processes and (3) a balance between excitation and inhibition and derived four types based on these three properties. He extended the definitions of the four temperament types under study at the time: choleric, phlegmatic, sanguine, and melancholic, updating the names to "the strong and impetuous type, the strong equilibrated and quiet type, the strong equilibrated and lively type, and the weak type", respectively.

Pavlov and his researchers observed and began the study of transmarginal inhibition