Pupillometry is a robust, non-invasive indicator of cognitive load; however, its application in virtual reality (VR) is compromised by luminance-driven pupillary light reflexes (PLR) that mask subtle task-evoked pupillary responses (TEPR). We introduce a strict iso-luminant VR protocol to isolate cognitive load-related autonomic responses. The framework comprises a PLR validation phase establishing reflex dynamics via controlled luminance alternations, followed by a cognitive isolation phase…
