Eye movements and poor reading: does the Developmental Eye Movement test measure cause or effect?

Area of Science:

• Ophthalmology
• Developmental Psychology
• Cognitive Science

Background:

• Reading difficulties are often associated with abnormal eye movements.
• The Developmental Eye Movement (DEM) test assumes poor eye movement control causes reading issues.
• This study investigates the causal relationship between reading practice and eye movement control.

Purpose of the Study:

• To test the hypothesis that fluent reading practice improves eye movements, leading to better DEM scores.
• To determine if poor readers have low DEM scores due to insufficient reading practice.
• To examine the impact of reading direction on eye movement control in different age groups and languages.

Main Methods:

• Recruited English and Arabic readers (children and adults).
• Administered the DEM test twice: once in the habitual reading direction and once in the opposite direction.
• Compared DEM test ratios between the two reading directions using paired t-tests.

Main Results:

• A significant difference in eye movements (DEM ratio) between opposing reading directions was observed in English adults, English children, and Arabic children.
• No significant difference was found in Arabic adults, who had equal practice in both reading directions.
• These findings suggest that reading directionality and practice significantly impact eye movement patterns.

Conclusions:

• Abnormal eye movements are more likely an effect, rather than the cause, of reading difficulties.
• The Developmental Eye Movement (DEM) test may not be a reliable diagnostic tool for eye movement difficulties in individuals with poor reading ability.
• Reading practice and experience play a crucial role in developing efficient eye movement control for reading.