Which symptom revealed by PET scans might explain why people with schizophrenia sometimes experience emotions that are inappropriate for the occasion?

neural pathway blockage would be the symptom.

The neural pathway blockage disrupt the initial function of several structures of the brain, which often make them unable to process the information the same way normal people have. Even though they may not notice anything wrong with them, people would perceive patient with schizophrenia as someone that lost touch with reality