Stringer Carsen, Michaelos Michalis, Tsyboulski Dmitri, Lindo Sarah E, Pachitariu Marius
HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
Cell. 2021 May 13;184(10):2767-2778.e15. doi: 10.1016/j.cell.2021.03.042. Epub 2021 Apr 14.
Individual neurons in visual cortex provide the brain with unreliable estimates of visual features. It is not known whether the single-neuron variability is correlated across large neural populations, thus impairing the global encoding of stimuli. We recorded simultaneously from up to 50,000 neurons in mouse primary visual cortex (V1) and in higher order visual areas and measured stimulus discrimination thresholds of 0.35° and 0.37°, respectively, in an orientation decoding task. These neural thresholds were almost 100 times smaller than the behavioral discrimination thresholds reported in mice. This discrepancy could not be explained by stimulus properties or arousal states. Furthermore, behavioral variability during a sensory discrimination task could not be explained by neural variability in V1. Instead, behavior-related neural activity arose dynamically across a network of non-sensory brain areas. These results imply that perceptual discrimination in mice is limited by downstream decoders, not by neural noise in sensory representations.
视觉皮层中的单个神经元为大脑提供的视觉特征估计并不可靠。尚不清楚单个神经元的变异性在大型神经群体中是否相关，从而损害刺激的全局编码。我们同时记录了小鼠初级视觉皮层（V1）和更高阶视觉区域中多达50,000个神经元的活动，并在方向解码任务中分别测量了0.35°和0.37°的刺激辨别阈值。这些神经阈值比小鼠报告的行为辨别阈值小近100倍。这种差异无法用刺激特性或觉醒状态来解释。此外，感觉辨别任务期间的行为变异性无法用V1中的神经变异性来解释。相反，与行为相关的神经活动在非感觉脑区网络中动态出现。这些结果表明，小鼠的知觉辨别受下游解码器的限制，而非感觉表征中的神经噪声。
