Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands;
Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands.
Proc Natl Acad Sci U S A. 2019 Mar 12;116(11):5096-5101. doi: 10.1073/pnas.1814504116. Epub 2019 Feb 26.
The specific contents of human consciousness rely on the activity of specialized neurons in cerebral cortex. We hypothesized that the conscious experience of a specific visual motion axis is reflected in response amplitudes of direction-selective clusters in the human motion complex. Using submillimeter fMRI at ultrahigh field (7 T) we identified fine-grained clusters that were tuned to either horizontal or vertical motion presented in an unambiguous motion display. We then recorded their responses while human observers reported the perceived axis of motion for an ambiguous apparent motion display. Although retinal stimulation remained constant, subjects reported recurring changes between horizontal and vertical motion percepts every 7 to 13 s. We found that these perceptual states were dissociatively reflected in the response amplitudes of the identified horizontal and vertical clusters. We also found that responses to unambiguous motion were organized in a columnar fashion such that motion preferences were stable in the direction of cortical depth and changed when moving along the cortical surface. We suggest that activity in these specialized clusters is involved in tracking the distinct conscious experience of a particular motion axis.
人类意识的具体内容依赖于大脑皮层中专门神经元的活动。我们假设，特定视觉运动轴的意识体验反映在人类运动复合体中方向选择性簇的反应幅度上。我们使用超高场 (7T) 的亚毫米 fMRI 来识别对明确运动显示中的水平或垂直运动有调谐的精细簇。然后，当人类观察者报告模糊的明显运动显示的感知运动轴时，我们记录了它们的反应。尽管视网膜刺激保持不变，但受试者每 7 到 13 秒就会报告水平和垂直运动感知之间反复出现的变化。我们发现，这些知觉状态在识别出的水平和垂直簇的反应幅度上分离地反映出来。我们还发现，对明确运动的反应以柱状方式组织，使得运动偏好在皮层深度的方向上稳定，而当沿着皮层表面移动时则会改变。我们认为，这些专门簇的活动参与了跟踪特定运动轴的独特意识体验。
