Sampling Rate Guidelines for Eye-Tracking in Neurological Disorders: A Task-Specific Multimetric Analysis

Variations in eye-tracking sampling rates across devices pose challenges for research characterizing Neurodegenerative Disorders (ND) where precise measurement of eye movements is essential for detection of disease-specific features. This study proposes three metrics-TOST Test Equivalence (TTE), Mean Absolute Error Percentage (MAE%), and Kullback-Leibler Divergence (KLD)-to systematically evaluate how downsampling impacts data quality and feature integrity. Applied to three common tasks (prosaccade, text reading, picture description), results revealed task-specific sampling rate requirements: ⩾400Hz preserved saccadic dynamics in prosaccade, while cognitively complex reading and picture description tasks demanded ⩾600Hz to maintain fidelity. Downsampling degraded key features that are salient to differentiating neurological disorders. ⩾200Hz is required to maintain the discriminative power of key saccade and fixation features. We propose task- and feature-specific recommendations for sampling selection to balance analytical rigor with practical constraints. These findings provide actionable guidelines for standardizing eye-tracking protocols in behavioral research, enhancing reproducibility and robust cross-study comparisons and biomarker validation.Clinical relevanceThis study provides guidelines for selecting eye-tracking sampling rates to ensure reliable detection of disease-specific eye movement features in Alzheimer's, Parkinson's, and related disorders.