The cognitive and neural bases of human tool use

It is a euphemism to say that humans use tools. Humans possess a vast repertoire of tools they use every day. In fact, as language or bipedal locomotion, tool use is a hallmark of humans. Tool use has also been often viewed as an important step during evolution (van Schaik et al., 1999) or even as a marker of the evolution of human intelligence (Wynn, 1985). So a fundamental issue is, what are the cognitive and neural bases of human tool use? The present series of papers in this special topic represents the newest additions to that research topic

Editors' introduction to tasks, tools, and techniques

Tasks, tools, and techniques that we perform, use, and acquire, define the elements of expertise which we value as the hallmarks of goal-driven behavior. Somehow, the creation of tools enables us to define new tasks, or is it that the envisioning of new tasks drives us to invent new tools? Or maybe it is that new tools engender new techniques which then result in new tasks? This jumble of issues will be explored and discussed in this diverse collection of papers. Individually, few of the papers are related to each other by topic or by techniques of analysis. Collectively, all focus on tasks performed using tools and discuss the techniques of tool use which enable differences in performance and expertise across individuals, societies, and (even) species

Unusual use of objects after unilateral brain damage. The technical reasoning model.

International audienceIt has been suggested that gesture engrams, conceptual knowledge and/or the ability to infer function from structure can support object use. The present paper proposes an alternative view which is based upon the idea that object use requires solely the ability to reason about technical means provided by objects. Technical means are abstract principles which are not linked with any object representation (e.g., cutting involves the opposition between dense and permeable material). The technical reasoning model predicts that the inability to perform technical reasoning should impair performance in any situation requiring the use of objects (in a conventional way or not). Twenty left brain-damaged (LBD) patients, 11 right brain-damaged (RBD) patients and 41 healthy controls were examined on experimental tests assessing the conventional use of objects (e.g., screwing a screw with a screwdriver), conceptual knowledge about object function, pantomime of object use and recognition of object utilization gestures. We also designed the Unusual Use of Objects test, which demands unusual applications of objects to achieve a purpose for which the usually applied object is not provided (e.g., screwing a screw with a knife). The key findings are that only LBD patients have more difficulties on the Unusual Use of Objects Test than controls or RBD patients, and that the severity of their impairment is correlated with that on conventional use of objects. Correlations with tests assessing conceptual knowledge as well as with tests of pantomime of object use and recognition of object utilization gestures were weaker. These results support the technical reasoning model and question the role of conceptual knowledge and gesture engrams in object use. Since the technical reasoning model also predicts two distinct technical disorders, the discussion focuses on the existence of these disorders in regard to individual performance profiles obtained in the Unusual Use of Objects test

On the psychological origins of tool use

The ubiquity of tool use in human life has generated multiple lines of scientific and philosophical investigation to understand the development and expression of humans' engagement with tools and its relation to other dimensions of human experience. However, existing literature on tool use faces several epistemological challenges in which the same set of questions generate many different answers. At least four critical questions can be identified, which are intimately intertwined-(1) What constitutes tool use? (2) What psychological processes underlie tool use in humans and nonhuman animals? (3) Which of these psychological processes are exclusive to tool use? (4) Which psychological processes involved in tool use are exclusive to Homo sapiens? To help advance a multidisciplinary scientific understanding of tool use, six author groups representing different academic disciplines (e.g., anthropology, psychology, neuroscience) and different theoretical perspectives respond to each of these questions, and then point to the direction of future work on tool use. We find that while there are marked differences among the responses of the respective author groups to each question, there is a surprising degree of agreement about many essential concepts and questions. We believe that this interdisciplinary and intertheoretical discussion will foster a more comprehensive understanding of tool use than any one of these perspectives (or any one of these author groups) would (or could) on their own

Etude neuropsychologique des rapports entre outil, geste et usage

The investigation of object use impairement raises the question of the nature of psychological enabling the ability to use tools. It has suggested that this disorder might result from excutive deficts and/or the inability to retrieve sensory motor knowledge about object manipulation (i.e., gesture engrams). Since manufactured objects are always designed to a specific conventional purpose, it has also been assumed that patients with objet use impairemnt might suffer from detective conceptual knowledge about object function. The present thesis proposes an alternative view by suggesting the object use depends upon a specific technical, rational and implicit ability to analyse natural activity. To contribute to the discussion, we address many epistemological and theoretical issues about the definition of human tool, and report four studies with brain-damaged patients that aimed to examine the relevance of the concepts of "tool", "gesture" and "usage". In sum, the present thesis suggests that the investigation of object use impairement would gain by conceiving this disorder as a singular inability to use tools.L'investigation des troubles d'utilisation d'objets pose la question de savoir quelle est la nature des processus psychologiques qui sous-tendent la capacité d'outiller. Sous le constat qu'utiliser impose de "mettre la main à la patte", ces perturbations ont été attribuées à l'incapacité de concevoir et/ou d'exécuter les gestes associés. Par ailleurs, puisque tout objet manufacturé est dévolu à un usage spécifique, l'hypothèse d'un déficit conceptuel concernant les connaissances sur les relations fonctionnelles entre objets a également été formulée. La présente thèse propose une approche alternative en suggérant que l'emploi d'objets ne ressort ni au geste ni à l'usage, mais à une capacité technique, rationnelle et implicite. Bien que traversé par des questionnements d'ordre théorique et épistémologique, le présent travail s'inscrit avant tout dans une tradition neuropsychologique clinique et expérimentale. Quatre études menées auprès de patients neurologiques ont été conduites afin d'examiner la pertinence des concepts d'outil, de geste et d'usage. En conclusion, la présente thèse contribue à démontrer que l'investigation des troubles d'utilisation des objets gagnerait à concevoir un désordre singulier de la capacité d'outiller

How Our Cognition Shapes and Is Shaped by Technology: A Common Framework for Understanding Human Tool-Use Interactions in the Past, Present, and Future

Over the evolution, humans have constantly developed and improved their technologies. This evolution began with the use of physical tools, those tools that increase our sensorimotor abilities (e.g., first stone tools, modern knives, hammers, pencils). Although we still use some of these tools, we also employ in daily life more sophisticated tools for which we do not systematically understand the underlying physical principles (e.g., computers, cars). Current research is also turned toward the development of brain–computer interfaces directly linking our brain activity to machines (i.e., symbiotic tools). The ultimate goal of research on this topic is to identify the key cognitive processes involved in these different modes of interaction. As a primary step to fulfill this goal, we offer a first attempt at a common framework, based on the idea that humans shape technologies, which also shape us in return. The framework proposed is organized into three levels, describing how we interact when using physical (Past), sophisticated (Present), and symbiotic (Future) technologies. Here we emphasize the role played by technical reasoning and practical reasoning, two key cognitive processes that could nevertheless be progressively suppressed by the proficient use of sophisticated and symbiotic tools. We hope that this framework will provide a common ground for researchers interested in the cognitive basis of human tool-use interactions, from paleoanthropology to neuroergonomics