Duke Institute for Brain Sciences, Duke University, Durham, NC, 27708, USA.
Center for Cognitive Neuroscience, Duke University, Durham NC, 27708, USA.
Nat Commun. 2018 Jul 13;9(1):2715. doi: 10.1038/s41467-018-05121-8.
How the brain preserves information about multiple simultaneous items is poorly understood. We report that single neurons can represent multiple stimuli by interleaving signals across time. We record single units in an auditory region, the inferior colliculus, while monkeys localize 1 or 2 simultaneous sounds. During dual-sound trials, we find that some neurons fluctuate between firing rates observed for each single sound, either on a whole-trial or on a sub-trial timescale. These fluctuations are correlated in pairs of neurons, can be predicted by the state of local field potentials prior to sound onset, and, in one monkey, can predict which sound will be reported first. We find corroborating evidence of fluctuating activity patterns in a separate dataset involving responses of inferotemporal cortex neurons to multiple visual stimuli. Alternation between activity patterns corresponding to each of multiple items may therefore be a general strategy to enhance the brain processing capacity, potentially linking such disparate phenomena as variable neural firing, neural oscillations, and limits in attentional/memory capacity.
大脑如何保留关于多个同时出现的项目的信息还知之甚少。我们报告说，单个神经元可以通过在时间上交错信号来表示多个刺激。我们在听觉区域下丘记录单个单元，同时猴子定位 1 或 2 个同时出现的声音。在双音试验中，我们发现有些神经元在每个单音的观察到的发射率之间波动，无论是在整个试验还是在子试验的时间尺度上。这些波动在成对的神经元中是相关的，可以通过声音出现前局部场电位的状态来预测，并且在一只猴子中，可以预测哪个声音将首先报告。我们在涉及多视觉刺激的下颞皮质神经元反应的另一个独立数据集发现了波动活动模式的佐证证据。对应于多个项目中的每一个的活动模式的交替可能因此是增强大脑处理能力的一般策略，可能将可变的神经放电、神经振荡和注意力/记忆容量的限制等不同现象联系起来。
