Hemispheric asymmetry in the processing of Japanese script

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Neuroscience of Language

Background:

• Japanese written language integrates logographic (kanji) and phonetic (kana) scripts.
• Previous research indicates differing patterns of hemispheric asymmetry for kanji and kana encoding.
• The impact of orthographic encoding asymmetries on lexical access remains an area for investigation.

Purpose of the Study:

• To investigate how hemispheric differences in orthographic encoding influence lexical access.
• To compare the visual field advantages for processing Japanese kana and kanji scripts.
• To explore the temporal dynamics of priming effects for logographic and phonetic scripts.

Main Methods:

• A lexical decision task was employed within an associative priming paradigm.
• Thirty-two participants processed both kanji and kana stimuli.
• Visual field advantages and priming effects were analyzed for each script.

Main Results:

• A right visual field advantage was observed for kana processing.
• No significant lateralized advantage was found for kanji stimuli.
• Kanji stimuli exhibited a late-developing, stronger priming effect in the left visual field.

Conclusions:

• Hemispheric asymmetry in orthographic encoding differentially impacts lexical access for kana and kanji.
• Kana processing is associated with right visual field advantage, suggesting distinct neural pathways.
• The findings support models like recognition-with-phonology for logographic script processing, highlighting script-specific cognitive mechanisms.