Gattass Ricardo, Nascimento-Silva Sheila, Soares Juliana G M, Lima Bruss, Jansen Ana Karla, Diogo Antonia Cinira M, Farias Mariana F, Botelho Marco Marcondes Eliã P, Mariani Otávio S, Azzi João, Fiorani Mario
Departamento de Neurobiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G, CCS, Ilha do Fundão, Rio de Janeiro, RJ 21941-900, Brazil.
Philos Trans R Soc Lond B Biol Sci. 2005 Apr 29;360(1456):709-31. doi: 10.1098/rstb.2005.1629.
The visual system is constantly challenged to organize the retinal pattern of stimulation into coherent percepts. This task is achieved by the cortical visual system, which is composed by topographically organized analytic areas and by synthetic areas of the temporal lobe that have more holistic processing. Additional visual areas of the parietal lobe are related to motion perception and visuomotor control. V1 and V2 represent the entire visual field. MT represents only the binocular field, and V4 only the central 30 degrees-40 degrees. The parietal areas represent more of the periphery. For any eccentricity, the receptive field grows at each step of processing, more at anterior areas in the temporal lobe. Minimal point image size increases towards the temporal lobe, but remains fairly constant toward the parietal lobe. Patterns of projection show asymmetries. Central V2 and V4 project mainly to the temporal lobe, while peripherals V2 (more than 30 degrees) and V4 (more than 10 degrees) also project to the parietal lobe. Visual information that arrives at V1 projects to V2, MT and PO, which then project to other areas. Local lateral propagation and recursive loops corroborate to perceptual completion and filling in. Priority connections to temporal, parietal and parieto-temporal cortices help construct crude early representations of objects, trajectories and movements.
视觉系统一直面临着将视网膜上的刺激模式组织成连贯感知的挑战。这项任务由皮质视觉系统完成，该系统由按地形组织的分析区域以及颞叶中具有更整体处理功能的合成区域组成。顶叶的其他视觉区域与运动感知和视觉运动控制有关。V1和V2代表整个视野。MT仅代表双眼视野，V4仅代表中央30度至40度。顶叶区域代表更多的周边区域。对于任何偏心率，感受野在处理的每个步骤中都会扩大，在颞叶的前部区域扩大得更多。最小点图像尺寸向颞叶方向增加，但向顶叶方向保持相当恒定。投射模式显示出不对称性。中央V2和V4主要投射到颞叶，而周边的V2（超过30度）和V4（超过10度）也投射到顶叶。到达V1的视觉信息投射到V2、MT和PO，然后它们再投射到其他区域。局部横向传播和递归回路有助于感知完成和填补。与颞叶、顶叶和顶颞皮质的优先连接有助于构建物体、轨迹和运动的粗略早期表征。
