Neural network simulations, cortical connectivity, and schizophrenic psychosis.
Recent studies have suggested that reduced corticocortical connectivity is associated with schizophrenia. My colleagues and I have used neural network simulations to explore parallel, distributed processing systems with reduced connectivity. These systems often behaved in a "schizophrenic-like" manner. Excessively pruned attractor networks became functionally fragmented, suggesting "loose associations," and produced recurrent, intrusive representations suggestive of delusions. Pruning backpropagation simulations of speech perception networks produced spontaneous output, which provided a model of auditory hallucination or "voices." This model also suggested how dopamine-blocking drugs may reduce positive symptoms, and why negative symptoms arise in the wake of positive symptoms.
Hoffman
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Yale Psychiatric Institute, New Haven, CT 06520-8038, USA. hoffman@biomed.med.yale.edu
D015982:Bias; D003198:Computer Simulation; D003344:Cortical Synchronization; D003702:Delusions; D006212:Hallucinations; D006801:Humans; D016571:Neural Networks, Computer; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013067:Speech Perception