縦書き・横書き文章における読書時の眼球運動の比較

Differences in eye movement during reading vertically and horizontally printed sentences

要約　目的：縦書きと横書きの文章を読むときの眼球運動の比較。対象と方法：19～23歳の健康人19名を対象とした。読書時の眼球運動は赤外線眼鏡型眼球運動記録装置で記録し，自覚的な読みやすさを聴取した。読書材料として，1辺が3.5mmの明朝体の文字を，A4用紙に1行45文字，15行で縦または横に印刷したものを使った。結果：眼球運動波形は，縦書きと横書きともに視線移動（saccade）と固視からなる階段状波形を示した。視線移動の速度は横書きのほうが速く，固視回数は縦書きのほうが有意に多かった。自覚的には横書きのほうが読みやすいという回答が多かった。結論：縦読みでは固視回数が多くなり，視線移動速度が遅くなることが読みやすさに影響していると解釈される。

Abstract.　Purpose：To compare eye movements during reading vertically and horizontally printed sentences. Subjects and Method：This study was made on 19 healthy volunteers aged from 19 to 23 years. They were asked to read a printed material written vertically or horizontally. They were also interviewed regarding easiness of reading. Eye movement was recorded by an infrared recorder shaped like spectacles. Results：Recorded eye movements showed a staircase-pattern consisting of saccades and periods of fixation. Saccades were faster while reading horizontally printed material. Period of fixation was more frequent while reading vertically printed material. Majority of cases reported that horinzontally printed material was easier to read. Conclusion：There is more frequent period of fixation with slower saccades while reading vertically written material. This feature is a major factor that affects reading ability.