Debes Samantha R, Dragoi Valentin
Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas at Houston, Houston, TX 77030, USA.
Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
Science. 2023 Feb 3;379(6631):468-473. doi: 10.1126/science.ade1855. Epub 2023 Feb 2.
Attention improves perception by enhancing the neural encoding of sensory information. A long-standing hypothesis is that cortical feedback projections carry top-down signals to influence sensory coding. However, this hypothesis has never been tested to establish causal links. We used viral tools to label feedback connections from cortical area V4 targeting early visual cortex (area V1). While monkeys performed a visual-spatial attention task, inactivating feedback axonal terminals in V1 without altering local intracortical and feedforward inputs reduced the response gain of single cells and impaired the accuracy of neural populations for encoding external stimuli. These effects are primarily manifested in the superficial layers of V1 and propagate to downstream area V4. Attention enhances sensory coding across visual cortex by specifically altering the strength of corticocortical feedback in a layer-dependent manner.
注意力通过增强感觉信息的神经编码来改善感知。一个长期存在的假设是，皮层反馈投射携带自上而下的信号来影响感觉编码。然而，这一假设从未经过测试以建立因果联系。我们使用病毒工具标记从皮层V4区到早期视觉皮层（V1区）的反馈连接。当猴子执行视觉空间注意力任务时，在不改变局部皮层内和前馈输入的情况下，使V1区的反馈轴突终末失活，会降低单细胞的反应增益，并损害神经群体编码外部刺激的准确性。这些效应主要表现在V1区的浅层，并传播到下游的V4区。注意力通过以层依赖的方式特异性改变皮层间反馈的强度来增强整个视觉皮层的感觉编码。
