Robot learning of lexical semantics from sensorimotor interaction and the unrestricted speech of human tutors

This paper describes a HRI case study which demonstrates how a humanoid robot can use simple heuristics to acquire and use vocabulary in the context of being shown a series of shapes presented to it by a human and how the interaction style of the human changes as the robot learns and expresses its learning through speech. The case study is based on findings on how adults use childdirected speech when socially interacting with infants. The results indicate that humans are generally willing to engage with a robot in a similar manner to their engagement with a human infant and use similar styles of interaction varying as the shared understanding between them becomes more apparent. The case study also demonstrates that a rudimentary form of shared intentional reference can sufficiently bias the learning procedure. As a result, the robot associates humantaught lexical items for a series of presented shapes with its own sensorimotor experience, and is able to utter these words, acquired from the particular tutor, appropriately in an interactive, embodied context exhibiting apparent reference and discrimination.