Visual tracking efficiency across different spacing widths: a text-free eye-tracking study

This study examined how spatial spacing influences visual tracking efficiency using a novel text-free eye-tracking paradigm designed to minimize the influence of reading-related processes. Twenty participants visually followed straight, curved, and angular paths with five different widths (0.5-3 cm), while eye movements were recorded using a Tobii Eye Tracker T120. Results showed that narrow angular paths (0.5-1 cm) were associated with significantly higher fixation counts and longer fixation durations compared to wider angular paths and other paths. For angular paths, fixation counts differed significantly between 0.5 cm and 2.5 cm (p = .005), and between 0.5 cm and 3 cm (p = .003). Total fixation counts and total fixation durations were significantly greater for angular paths than for straight and curved paths. The findings indicate that narrower spatial constraints increase visual-perceptual load and reduce oculomotor fluency, whereas moderate spacing (approximately 2.5 cm) facilitates smoother visual guidance. The results are limited to visual tracking and oculomotor control within constrained geometric layouts and do not reflect reading behavior. The study highlights the utility of text-free visual tracking tasks for isolating low-level perceptual and oculomotor processes and informing future research on spatial layout and visual guidance in digital environments.