Online correction of orientation estimates using spatial memory in a neuromorphic head direction system

Many animals are known to maintain an internal estimate of their orientation in the environment. In the absence of external sensory cues, this estimate inevitably exhibits drift. When sensory information is available, associations between sensory landmarks and the internal estimate can be used to correct for drift. In this paper we present a neuromorphic system to model such associations between sensory landmarks in the environment (as provided by sonar) and the activity of a hardware-based head direction cell system (HDS) that continuously integrates angular velocity signals to maintain an estimate of the orientation. These associations are shown to correct for drift errors that are encountered in the HDS.