Criteria for unconscious cognition: Three types of dissociation

Abstract

To demonstrate unconscious cognition, researchers commonly compare a direct measure (D) of awareness for a critical stimulus with an indirect measure (T) showing that the stimulus was cognitively processed at all. We discuss and empirically demonstrate three types of dissociation with distinct appearances in D-I plots, in which direct and indirect effects are plotted against each other in a shared effect size metric. Simple dissociations between D and I occur when I has some nonzero value and D is at chance level; the traditional requirement of zero awareness is necessary for this criterion only. Sensitivity dissociations only require that I be larger than D; double dissociations occur when some experimental manipulation has opposite effects on I and D. We show that double dissociations require much weaker measurement assumptions than do other criteria. Several alternative approaches can be considered special cases of our framework. Copyright 2006 Psychonomic Society, Inc.