The impact of text orientation on form priming effects in four-character Chinese words

Does visuospatial orientation influence repetition and transposed character (TC) priming effects in logographic scripts? According to perceptual learning accounts, the nature of orthographic (form) priming effects should be influenced by text orientation (Dehaene, Cohen, Sigman, & Vinckier, 2005; Grainger & Holcomb, 2009). In contrast, Witzel, Qiao, and Forster's (2011) abstract letter unit account argues that the mechanism responsible for such effects acts at a totally abstract orthographic level (i.e., the visuospatial orientation is irrelevant to the nature of the relevant orthographic code). The present experiments expanded this debate beyond alphabetic scripts and the syllabic Kana script used by Witzel et al. to a logographic script (Chinese). Experiment 1 showed masked repetition and TC priming effects with primes and targets presented in both the conventional left-to-right horizontal orientation and the vertical top-to-bottom orientation, replicating Witzel et al. Experiment 2 showed masked repetition and TC priming effects even when both the primes and targets were presented in the right-to-left orientation, a rare but existent text orientation in Chinese. In Experiment 3, the primes, but not the targets, were presented in the right-to-left orientation. Priming effects were again obtained regardless of the fact that the primes and targets appeared in different orientations. Experiment 4, which involved primes and targets presented in a completely novel bottom-to-top orientation, also produced a TC priming effect. These results support abstract letter/character unit accounts of form priming effects while failing to support perceptual learning accounts.