The neural basis of preference for curvature in architecture

People prefer curvilinear over angular visual forms, across different object categories, including architectural scenes (Chuquichambi et al, 2022). It has been proposed that curvilinear forms were associated with rewarding experiences in our evolutionary history, thus, they strongly influence our behaviours towards objects (Bar & Neta, 2006). What is the neural basis of curvature processing in the visual cortex? Yue et al. (2020) made important inroads in answering this question by investigating regions of the brain that exhibit sensitivity to curvature while participants passively viewed images in the fMRI scanner and found that activation in early visual areas and the temporal cortex is modulated by curvature. We extended these findings to curvature processing while participants made active judgements about architectural scenes. We reanalyzed fMRI data collected from participants while they engaged in beauty judgements (beautiful/not beautiful) or approach-avoidance decisions (enter/exit) in relation to images of architectural interiors (Vartanian et al., 2013). Adopting a computational approach, we obtained a normalized metric to measure curvature variation in each image and used a parametric analysis to examine the co-variation between curvature and brain activation, correcting for luminance and contrast. The results show that bilateral activation in early visual areas covaried with curvature, and critically, inferior occipital gyrus (BA 17/18) exhibited sensitivity to curvature under both conditions. This finding suggests that early visual areas respond to variation in curvature while people are actively engaged in hedonic and utilitarian valuations of architecture.