Is the Neural Basis of Vocalisation Different in Non-Human Primates and Homo Sapiens?

Author(s):  
Detlev Ploog

From an evolutionary perspective, the voice was a prerequisite for the emergence of speech. Speech, the most advanced mode of vocal communication, became possible only after gradual transformations of the sound-producing system and its central nervous control, in co-evolution with the transformations of the auditory system, had taken place. The discussion suggests that the last step in the evolution of the phonatory system in the brain was the outgrowing and augmenting of the fine fibre portion of the pyramidal tract synapsing directly with the motor nuclei for the vocal cords and the tongue, so that the direct and voluntary control of vocal behaviour became possible. It holds that the answer to the question raised in the title is ‘yes’. The neural basis is in fact quite different. The chapter also explains this difference and its consequences for the evolution of language.

This volume addresses the question of the speciation of modern Homo Sapiens. The subject raises profound questions about the nature of the species, our defining characteristic (it is suggested it is language), and the brain changes and their genetic basis that make us distinct. The British Academy and the Academy of Medical Sciences have brought together experts from palaeontology, archaeology, linguistics, psychology, genetics and evolutionary theory to present evidence and theories of our understanding of these issues. Palaeontological and genetic work suggests that the transition from a precursor hominid species to modern man took place between 100,000 and 150,000 years ago. Some chapters discuss what is most characteristic of the species, focussing on language and its possible basis in brain lateralization. This work is placed in the context of speciation theory, which has remained a subject of considerable debate since the evolutionary synthesis of Mendelian genetics and Darwinian theory. The timing of specific transitions in hominid evolution is discussed, as also is the question of the neural basis of language. Other chapters address the possible genetic nature of the transition, with reference to changes on the X and Y chromosomes that may account for sex differences in lateralization and verbal ability. These differences are discussed in terms of the theory of sexual selection, and with reference to the mechanisms of speciation.


2005 ◽  
Vol 5 (1) ◽  
pp. 29-37
Author(s):  
elisabeth townsend

Humans: The Cooking Ape Perhaps the first to suggest that humans were cooking as early as 1.9 million years ago, Richard Wrangham shows through his new research and his imagination how and possibly when cooking changed humans dramatically. Wrangham, Harvard University primatologist and MacArthur Fellow, has been studying the evolution of human cooking. After 25 years of primate research at his site in Kibale, Uganda, Wrangham is best known for explaining the similarity and differences across species of primate social organizations. In Kibale, he has analyzed chimpanzees’ behavior: how it’s changed when they interact with the environment and how their social groups have evolved. In particular, he noticed how food changed their interactions with each other. Like that of chimps, human behavior has been affected by food, especially as they shifted from raw to cooked food. Moving from eating food as it was discovered to collecting edibles and cooking them altered our social relationships. Cooked food has changed Homo sapiens physically by making food more digestible thereby altering jaws, teeth, and guts, and providing more calories for more expensive organs such as the brain. Wrangham discusses when and how humans may have started using fire to cook food, what they cooked, and the transition from cooking in an outdoor fire to hearths and open ovens.


2021 ◽  
Author(s):  
Chiara De Gregorio ◽  
Filippo Carugati ◽  
Vittoria Estienne ◽  
Daria Valente ◽  
Teresa Raimondi ◽  
...  

