A Model of Sensorimotor Coordination in the Rat Whisker System

The rat has a sophisticated tactile sensory system centred around the facial whiskers. During normal behaviour, rats sweep their longer whiskers (macrovibrissae) through the environment to obtain largescale information, whilst gathering small-scale information with the sensory apparatus around their snout. The macrovibrissae are actively and differentially controlled. Using high-speed video recording, we have observed that temporal and spatial parameters of whisking pattern generation are modulated to match environmental features such as the position and orientation of nearby surfaces. Whisking is also closely co-ordinated with head and body movements, allowing the animal to locate and orient to interesting stimuli detected through whisker contact. In this paper, we present a hybrid (spiking-neuron/arithmetic) model of the neural systems underlying these observed adaptive sensorimotor behaviours, and demonstrate its performance in a simulated robot with rat-like morphology. We also report progress towards embedding these control systems in a physical robot with biomimetic whiskers.