Human–human interaction in natural environments relies on a variety of perceptual cues. Humanoid robots are becoming increasingly refined in their sensorimotor capabilities, and thus should now be able to manipulate and exploit these social cues in cooperation with their human partners. Previous studies have demonstrated that people follow human and robot gaze, and that it can help them to cope with spatially ambiguous language. Our goal is to extend these findings into the domain of action, to determine how human and robot gaze can influence the speed and accuracy of human action. We report on results from a human–human cooperation experiment demonstrating that an agent’s vision of her/his partner’s gaze can significantly improve that agent’s performance in a cooperative task. We then implement a heuristic capability to generate such gaze cues by a humanoid robot that engages in the same cooperative interaction. The subsequent human–robot experiments demonstrate that a human agent can indeed exploit the predictive gaze of their robot partner in a cooperative task. This allows us to render the humanoid robot more human-like in its ability to communicate with humans. The long term objectives of the work are thus to identify social cooperation cues, and to validate their pertinence through implementation in a cooperative robot. The current research provides the robot with the capability to produce appropriate speech and gaze cues in the context of human–robot cooperation tasks. Gaze is manipulated in three conditions: Full gaze (coordinated eye and head), eyes hidden with sunglasses, and head fixed. We demonstrate the pertinence of these cues in terms of statistical measures of action times for humans in the context of a cooperative task, as gaze significantly facilitates cooperation as measured by human response times.

The current research presents a system that learns to understand object names, spatial relation terms and event descriptions from observing narrated action sequences. The system extracts meaning from observed visual scenes by exploiting perceptual primitives related to motion and contact in order to represent events and spatial relations as predicate-argument structures. Learning the mapping between sentences and the predicate-argument representations of the situations they describe results in the development of a small lexicon, and a structured set of sentence form-to-meaning mappings, or simplified grammatical constructions. The acquired grammatical construction knowledge generalizes, allowing the system to correctly understand new sentences not used in training. In the context of discourse, the grammatical constructions are used in the inverse sense to generate sentences from meanings, allowing the system to describe visual scenes that it perceives. In question and answer dialogs with naïve users the system exploits pragmatic cues in order to select grammatical constructions that are most relevant in the discourse structure. While the system embodies a number of limitations that are discussed, this research demonstrates how concepts borrowed from the construction grammar framework can aid in taking initial steps towards building systems that can acquire and produce event language through interaction with the world.

One of the defining characteristics of human cognition is our outstanding capacity to cooperate. A central requirement for cooperation is the ability to establish a "shared plan" -which defines the interlaced actions of the two cooperating agents -in real time, and even to negotiate this shared plan during its execution.In the current research we identify the requirements for cooperation, extending our earlier work in this area. These requirements include the ability to negotiate a shared plan using spoken language, to learn new component actions within that plan, based on visual observation and kinesthetic demonstration, and finally to coordinate all of these functions in real time. We present a cognitive system that implements these requirements, and demonstrate the system's ability to allow a Nao humanoid robot to learn a non-trivial cooperative task in real-time. We further provide a concrete demonstration of how the real-time learning capability can be easily deployed on different platform, in this case the iCub humanoid. The results are considered in the context of how the development of language in the human infant provides a powerful lever in the development of cooperative plans from lower-level sensorimotor capabilities.Index Terms-cooperation, humanoid robot, spoken language interaction, shared plans, situated and social learning.

The objective of this research is to develop a system for language learning based on a minimum of pre-wired language-specific functionality, that is compatible with observations of perceptual and language capabilities in the human developmental trajectory. In the proposed system, meaning (in terms of descriptions of events and spatial relations) is extracted from video images based on detection of position, motion, physical contact and their parameters. Mapping of sentence form to meaning is performed by learning grammatical constructions that are retrieved from a construction inventory based on the constellation of closed class items uniquely identifying the target sentence structure. The resulting system displays robust acquisition behavior that reproduces certain observations from developmental studies, with very modest "innate" language specificity.