The processing of feature discontinuities for different cue types in primary visual cortex.
The processing of feature discontinuities for different cue types in primary visual cortex.
复制标题
初级视觉皮层中不同提示类型的特征不连续性的处理。
DOI：
10.1016/j.brainres.2008.08.029
复制
发表时间：
2008
期刊：
影响因子：
2.9
通讯作者：
Schmid,AnitaM
中科院分区：
文献类型：
--
作者：
Schmid,AnitaM
本研究探讨了猫的初级视觉皮层（V1）（也称为17区）中的神经元是否对由亮度对比度以外的特征差异划定的边界敏感。关于这个问题的大多数研究都集中在对纹理边界（例如“虚幻轮廓”）的反应上，并发现神经元对V2中的这种边界敏感，而在V1中的程度较小。在这里，猫区域17（V1）中的神经元暴露于与神经元的取向偏好倾斜的边界，该边界由两个漂移正弦波光栅的相位、取向或运动方向的差异产生。在麻醉猫的17区（V1）记录的98个神经元中有15个神经元的近相位边界引起了放电增加，98个神经元中有18个神经元的方向边界引起了放电增加，70个神经元中有15个神经元的方向边界引起了放电增加。这些神经元的放电率增强时，一个功能边界呈现接近其感受野，部分独立的线索。对比边界的对照实验表明，增强的发射是由于释放抑制，而不是促进。提出了一个概念模型，可以描述的数据和揭示的特性相域相比，方向和方向域。该模型统一了在这里获得的知识，特定方向的中心-周围的相互作用，上下文的影响，和结束停止。数据和模型表明，这些现象是一个单一机制的一部分，该机制使大脑能够检测到一系列特征的特征不连续性。
This study examines whether neurons in the primary visual cortex (V1) of the cat (also referred to as area 17) are sensitive to boundaries that are delineated by a difference in features other than luminance contrast. Most research on this issue has concentrated on the responses to texture borders (e.g. ‘illusory contours’) and has found neurons that are sensitive to such borders in V2 and to a lesser extent in V1. Here neurons in cat area 17 (V1) were exposed to borders that were oblique to the orientation preference of the neuron and that were created by differences in phase, orientation or direction of motion of two drifting sinewave gratings. Nearby phase borders evoked increased firing in 15 out of 98 neurons, orientation borders in 18 out of 98, and direction borders in 15 out of 70 neurons recorded in area 17 (V1) of anesthetized cats. The firing rates of these neurons were enhanced when a feature border was presented close to their receptive field, partly independent of the cue involved. Control experiments with a contrast border showed that the enhanced firing was due to a release of suppression rather than facilitation. A conceptual model is presented that can describe the data and uncovers a peculiarity of the phase domain compared to the orientation and direction domain. The model unifies the knowledge gained here about orientation-specific center–surround interactions, contextual effects, and end-stopping. The data and model suggest that these phenomena are part of a single mechanism that enables the brain to detect feature discontinuities across a range of features.