Abstract In animal vocal communication, the development of adult-like vocalization is fundamental to interact appropriately with conspecifics. However, the factors that guide ontogenetic changes in the acoustic features remains poorly understood. In contrast with a historical view of nonhuman primate vocal production as substantially innate, recent research suggests that inheritance and physiological modification can only explain some of the developmental changes in call structure during growth. A particular case of acoustic communication is the indris' singing behavior, a peculiar case among Strepsirrhine primates. Thanks to a decade of intense data collection, this work provides the first long-term quantitative analysis on song development in a singing primate. To understand the ontogeny of such a complex vocal output, we investigated juvenile and sub-adult indris' vocal behaviour, and we found that young individuals started participating in the chorus years earlier than previously reported. Our results indicated that spectro-temporal song parameters underwent essential changes during growth. In particular, the age and sex of the emitter influenced the indris' vocal activity. We found that frequency parameters showed consistent changes across the sexes, but the temporal features showed different developmental trajectories for males and females. Given the low level of morphological sexual dimorphism and the marked differences in vocal behavior, we hypothesize that factors like social influences and auditory feedback may affect songs' features, resulting in high vocal flexibility in juvenile indris. This trait may be pivotal in a species that engages in choruses with rapid vocal turn-taking.


2009 ◽  
Vol 9 ◽  
pp. 588-605 ◽  
Author(s):  
Bjørn Grinde

The evolutionary perspective is relevant for the study of quality of life in that the brain, including its capacity for positive and negative states of mind, has been shaped by the forces of evolution. The present text uses this perspective to discuss three questions related to the observation that human interactions are a particular important factor for well-being: (1) What is known about the inherent nature of our social propensities? (2) Is the present situation responsible for a suboptimal quality of life? (3) Are there alternatives to the organization of mainstream Western society? Based on this discussion, the question is raised as to whether it is possible to suggest improvements. Briefly, it seems possible to create conditions that enhance social relations and to the extent that happiness is considered an important objective, this is a relevant endeavor.


2021 ◽  
Vol 2021 (9) ◽  
pp. pdb.prot106872
Author(s):  
Ayako Yamaguchi

Understanding the neural basis of behavior is a challenging task for technical reasons. Most methods of recording neural activity require animals to be immobilized, but neural activity associated with most behavior cannot be recorded from an anesthetized, immobilized animal. Using amphibians, however, there has been some success in developing in vitro brain preparations that can be used for electrophysiological and anatomical studies. Here, we describe an ex vivo frog brain preparation from which fictive vocalizations (the neural activity that would have produced vocalizations had the brain been attached to the muscle) can be elicited repeatedly. When serotonin is applied to the isolated brains of male and female African clawed frogs, Xenopus laevis, laryngeal nerve activity that is a facsimile of those that underlie sex-specific vocalizations in vivo can be readily recorded. Recently, this preparation was successfully used in other species within the genus including Xenopus tropicalis and Xenopus victorianus. This preparation allows a variety of techniques to be applied including extracellular and intracellular electrophysiological recordings and calcium imaging during vocal production, surgical and pharmacological manipulation of neurons to evaluate their impact on motor output, and tract tracing of the neural circuitry. Thus, the preparation is a powerful tool with which to understand the basic principles that govern the production of coherent and robust motor programs in vertebrates.


Author(s):  
Peter Gärdenfors ◽  
Anders Högberg

Only among humans is teaching intentional, socially structured, and symbolically mediated. In this chapter, evidence regarding the evolution of the mindreading and communicative capacities underlying intentional teaching is reviewed. Play, rehearsal, and apprenticeship are discussed as central to the analyses of teaching. We present a series of levels of teaching. First of all, we separate non-intentional from intentional teaching. For non-intentional teaching, we discuss facilitation and approval/disapproval and analyze examples from non-human species. We then distinguish between six levels of intentional teaching: (1) intentional approval/disapproval, (2) drawing attention, (3) demonstrating, (4) communicating concepts, (5) explaining concept relations, and (6) narrating. We hypothesize that level after level has been added during the evolution of teaching. We analyze communicative requirements for the levels, concluding that displaced communication is required for level 4 and symbolic language only for levels 5 to 6. We focus on the role of demonstration and pantomime and argue that pantomime has been instrumental in the evolution of language. We present archaeological evidence for when the different levels of teaching emerge. We argue that learning Oldowan technology requires teaching by demonstration, and that learning Acheulean hand-axe technology requires communicating concepts. It follows that several levels of intentional teaching predate homo sapiens.


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