Netherlands Institute for Neuroscience , 1105 BA Amsterdam, Netherlands.
Johns Hopkins University , Baltimore, MD, 21218.
eNeuro. 2016 Dec 29;3(6). doi: 10.1523/ENEURO.0127-16.2016. eCollection 2016 Nov-Dec.
Figure-ground organization and border-ownership assignment are essential for understanding natural scenes. It has been shown that many neurons in the macaque visual cortex signal border-ownership in displays of simple geometric shapes such as squares, but how well these neurons resolve border-ownership in natural scenes is not known. We studied area V2 neurons in behaving macaques with static images of complex natural scenes. We found that about half of the neurons were border-ownership selective for contours in natural scenes, and this selectivity originated from the image context. The border-ownership signals emerged within 70 ms after stimulus onset, only ∼30 ms after response onset. A substantial fraction of neurons were highly consistent across scenes. Thus, the cortical mechanisms of figure-ground organization are fast and efficient even in images of complex natural scenes. Understanding how the brain performs this task so fast remains a challenge.
图形-背景组织和边界归属分配对于理解自然场景至关重要。已经表明，猕猴视觉皮层中的许多神经元在显示简单几何形状（如正方形）的显示中会发出边界归属信号，但这些神经元在自然场景中对边界归属的分辨率尚不清楚。我们使用复杂自然场景的静态图像研究了行为猕猴的 V2 区神经元。我们发现，大约一半的神经元对自然场景中的轮廓具有边界归属选择性，并且这种选择性源于图像上下文。边界归属信号在刺激开始后 70 毫秒内出现，仅在响应开始后 30 毫秒左右。相当一部分神经元在不同场景中具有高度一致性。因此，即使在复杂的自然场景图像中，图形-背景组织的皮质机制也非常快速和高效。了解大脑如何如此快速地完成此任务仍然是一个挑战。
