The central-peripheral dichotomy (CPD, Zhaoping 2017, 2019) is the hypothesis that central vision is mainly devoted to seeing or recognition, peripheral vision is mainly concerned with looking or attentional selection, and top-down feedback to aid seeing is more strongly directed to the central visual field. CPD has led to behavioral predictions, such as illusions that are stronger or only present in the peripheral visual field, that have subsequently been confirmed (Zhaoping & Ackermann 2018, Zhaoping 2020). CPD’s anatomical prediction that central vision should receive more top-down feedback is consistent with functional connectivity data from human functional magnetic resonance imaging (fMRI) (Sims et al 2021). Here, I evaluate CPD further using data from the Human Connectome Project (Benson et al 2018). Firstly, I examine whether, on average, the proportion of fMRI voxels devoted to central visual field locations increases from V1 to V2, V3, V4, IT, etc, along the ventral visual pathway. The rationale is that higher areas along the (recognition-preferring) ventral stream should be more strongly devoted to seeing within the attentional spotlight rather than looking (by shifting gaze to the attended objects). Hence, CPD predicts increasingly higher proportions of voxels for central vision in higher processing levels along the ventral stream. Secondly, I evaluate whether the physical distance (in 3-dimensional space) between retinotopically corresponding locations in different visual cortical areas is on average shorter for cortical locations representing visual locations having smaller eccentricities. The rationale is that the stronger feedback that CPD predicts for the central field, requires more feedback fibers, which, to save space, should be shorter. Preliminary data analyses support both these predictions of CPD.
Acknowledgements: Work supporte by the Max Planck Society and University of Tübingen