Tool-use behavior is currently one of the most intriguing and widely debated topics in cognitive neuroscience. Different accounts of our ability to use tools have been proposed. In the first part of the paper we review the most prominent interpretations and suggest that none of these accounts, considered in itself, is sufficient to explain tool use. In the second part of the paper we disentangle three different types of reasoning on tools, characterized by a different distribution of motor and cognitive (...) ingredients. At the conceptual level, these types of reasoning reflect the distinction between three types of abductive inference as they are described in semiotic studies. At the functional level, we suggest that these types of reasoning on tools may correspond to different mental processes, possibly implemented in different regions of the left inferior parietal lobe. This proposal can account for the different interpretations commonly associated with the role of the left parietal cortex in tool use. (shrink)

Physical cognition involves a host of cognitive abilities that enable understanding and manipulation of the physical world. Corvids, the bird family that includes crows, ravens and jays, are renowned for their cognitive abilities, but still little is known about their folk physics. This thesis explores the origins of physical cognition in corvids by investigating its mechanisms, development,fitness value and phylogeny in a wide context that includes theoretical and empirical studies.String pulling is a valuable paradigm for addressing these questions. Many animals (...) can pull a string with food attached to its end, but uncovering the cognitive abilities involved in this behaviour requires further testing. Paper I reviews the string-pulling paradigm, which is one of the oldest tests of animal cognition.It is a highly suitable test for species comparisons, socio-ecological correlations, and phylogenetic questions. Paper II tests several corvids, apes and peafowl on a string-pulling task where the first pulls do not result in the food moving closer. Despite the absence of such visual feedback, most subjects pulled strings in completely, although corvids appeared to choose randomly.Tool use is the archetypical example of physical cognition. Many corvids are remarkably adept at using tools in experimental settings. Paper III reviews animal tool use in general. It is now clear that customary tool-using species do not necessarily outperform their non-tool-using relatives on tests of physical cognition. For corvids that frequently use tools in the wild, such as New Caledonian crows and‘Alalā, tool use appears to have a significant fitness value and may have resulted in morphological adaptations. Paper IV describes a novel tool-use mode in New Caledonian crows. They inserted sticks into objects and then moved away,thereby transporting both. One crow could not grasp the target object, which suggests that such insert-and-transport tool use facilitates control over unwieldy objects. Paper V briefly argues that some corvids have shown the ability to make novel causal interventions, although this question should be addressed in a clearer theoretical framework that makes testable predictions.Sensorimotor cognition is a set of fundamental cognitive abilities that enables the integration of sensory and motor information into practical behaviour. It underlies much of corvid physical cognition. Paper VI investigates the development of sensorimotor cognition in ravens. Their skills developed rapidly and exceeded those of some mammals. They reached the same final sensorimotor stage as great apes, albeit at a markedly accelerated rate. The propensity of corvids to cache objects was investigated in Paper VII. Ravens, which often cache food,frequently cached objects, but surprisingly at similar rates as non-food-caching jackdaws. New Caledonian crows mostly cached objects that resembled functional tools.Anthropomorphism is the attribution of human traits to animals. Fear of mistakenly anthropomorphising animals has resulted in biased principles and an uneven burden of proof, which may hinder scientific progress more than it is supposed to offer protection against making mistakes. Cognitive zoology should not be misguided by overcompensating for such potential pitfalls. (shrink)