In blindness, PPA-like responses to scene sounds are driven by stronger deactivation for human vocalizations, not activation for scenes

A prominent view is that the parahippocampal place area (PPA) preserves a role in scene perception, regardless of visual experience. This claim is based on findings that in congenitally blind people the medial vOTC (i.e., PPA) responds more to scene sounds (e.g., waves on a beach) than to human vocalizations (e.g., laughter, crying) - so called ‘face sounds’ (e.g., van den Hurk et al., 2017, PNAS). We tested whether in blindness the PPA: 1) responds to place sounds or deactivates to vocalizations, 2) whether the same vertices respond to scene sounds and tactile scenes and 3) whether there is specialization across left/right and anterior/posterior PPA. Fifteen English-speaking, congenitally blind adults performed a 1-back auditory task during fMRI. Conditions were scene sounds (e.g., waves crashing on a beach, city traffic; van den Hurk et al., 2017), non-verbal vocal sounds (e.g., laughter), language (English sentences), and foreign speech (Russian, Korean, Mandarin). The same participants also performed a tactile 1-back task, touching 3D-printed models of scenes and faces (Ratan Murty et al., 2020, PNAS). We replicate the previous finding of greater response to scene sounds than non-verbal vocalizations in medial vOTC. However, this effect is driven by greater deactivation to vocalizations, while responses to scene sounds are below (left PPA) or not different (right PPA) from rest. There is no evidence for anterior/posterior specialization. Responses to tactile scenes in the PPA were either below (left) or barely above rest (right) and no different than in lateral vOTC, where the fusiform face area is typically located. Rather, medial vOTC is distinguished from lateral vOTC by its deactivation to vocalizations. Results are not consistent with a role of medial vOTC for perception of places in blindness. We find no evidence that this region preserves its function for scene perception in the absence of visual experience.