COMPUTATIONAL MODEL OF OBSESSIVE–COMPULSIVE DISORDER: A UNIFIED EXPLANATION OF THE TREATMENTS

We propose a computational model explaining the pharmacological, behavioral, and neurosurgical treatments of obsessive–compulsive disorder (OCD) in a unified framework. On the basis of the concept that the striatum stores information linked to OCD symptoms, we analyze dynamical changes of a chaotic neural network modeling the striatum. The effect of pharmacological treatment is explained by the increase in refractoriness induced by the neurotransmitter serotonin. The effect of behavior therapy is explained by the time-variant input stimulus weakening neural interconnections according to the covariance rule concerning synaptic plasticity. The effect of neurosurgical treatment is explained by the lesions to the cortical-striatal-thalamic-cortical loop decreasing the feedback of the closed loop. These treatments have a common property that they decrease the stability of stored information in the striatum.