A hybrid neuromorphic circuit demonstrating schizophrenic symptoms

The neural system in the human brain can identify regularities in received stimuli and, based on that, predict future stimuli [1]. Neural prediction circuits reduce responses to predictable and thus possibly redundant events. Failures in predictions that result in erroneous responses may cause positive and negative symptoms in people who suffer from schizophrenia [2]. Here, we have designed a bio-inspired, neuromorphic circuit that mimics this “prediction” in the human brain and its response to stimuli with a predictable pattern. Furthermore, it shows how alteration in the neural circuitry can cause the circuit to recognize stimuli that do not occur (hallucination) or fail to recognize the expected pattern (negative symptom). Noisy signals are also used to invoke atypical behavior in a novel manner. The synaptic layer is modeled with Carbon NanoTube transistors (CNT) and neurons are modeled with CMOS technology.