Spatial interactions in upright and inverted faces: Re-exploration of spatial scale influence

Face features are hardly processed in isolation; they rather strongly interact over space. Spatial interactions are strong at upright, but not inverted orientation. Recent evidence indicated spatial interactions root in the low spatial frequencies (LSF) of face stimulus. Here, a balanced congruency paradigm was employed with upright and inverted filtered faces to circumvent the limits of previous investigations. Results confirm the LSF predominant contribution to spatial interactions and exclude lesser local information availability or methodological confounds as alternative accounts. Results further show that spatial interactions are driven by LSF, independently of the spectral properties of the attended face region.