Cohen Marlene R, Maunsell John H R
Howard Hughes Medical Institute and Harvard Medical School Department of Neurobiology, Boston, Massachusetts, USA.
Nat Neurosci. 2009 Dec;12(12):1594-600. doi: 10.1038/nn.2439. Epub 2009 Nov 15.
Visual attention can improve behavioral performance by allowing observers to focus on the important information in a complex scene. Attention also typically increases the firing rates of cortical sensory neurons. Rate increases improve the signal-to-noise ratio of individual neurons, and this improvement has been assumed to underlie attention-related improvements in behavior. We recorded dozens of neurons simultaneously in visual area V4 and found that changes in single neurons accounted for only a small fraction of the improvement in the sensitivity of the population. Instead, over 80% of the attentional improvement in the population signal was caused by decreases in the correlations between the trial-to-trial fluctuations in the responses of pairs of neurons. These results suggest that the representation of sensory information in populations of neurons and the way attention affects the sensitivity of the population may only be understood by considering the interactions between neurons.
视觉注意力可通过让观察者聚焦于复杂场景中的重要信息来提高行为表现。注意力通常还会提高皮层感觉神经元的 firing 率。 firing 率的增加改善了单个神经元的信噪比，并且这种改善被认为是行为中与注意力相关的改善的基础。我们同时在视觉区域 V4 记录了数十个神经元，发现单个神经元的变化仅占群体敏感度提高的一小部分。相反，群体信号中超过 80% 的注意力改善是由成对神经元反应的逐次试验波动之间的相关性降低引起的。这些结果表明，只有通过考虑神经元之间的相互作用，才能理解神经元群体中感觉信息的表征以及注意力影响群体敏感度的方式。
