Transdiagnostic eye-tracking biomarkers of inattention across psychiatric disorders: a systematic review.

BACKGROUND: Attention impairment is a dimensional and heterogeneous trait, distributed continuously across the population. Understanding the pathophysiology of eye movement control offers valuable insight into attention dysfunctions and their underlying neural circuits. This systematic review aims to map different oculomotor paradigms and metrics to key attention systems across a range of psychiatric conditions, highlighting their potential for identifying biological markers of attention. METHODS: We conducted a systematic search on PubMed, Scopus, and Web of Science databases using keywords related to ‘eye-tracking,’ ‘(in)attention,’ and ‘mental disorders.’ Seventy-five studies were included, categorized into three core domains of attention: Selective Attention (spatial/feature), Sustained Attention, and Executive Control, based on the associated oculomotor paradigms. These studies covered various psychiatric conditions, including Attention Deficit Hyperactivity Disorder (ADHD), Autism Spectrum Disorder (ASD), Tourette Syndrome (TS), Obsessive-Compulsive Disorder (OCD), Borderline Personality Disorder (BPD), Developmental Coordination Disorder (DCD), and Schizophrenia Spectrum and Other Psychotic Disorders (SSD). RESULTS: The findings highlighted impairments in several key oculomotor metrics shared across psychiatric conditions, and moderately correlated with self-reported and behavioral measures of inattention symptoms. These include antisaccade direction errors, fixation durations on task-relevant/irrelevant areas, the latency to first fixation, and anticipatory and intrusive saccades. These metrics are particularly important in paradigms requiring endogenous shifts of attention. CONCLUSIONS: Eye-tracking metrics could serve as transdiagnostic biomarkers for identifying inattention symptoms across normative and psychiatric conditions. Further research is needed to transition eye-tracking from a research tool to a clinically actionable biomarker for personalized assessment and intervention.