title: Neural Responses to Central and Peripheral Objects in the Lateral Occipital Cortex.
abstract: Human object recognition and classification depend on the retinal location where the object is presented and decrease as eccentricity increases. The lateral occipital complex (LOC) is thought to be preferentially involved in the processing of objects, and its neural responses exhibit category biases to objects presented in the central visual field. However, the nature of LOC neural responses to central and peripheral objects remains largely unclear. In the present study, we used functional magnetic resonance imaging (fMRI) and a wide-view presentation system to investigate neural responses to four categories of objects (faces, houses, animals, and cars) in the primary visual cortex (V1) and the lateral visual cortex, including the LOC and the retinotopic areas LO-1 and LO-2. In these regions, the neural responses to objects decreased as the distance between the location of presentation and center fixation increased, which is consistent with the diminished perceptual ability that was found for peripherally presented images. The LOC and LO-2 exhibited significantly positive neural responses to all eccentricities (0-55°), but LO-1 exhibited significantly positive responses only to central eccentricities (0-22°). By measuring the ratio relative to V1 (RRV1), we further demonstrated that eccentricity, category and the interaction between them significantly affected neural processing in these regions. LOC, LO-1, and LO-2 exhibited larger RRV1s when stimuli were presented at an eccentricity of 0° compared to when they were presented at the greater eccentricities. In LOC and LO-2, the RRV1s for images of faces, animals and cars showed an increasing trend when the images were presented at eccentricities of 11 to 33°. However, the RRV1s for houses showed a decreasing trend in LO-1 and no difference in the LOC and LO-2. We hypothesize, that when houses and the images in the other categories were presented in the peripheral visual field, they were processed via different strategies in the lateral visual cortex.
authors.affiliation: College of Computer Science and Technology, Taiyuan University of Technology Taiyuan, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University Okayama, Japan.
authors.forename: Jiayue
authors.initials: J
authors.lastname: Guo
authors.affiliation: School of Life Science, Beijing Institute of TechnologyBeijing, China; Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, The Ministry of Industry and Information Technology, Beijing Institute of TechnologyBeijing, China.
authors.forename: Tianyi
authors.initials: T
authors.lastname: Yan
authors.affiliation: Department of Radiology, Okayama University Hospital, Okayama University Okayama, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ohno
authors.affiliation: Graduate School of Medicine, Dentistry, Pharmaceutical Sciences, Okayama University Okayama, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
authors.affiliation: Key Laboratory of Biomimetic Robots and Systems, Ministry of Education, Beijing Institute of Technology Beijing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Key Laboratory of Biomimetic Robots and Systems, Ministry of Education, Beijing Institute of TechnologyBeijing, China; Graduate School of Natural Science and Technology, Okayama UniversityOkayama, Japan.
authors.forename: Jinglong
authors.initials: J
authors.lastname: Wu
keywords: fMRI; lateral occipital cortex; object category; retinotopic maps; wide-view visual field