The cyclic nature of speech production, as manifested in the syllabic organization of spoken language, is likely to reflect general properties of sensori-motor integration rather than merely a phylogenetic progression from mastication, teeth chattering, and lipsmacks. The temporal properties of spontaneous speech reflect the entropy of its underlying constituents and are optimized for rapid transmission and decoding of linguistic information conveyed by a complex constellation of acoustic and visual cues, suggesting that the dawn of human language may have (...) occurred when the articulatory cycle was efficiently yoked to the temporal dynamics of sensory coding and rapid retrieval from referential memory. (shrink)

The species-specific organizational property of speech is a continual mouth open-close alternation, the two phases of which are subject to continual articulatory modulation. The cycle constitutes the syllable, and the open and closed phases are segments framescontent displays that are prominent in many nonhuman primates. The new role of Broca's area and its surround in human vocal communication may have derived from its evolutionary history as the main cortical center for the control of ingestive processes. The frame and content (...) components of speech may have subsequently evolved separate realizations within two general purpose primate motor control systems: (1) a motivation-related medial system, including anterior cingulate cortex and the supplementary motor area, for self-generated behavior, formerly responsible for ancestral vocalization control and now also responsible for frames, and (2) a lateral system, including Broca's area and surround, and Wernicke's area, specialized for response to external input (and therefore the emergent vocal learning capacity) and more responsible for content. (shrink)

The Frame/Content theory deals with how and why the first language evolved the present-day speech mode of programming syllable “Frame” structures with segmental “Content” elements. The first words are considered, for biomechanical reasons, to have had the simple syllable frame structures of pre-speech babbling, and were perhaps parental terms, generated within the parent–infant dyad. Although all gestural origins theories have iconicity as a plausible alternative hypothesis for the origin of the meaning-signal link for words, they all share the (...) problems of how and why a fully fledged sign language, necessarily involving a structured phonology, changed to a spoken language. (shrink)

Temporal regularities in speech, such as interdependencies in the timing of speech events, are thought to scaffold early acquisition of the building blocks in speech. By providing on-line clues to the location and duration of upcoming syllables, temporal structure may aid segmentation and clustering of continuous speech into separable units. This hypothesis tacitly assumes that learners exploit predictability in the temporal structure of speech. Existing measures of speech timing tend to focus on first-order (...) regularities among adjacent units, and are overly sensitive to idiosyncrasies in the data they describe. Here, we compare several statistical methods on a sample of 18 languages, testing whether syllable occurrence is predictable over time. Rather than looking for differences between languages, we aim to find across languages (using clearly defined acoustic, rather than orthographic, measures), temporal predictability in the speech signal which could be exploited by a language learner. First, we analyse distributional regularities using two novel techniques: a Bayesian ideal learner analysis, and a simple distributional measure. Second, we model higher-order temporal structure—regularities arising in an ordered series of syllable timings—testing the hypothesis that non-adjacent temporal structures may explain the gap between subjectively-perceived temporal regularities, and the absence of universally-accepted lower-order objective measures. Together, our analyses provide limited evidence for predictability at different time scales, though higher-order predictability is difficult to reliably infer. We conclude that temporal predictability in speech may well arise from a combination of individually weak perceptual cues at multiple structural levels, but is challenging to pinpoint. (shrink)

This commentary supports MacNeilage's dismissal of an evolutionary development from sign language to spoken language but presents evidence of a feature in sign language (echo phonology) that links iconic signs to abstract vocal syllables. These data provide an insight into possible mechanism by which iconic manual gestures accompanied by vocalisation could have provided a route for the evolution of spoken language with its characteristically arbitrary form–meaning relationship.

Many animals, including dogs, produce vocal signals in which their mouths open and close producing In contrast, the vocal signals of species other than humans are tied to emotional states. The Broca's-Wernicke's area model of the brain bases of language is wrong.

A textbook for third year undergraduates and postgraduates. In a challenging philosophic investigation of the origin of consciousness and human culture, Dewart (religion, emeritus, U. of Toronto) proposes a theory to explain the origin of all specifically human traits. Complementing the theory of evolution through natural selection, it explains the emergence and those the continuing evolution of characterstics through the interaction of experience and speech. Annotation copyrighted by Book News, Inc., Portland, OR.

