原理的模型系统。虽然单个位置记忆的神经元机制已得到充分阐明，但对多个位置的记忆却知之甚少。在这里，我们检查了猴子记住一个或两个视觉线索位置时前额叶神经元的活动。当两个线索分别出现在左、右视野时，神经元对单独呈现的首选线索的反应与该线索相似。当两个线索出现在同一半视野时，神经元的反应介于单独呈现的两个线索之间。随后的计算机模拟预测在后者条件下信号噪声比降低，行为实验进一步验证了这一点。考虑到对侧和同侧视觉处理的分离，局部回路中的侧向抑制可能会隐含地确定双侧和单侧显示的不同神经元计算和记忆能力。
