Beyond Gazing, Pointing, and Reaching A Survey of Developmental Robotics Authors: Max Lungarella, Giorgio Metta

Overview  Introduction  Research areas  Existing theories  Observations and future directions

Introduction  What is developmental robotics?  Use robots to test models from developmental psychology and neuroscience  Applies insights from ontogenetic development  Why combine robotics with psychology?  Novel methodologies  New research tools  Aim of the article?  Present state of developmental robotics  Motivate use of robots as research tool

Research areas  Criteria  Situatedness  Addressing hypotheses raised by either developmental psychology or neuroscience  Order of identified research articles  Social Interaction  Sensorimotor control  Categorization  Value systems  Developmental plasticity  Motor skill acquisition and morphological changes

Research area: social interaction  What kind of social interaction?  Joint attention  Scassellati (1998, 2001)  Nagai (2002)  Low-level imitation  Demiris (1999)  Development of language  Varshavskaya (2002)  Social regulation  Dautenhahn and Billard (1999)

Research area: sensorimotor control  Crucial to interact with world  Examples  Control of reaching  Marjanovic (1996)  Metta (1999)  Control of grasp  Coehlo (2001)  Interaction with objects  Metta and Fitzpatrick (2003)  Interaction with environment  Berthouze (1996)

Research area: categorisation  Categorisation in developmental robotics  How categories are formed  By interaction with environment, searching for correlations between sensors  Categorisation of objects  Scheuer and Lambrinos (1996)  Sensorimotor related categorisation  Berthouze and Kuniyoshi (1998)

Research area: value system  Value systems in robotics  Internal mediator of environmental stimuli/events  Used to guide exploration process  Value dependant learning  Learning technique where value system alters the learning by:  Specifying mechanisms by which stimuli can modulate learning  Providing system with input that essentially is signal filtered by agent’s value system  Almassy (1998) – simulated neural model, value system altered strength of connection from neurons of visual area to ones of motor area  Lungarella and Berthouze (2002) – value system used to explore parameter space

Research area: developmental plasticity  Brain inspired  developing a brain is plastic (flexible) and the plasticity is experience dependent  Almassy (1998)  Self generated movements crucial for emergence and development of visual responses  Foveal preference

Research area: morphological changes and motor skill acquisition  Morphological changes  For example: body growth  One of the most explicit characteristics of ongoing developmental processes  Articles:  Lungarella and Berthouze (2002)  How morphological changes influence acquisition of motor skills?  Does inherent adaptivity of motor development lead to behaviours not obtainable by simple value based regulation of neural parameters?  Comparative analysis between simultaneous and progressive use of available DOFs.  Simultaneous use of available DOFs reduces probability of physical entrainment.

Exisiting theories  Developmental engineering:  Brooks and Stein (1991): development as way to construct intelligent robotic systems  Aim: “to show that adoption of framework of biological development is suitable for construction of artificial systems”.  Recognising long sequences of cause-effect relationships characterises learning in real context  Features of human-like intelligent systems (Brooks, 1998):  Development  Embodiment  Social interaction  Multisensory integrations  Key assumptions:  Human intelligence not as general purpose as thought  Intelligence does not require monolithic control system  Intelligent agent does not require centrally stored model of real world

Existing theories cont.  Cognitive Developmental Robotics:  Asada (2001)  Aim: “to avoid implementing robot’s control structure according to designer’s understanding of robot’s physics, but to allow robot develop its own understanding”.  Robot no longer given externally designed structure  Autonomous Mental Development:  Weng (2001)  States that for robot to be truly mental developed means to be non-task specific  Aim: to develop robots that are non-task specific and able to develop own task representation that could not be possibly embedded a priori by designer

Observations and future directions  Majority of studies reviewed in paper belong to either social interaction or sensorimotor control.  Researchers underline importance of developing robots with social and early motor competencies – very few try to achieve it.  Future direction: going beyond “gazing, pointing and reaching”