Abstract
We examined the relationship between anatomy, category selectivity, and retinotopy in ventral visual cortex of 13 subjects using fMRI. Each subject participated in 3 experiments: 1) a functional localizer identifying face- and place-selective regions, 2) phase-encoded retinotopy to define retinotopic maps, & 3) an experiment where faces or houses were presented either foveally or peripherally to examine the relationship between category selectivity and eccentricity preference (Levy 2001). First, we replicate previous findings regarding the organization of ventral visual cortex including: 1) multiple face patches: IOG, mFus, pFus, and aFus (Weiner, 2010,Tsao 2008, Rajimehr, 2009), 2) hV4/VO organization (Brewer 2005), 3) overlap of parahippocampal (PHC) visual field maps with the PPA (Arcaro 2009), and 4) alignment of eccentricity preferences with category selectivity (Levy 2001). Second, we integrated these findings with anatomical constraints into a single organization extending that of Weiner 2010 by including: 1) Posterior posterior transverse collateral sulcus (COS) to guide the location of hV4/VO and face-selective IOG, 2) anterior transverse COS to distinguish between mFus and aFus, 3) posterior extent of the hippocampus as landmark for the anterior extent of retinotopy, a boundary between mFus and aFus patches, and marking where place selectivity spreads from the COS onto the PHC, and 4) alignment of face patches with distinct retinotopic clusters (hV4, VO, PHC).Third, we examined the eccentricity preferences of face and place regions finding 1) increased position tolerance from posterior to anterior with different preferences across IOG, pFus, mFus and aFus face patches and position invariance in place-selective regions appearing only anterior to visual field maps, and 2) different pattern of eccentricity bias for face and place-selective regions. The results bear directly on systematically defining commonly used functional regions (FFA, PPA), and suggest a hierarchical axis of visual processing from posterior to anterior in ventral cortex.
Meeting abstract presented at VSS 2012