Sun Meirong, Huang Jing, Wang Fang, An An, Tian Fenghua, Liu Hanli, Niu Haijing, Song Yan
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
Neuroreport. 2013 May 8;24(7):354-8. doi: 10.1097/WNR.0b013e32835f680b.
Evidence has been accumulated for over a century indicating that the visual system of humans and many animals is more sensitive to contour stimulation at vertical or horizontal orientations than oblique orientations. However, the neural basis for this orientation anisotropy is still a subject of debate. In the present study, we recorded brain activity over the parietal-occipital and frontal lobes with functional near-infrared spectroscopy (fNIRS) when human participants were presented with gratings in different orientations. The oblique gratings induced a much larger change in the oxygenated hemoglobin concentration than vertical and horizontal gratings in the left occipital lobe. However, we did not find any significant orientation anisotropy in the frontal lobe. Our study showed that different quantitative changes in the hemoglobin concentrations occurred in response to differently oriented stimuli in the visual cortex and that fNIRS could potentially be a valuable tool in the assessment of the hemodynamic responses of the visual system.
一个多世纪以来，已有证据表明，人类和许多动物的视觉系统对垂直或水平方向的轮廓刺激比倾斜方向更为敏感。然而，这种方向各向异性的神经基础仍是一个争论的话题。在本研究中，当人类参与者面对不同方向的光栅时，我们使用功能近红外光谱技术（fNIRS）记录了顶枕叶和额叶的大脑活动。与垂直和水平光栅相比，倾斜光栅在左枕叶引起的氧合血红蛋白浓度变化要大得多。然而，我们在额叶未发现任何显著的方向各向异性。我们的研究表明，视觉皮层中不同方向的刺激会引起血红蛋白浓度的不同定量变化，并且fNIRS可能是评估视觉系统血流动力学反应的一种有价值的工具。
