Developmental trajectories of sensorimotor control of mechanical tools – Developmental_Tool_Mastery

Along the evolutionary history, humans have reached a high level of sophistication in the way they interact with the environment. One important step in this process has been the introduction of tools, enabling humans to go beyond the boundaries of their physical possibilities to both sense and act upon objects in the environment. The ability to use tools is one of the most remarkable skills of the human species and, although it should not necessarily be considered a unique feature of the human kind (Johnson-Frey 2003) as quite sophisticated animal tool-use has been observed in the wild and in captivity, the humans’ mastering of tools has reached an exquisite level of complexity (Farnè et al. 2007; Martel et al, in press).
Quite paradoxically, however, very little is known about what makes of humans such good masters of tools. One key aspect is the ability to learn how to adaptively control the action performed with a tool (Fagard et al, 2014). Motor control theories (Wolpert & Flanagan 2010) postulate that the central nervous system controls movements by generating predictions of the action outcome and comparing them with the sensory feedback. The relation between action performance and its consequences is acquired with experience mainly during development and remains more or less constant in the adult life. Tool-use particularly challenges the sensorimotor system, in that the control of arms and hands, otherwise typical final effectors, has to be transferred to the prehensile part of the tool. This functional distalization (Arbib et al, 2009) requires plastic changes to take place at the level of the body representation the brain uses to control movements of our limbs, the so-called body schema (BS). Another major unknown in this domain is how humans can sense through tools. Most of the studies to date focussed on using tools to grasp objects. However, our hands can extract an incredible amount of information about the objects we explore with a tool, as well as about the tool itself, even without vision (Serino et al, 2007). Philosophy has posited the theoretical frame to this issue since Descartes’ work (1637). When we touch something with a stick, we feel touch as originating from its distal edge, not from the actual source of inputs, which is the glabrous skin of the hand that handles it. Thus, also sensory perception is distalized to the tool-tip. There have been relatively few studies, however, providing empirical support to this widely accepted idea (Yamamoto & Kitazawa, 2001). How the brain extracts object and tool-related features from physical remote sensing, remains very poorly understood.
In this proposal, we aim at deciphering the key developmental steps and the sensorimotor factors that allow for acquisition of the sensorimotor plasticity induced by tool-use for 1) grasping and 2) sensing objects in the environment. The proposal objectives are to answer three questions: A) How do young humans acquire control of tools to reach and grasp objects and to sense and explore their environment? B) How does the adult human brain code for these abilities and their plasticity? C) How do multiple sensory modalities contribute acquiring and regulating these abilities?
The project’s partners and their collaborators merge a highly interdisciplinary array of competences in psychology, cognitive neuroscience, philosophy of mind, and bio-robotics. This fully interdisciplinary consortium offers the ideal opportunity for understanding the sophisticated ability of using tools and its neural bases. Inspired by philosophy, taking advantage of an original coupling of cutting-edge immersive virtual reality systems and robotics, with state-of-art cognitive neuroscience methods, we will originally combine different scholar’s competences and will gain unrivalled knowledge about the multisensory contribution to the acquisition and adaptive control of tool-use.