A Multimodal Predictive Agent Model for Human Interaction Generation

Perception and action are inextricably tied together. We propose an agent model which consists of perceptual and proprioceptive pathways. The agent actively samples a sequence of percepts from its environment using the perception-action loop. The model predicts to complete the partial percept and propriocept sequences observed till each sampling instant, and learns where and what to sample from the prediction error, without supervision or reinforcement. The model is implemented using a multimodal variational recurrent neural network. The model is exposed to videos of two-person interactions, where one person is the modeled agent and the other person's actions constitute its visual observation. For each interaction class, the model learns to selectively attend to locations in the other person's body. The proposed attention-based agent is the first of its kind to interact with and learn end-to-end from human interactions, and generate realistic interactions with performance comparable to models without attention and using significantly more computational resources.