A Data Collection of Infants’ Visual, Physical, and Behavioral Reactions to a Small Humanoid Robot Rebecca Funke 1 , Naomi T. Fitter 1 , Joyce T. de Armendi 2 , Nina S. Bradley 2 , Barbara Sargent 2 , Maja J. Mataric 1 , and Beth A. Smith 2 Abstract— Exploratory movements during infancy help typ- ically developing infants learn the connections between their own actions and desired outcomes. In contrast, infants who are at risk for developmental delays often have neuromotor impairments that negatively influence their motivation for movement. The goal of this work is to expand our under- standing of infant responses to non-contact interactions with a small humanoid robot. In the initial work presented here, we focus on understanding how this type of robotic system might help to encourage typically developing infant motor exploration. A data collection with N = 9 infants compared infant reactions to four robot conditions: saying “yay” with arm movement, saying “kick” with leg movement, saying “yay” with no movement, and saying “kick” with no movement. The results indicate that infants visually gazed at the robot while it moved, looking specifically to the part of the robot that was moving. Infants tended to move more during periods of robot inactivity. When the robot was moving, the infants also seemed more alert. Overall, these results can inform future studies of how to develop interventions to encourage movement practice by typically developing and at-risk infants. I. I NTRODUCTION Typically developing infants engage in exploratory move- ments that help them learn how their own actions are connected to different outcomes, from making a caregiver smile to grasping a favorite toy. Through this perception- action learning process, infants learn to control their bodies and interact with the environment. In contrast to typically developing (TD) infants, infants at risk (AR) for develop- mental delays often have neuromotor impairments involving strength, proprioception, and coordination. These challenges can lead to greater difficulty with movement and decreased motivation for motor babbling. The goal of this work is to expand our understanding of infant responses to non- contact interactions with a small humanoid robot. Initially, these efforts focus on how this type of robotic system might help to encourage TD infant movement. This foundational work also will equip us with appropriate strategies for future interventions with the more vulnerable population of AR infants. A recent estimate determined that approximately 9% of all infants in the United States are AR and could benefit from early intervention services to address motor, cognitive, and/or 1 Interaction Lab, Department of Computer Science, University of South- ern California, Los Angeles, CA 90089, USA {rfunke, nfitter, mataric}@usc.edu 2 Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA {jdearmen, nbradley, bsargent, beth.smith}@usc.edu social development [1]. Because of connections between these different types of development, motor, cognitive, and social domains can all be positively impacted by an inter- vention in just one of these areas [2]. The current standard of care for early intervention practice is to provide infre- quent, low-intensity movement therapy or no intervention in infancy [3], [4]. However, early, intense, and targeted therapy intervention has the potential to improve neurodevelopmental structure and function [5]. Despite this potential gain, it can be challenging to find feasible and resource-efficient ways to deliver this type of intervention to AR infants. Non- contact infant-robot interactions that provide demonstrations and feedback are one such possible solution for encouraging infant motor exploration. Before working with AR infants, we first aim to un- derstand TD infant responses to non-contact interactions with a humanoid robot. This paper summarizes related work (Section II), describes our methods for conducting a data collection on TD infant interactions with a small humanoid robot (Section III), presents the results of the data collection (Section IV), and discusses our findings (Section V). II. RELATED WORK Overall, the work presented in this paper aims to explore how TD infants respond to non-contact interactions with a small humanoid robot. Because of the humanoid form of the robot, one goal of this work is to determine if infants might be inclined to imitate the robot’s motions. Related literature also suggests that robot motion might capture the attention of infants and provide contingent rewards for motion explo- ration. The related work discussed in the following sections motivates the design of the data collection, demonstrates the potential of socially assistive robots, and explains possible future applications of this work. A. Infant Motor Learning and Adaptation Infants acquire motor skills through a dynamic process of exploration and discovery during which the spontaneous movements of infancy modulate into task-specific actions such as reaching, crawling, and walking [6], [7]. The process by which task-specific action emerges from spontaneous movement is a fundamental topic of study in infant develop- ment. One previously studied paradigm of infant behavior is infant replication of demonstrated actions. This replication qualifies as imitation if the infant repeats the action more with the demonstration than without the demonstration [8].