Barton Brian, Brewer Alyssa A
Department of Cognitive Sciences, University of California, Irvine, Irvine CA, USA.
Department of Cognitive Sciences, University of California, Irvine, IrvineCA, USA; Department of Linguistics, University of California, Irvine, IrvineCA, USA; Center for Hearing Research, University of California, Irvine, IrvineCA, USA.
Front Integr Neurosci. 2017 Feb 28;11:4. doi: 10.3389/fnint.2017.00004. eCollection 2017.
The cortical hierarchy of the human visual system has been shown to be organized around retinal spatial coordinates throughout much of low- and mid-level visual processing. These regions contain visual field maps (VFMs) that each follows the organization of the retina, with neighboring aspects of the visual field processed in neighboring cortical locations. On a larger, macrostructural scale, groups of such sensory cortical field maps (CFMs) in both the visual and auditory systems are organized into roughly circular cloverleaf clusters. CFMs within clusters tend to share properties such as receptive field distribution, cortical magnification, and processing specialization. Here we use fMRI and population receptive field (pRF) modeling to investigate the extent of VFM and cluster organization with an examination of higher-level visual processing in temporal cortex and compare these measurements to mid-level visual processing in dorsal occipital cortex. In human temporal cortex, the posterior superior temporal sulcus (pSTS) has been implicated in various neuroimaging studies as subserving higher-order vision, including face processing, biological motion perception, and multimodal audiovisual integration. In human dorsal occipital cortex, the transverse occipital sulcus (TOS) contains the V3A/B cluster, which comprises two VFMs subserving mid-level motion perception and visuospatial attention. For the first time, we present the organization of VFMs in pSTS in a cloverleaf cluster. This pSTS cluster contains four VFMs bilaterally: pSTS-1:4. We characterize these pSTS VFMs as relatively small at ∼125 mm with relatively large pRF sizes of ∼2-8° of visual angle across the central 10° of the visual field. V3A and V3B are ∼230 mm in surface area, with pRF sizes here similarly ∼1-8° of visual angle across the same region. In addition, cortical magnification measurements show that a larger extent of the pSTS VFM surface areas are devoted to the peripheral visual field than those in the V3A/B cluster. Reliability measurements of VFMs in pSTS and V3A/B reveal that these cloverleaf clusters are remarkably consistent and functionally differentiable. Our findings add to the growing number of measurements of widespread sensory CFMs organized into cloverleaf clusters, indicating that CFMs and cloverleaf clusters may both be fundamental organizing principles in cortical sensory processing.
人类视觉系统的皮质层级结构已被证明，在大部分低、中级视觉处理过程中，是围绕视网膜空间坐标组织起来的。这些区域包含视野图（VFM），每个视野图都遵循视网膜的组织方式，视野的相邻部分在相邻的皮质位置进行处理。在更大的宏观结构尺度上，视觉和听觉系统中此类感觉皮质场图（CFM）的组被组织成大致圆形的三叶草叶状簇。簇内的CFM往往具有共同的特性，如感受野分布、皮质放大率和处理特化。在这里，我们使用功能磁共振成像（fMRI）和群体感受野（pRF）建模，通过检查颞叶皮质中的高级视觉处理来研究VFM和簇组织的程度，并将这些测量结果与枕叶背侧皮质中的中级视觉处理进行比较。在人类颞叶皮质中，后颞上沟（pSTS）在各种神经影像学研究中被认为与高阶视觉有关，包括面部处理、生物运动感知和多模态视听整合。在人类枕叶背侧皮质中，枕横沟（TOS）包含V3A/B簇，该簇由两个视野图组成，用于中级运动感知和视觉空间注意。我们首次展示了pSTS中三叶草叶状簇内的视野图组织。这个pSTS簇双侧包含四个视野图：pSTS-1:4。我们将这些pSTS视野图的特征描述为相对较小，面积约为125平方毫米，在视野中央10°范围内，其pRF大小相对较大，约为2-8°视角。V3A和V3B的表面积约为230平方毫米，在同一区域的pRF大小同样约为1-8°视角。此外，皮质放大率测量表明，与V3A/B簇相比，pSTS视野图表面积的更大范围用于外周视野。pSTS和V3A/B中视野图的可靠性测量表明，这些三叶草叶状簇非常一致且在功能上具有可区分性。我们的研究结果增加了对组织成三叶草叶状簇的广泛感觉CFM的测量数量，表明CFM和三叶草叶状簇可能都是皮质感觉处理中的基本组织原则。
