Donbaloglu et al. (2025) compared the cognitive and reading performance of neuro-typical children with children who had diagnosed ADHD or dyslexia. In the Central Nervous System Vital Signs phase of the study, the performance of children in the ADHD and dyslexia groups showed significant differences from each other and from the neuro-typical children in various areas.
Previous research has shown that the reading process is a high-level cognitive process requiring the use of multiple areas of the brain. In addition, eye movements and attention are considered to be linked during this process. During the reading process the eyes fluctuate between fixations (i.e., it is relatively still and focused on a specific target) and saccades (i.e., rapid movements from one fixation point to another while scanning and processing information).
The Method
The study consisted of 78 children between the ages of 8-12 years – 26 with ADHD, 26 with dyslexia and 26 neuro-typical children. Children who had past or current use of psychotropic medication were excluded from the study.
All children were administered the Central Nervous System Vital Signs which included 7 neuropsychological tests – Verbal Memory Test, Visual Memory Test, Finger Tapping Test, Symbol Digit Coding Test, Stroop Test, Shifting Attention Test and Continuous Performance Test. These tests provide information regarding composite memory, psychomotor speed, reaction time, complex attention, cognitive flexibility, working memory and general neurocognition.
In the eye tracking phase, children were asked to read a passage silently and their eye tracking was recorded using iViewX software. The software recorded the number and duration of fixations, the number and duration of saccades as well as the amplitude of saccades and total reading time.
The Results
Compared to the neuro-typical group, children in the ADHD and dyslexia groups had significantly lower psychomotor speed, cognitive attention, cognitive flexibility and verbal memory. In addition, the dyslexia group had significantly lower scores than the ADHD group and the neuro-typical group in the composite memory domain, verbal and visual memory, working memory and reaction time.
The eye tracking data showed that the dyslexia group had a higher number of and longer fixations, a higher number, longer duration and a higher altitude of saccades and a longer reading time than both the ADHD group and the neuro-typical group. While the ADHD group did not differ significantly from the neuro-typical group.
The Interpretations
Donbaloglu et al. argued that these results indicate that:
- Dyslexia has a disruptive effect on visual and verbal memory, while ADHD is more associated with verbal memory problems.
- Dyslexia, but not ADHD, is associated with a slower reaction time compared to neuro-typical children. Reaction time difficulties described in previous research of participants with ADHD may be related to reaction time variability rather than response speed.
- Poor working memory (in particular visual-spatial memory) is a common area of weakness among those with dyslexia, but not ADHD. Working memory deficits appear to vary widely among those diagnosed with ADHD.
- It is recommend that teaching strategies using different sensory modalities (visual, auditory, tactile), in short intervals with frequent repetitions can contribute to learning for children with dyslexia and ADHD.
- Inadequate oculomotor performance in children with dyslexia suggests that eye tracking may be a useful biomarker of the disorder. In addition, recording eye tracking may provide concrete data of the effectiveness of a particular reading intervention.
Reference
Donbaloğlu, M., Demirdöğen, E., Akıncı, M., & Bozkurt, A. (2025). An Eye‐Tracking Study: Comparison of Neuropsychological Profiles and Reading Performance of Children with Attention Deficit‐Hyperactivity Disorder and Dyslexia. Reading Research Quarterly. 60. 10.1002/rrq.70047.