Objects, faces, and spaces: Organizational principles of visual object perception as evidenced by individual differences in behavior

What are the diagnostic dimensions on which objects differ visually? We constructed a two-dimensional object space based on such attributes captured by a deep convolutional neural network. These attributes can be approximated as stubby/spiky and animate-/inanimate-looking. If object space contributes to human visual cognition, this should have a measurable effect on object discrimination abilities. We administered an object foraging task to a large, diverse sample (N=511). We focused on the stubby animate-looking "face quadrant" of object space given known variations in face discrimination abilities. Stimuli were picked out of tens of thousands of images to either match or not match with the coordinates of faces in object space. Results show that individual differences in face perception can to a large part be explained by variability in general object perception abilities (o-factor). However, additional variability in face processing can be attributed to visual similarity with faces as captured by dimensions of object space; people who struggle with telling apart faces also have difficulties with discriminating other objects with the same object space attributes. This study is consistent with a contribution of object space to human visual cognition. Public Significance StatementThe study emphasizes individual differences in visual cognition, a relatively neglected field of research. Unlike differences in other cognitive traits (e.g., Big Five personality traits, g-factor of general intelligence), we have limited knowledge on how people differ in their object processing capacity, and whether such abilities are fractionated or unitary. In this study, we ask whether visual object perception abilities are organized around an object space as evidenced by individual differences in behavior.