Developmental Eye Movement (DEM) Test Norms for Mandarin Chinese-Speaking Chinese Children

Abstract

The Developmental Eye Movement (DEM) test is commonly used as a clinical visual-verbal ocular motor assessment tool to screen and diagnose reading problems at the onset. No established norm exists for using the DEM test with Mandarin Chinese-speaking Chinese children. This study aims to establish the normative values of the DEM test for the Mandarin Chinese-speaking population in China; it also aims to compare the values with three other published norms for English-, Spanish-, and Cantonese-speaking Chinese children. A random stratified sampling method was used to recruit children from eight kindergartens and eight primary schools in the main urban and suburban areas of Nanjing. A total of 1,425 Mandarin Chinese-speaking children aged 5 to 12 years took the DEM test in Mandarin Chinese. A digital recorder was used to record the process. All of the subjects completed a symptomatology survey, and their DEM scores were determined by a trained tester. The scores were computed using the formula in the DEM manual, except that the “vertical scores” were adjusted by taking the vertical errors into consideration. The results were compared with the three other published norms. In our subjects, a general decrease with age was observed for the four eye movement indexes: vertical score, adjusted horizontal score, ratio, and total error. For both the vertical and adjusted horizontal scores, the Mandarin Chinese-speaking children completed the tests much more quickly than the norms for English- and Spanish-speaking children. However, the same group completed the test slightly more slowly than the norms for Cantonese-speaking children. The differences in the means were significant (P<0.001) in all age groups. For several ages, the scores obtained in this study were significantly different from the reported scores of Cantonese-speaking Chinese children (P<0.005). Compared with English-speaking children, only the vertical score of the 6-year-old group, the vertical-horizontal time ratio of the 8-year-old group and the errors of 9-year-old group had no significant difference (P>0.05); compared with Spanish-speaking children, the scores were statistically significant (P<0.001) for the total error scores of the age groups, except the 6-, 9-, 10-, and 11-year-old age groups (P>0.05). DEM norms may be affected by differences in language, cultural, and educational systems among various ethnicities. The norms of the DEM test are proposed for use with Mandarin Chinese-speaking children in Nanjing and will be proposed for children throughout China.

Vision and academic performance in primary school children

“…The DEM ratio, which has been purported to provide a measure of reading‐related saccadic eye movement performance independent of RAN, was not significantly associated with any of the NAPLAN academic measures in the current study. This lack of association could not be explained by a lack of variation in performance in the group, which ranged from 0.85 to 1.91, suggesting that a number of children within the sample had oculomotor dysfunction when compared to samples of similar age . While other studies have reported significant relationships between the DEM ratio and reading outcomes, they also noted that the associations were stronger for the horizontal and vertical times.…”

“…This lack of association could not be explained by a lack of variation in performance in the group, which ranged from 0.85 to 1.91, suggesting that a number of children within the sample had oculomotor dysfunction when compared to samples of similar age. 43 While other studies have reported significant relationships between the DEM ratio and reading outcomes, 36,39 they also noted that the associations were stronger for the horizontal and vertical times. Furthermore, the horizontal and vertical DEM times have shown better repeatability than the ratio, 44 which may explain their stronger associations with academic outcomes in the present study.…”

Spotlight on the Developmental Eye Movement (DEM) Test

“…Since the DEM test is a language-specific test and there is a different learning curve for each country which depends on socio-demographic, political, and cultural differences, the normative data in the first years of school become important. Normative values are actually available for nine languages and countries: English, 5 two for Spanish, 14 , 57 Cantonese, 15 Japanese, 56 Portuguese, 58 Italian, 30 Mandarin, 59 Latvian, 16 and French 60 languages.…”

“…Some comparisons that have been made with seven of them showed that some are different, particularly for the younger group and in the lower percentile rank. 15 , 30 , 58 , 59 Coherently, each specific norm has to be used for each language. Conversely, other direct comparisons did not find differences.…”

An Extended Method for Saccadic Eye Movement Measurements Using a Head-Mounted Display

“…The authors in [8,14] explained the differences between the DEM test and the adult DEM test. Furthermore, the DEM test can be used to determine the normative values of the DEM test for children speaking different languages [15], and can show the effects of amblyopia in children [16]. It can also be used to determine whether colored overlays could enhance reading performance or scanning ability [17].…”