Concavity as a diagnostic feature of visual scenes

• Type of Material: Article
• Authors: Daniel Dilks, Emory University; Annie Cheng, Emory University; Dirk B Walther, University of Toronto; Soojin Park, Yonsei University
• Language: English
• Date: 2021-03-10
• Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2021 The Author(s). Published by Elsevier Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neuroimage.2021.117920
• Title of Journal or Parent Work: NEUROIMAGE
• Volume: 232
• Start Page: 117920
• End Page: 117920
• Grant/Funding Information: This work was supported by a National Eye Institute (NEI) grant (R01EY029724) (DDD), an NSERC Discovery Grant (RGPIN-2015-06696) to DBW, and a National Eye Institute (NEI) grant (R01EY026042), National Research Foundation of Korea (NRF) grant (funded by MSIP-2019028919) and Yonsei University Future-leading Research Initiative (2018-22-0184) to SP
• Keywords: High-level vision; Neurosciences; REPRESENTATION; INVARIANCE; Lateral occipital complex; Occipital place area; SENSITIVITY; Parahippocampal place area; CORTEX; Science & Technology; Life Sciences & Biomedicine; OCCIPITAL PLACE AREA; Scene selectivity; OBJECT; fMRI; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging; Neurosciences & Neurology; Scene perception

Abstract

Despite over two decades of research on the neural mechanisms underlying human visual scene, or place, processing, it remains unknown what exactly a “scene” is. Intuitively, we are always inside a scene, while interacting with the outside of objects. Hence, we hypothesize that one diagnostic feature of a scene may be concavity, portraying “inside”, and predict that if concavity is a scene-diagnostic feature, then: 1) images that depict concavity, even non-scene images (e.g., the “inside” of an object – or concave object), will be behaviorally categorized as scenes more often than those that depict convexity, and 2) the cortical scene-processing system will respond more to concave images than to convex images. As predicted, participants categorized concave objects as scenes more often than convex objects, and, using functional magnetic resonance imaging (fMRI), two scene-selective cortical regions (the parahippocampal place area, PPA, and the occipital place area, OPA) responded significantly more to concave than convex objects. Surprisingly, we found no behavioral or neural differences between images of concave versus convex buildings. However, in a follow-up experiment, using tightly-controlled images, we unmasked a selective sensitivity to concavity over convexity of scene boundaries (i.e., walls) in PPA and OPA. Furthermore, we found that even highly impoverished line drawings of concave shapes are behaviorally categorized as scenes more often than convex shapes. Together, these results provide converging behavioral and neural evidence that concavity is a diagnostic feature of visual scenes.