Optimal viewing position in vertically and horizontally presented Japanese words

Area of Science:

• Cognitive Psychology
• Visual Perception
• Linguistics

Background:

• The optimal viewing position (OVP) phenomenon describes how word recognition varies based on viewing location.
• Previous research on Roman scripts indicates asymmetric OVP curves, influenced by visual field laterality.

Purpose of the Study:

• To investigate the OVP phenomenon in Japanese Hiragana, comparing vertical and horizontal text orientations.
• To examine character visibility across vertical and horizontal meridians.
• To evaluate existing models and propose an improved one for OVP in Japanese script.

Main Methods:

• Experiment 1: Measured word recognition scores for vertically and horizontally displayed Japanese Hiragana words at various fixation points.
• Experiment 2: Assessed individual character visibility within strings along vertical and horizontal visual field meridians.

Main Results:

• Asymmetric OVP curves were observed for both vertical and horizontal Hiragana, with less pronounced asymmetry in vertical text.
• Letter identification was superior in the right visual field compared to the left.
• No significant difference in identification scores was found between the upper and lower visual fields along the vertical meridian.

Conclusions:

• The OVP phenomenon in Japanese Hiragana differs from Roman scripts, particularly in the degree of asymmetry.
• The findings challenge the adequacy of existing models, like Nazir, O'Regan, and Jacobs (1991), for explaining Japanese script.
• A new model integrating visual and lexical factors is proposed to better account for the observed OVP effects.