Online research in philosophy

Human, cognition, interaction, and culture are thoroughly intertwined. Without cognition and interaction, there would be no culture. Without culture, cognition and interaction would be very different affairs, as they are among other social species. The effect of culture on mental life has always been a main concern of the social sciences and, after a long period of almost total neglect, it is more and more taken into consideration in cognitive psychology. The effect of cognition, and in particular of the ability to attribute mental states to others, on interaction has become a important topic of investigation in developmental and social psychology. Little attention, on the other hand, is paid to the effect of cognition on culture. All would agree, of course that the human mind is what makes human culture possible. Quite generally, however, the mind is seen as a mere enabler of culture, a pure opportunity with no constraints attached, nothing that might contribute to shaping, or at least to biasing cultural contents. Against this neglect of cognition, I will argue that understanding the mind is doubly important to the study of culture. Psychological considerations are crucial both to a proper characterization of what is cultural and to a proper explanation of cultural phenomena. Most anthropologists may be too savvy to still talk of the mind as a “blank slate”, but they too often meet any discussion of psychological factors in culture with a blank stare. Most evolutionary theorists who see cultural evolution as an analogue of biological evolution by natural selection postulate rather than investigate the few particulars of the human mind..

Perhaps the greatest evolutionary advantage conferred by spoken language was its ability to communicate mentalistic concepts, rather than just extending the vocabulary of action already served by an imitation function. An appreciation that the mirror-neuron system served a simple mentalising function before gestural communication sets Arbib's theory in a more appropriate social cognitive context.

Explaining the transition from a signed to a spoken protolanguage is a major problem for all gestural theories. I suggest that Arbib's improved “beyond the mirror” hypothesis still leaves this core problem unsolved, and that Darwin's model of musical protolanguage provides a more compelling solution. Second, although I support Arbib's analytic theory of language origin, his claim that this transition is purely cultural seems unlikely, given its early, robust development in children.

Selected contributions to the symposium on "Mirror neurons and the evolution of brain and language" held on July 5-8, 2000 in Delmenhorst, Germany.

Sign languages exhibit all the complexities and evolutionary advantages of spoken languages. Consequently, sign languages are problematic for a theory of language evolution that assumes a gestural origin. There are no compelling arguments why the expanding spiral between protosign and protospeech proposed by Arbib would not have resulted in the evolutionary dominance of sign over speech.

The notion that manual gestures played an important role in the evolution of human language was strengthened by the discovery of mirror neurons in monkey area F5, the proposed homologue of human Broca's area. This idea is central to the thesis developed by Arbib, and lending further support to a link between motor resonance mechanisms and language/communication development is the case of autism and congenital blindness. We provide an account of how these conditions may relate to the aforementioned theory.

We commend Arbib for his original proposal that a mirror neuron system may have participated in language origins. However, in our view he proposes a complex evolutionary scenario that could be more parsimonious. We see no necessity to propose a hand-based signing stage as ancestral to vocal communication. The prefrontal system involved in human speech may have its precursors in the monkey's inferior frontal cortical domain, which is responsive to vocalizations and is related to laryngeal control.

We focus on the evolution of action capabilities which set the stage for language, rather than analyzing how further brain evolution built on these capabilities to yield a language-ready brain. Our framework is given by the Mirror System Hypothesis, which charts a progression from a monkey-like mirror neuron system (MNS) to a chimpanzee-like mirror system that supports simple imitation and thence to a human-like mirror system that supports complex imitation and language. We present the MNS2 model, a new model of action recognition learning by mirror neurons of the macaque brain and augmented competitive queuing, a model of opportunistic scheduling of action sequences as background for analysis of modeling strategies for simple imitation as seen in the great apes and complex/goal-directed imitation as seen in humans. Implications for the study of language are briefly noted.

The article analyzes the neural and functional grounding of language skills as well as their emergence in hominid evolution, hypothesizing stages leading from abilities known to exist in monkeys and apes and presumed to exist in our hominid ancestors right through to modern spoken and signed languages. The starting point is the observation that both premotor area F5 in monkeys and Broca's area in humans contain a “mirror system” active for both execution and observation of manual actions, and that F5 and Broca's area are homologous brain regions. This grounded the mirror system hypothesis of Rizzolatti and Arbib (1998) which offers the mirror system for grasping as a key neural “missing link” between the abilities of our nonhuman ancestors of 20 million years ago and modern human language, with manual gestures rather than a system for vocal communication providing the initial seed for this evolutionary process. The present article, however, goes “beyond the mirror” to offer hypotheses on evolutionary changes within and outside the mirror systems which may have occurred to equip Homo sapiens with a language-ready brain. Crucial to the early stages of this progression is the mirror system for grasping and its extension to permit imitation. Imitation is seen as evolving via a so-called simple system such as that found in chimpanzees (which allows imitation of complex “object-oriented” sequences but only as the result of extensive practice) to a so-called complex system found in humans (which allows rapid imitation even of complex sequences, under appropriate conditions) which supports pantomime. This is hypothesized to have provided the substrate for the development of protosign, a combinatorially open repertoire of manual gestures, which then provides the scaffolding for the emergence of protospeech (which thus owes little to nonhuman vocalizations), with protosign and protospeech then developing in an expanding spiral. It is argued that these stages involve biological evolution of both brain and body. By contrast, it is argued that the progression from protosign and protospeech to languages with full-blown syntax and compositional semantics was a historical phenomenon in the development of Homo sapiens, involving few if any further biological changes. Key Words: gestures; hominids; language evolution; mirror system; neurolinguistics; primates; protolanguage; sign language; speech; vocalization.

Mirror neurons form a poor basis for Arbib's account of language evolution, failing to explain the creativity that must precede imitation, and requiring capacities (improbable in hominids) for categorizing situations and unambiguously miming them. They also commit Arbib to an implausible holophrastic protolanguage. His model is further vitiated by failure to address the origins of symbolization and the real nature of syntax.