Name needed for psychological practice which uses objects that represent humans [dolls/pictures/etc.] during patient treatment
It's often referred to as "doll therapy" or "play therapy" and applies to adults as much as it does to children. For example, this new product, the "Inner Critic Doll" enables adults to hold a physical manifestation of their inner critic and start a dialogue with it. It has a zipper mouth which can be zipped shut to physically silence this inner voice.

The doll enables adults to confront an otherwise "formless" part of their psyche and has proven to be highly effective.
It's used frequently by writers, artists, those suffering low self-esteem, etc., and I've even seen family members address each other on challenging topics via their inner critic doll, as it was easier than talking face-to-face.