Shared Neural Mechanisms of Visual Perception and Imagery.

For decades, the extent to which visual imagery relies on the same neural mechanisms as visual perception has been a topic of debate. Here, we review recent neuroimaging studies comparing these two forms of visual experience. Their results suggest that there is a large overlap in neural processing during perception and imagery: neural representations of imagined and perceived stimuli are similar in the visual, parietal, and frontal cortex. Furthermore, perception and imagery seem to rely on similar top-down connectivity. The most prominent difference is the absence of bottom-up processing during imagery. These findings fit well with the idea that imagery and perception rely on similar emulation or prediction processes.