Levin studies the symptom of cataplexy particularly in its psychosomatic aspects. He relates both narcolepsy and cataplexy to conditioned inhibition, the former being a more widespread involvement of cortical inhibition and the latter a more localized inhibition involving only the motor cortex. He develops the thesis, which he supports by clinical examples, that the symptom of cataplexy results when an aggressive impulse is being suppressed. The hostile impulse, whether conscious or unconscious, when associated with guilt or shame or fear