Language is a unique feature of human beings. In addition to having the ability to use language, humans can conjecture about language consciously and even create realistic constructed languages from scratch. In How the brain got language, Michael A. Arbib, whose work has been influential in shaping the field of computational [End Page 410] neuroscience, addresses the title question by exploring the multimodality of language and the Mirror System Hypothesis.
The main concept that Arbib stresses throughout this volume is the multimodality of language, based on the Mirror System Hypothesis. According to this hypothesis, developed by , “the mechanisms that support language in the human brain evolved atop a basic mechanism not originally related to communication. Instead, the mirror system for grasping with its capacity to generate and recognize a set of actions provides the evolutionary basis for language parity” (p. 173). Arbib argues that the evolution of language is rooted in the execution and observation of hand movements, leading to the emergence of sign-language, which is thereafter extended to speech.
Unlike any other species, humans can learn and use language. This book explains how the brain evolved to make language possible, through what Michael Arbib calls the Mirror System Hypothesis. Because of mirror neurons, monkeys, chimps, and humans can learn by imitation, but only "complex imitation," which humans exhibit, is powerful enough to support the breakthrough to language. This theory provides a path from the openness of manual gesture, which we share with nonhuman primates, through the complex imitation of manual skills, pantomime, protosign (communication based on conventionalized manual gestures), and finally to protospeech. The theory explains why we humans are as capable of learning sign languages as we are of learning to speak. This fascinating book shows how cultural evolution took over from biological evolution for the transition from protolanguage to fully fledged languages. The author explains how the brain mechanisms that made the original emergence of languages possible, perhaps 100,000 years ago, are still operative today in the way children acquire language, in the way that new sign languages have emerged in recent decades, and in the historical processes of language change on a time scale from decades to centuries. Though the subject is complex, this book is highly readable, providing all the necessary background in primatology, neuroscience, and linguistics to make the book accessible to a general audience.
He is also engaged in research on the evolution of brain mechanisms for human language, pursuing the Mirror System Hypothesis that links language parity (the fact that what the speaker intends is roughly what the hearer understands) to the properties of the mirror system for grasping -- neurons active for both the execution and observation of actions -- to explain (amongst many other things) why human brains can acquire sign language as readily as speech.
A new interest is working with architects to better understand the neuroscience of the architectural experience and to develop a new field of neuromorphic architecture, "brains for buildings".
The author or editor of almost 40 books, Arbib has most recently edited "Who Needs Emotions?
To explain how the human brain evolved to enable us to learn and use language, Arbib discusses the processes of vocalization, facial expression, and manual gesture as means of communication, comparing humans and primates in these respects (Chapters 3 and 4). He emphasizes that activation for the execution and observation of grasping happens in the frontal lobe of the human brain, in or near Broca’s area, a region associated with speech production (Chapter 5). To further support the Mirror Neuron Hypothesis, Arbib discusses how hands are used to complement speech, and also the way sign-language users use their hands and face to communicate with no use of speech, highlighting the ancestral link between hands and language. He then argues that complex imitation for hand movements evolved adaptively because of its utility in the social sharing of practical skills and in the increased transfer of manual skills (Chapter 7). Both these types of skill-sharing existed long before there was language, when there was instead an open-ended form of communication that was “more powerful than the call and gesture systems of nonhuman primates but lacking the full richness of modern human languages’(p. 157).