Assessing automatic activation of valence: a multinomial model of EAST performance.

The Extrinsic Affective Simon Task (EAST; De Houwer, 2003) has been introduced as an indirect measure of automatic activation of valence. EAST effects provide nonrelative valence measures of single stimuli compared to relative measures (e.g., Implicit Association Test) that imply a comparison between two stimuli or concepts. However, EAST effects can be biased by response tendencies. A multinomial process dissociation model of EAST performance is proposed and successfully validated in four experiments. Its parameters provide pure and unbiased measures of automatic valence activation, controlled processing of task-relevant features, and response tendency. A first application of latent-class hierarchical multinomial models reveals a significant amount of parameter heterogeneity resulting from interindividual differences in accuracy motivation.