Scholars have long been captivated by the parallels between birdsong and human speech and language. In this book, leading scholars draw on the latest research to explore what birdsong can tell us about the biology of human speech and language and the consequences for evolutionary biology. They examine the cognitive and neural similarities between birdsong learning and speech and language acquisition, considering vocal imitation, auditory learning, an early vocalization phase, the structural properties of birdsong and human language, (...) and the striking similarities between the neural organization of learning and vocal production in birdsong and human speech. After outlining the basic issues involved in the study of both language and evolution, the contributors compare birdsong and language in terms of acquisition, recursion, and core structural properties, and then examine the neurobiology of song and speech, genomic factors, and the emergence and evolution of language. Contributors: Hermann Ackermann, Gabriël J.L. Beckers, Robert C. Berwick, Johan J. Bolhuis, Noam Chomsky, Frank Eisner, Martin Everaert, Michale S. Fee, Olga Fehér, Simon E. Fisher, W. Tecumseh Fitch, Jonathan B. Fritz, Sharon M.H. Gobes, Riny Huijbregts, Eric Jarvis, Robert Lachlan, Ann Law, Michael A. Long, Gary F. Marcus, Carolyn McGettigan, Daniel Mietchen, Richard Mooney, Sanne Moorman, Kazuo Okanoya, Christophe Pallier, Irene M. Pepperberg, Jonathan F. Prather, Franck Ramus, Eric Reuland, Constance Scharff, Sophie K. Scott, Neil Smith, Ofer Tchernichovski, Carel ten Cate, Christopher K. Thompson, Frank Wijnen, Moira Yip, Wolfram Ziegler, Willem Zuidema. (shrink)

Two computer simulations are investigated that model interaction of cultural evolution of language and biological evolution of adaptations to language. Both are agent‐based models in which a population of agents imitates each other using realistic vowels. The agents evolve under selective pressure for good imitation. In one model, the evolution of the vocal tract is modeled; in the other, a cognitive mechanism for perceiving speech accurately is modeled. In both cases, biological adaptations to using and learning (...) speech evolve, even though the system of speech sounds itself changes at a more rapid time scale than biological evolution. However, the fact that the available acoustic space is used maximally (a self‐organized result of cultural evolution) is constant, and therefore biological evolution does have a stable target. This work shows that when cultural and biological traits are continuous, their co‐evolution may lead to cognitive adaptations that are strong enough to detect empirically. (shrink)

Two computer simulations are investigated that model interaction of cultural evolution of language and biological evolution of adaptations to language. Both are agent-based models in which a population of agents imitates each other using realistic vowels. The agents evolve under selective pressure for good imitation. In one model, the evolution of the vocal tract is modeled; in the other, a cognitive mechanism for perceiving speech accurately is modeled. In both cases, biological adaptations to using and learning (...) speech evolve, even though the system of speech sounds itself changes at a more rapid time scale than biological evolution. However, the fact that the available acoustic space is used maximally is constant, and therefore biological evolution does have a stable target. This work shows that when cultural and biological traits are continuous, their co-evolution may lead to cognitive adaptations that are strong enough to detect empirically. (shrink)

Leading scholars draw on the latest research to explore what birdsong can tell us about the biology of human speech and language and the consequences for evolutionary biology.

The sound system of a language must be able to support a perceptual contrast between different words in order to signal communicatively relevant meaning distinctions. In this paper, we use a simple agent-based exemplar model in which the evolution of sound-category systems is understood as a co-evolutionary process, where the range of variation within sound categories is constrained by functional pressure to keep different words perceptually distinct. We show that this model can reproduce several observed effects on the range (...) of sound variation. We argue that phonological systems can be seen as finding a relative optimum of variation: Efficient communication is sustained while at the same time, hidden category variation provides pathways for future evolution. (shrink)

Inferences made from endocasts of fossil skulls cannot provide information on the function of particular neocortical areas or the subcortical pathways to prefrontal cortex that form part of the neural substrate for speech, syntax, and certain aspects of cognition. The neural bases of syntax cannot be disassociated from “communication.” Manual motor control was probably a preadaptive factor in the evolution of humansyntactic ability, but neurophysiological data on living humans show that speech motor control and syntax are more (...) closely linked. The evolution of fully modern speech occurred fairly recently; thoughHomo habilismay have had some degree of speech and syntactic ability, it was not fully modern. Stone tools are uncertain indices of language or cognition. (shrink)

The target article by Christiansen & Chater offers an integrated framework for the study of language acquisition and, possibly, a novel role for internal speech in language acquisition. However, the “Now-or-Never bottleneck” raises a paradox for language evolution. It seems to imply that language complexity has been either reduced over time or has remained the same. How, then, could languages as complex as ours have evolved in prelinguistic ancestors? Linguistic Platonism could offer a solution to this paradox.

