A Developmental Approach to the Study of Affective Bonds for Human-Robot Interaction Antoine Hiolle A thesis submitted in partial fulfilment of the requirements of the University of Hertfordshire for the degree of Doctor of Philosophy The programme of research was carried out in the School of Computer Science, Faculty of Science, Technology and Creative Arts, University of Hertfordshire. February 2015 Acknowledgements I would like to thank my main supervisor Lola Cañamero for her constant support and the opportunities she has given me during all these years. I am grateful to the second and third members of the supervising team, Neil Davey and Rod Adams, for their valuable feedback. I am also grateful to Lorraine Nicholls and all the administrative staff of STRI for their constant help and positive attitude. I am of course extremely grateful to all the members of the two EU projects I worked on (ALIZ-e and FEELIX-GROWING). Too many names to name but I have rarely met on two different occasions a group of such enthusiastic and stimulating persons. Our interactions helped me develop as a person and a researcher, and built some long lasting friendships. I am also grateful to all the members of the Adaptive Systems Research Group, especially the few that would stay after hours to discuss exciting topics or program for an all-nighter. Throughout this work, I was first supported by a research studentship from the Adaptive Systems Research Group, School of Computer Science, University of Hertfordshire. This research has also received support from the EU FP6 funded Project FEELIX GROWING, contract FP6 IST-045169 and the EU FP7 ALIZ-e project (grant 248116). Finally, I am greatly indebted to two amazing women. Sandra Costa, the love of my life, for her just being constantly amazing, supportive, motivating, and surprising. And my mother, who is probably the best human being in the world and has always been. Antoine Hiolle i Abstract Robotics agents are meant to play an increasingly larger role in our everyday lives. To be successfully integrated in our environment, robots will need to develop and display adap- tive, robust, and socially suitable behaviours. To tackle these issues, the robotics research community has invested a considerable amount of efforts in modeling robotic architectures inspired by research on living systems, from ethology to developmental psychology. Fol- lowing a similar approach, this thesis presents the research results of the modeling and experimental testing of robotic architectures based on affective and attachment bonds be- tween young infants and their primary caregiver. I follow a bottom-up approach to the modelling of such bonds, examining how they can promote the situated development of an autonomous robot. Specifically, the models used and the results from the experiments carried out in laboratory settings and with naive users demonstrate the impact such affec- tive bonds have on the learning outcomes of an autonomous robot and on the perception and behaviour of humans. This research leads to the emphasis on the importance of the interplay between the dynamics of the regulatory behaviours performed by a robot and the responsiveness of the human partner. The coupling of such signals and behaviours in an attachment-like dyad determines the nature of the outcomes for the robot, in terms of learning or the satisfaction of other needs. The experiments carried out also demonstrate of the attachment system can help a robot adapt its own social behaviour to that of the human partners, as infants are thought to do during their development. ii Contents Acknowledgments i Abstract ii Chapter 1 Introduction 1 1.1 Motivations, Scope, and Problem Statement . ....... 3 1.2 OutlineoftheThesis.............................. 6 1.3 Contributions to Knowledge . ... 9 1.4 ResearchProjects................................ 11 1.4.1 The FEELIX GROWING Project . 11 1.4.2 TheALIZ-Eproject ........................... 12 Chapter 2 Attachment Theory and Affective Bonds: The Caregiver as an External Regulator of Affect 14 2.1 The Origins of Attachment theory . 14 2.2 Development of the Bond between the Infant and the Attachment Figure . 15 2.3 The Caregiver as a Secure Base and its Role in the Regulation of the Affect ofInfants ..................................... 18 2.4 The Neurophysiology of Mother-Infant Affective Interactions . 21 iii 2.5 Artificial Models of Mother-Infant Attachment . ........ 23 2.6 Summary ..................................... 24 Chapter 3 Affective Processes and Interactions for Autonomous Robots 26 3.1 Affective Processes: Motivations and Emotions in Humans and Other Animals 26 3.1.1 Definitions and functions of affect and emotions . ...... 26 3.1.2 Emotional Arousal . 28 3.1.3 Affective Components for the Attachment System . ..... 