From Sensory Details to Verbal Codes: Visual Memory Reinstatement of Location and Color Features.

Successful episodic memory depends on the reinstatement of encoding content and processes during retrieval. However, it remains unclear how such reinstatement (1) differs for various perceptual features, (2) supports subjective versus objective memory retrieval, and (3) relies on linguistic information. To investigate these three issues, we designed an fMRI study in which participants encoded and recalled the colors and spatial locations of object pictures, and provided subjective vividness and objective precision measures. We used encoding-retrieval similarity (ERS) to identify feature-level reinstatement for location or color features, and trial-specific reinstatement for individual location trials or individual color trials. The study yielded three main findings. First, feature-level reinstatement in frontoparietal and visual regions supported both location and color memory, whereas trial-specific reinstatement in early visual cortex contributed to location memory and feature-level reinstatement in lateral/anterior temporal cortices, to color memory. Second, trial-specific reinstatement in early visual cortex supported both location vividness and precision, while feature-level reinstatement in inferior frontal gyrus contributed to color vividness, and trial-specific reinstatement in posterior inferior temporal gyrus (including the color area), to color precision. Finally, color name richness (the number of names associated with a particular color) enhanced color memory precision and modulated trial-specific color reinstatement in right anterior inferior temporal gyrus. Together, these findings suggest that perceptual and linguistic reinstatement play complementary roles in visual episodic memory: perceptual replay provides fine-grained sensory details, whereas linguistic replay can scaffold and refine these representations, especially for features that are easier to verbalize such as colors.