Deictic Pronoun Learning and Mirror Self-Identification

The ability to identify the self in a mirror reflection and the ability to use the word “I” effectively are commonly seen as major milestones in a human infant’s development of a concept of self. In addition, deictic pronouns such as “I” and “you” present a technical challenge to computational methods for grounded word learning, which have commonly associated word definitions with sensory patterns instead of pragmatic roles. Here, a robot learns the usage of the words “I” and “you” by observing others playing a game of catch, then correctly uses the terms to refer to its mirror image and to a conversational partner, respectively. Word learning occurs by using already understood words (“got the ball”) to infer the referents of spoken sentences. The properties of those referents, including the conversational roles of “speaker” and “addressee” as well as properties unique to each person, are then associated with the unknown words, and the significance of these associations ranked via chi-square tests. After sufficient observation of others using “I” and “you,” the robot’s own usage is correct without any need for supervised learning. To achieve mirror selfrecognition, the robot uses the timing of the visual feedback that results from its arm’s movement. The part of the image that is labeled as “self” is then treated as the robot’s location in the image for the purpose of responding to the command, “Say who got the ball.”