Abstract
When we imagine an object and when we actually see that object, similar brain regions become active. Yet, the time course and mechanisms with which imagery engages perceptual networks remain to be better understood. An emerging view holds that imagery and perception follow distinct dynamics during early visual processing with similarities arising only during later, high-level visual processing. However, confounds of visual stimulation and paradigms favoring observation of high-level processes associated with subjective imagery strength may have precluded evidence of earlier shared mechanisms. We therefore manipulated prior knowledge that informs early-stage top-down predictions and tracked electrophysiological brain responses while fully controlling visual stimulation. Participants saw and imagined objects associated with varying amounts of semantic knowledge. Imagery and perception were equally influenced by knowledge at an early stage (P1 component), revealing shared mechanisms that support low-level visual processing. This finding complements previous research by showing that imagery is not merely perception in reverse. Instead, in line with the predictive processing framework, both, perception and imagery are active and constructive processes that share top-down mechanisms already in early phases of processing.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2002/1 “Science of Intelligence” – project number 390523135 and DFG grant AB 277-6 to Rasha Abdel Rahman. Martin Maier was supported by the state of Berlin and the Berlin School of Mind and Brain.
We have no known conflict of interest to disclose.