Hyunwoo Gu
hyunwoogu.bsky.social
Hyunwoo Gu
@hyunwoogu.bsky.social
Ph.D. student at Stanford. Interested in how the brain makes sense of the world.
Trained RNNs suggest possible mechanisms. First, asymmetric feedback from decision to memory populations push memory states toward the chosen directions. Second, a warped representational geometry of orientations induces drift, amplifying decision-consistent bias near diverging stimuli. (11/13)
July 29, 2025 at 4:02 PM
Next, going beyond sparse behavioral measurements, we tracked working memory states using simultaneously recorded BOLD signals from early visual cortex. Combined decoding and event-based analyses reveal neural signatures consistent with our drift-diffusion scenario. (9/13)
July 29, 2025 at 4:02 PM
The model makes nuanced predictions about how bias evolves after choice. First, earlier decisions during a delay allow more time for decision-consistent biases to grow. Second, this growth is pronounced near diverging points, and reduced around attractors—consistent with human behavior. (8/13)
July 29, 2025 at 4:02 PM
We tested our model predictions with a paradigm where participants performed both discrimination and estimation tasks on the same stimulus. Long delays between tasks allowed us to track slow memory dynamics through both behavior and fMRI. (5/13)
July 29, 2025 at 4:02 PM
We modeled these scenarios using a drift-diffusion framework constrained by efficient coding. Drift shifts memory in a stimulus-specific way and can amplify the decision-consistent bias by biasing the choice and then continuing to bias memory in line with that choice. (4/13)
July 29, 2025 at 4:02 PM