Liu X, Robinson P A
School of Physics, The University of Sydney, NSW 2006, Australia and Center for Integrative Brain Function, The University of Sydney, NSW 2006, Australia.
Phys Rev E. 2023 Jun;107(6-1):064401. doi: 10.1103/PhysRevE.107.064401.
The primary visual cortex (V1) is the first cortical area that processes visual information relayed from the thalamus. The topologies permitted in joint ocular dominance (OD), orientation preference (OP), and direction preference (DP) maps in V1 are considered, with the aim of finding a maximally symmetric periodic case that can serve as the basis for perturbations toward natural realizations. It is shown that mutual consistency of the maps selects just two possible such lattice structures, and that one of these is much closer to experiment than the other. This comprises a hexagonal lattice of alternating positive and negative OP singularities, with each unit cell or hypercolumn containing four such singularities, each of which radiates three DP discontinuities that follow OP contours and end at OP singularities of opposite sign. Other DP discontinuities emanate at 90 degrees to the midpoints of the ones that link OP singularities, and cross OP contours perpendicularly. These features explain experimentally observed relationships between DP discontinuities and OP contours, including sudden approximately 90-degree changes of direction in the former.
初级视觉皮层（V1）是处理从丘脑传来的视觉信息的第一个皮层区域。我们考虑了V1中联合眼优势（OD）、方向偏好（OP）和方向选择性（DP）图谱所允许的拓扑结构，目的是找到一个最大对称的周期性情况，作为向自然实现进行微扰的基础。结果表明，这些图谱的相互一致性仅选择了两种可能的这种晶格结构，并且其中一种比另一种更接近实验结果。这包括一个由正负交替的OP奇点组成的六边形晶格，每个单元细胞或超柱包含四个这样的奇点，每个奇点发出三个沿着OP轮廓并终止于相反符号的OP奇点的DP不连续性。其他DP不连续性在与连接OP奇点的那些不连续性的中点成90度角的方向发出，并垂直穿过OP轮廓。这些特征解释了实验观察到的DP不连续性与OP轮廓之间的关系，包括前者方向上突然的大约90度变化。
