ABSTRACT
The standard picture is that perception starts with sensory input. But perceptual processing often happens without being triggered by the sensory input. This phenomenon is sometimes referred to as offline perception or quasi-perception. This is what happens when we dream or hallucinate and in the various uses of mental imagery.
Perception without input – offline perception – is often combined with input-driven perception in our everyday perceptual experiences. This gives rise to a hybrid offline/online perception, which has been an influential thought in the history of philosophy, but which is also supported by a variety of empirical findings from neuroscience and psychology.
