INTRODUCTION: Checkerboard stimulation is a classical method for eliciting visual cortex activation. Three-dimensional (3D) environments have been shown to enhance cortical responses compared to two-dimensional stimuli. However, there is a lack of informations about age-related differences in occipital responses to dynamic 3D stimulation in virtual reality (VR).

AIM(S): The aim of this study was to evaluate visual cortex responses to a moving 3D checkerboard stimulus presented in VR and to compare response patterns in younger and older neurologically healthy individuals.

METHOD(S): The stimulus was an 8 Hz flickering checkerboard mapped onto a sphere in VR, moving alternately from the center to the left and right (10 repetitions per direction; 20 cycles total). Each 15 s stimulation block was followed by 20 s of a black screen. Visual cortex activity was recorded using fNIRS, and changes in oxygenated (HbO) and deoxygenated hemoglobin (HbR) were analyzed with a general linear model and random effects analysis.

RESULTS: In the younger group, dynamic 3D stimulation elicited robust bilateral occipital activation, with significant HbO increases and HbR decreases relative to baseline. Responses were spatially consistent at the group level. In older adults, activation was present individually but less spatially consistent and not stable at the group level. No global hemispheric dominance was observed. Greater variability in older adults aligns with reports of age-related functional reorganization and increased inter-individual variability.

CONCLUSIONS: Dynamic 3D checkerboard stimulation in VR effectively activates the visual cortex, particularly in younger adults. The greater spatial variability observed in the older group may reflect age-related functional reorganization. These findings provide a basis for further development of VR applications targeting visual stimulation, including future rehabilitation applications for patients with hemispatial neglect.

FINANCIAL SUPPORT: The publication was funded by Project No. FESL.10.25-IZ.01-07E7/23.