Hallucinations and mental imagery demonstrate top-down effects on visual perception

Perception can be actively shaped by top-down processes such as prior knowledge and expectations, not merely influenced by them. Two clear examples—hallucinations and mental imagery—demonstrate this, and importantly, both avoid the six confounds that Firestone and Scholl previously argued undermined claims of top-down effects on perception. This suggests that top-down influences on perception are real and not artifacts of experimental design.

Study at a glance

Abstract

In this commentary, we present two examples where perception is not only influenced by, but also in fact driven by, top-down effects: hallucinations and mental imagery. Crucially, both examples avoid all six of the potential confounds that Firestone & Scholl (F&S) raised as arguments against previous studies claiming to demonstrate the influence of top-down effects on perception.