How large are root and affix priming effects in visual word recognition? Estimation from original data and a Bayesian meta-analysis

Priming effects for morphological roots support theories that grant them a unique representational status in visual word recognition. However, effects for other morphemes, including inflectional affixes, have been inconsistent. In a large-N experiment, we test the reliability of inflectional affix priming and add a meta-analysis to quantify priming effect size for roots and affixes. Study 1 probes priming for the English past tense suffix –ed at short (34 ms) and long (150 ms) stimulus-onset asynchrony; pure morphological priming is not obtained that is statistically distinguishable from form-based priming effects. A Bayesian meta-analysis (Study 2) demonstrates priming for roots and prefixes, but not suffixes, that are statistically larger than form-based priming effects. Taken together the absence of suffix priming contrasts with robust root and prefix effects, which may reflect the left-to-right nature of visual word recognition in the languages studied in this work.