29 3.2 Affective Interactions and Exploration for Autonomous Robots . 30 3.2.1 Artificial Affective Systems for Human-Robot Interactions . 31 3.3 Exploration and Comfort Systems for Autonomous Robots . ......... 33 3.3.1 Robotic Comfort Zones . 33 3.3.2 Bottom-up Approach to the Imprinting Phenomenon . 33 3.3.3 Exploration, Novelty, and Curiosity . ..... 35 3.4 Summary and Proposed Methodology for the Design and Operationalization of a Minimal Attachment System . 37 Chapter 4 A Model of Attachment-based Regulation of Affect for Au- tonomous Robots 39 4.1 Outline ...................................... 39 4.1.1 Contributors and Funding Bodies . 40 4.2 Adaptation of the Paradigms and Mechanisms of the Attachment System . 40 4.3 The Dyadic Regulation Model for Attachment: Interactions between Arousal andComfort ................................... 41 4.3.1 Arousal as an Average of the External Stimulation . ...... 42 4.3.2 Evaluation of the comfort . 45 iv 4.4 Comparison of the Attachment Model to the Simulation Model of Stevens andZhang..................................... 49 4.5 Novelty and Learning Accuracy as Sources of Stimulation for the Arousal of aLearningRobot................................. 54 4.5.1 The Auto-Associative Memory . 56 4.5.2 The Self-Organizing Map for the Categorisation of Perceptual Features 60 4.6 Robot Architecture with the Attachment System . ....... 66 4.7 Summary ..................................... 71 Chapter 5 An Artificial Arousal System for Robot Exploration 73 5.1 Outline ...................................... 73 5.2 Contributors and funding bodies . 74 5.3 The Robotic Platform used: The Sony AIBO ERS-7 Robot . 74 5.3.1 Software interface . 75 5.3.2 Perceptions used in the experiment . 77 5.3.3 Regulatory and Exploratory Behaviours . 80 5.4 Experiments.................................... 82 5.4.1 Experimental Setup and Research Hypotheses . ..... 82 5.5 Results of the Variation of the Responsiveness of the Caregiver . 84 5.5.1 HighResponsiveness .. .. .. .. .. .. .. .. .. .. .. .. 84 5.5.2 MediumResponsiveness . 87 5.5.3 LowResponsiveness .. .. .. .. .. .. .. .. .. .. .. .. 90 5.6 Discussion..................................... 93 5.7 Summary ..................................... 96 Chapter 6 Human-Robot Caregiving Interactions with Naive Users 98 v 6.1 Outline ...................................... 98 6.2 Contributors and funding bodies . 99 6.3 Experimental Setting for Caregiving Interactions . ........... 99 6.3.1 Research Questions, Hypotheses, and Measures . 100 6.3.2 Experimental Setup and Protocol . 101 6.3.3 Questionnaire...............................104 6.4 Results.......................................107 6.4.1 Results from the questionnaires . 107 6.4.2 Results per Subjects Group . 109 6.4.3 Comfort and Stimulation of the Robot . 111 6.4.4 Annotation of the video recordings . 111 6.5 Discussion.....................................115 6.5.1 Summary .................................117 Chapter 7 Regulatory Profile Influence on Exploration and Learning 119 7.1 Outline ......................................119 7.2 Contributors and funding bodies . 120 7.3 The Robotic Platform Used: Aldebaran’s Humanoid Robot NAO . 120 7.4 New Experimental Setup and Research Questions . .......123 7.4.1 ResearchQuestions. .123 7.4.2 The Experimental Setup . 124 7.4.3 Perceptual System . 125 7.4.4 TheArousalSystem .. .. .. .. .. .. .. .. .. .. .. ..127 7.4.5 Action Selection and the Behavioral System . 128 7.4.6 Caregiver Responses for Equal Responsiveness . .......129 7.4.7 TwoRobotProfiles. .. .. .. .. .. .. .. .. .. .. .. ..130 vi 7.5 Results.......................................132 7.5.1 Reaction to a global change in the environment . 132 7.5.2 Local sources of Arousal increase . 133 7.5.3 Effect of the Profiles in the Exploration in a Simple Environment . 134 7.5.4 Effect of the Profiles in the Exploration in a more Complex Environ- ment....................................137 7.5.5 Experiments with Varying Responsiveness of the Caregiver: Affec- tiveAdaptation..............................142 7.6 Summary .....................................146 Chapter 8 Attachment and Dyadic Regulation in Motivational Systems 150 8.1 Outline ......................................150 8.1.1 Contributors and funding bodies . 151 8.2 The Diabetic Robot Toddler . 152 8.2.1 Paradigm and Interactive Scenario . 152 8.2.2 Principles for the Adaptation of the Attachment System to the Sce- nario and the Motivational System of the Robot . 154 8.3 Subset of the Architecture used for the Attachment System .........159 8.3.1 Perception of the Human Caregiver and Social Motivation . 160 8.3.2 Dynamics of the Motivations . 160 8.3.3 Behaviours and Action Selection . 162 8.4 Influence of the Comfort, Arousal,