Abstract:
Attention is often viewed as a mental spotlight, which can be scaled like a zoom lens at specific spatial locations and features a center-surround gradient. Here, we demonstrate a neural signature of attention spotlight in signal transmission along the visual hierarchy. fMRI background connectivity analysis was performed between retinotopic V1 and downstream areas to characterize the spatial distribution of inter-areal interaction under two attentional states. We found that, compared to diffused attention, focal attention sharpened the spatial gradient in the strength of the background connectivity. Dynamic causal modeling analysis further revealed the effect of attention in both the feedback and feedforward connectivity between V1 and extrastriate cortex. In a context which induced a strong effect of crowding, the effect of attention in the background connectivity profile diminished. Our findings reveal a context-dependent attention prioritization in information transmission via modulating the recurrent processing across the early stages in human visual cortex.
摘要:
注意力通常被视为精神上的聚光灯,它可以像变焦镜头一样在特定的空间位置进行缩放,并具有中心环绕梯度。这里,我们展示了沿着视觉层次结构的信号传输中注意力聚光灯的神经特征。在视网膜V1和下游区域之间进行了fMRI背景连通性分析,以表征两种注意状态下区域间相互作用的空间分布。我们发现,与分散的注意力相比,焦点注意力增强了背景连通性强度的空间梯度。动态因果模型分析进一步揭示了注意力在V1和语外皮层之间的反馈和前馈连接中的作用。在引发强烈拥挤效应的背景下,注意力在背景连通性配置文件中的影响减弱。我们的发现揭示了通过调节人类视觉皮层早期阶段的反复处理来实现信息传输中与上下文相关的注意力优先顺序。