Nordhjem Barbara, Ćurčić-Blake Branislava, Meppelink Anne Marthe, Renken Remco J, de Jong Bauke M, Leenders Klaus L, van Laar Teus, Cornelissen Frans W
Laboratory for Experimental Ophthalmology, University Medical Center Groningen, University of GroningenGroningen, Netherlands; NeuroImaging Center, Department of Neuroscience, University Medical Center Groningen, University of GroningenGroningen, Netherlands.
NeuroImaging Center, Department of Neuroscience, University Medical Center Groningen, University of Groningen Groningen, Netherlands.
Front Hum Neurosci. 2016 Jan 6;9:678. doi: 10.3389/fnhum.2015.00678. eCollection 2015.
Several studies suggest different functional roles for the medial and the lateral sections of the ventral visual cortex in object recognition. Texture and surface information is processed in medial sections, while shape information is processed in lateral sections. This begs the question whether and how these functionally specialized sections interact with each other and with early visual cortex to facilitate object recognition. In the current research, we set out to answer this question. In an fMRI study, 13 subjects viewed and recognized images of objects and animals that were gradually revealed from noise while their brains were being scanned. We applied dynamic causal modeling (DCM)-a method to characterize network interactions-to determine the modulatory effect of object recognition on a network comprising the primary visual cortex (V1), the lingual gyrus (LG) in medial ventral cortex and the lateral occipital cortex (LO). We found that object recognition modulated the bilateral connectivity between LG and LO. Moreover, the feed-forward connectivity from V1 to LG and LO was modulated, while there was no evidence for feedback from these regions to V1 during object recognition. In particular, the interaction between medial and lateral areas supports a framework in which visual recognition of objects is achieved by networked regions that integrate information on image statistics, scene content and shape-rather than by a single categorically specialized region-within the ventral visual cortex.
多项研究表明，腹侧视觉皮层的内侧和外侧部分在物体识别中具有不同的功能作用。纹理和表面信息在内侧部分进行处理，而形状信息在外侧部分进行处理。这就引出了一个问题，即这些功能特化的部分是否以及如何相互作用，以及如何与早期视觉皮层相互作用以促进物体识别。在当前的研究中，我们着手回答这个问题。在一项功能磁共振成像（fMRI）研究中，13名受试者在大脑被扫描时观看并识别从噪声中逐渐显现的物体和动物图像。我们应用动态因果建模（DCM）——一种表征网络相互作用的方法——来确定物体识别对一个由初级视觉皮层（V1）、内侧腹侧皮层的舌回（LG）和枕外侧皮层（LO）组成的网络的调节作用。我们发现物体识别调节了LG和LO之间的双侧连接。此外，从V1到LG和LO的前馈连接受到了调节，而在物体识别过程中没有证据表明这些区域向V1有反馈。特别是，内侧和外侧区域之间的相互作用支持了一个框架，即在腹侧视觉皮层内，物体的视觉识别是由整合图像统计、场景内容和形状信息的网络化区域实现的，而不是由单个分类特化区域实现的。
