Sensorimotor neuronal learning requires cortical topography

Topographic representations of the peripheral sensory organs are a prominent feature of primary sensory areas in the cerebral cortex. In particular, the whisker representation in the primary somatosensory cortex of rodents is composed of spatially distinct 9barrel9 columns, each corresponding to a different whisker on the snout. Although the relationship between the sensory coding properties of neurons and their position in the barrel map has been extensively studied, the functional role of cortical maps remains unclear. We hypothesize that the body map in the primary somatosensory cortex is a framework for the integration of sensory information into motor control. First, we trained head-fixed mice in a cortical closed-loop brain-machine interface task where learning necessitates the integration of sensory feedback. Second, we show that in this task a biomimetic, topographic organization of the sensory feedback is required for learning. Finally, we show that enhanced performance in the biomimetic feedback condition correlates with improved motor control. Overall our findings support the view that cortical maps are necessary for optimal cortical sensorimotor integration. They should therefore be fully considered when designing direct cortical feedback for brain-machine interfaces with clinical applications .