A model of sensorimotor co-ordination in the rat whisker system

Abstract. 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 large-scale information, whilst gathering small-scale information with the sen-sory apparatus around their snout. The macrovibrissae are actively and differentially controlled. Using high-speed video recording, we have ob-served that temporal and spatial parameters of whisking pattern genera-tion 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 ori-ent to interesting stimuli detected through whisker contact. In this paper, we present a hybrid (spiking-neuron/arithmetic) model of the neural sys-tems underlying these observed adaptive sensorimotor behaviours, and demonstrate its performance in a simulated robot with rat-like morphol-ogy. We also report progress towards embedding these control systems in a physical robot with biomimetic whiskers.