Participants watched natural videos while maintaining gaze fixation, and EEG signals were recorded across three tasks that manipulated object eccentricity — the distance between a visual object and the fixation point — and attention conditions. The team used correlation analysis and match-mismatch decoding to quantify neural tracking of object motion.
The analysis supports three conclusions: neural tracking of object motion in natural videos works under gaze fixation; the strength of that tracking is modulated by attention; and there is a significant eccentricity confound in the EEG responses, with poorer neural tracking of motion at larger eccentricities.
The researchers say the findings indicate that results from previous free-viewing studies reflect genuine neural processing rather than mere oculomotor artifacts. But the eccentricity effect also highlights a major limitation for current decoding approaches, which assume coupling strength reflects attention levels alone.
The authors are Yao Y, Salamanca González C, Geirnaert S, Gillebert CR, Tuytelaars T and Bertrand A, affiliated with the KU Leuven STADIUS Center for dynamic systems signal processing and data analysis, KU Leuven Brain and Cognition, and KU Leuven Processing Speech And Images. The DOI is 10.1088/1741-2552/aea449 and the PubMed ID is 42710532.