Perception and Action Lab, Department of Psychology, University of Manitoba, Winnipeg, Canada.
Thunder Bay Regional Health Research Institute, Ontario, Canada.
Perception. 2020 May;49(5):495-514. doi: 10.1177/0301006620912134.
Grouping local elements of the visual environment together is crucial for meaningful perception. While our attentional system facilitates perception, it is limited in that we are unaware of some aspects of our environment that can still influence how we experience it. In this study, the neural mechanisms underlying the Ponzo illusion were examined under inattention and divided-attention conditions using functional magnetic resonance imaging to investigate the brain regions responsible for accessing visual stimuli. A line discrimination task was performed in which two horizontal lines were superimposed on a background of black and white dots that, on occasion, induced the Ponzo illusion if perceptually grouped together. Our findings revealed activation for perceptual grouping in the frontal, parietal, and occipital regions of the brain and activation in the bilateral frontal, temporal, and cingulate gyrus in response to divided attention compared with inattention trials. A direct comparison between grouping and attention showed involvement of the right supramarginal gyrus in grouping specifically under conditions of inattention, suggesting that even during implicit grouping complex visual processing occurs. Given that much of the visual world is not represented in conscious perception, these findings provide crucial information about how we make sense of visual scenes in the world.
将视觉环境的局部元素组合在一起对于有意义的感知至关重要。虽然我们的注意力系统有助于感知，但它是有限的，因为我们无法意识到环境的某些方面仍然会影响我们对它的体验。在这项研究中，使用功能磁共振成像在不注意和分散注意力条件下检查了庞佐错觉的神经机制，以研究负责访问视觉刺激的大脑区域。进行了线辨别任务，其中两条水平线叠加在黑白点的背景上，如果知觉上组合在一起，有时会引起庞佐错觉。我们的发现揭示了大脑额叶、顶叶和枕叶的知觉分组激活，以及与不注意试验相比，双侧额叶、颞叶和扣带回回的注意力分散激活。分组和注意力的直接比较显示，右缘上回在不注意条件下特别是在分组中涉及，这表明即使在隐含分组的情况下，也会发生复杂的视觉处理。鉴于大部分视觉世界并未在有意识的感知中呈现，这些发现提供了有关我们如何理解世界中视觉场景的重要信息。
