Summary
In the mammalian sensory cortex, hierarchically-organized areas are reciprocally connected via feedforward (FF) and feedback (FB) circuits. FF connections generate the more complex response properties of neurons in higher areas within parallel streams specialized in processing specific stimulus attributes. In contrast, the function of FB connections remains unknown. In the visual cortex, FB has been implicated in top-down phenomena, such as visual attention, prediction, and visual context. However, these roles have remained hypothetical, due to the lack of tools to selectively label, record, a
