Combining stimulus types for improved coverage in population receptive field mapping

• Published in: NeuroImage (Orlando, Fla.) Vol. 238; p. 118240
• Main Authors: Linhardt, David, Pawloff, Maximilian, Hummer, Allan, Woletz, Michael, Tik, Martin, Ritter, Markus, Schmidt-Erfurth, Ursula, Windischberger, Christian
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.09.2021; Elsevier Limited; Elsevier
• Subjects: Brain architecture; Brain mapping; Coverage map; fMRI; Functional magnetic resonance imaging; pRF mapping; Receptive field; Retinotopy; Spatial distribution; Topography; Visual field; Visual pathways; Visual stimuli; fMRI; Retinotopy; Visual stimuli; Coverage map; pRF mapping
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2021.118240

Retinotopy experiments using population receptive field (pRF) mapping are ideal for assigning regions in the visual field to cortical brain areas. While various designs for visual stimulation were suggested in the literature, all have specific shortcomings regarding visual field coverage. Here we acquired high-resolution 7 Tesla fMRI data to compare pRF-based coverage maps obtained with the two most commonly used stimulus variants: moving bars; rotating wedges and expanding rings. We find that stimulus selection biases the spatial distribution of pRF centres. In addition, eccentricity values and pRF sizes obtained from wedge/ring or bar stimulation runs show systematic differences. Wedge/ring stimulation results show lower eccentricity values and strongly reduced pRF sizes compared to bar stimulation runs. Statistical comparison shows significantly higher pRF centre numbers in the foveal 2° region of the visual field for wedge/ring compared to bar stimuli. We suggest and evaluate approaches for combining pRF data from different visual stimulus patterns to obtain improved mapping results.