Horizontal orthography versus vertical orthography: The effects of writing direction and syllabic format on visual word recognition in Korean Hangul

The Korean writing system has the flexibility of writing horizontally and vertically as well as two syllabic formats that cannot be found in any other alphabetic script. Consolidating these two characteristics, this study investigated the differential extractions of visual information from the mutilated stimuli of the two syllabic formats of CVC syllables and two writing directions using a lexical decision task. In Experiment 1, the two syllabic formats (i.e., balanced syllables, and vertical syllables, ) were mutilated downwards and upwards (i.e., respectively), along with whole stimuli, in horizontal writing direction. In Experiment 2, the same stimuli and syllabic formats were mutilated rightwards and leftwards (i.e., respectively) in vertical writing direction. Linear mixed effects models showed significant syllabic format effects and writing direction effects, indicating an upper-part superiority in horizontal writing and a right-part advantage in vertical writing. In particular, the right-part superiority in vertical writing is different from a left-part advantage found in Chinese characters. While the upper-part superiority is script-universal, the leftward or rightward bias seems to be script-specific, as readers’ perceptual integration depends on the nature of orthography.