Dr. xavier encourages his client to relax and say whatever comes to mind at the moment. dr. xavier is using to treat his client.

In this case, dr. Xavier is using: free association to treat his client
In a free association method, a psychologist will try to find the underlying cause of the problem by letting the patient share his/her thought.
From the patient's story, Dr. Xavier could determine the way patient thinks and determine which way of thinking cause the patient's disorder