Retinotopic coding organizes the interaction between internally and externally oriented brain networks.

Retinotopic coding reveals voxel-level interactions between internal and external brain networks, with 70% of voxels showing retinotopically specific coupling.

• Why it matters: Understanding how the brain integrates internally generated thoughts with sensory input is crucial, as the default network (DN) and dorsal attention network (dATN) are traditionally seen as independent, limiting insights into their coordination.
• What they did: Using densely sampled 7T fMRI, individualized resting-state parcellations, and voxel-wise population-receptive-field mapping, the study examined retinotopic preferences and spontaneous coupling across these networks.
• The result: Findings demonstrate that retinotopic coding underpins voxel-specific interactions, with retinotopically aligned voxels showing stronger coupling, enabling dynamic perception-thought coordination even during elevated DN activity.