Sensory integration across space and in time for decision making in the somatosensory system of rodents

TLDR

The brain encodes environmental information through spatiotemporal patterns of sensory input, where neurons inhibit responses to near‑simultaneous stimuli, yet the behavioral consequences of this suppression remain unclear. The study examined how spatially distributed, near‑simultaneous whisker inputs influence decision making in a whisker‑dependent learning task. Mice performed the task using either a single whisker or multiple whiskers, allowing comparison of learning with different spatial input configurations. Both groups achieved similar learning curves and success rates, but mice with multiple whiskers responded about half as fast, indicating that redundant spatial inputs speed decisions without improving accuracy, suggesting that suppressing near‑simultaneous inputs could reduce redundancy.

Abstract

Environment is represented in the brain by a neural code that is a result of the spatiotemporal pattern of incoming sensory information. Sensory neurons encode inputs across space and in time such that activity of a given cell inhibits the ability of near-simultaneously arriving sensory stimuli to excite the cell. At the behavioral level, consequences of such suppression are unknown. We investigated the contribution of spatially distributed, near-simultaneous sensory inputs to decision making in a whisker-dependent learning task. Mice learned the task with a single whisker or multiple whiskers alike. Both groups of mice had similar learning curves and final success rates. However, multiple-whisker animals had faster response times than single-whisker mice, requiring only about half the time to perform the task successfully. The results show that spatially distributed sensory inputs in a highly redundant sensory environment improve speed but not accuracy of the decisions made during simple sensory detection. Suppression of the near-simultaneous sensory inputs could, therefore, act to reduce the sensory redundancy.