Horizontal versus Vertical Reading in Neglect Dyslexia: A Case Study

Lee, Byung H; Lee, Kyung Sook; Yoon, Soo Jin; Lee, Young Mi; Kim, Hyang Hee; Kwon, Jay C; Kang, Sue J; Na, Duk L

Abstract

BACKGROUND: Neglect dyslexia is a type of neglect syndrome, in which patients with unilateral hemisphere injury omit or misread the contralateral side of a text or the initial letters of a word. Hangul can be arrayed vertically (vertical reading, VR) as well as horizontally (horizontal reading, HR). Thus, HR and VR can be differentially affected in neglect dyslexia. We conducted an experiment in a 66 year-old woman who suffered from neglect dyslexia after a right cerebral infarction. We compared HR with VR in terms of error frequencies and patterns.
METHODS
Stimuli for neglect dyslexia consisted of 227 words. The 227 words were written horizontally or vertically (total 554 words) and were pre-sented in random order. The patient was asked to read the words and the examiner recorded the patient's responses and reaction times.
RESULTS
The differences in HR and VR were as follows: 1) the error frequency in HR (59.0%) was higher than the error frequency in VR (20.3%), 2) the most frequent error in HR was syllabic deletion (79.1%) whereas phonemic substitution (89.1%) predominated in VR, 3) the error rate was highest at the first syllabic position in HR whereas no position effect was noted in VR.
CONCLUSIONS
Patients with neglect dyslexia make less error in VR than in HR. The neural processing of HR may be different from that of VR. VR may be an alternative reading strategy that may be useful during the recovery stage of neglect dyslexia.