时间：2026年4月9日（周四）中午 12:30
地点：清华大学吕大龙楼11层1100
报告主题 意识作为由前额叶皮层组织的几何状态空间（Consciousness as a Geometric State Space Organized by Prefrontal Cortex）
报告人：张艺源
内容：
In natural vision, the brain is continuously confronted with competing interpretations of the same sensory input, yet conscious experience remains coherent and structured rather than fragmented. Classical accounts, including Global Workspace Theory, have emphasized selection and amplification, proposing that one representation wins access to a global workspace through ignition and is subsequently broadcast across cortical systems. However, this framework leaves unresolved a fundamental question: what is the format of the information that is being selected, maintained, and broadcast? Here, we address this question by leveraging binocular rivalry, a paradigm in which sensory input is held constant while conscious perception alternates between competing interpretations. Using fMRI and computational modeling, we show that the inferior frontal junction does not merely encode the currently dominant percept. Instead, it organizes competing representations into a low-dimensional, shared representational geometry in which multiple candidate percepts coexist. Within this geometry, the perceptually “mixed” state is not a transient or noisy intermediate, but a compressed and structurally distinct state embedded in a union subspace spanned by stable perceptual attractors. Furthermore, we demonstrate that prefrontal activity reshapes the geometry of this landscape, transforming discrete and segregated attractors into a continuous competition space that supports both switching and return dynamics. These findings suggest that conscious perception is not best understood as the selection of a single representation, but as a position within a structured neural state space defined by prefrontal integration.
