A MODULAR PLATFORM FOR MULTI-SENSORY DECISION-MAKING AND CHRONIC CORTICAL WIDEFIELD IMAGING

Studying brain-wide networks during multisensory decision-making requires precise control of sensory inputs and behavior. We therefore developed a modular behavioral platform for mice, enabling controlled multimodal stimulation that is compatible with optical and electrophysiological recordings. The system uses two movable reward spouts for lick-based choice reporting. Spout movements provide an explicit response cue, allowing temporal separation of sensory stimulation and choice reporting while reducing training time.
Using this setup, we trained ~40 mice on a visuo-tactile discrimination task and observed multisensory learning within 2-4 weeks. Animals achieved high task performance in both sensory modalities, with most showing a behavioral bias toward tactile over visual stimuli. Following unimodal training, mice immediately exhibited enhanced performance during multisensory stimulation, indicating effective integration of visual and tactile information.
We next performed cortex-wide functional imaging throughout multisensory learning to identify cortical signatures of task acquisition. To analyze these large-scale data, we developed an automated pipeline for preprocessing and aligning imaging data to the Allen Brain Atlas, enabling standardized cross-animal and cross-session comparisons. We then projected all data across sessions and animals into a common low-dimensional space to track learning-related changes in brain-wide dynamics. Learning was associated with increased signatures of sensory evidence accumulation in parietal and frontal regions, while choice-related dynamics remained largely stable.
Together, this framework supports systematic investigation of distributed cortical dynamics during decision-making and is extensible to complementary recording modalities. Overall, the platform provides a flexible, scalable, and reproducible approach for combining head-fixed behavior with large-scale neural recordings to study multisensory decision-making.