Introduction: Dyslexia is one of the most common learning disorders, characterized by persistent challenges in reading, phonological processing, and broader cognitive functions, including attention and perception. Emerging evidence highlights the role of auditory processing and attentional mechanisms in exacerbating the difficulties faced by dyslexic children. Despite these findings, current assessment tools often fail to comprehensively address linguistic and nonlinguistic tasks across both visual and auditory modalities, potentially overlooking the multifaceted nature of cognitive deficits in dyslexia.

This study sought to bridge this gap by investigating attention and perception impairments in children with dyslexia, comparing their performance with their typically developing peers. Utilizing a novel web-based platform adminstereating a series of cognitive tasks to evaluate visual and auditory processing under linguistic and nonlinguistic conditions. The goal was to identify distinctive performance patterns in dyslexic children, providing insights to guide targeted educational and clinical interventions. By elucidating how sensory modalities and language load intersect in dyslexia, our findings aim to support the development of more effective strategies for improving academic performance, attention regulation, and overall learning outcomes.

Methods: This cross-sectional study compared the cognitive performance of children with dyslexia to typically developing controls. Forty participants (20 with a formal dyslexia diagnosis and 20 controls) were recruited from Ziaian Hospital Growth and Development Center in Tehran, Iran through convenience sampling. Dyslexic participants were identified through clinical evaluations confirming reading and phonological impairments, while controls were free from any known learning or psychiatric disorders. Participants were aged between 7 and 12 years, with no uncorrected sensory deficits. Written informed consent was obtained from parents before enrollment.

Cognitive performance was assessed using a custom-built web-based platform, which delivered four tasks targeting attention and perception:

1. Oddball: Identifying rare target stimuli among frequent non-targets.
2. Attentional Blink: Detecting two sequential targets in a rapid stream of stimuli.
3. Posner Cueing: Manipulating spatial attention through cueing.
4. Similarity/Difference: Determining whether two simultaneously presented stimuli were identical.

Each task was administered under four conditions: Visual-Linguistic, Visual-Nonlinguistic, Auditory-Linguistic, and Auditory-Nonlinguistic. A brief introductory session familiarized participants with the platform to minimize procedural errors. Performance metrics included accuracy (percentage of correct responses) and reaction time (RT).
Descriptive statistics summarized participant demographics and overall task performance. Independent t-tests compared accuracy and RT between groups, while repeated-measures ANOVA assessed within-subject effects (linguistic vs. nonlinguistic, visual vs. auditory) and their interaction with group status. Effect sizes (partial eta-squared) quantified the magnitude of observed differences. Statistical significance was set at p < .05, and all analyses were conducted using SPSS (version 26).
Results: Descriptive analyses indicated no significant differences in age or gender distribution between groups (p > .05). The dyslexic cohort had a mean age of 9.26 years (SD = 1.3), while the control group averaged 9.20 years (SD = 1.4). Despite this demographic parity, group comparisons revealed marked differences in performance accuracy (Table 1). Dyslexic children underperformed in all tasks and stimulus types, with the largest gap in Auditory-Linguistic (AL) conditions (p < .01). Nonlinguistic (nL) deficits were also significant (p < .05), suggesting that both linguistic and nonlinguistic stimuli pose challenges; however, combining auditory input with linguistic load created the greatest cognitive burden.

Analysis of reaction time (RT) yielded smaller, yet noteworthy, group effects. Dyslexic children exhibited significantly slower response latencies in the auditory-linguistic condition (p < .05). In contrast, RTs in visual-linguistic and nonlinguistic tasks showed minimal intergroup differences, indicating that the combined auditory and linguistic processing demands uniquely exacerbate processing delays in dyslexia.

• Oddball Task: Participants with dyslexia showed reduced sensitivity to rare auditory-linguistic stimuli, highlighting diminished auditory discrimination under linguistic load.
• Attentional Blink: These children exhibited marked deficits in second-target detection, particularly in trials with embedded linguistic content, reflecting temporal attention impairments.
• Posner Cueing Task: Reduced facilitation from valid spatial cues indicated suboptimal attentional orienting mechanisms.
• Similarity/Difference Task: Elevated error rates in linguistically loaded trials suggested pronounced challenges in perceptual discrimination linked to language processing.

Collectively, the data suggest that dyslexia encompass impairments in both attentional and perceptual domains, particularly when cognitive load involves the integration of auditory and linguistic information. These results support a multifactorial model of dyslexia, extending beyond phonological deficits to include broader sensory-linguistic processing difficulties.
Conclusion: The findings of the present study offer compelling evidence that the cognitive difficulties observed in dyslexia extend beyond phonological deficits, encompassing broader impairments in attention and sensory-perceptual processing. Children with dyslexia demonstrated significantly lower accuracy and slower response times, specifically in auditory-linguistic tasks, suggesting that increased auditory complexity and linguistic load place disproportionate demands on their cognitive systems. In contrast, their performance on visual-linguistic and nonlinguistic tasks remained comparatively intact, reinforcing the hypothesis that auditory-linguistic integration constitutes a particular area of vulnerability. Performance across tasks further illuminated the nature of these impairments. Difficulties in detecting infrequent stimuli in the Oddball and Attentional Blink tasks, along with reduced spatial cue utilization in the Posner cueing task, collectively point to inefficiencies in temporal resolution and attentional allocation. These observations are consistent with neurocognitive theories implicating deficits in temporal processing and magnocellular pathway dysfunction, and they underscore the importance of multisensory integration mechanisms in reading development.
From an applied perspective, the data highlight the need for intervention strategies that address both auditory and visual processing limitations. Multisensory instructional approaches that target rapid information processing and attentional modulation may offer more comprehensive support for reading acquisition. Future investigations should incorporate larger, more demographically diverse cohorts and include individuals with comorbid conditions such as ADHD. Additionally, longitudinal methodologies will be essential to evaluating the sustained efficacy of such interventions.
Collectively, the findings reinforce the notion that dyslexia represent a multifactorial condition, warranting integrated approaches that combine phonological training with attentional and perceptual enhancement to optimize educational outcomes.