Neuronal correlates of parametric working memory in the prefrontal cortex
Neuronal correlates of parametric working memory in the prefrontal cortex
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作者：
Romo, R;Brody, CD;Lemus, L
人类和猴子具有类似的能力来区分连续施加到指尖的两个机械振动之间的频率差异(1-3)。这项感觉任务的一个关键组成部分是，将第二个刺激与第一个（基础）刺激留下的痕迹进行比较，这必须涉及工作记忆，这个痕迹在大脑中的位置和方式如何？这个问题是通过在猴子执行体感辨别任务时记录猴子前额叶皮层中的单个神经元来研究的。在这里，我们描述了前额叶皮层下凸面的神经元，其放电率在两个刺激之间的延迟期间变化，作为基本刺激频率的单调函数。我们将其描述为“单调刺激编码”：并且我们认为结果可以概括：单调刺激编码可能是工作记忆中一维感觉刺激量的基本表示。因此，我们预测需要在标量模拟刺激之间进行顺序比较的其他行为任务将引起与此处报告的类似的单调反应。
Humans and monkeys have similar abilities to discriminate the difference in frequency between two mechanical vibrations applied sequentially to the fingertips(1-3). A key component of this sensory task is that the second stimulus is compared with the trace left by the first (base) stimulus, which must involve working memory,Where and how is this trace held in the brain? This question was investigated by recording from single neurons in the prefrontal cortex of monkeys while they performed the somatosensory discrimination task, Here we describe neurons in the inferior convexity of the prefrontal cortex whose discharge rates varied, during the delay period between the two stimuli, as a monotonic function of the base stimulus frequency. We describe this as 'monotonic stimulus encoding: and we suggest that the result may generalize: monotonic stimulus encoding may be the basic representation of one-dimensional sensory stimulus quantities in working memory. Thus we predict that other behavioural tasks that require ordinal comparisons between scalar analogue stimuli would give rise to monotonic responses similar to those reported here.