The septo-hippocampal system and anxiety: a robot simulation

A computational model of the role of novelty detection and noradrenaline in anxiety and generalised anxiety disorder, GAD, is described. GAD arises from a chronic increase in the anxiety response. A theory for the role of the septo-hippocampal system in anxiety has been proposed by Gray (1982) and Gray and McNaughton (1996) but computational details were not given. Computational models of the hippocampus in which it plays a role in both memory and navigation have been described in the literature, but they do not take into account the extensive anxiety evidence. The model presented here takes into account data from all these areas. Results using a simulated mobile robot which show how an abnormal increase in the level of noradrenaline release could cause GAD are discussed. It is proposed that the major factor in GAD is an increase in the amount of novelty detected by the septo-hippocampal system