Wang Bin, Guo Jiayue, Yan Tianyi, Ohno Seiichiro, Kanazawa Susumu, Huang Qiang, Wu Jinglong
College of Computer Science and Technology, Taiyuan University of Technology Taiyuan, China.
Graduate School of Natural Science and Technology, Okayama University Okayama, Japan.
Front Hum Neurosci. 2016 Feb 19;10:54. doi: 10.3389/fnhum.2016.00054. eCollection 2016.
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.
人类的物体识别和分类取决于物体呈现的视网膜位置，并随着离心率的增加而降低。枕外侧复合体（LOC）被认为优先参与物体的处理，其神经反应对中央视野中呈现的物体表现出类别偏好。然而，LOC对中央和周边物体的神经反应的本质在很大程度上仍不清楚。在本研究中，我们使用功能磁共振成像（fMRI）和宽视角呈现系统，研究了初级视觉皮层（V1）和外侧视觉皮层（包括LOC以及视网膜拓扑区域LO-1和LO-2）对四类物体（面部、房屋、动物和汽车）的神经反应。在这些区域中，对物体的神经反应随着呈现位置与中心注视点之间距离的增加而降低，这与周边呈现图像的感知能力下降是一致的。LOC和LO-2对所有离心率（0-55°）均表现出显著的正向神经反应，但LO-1仅对中央离心率（0-22°）表现出显著的正向反应。通过测量相对于V1的比率（RRV1），我们进一步证明离心率、类别及其之间的相互作用显著影响这些区域的神经处理。与在较大离心率下呈现刺激相比，当刺激在离心率为°时呈现时，LOC、LO-1和LO-2表现出更大的RRV1。在LOC和LO-2中，当面部、动物和汽车图像在离心率为11至33°时呈现时，RRV1呈上升趋势。然而，房屋图像的RRV1在LO-1中呈下降趋势，在LOC和LO-2中没有差异。我们假设，当房屋和其他类别中的图像在外周视野中呈现时，它们在外侧视觉皮层中通过不同的策略进行处理。
