A patient in the late 19th century experiences a variety of unexplained physical symptoms, such as temporary paralysis and disturbances in vision. A physician encourages the patient to speak freely and in detail about any thoughts or memories that come to mind, particularly those associated with distressing events. The physician observes that as the patient verbalizes these experiences, their physical symptoms temporarily lessen. Based on this therapeutic approach, what is the most likely mechanism responsible for the patient's improvement?

A 19th-century physician finds that a patient's symptoms of hysteria, such as unexplained paralysis and anxiety, are lessened when the patient is encouraged to talk in detail about their troubling experiences and emotions. This approach was a significant departure from the purely biological and medicinal treatments common at the time. What was the core principle that made this verbal approach innovative?