Kramer, L. E.; Cohen, M. R.

Visual experience is organized in time. When riding the same bus route each day, the visual scene unfolds in a predictable order without requiring active choice. During goal-directed behavior, individuals organize actions into routines, such as repeatedly walking the same route to work even when alternatives are equally efficient. Because experience unfolds across sequences of events, identifying how it reshapes population activity requires examining representations over time. Many studies have shown that repeated experience reduces mean firing rates in visual cortex1-14. While firing rates effectively signal novelty or repetition, they are not well positioned to describe how populations of neurons represent temporal relationships. A growing body of work suggests that the geometry of population activity provides additional insight into how visual information is structured and read out15-26. We examined how experience with temporal structure reshapes the geometry of population activity in visual area V4. We recorded neuronal populations across three contexts that varied in temporal structure and behavioral relevance: repeated presentation of individual images, passive exposure to structured image sequences, and repeated execution of self-chosen visually guided action sequences for reward. Across contexts, experience constrained population responses toward a typical activity pattern. In sequence contexts, experience made temporal position more linearly accessible and, during active practice, increased the separability of task-relevant variables. These findings show that experience reorganizes the geometry of visual population activity to reflect temporal structure, constraining responses and altering how sequence-related information is represented.