Motor skills are a vital part of healthy development and are featured prominently both in physical examinations and in parents’ baby diaries. It has been known for a long time that motor development is critical for children’s understanding of the physical and social world. Learning occurs through dynamic interactions and exchanges with the physical and the social world, and consequently movements of eyes and head, arms and legs, and the entire body are a critical during learning. At birth, we start with relatively poorly developed motor skills but soon gain eye and head control, learn to reach, grasp, sit, and eventually to crawl and walk on our own. The opportunities arising from each of these motor milestones are profound and open new and exciting possibilities for exploration and interactions, and learning. Consequently, several theoretical accounts of child development suggest that growth in cognitive, social, and perceptual domains are influences by infants’ own motor experiences. Recently, empirical studies have started to unravel the direct impact that motor skills may have other domains of development. This volume is part of this renewed interest and includes reviews of previous findings and recent empirical evidence for associations between the motor domain and other domains from leading researchers in the field of child development. We hope that these articles will stimulate further research on this interesting question.

Reaching for objects in our surroundings is an everyday activity that most humans perform seamlessly a hundred times a day. It is nonetheless a complex behavior that requires the perception of objects’ features, action selection, movement planning, multi-joint coordination, force regulation, and the integration of all of these properties during the actions themselves to meet the successful demands of extremely varied task goals. Even though reach-to-grasp behavior has been studied for decades, it has, in recent years, become a particularly growing area of multidisciplinary research because of its crucial role in activities of daily living and broad range of applications to other fields, including physical rehabilitation, prosthetics, and robotics. This volume brings together novel and exciting research that sheds light into the complex sensory-motor processes involved in the selection and production of reach-to-grasp behaviors. It also offers a unique life-span and multidisciplinary perspective on the development and multiple processes involved in the formation of reach-to-grasp. It covers recent and exciting discoveries from the fields of developmental psychology and learning sciences, neurophysiology and brain sciences, movement sciences, and the dynamic field of developmental robotics, which has become a very active applied field relying on biologically inspired models. This volume is a rich and valuable resource for students and professionals in all of these research fields, as well as cognitive sciences, rehabilitation, and other applied sciences.

This Research Topic is devoted to arm and hand movement in health as well as in several disease conditions. It is a collection of several original research papers and reviews, clinical case studies, hypothesis and theory articles, opinions, commentaries, and methods papers that cover some important aspects of the topic from distinct scientific perspectives. We invite the readers to appreciate the range in methodologies and experimental designs that together have led to widen our understanding of this especially broad field of research.

Understanding the link between individual behaviour and population organization and functioning has long been central to ecology and evolutionary biology. Behaviour is a response to intrinsic and extrinsic factors including individual state, ecological factors or social interactions. Within a group, each individual can be seen as part of a network of social interactions varying in strength, type and dynamic. The structure of this network can deeply impact the ecology and evolution of individuals, populations and species. Within a group social interactions can take many forms and may significantly affect an individual’s fitness. These interactions may result in complex systems at the group-level, such as in the case of collective decisions (to migrate, to build nest or to forage). Among them, social transmission of information has been studied mostly in vertebrates: fish, birds and mammals including humans. In insects, social learning has been unambiguously demonstrated in social Hymenoptera but this probably reflects limited research effort and recent evidence show that even non-eusocial insects such as Drosophila, cockroaches and crickets can copy the behaviour of others. Compared to individual learning, which requires a trial and error period every generation, social learning can potentially result in the stable transmission of behaviours across generations, leading to cultural traditions in some species. The study of the processes which may facilitate or prevent this transmission and the analyses of the relationship between social network structure and efficiency of social transmission became these recent years an emerging and promising field of research. The goal of this research topic is to present the genetic and socio-environmental factors affecting social interaction and information or pathogen transmission with the integration of experimental approaches, social network analyses and modelling. Importantly, we aim to understand whether a relationship between social network structures and dynamics can reflect the efficiency of social transmission, i.e. can we use social network analysis to predict the social transmission of information or of pathogen, collective decision-making and ultimately the evolutionary trajectory of a group?

The burgeoning field of social neuroscience has begun to illuminate the complex biological bases of human social cognitive abilities. However, in spite of being based on the premise of investigating the neural bases of interacting minds, the majority of studies have focused on studying brains in isolation using paradigms that investigate offline social cognition, i.e. social cognition from a detached observer's point of view, asking study participants to read out the mental states of others without being engaged in interaction with them. Consequently, the neural correlates of real-time social interaction have remained elusive and may —paradoxically— represent the 'dark matter' of social neuroscience. More recently, a growing number of researchers have begun to study online social cognition, i.e. social cognition from a participant's point of view, based on the assumption that there is something fundamentally different when we are actively engaged with others in real-time social interaction as compared to when we merely observe them. Whereas, for offline social cognition, interaction and feedback are merely a way of gathering data about the other person that feeds into processing algorithms 'inside’ the agent, it has been proposed that in online social cognition the knowledge of the other —at least in part— resides in the interaction dynamics ‘between’ the agents. Furthermore being a participant in an ongoing interaction may entail a commitment toward being responsive created by important differences in the motivational foundations of online and offline social cognition. In order to promote the development of the neuroscientific investigation of online social cognition, this Frontiers Research Topic aims at bringing together contributions from researchers in social neuroscience and related fields, whose work involves the study of at least two individuals and sometimes two brains, rather than single individuals and brains responding to a social context. Specifically, this Research Topic will adopt an interdisciplinary perspective on what it is that separates online from offline social cognition and the putative differences in the recruitment of underlying processes and mechanisms. Here, an important focal point will be to address the various roles of social interaction in contributing to and —at times— constituting our awareness of other minds. For this Research Topic, we, therefore, solicit reviews, original research articles, opinion and method papers, which address the investigation of social interaction and go beyond traditional concepts and ways of experimentation in doing so. While focusing on work in the neurosciences, this Research Topic also welcomes contributions in the form of behavioral studies, psychophysiological investigations, methodological innovations, computational approaches, developmental and patient studies. By focusing on cutting-edge research in social neuroscience and related fields, this Frontiers Research Topic will create new insights concerning the neurobiology of social interaction and holds the promise of helping social neuroscience to really go social.

One remarkable ability of the human brain is to process large amounts of information about our surroundings to allow us to interact effectively with them. In everyday life, the most common way to interact with objects is by reaching, grasping, lifting and manipulating them. Although these may sound like simple tasks, the perceptual properties of the target object, such as its location, size, shape, and orientation all need to be processed in order to set the movement parameters that allow an accurate reach-to-grasp-to lift movement. Several brain areas work in concert to process this outstanding amount of visual information and drive the execution of a motor plan in just a few hundred milliseconds. How are these processes orchestrated? In developing this type of comprehensive knowledge about the interactions between objects perception and goal-directed actions, we have a window into the mechanisms underlying the functioning of the visuo-motor system. With this research topic we aim to further understand the neural mechanisms that mediate our interactions with the world. Therefore, we particularly encourage submission of papers that attempt to relate such findings to real-world situations by investigating behavioural and neural correlates of information processing related to eye-hand coordination and visually-guided actions, including reaching, grasping, and lifting movements. This topic welcomes submissions of original research using any relevant techniques and methods, from behavioural kinematics/kinetics, to neuroimaging and transcranial magnetic stimulation (TMS), as well as neuropsychological studies.