The strong predominance of right-handedness appears to be a uniquely human characteristic, whereas the left-cerebral dominance for vocalization occurs in many species, including frogs, birds, and mammals. Right-handedness may have arisen because of an association between manual gestures and vocalization in the evolution of language. I argue that language evolved from manual gestures, gradually incorporating vocal elements. The transition may be traced through changes in the function of Broca's area. Its homologue in monkeys has nothing to do with vocal (...) control, but contains the so-called “mirror neurons,” the code for both the production of manual reaching movements and the perception of the same movements performed by others. This system is bilateral in monkeys, but predominantly left-hemispheric in humans, and in humans is involved with vocalization as well as manual actions. There is evidence that Broca's area is enlarged on the left side in Homo habilis, suggesting that a link between gesture and vocalization may go back at least two million years, although other evidence suggests that speech may not have become fully autonomous until Homo sapiens appeared some 170,000 years ago, or perhaps even later. The removal of manual gesture as a necessary component of language may explain the rapid advance of technology, allowing late migrations of Homo sapiens from Africa to replace all other hominids in other parts of the world, including the Neanderthals in Europe and Homo erectus in Asia. Nevertheless, the long association of vocalization with manual gesture left us a legacy of right-handedness. Key Words: cerebral dominance; gestures; handedness; hominids; language evolution; primates; speech; vocalization. (shrink)

A classic problem in cognitive science concerns how listeners perceive and understand speech as comprised of discrete words. We propose a Syllable Inference account of spoken word recognition and segmentation, under which alternative hierarchical models of syllables, words, and phonemes are dynamically posited from cues that include current and past speech rate, with a goal of maximal prediction of sensory input. Three experiments using the Visual World eye‐tracking paradigm provide evidence supporting our proposal.

We consider Sussman et al. 's suggestion that auditory biases for processing low-noise relationships among pairs of acoustic variables is a preadaptation for human speech processing. Data from other animal communication systems, especially those involving sexual selection, also suggest that neural biases in the receiver system can generate strong selection on the form of communication signals.

Recently theorists have developed competing accounts of the origins and nature of protolanguage and the subsequent evolution of language. Debate over these accounts is lively. Participants ask: Is music a direct precursor of language? Were the first languages gestural? Or is language continuous with primate vocalizations, such as the alarm calls of vervets? In this article I survey the leading hypotheses and lines of evidence, favouring a largely gestural conception of protolanguage. However, the “sticking point” of gestural accounts, to (...) use Robbins Burling’s phrase, is the need to explain how language shifted to a largely vocal medium. So with a critical eye I consider Michael Corballis’s most recent expression of his ideas about this transition. Corballis’s view is an excellent foil to mine and I present it as such. Contrary to Corballis’s account, and developing Burling’s conjecture that musicality played some role, I argue that the foundations of an evolving musicality provided the means and medium for the shift from gestural to vocal dominance in language. In other words, I suggest that an independently evolving musicality prepared ancient hominins, morphologically and cognitively, for intentional articulate vocal production, enabling the evolution of speech. (shrink)

We agree with MacNeilage's claim that speech stems from a volitional vocalization pathway between the cingulate and the supplementary motor area (SMA). We add the vocal self- monitoring system as the first recruitment of the Broca-Wernicke circuit. SMA control for “frames” is supported by wrong consonant-vowel recurring utterance aphasia and an imaging study of quasi-reiterant speech. The role of Broca's area is questioned in the emergence of “content,” because a primary motor mapping, embodying peripheral constraints, seems sufficient. Finally, (...) we reject a uniquely peripheral account of speech emergence. (shrink)

Because the evolution of speech production is beyond our expertise (and perhaps beyond everyone's expertise) we restrict our comments to areas in which data actually exist. We provide articulatory evidence consistent with the claims made about syllable structure in adult speech and infant babbling, but we also voice some disagreement about speech errors and the typing data.

While influential works since the 1970s have widely assumed that imitation is an innate skill in both human and non-human primate neonates, recent empirical studies and meta-analyses have challenged this view, indicating other forms of reward-based learning as relevant factors in the development of social behavior. The visual input translation into matching motor output that underlies imitation abilities instead seems to develop along with social interactions and sensorimotor experience during infancy and childhood. Recently, a new visual stream has been identified (...) in both human and non-human primate brains, updating the dual visual stream model. This third pathway is thought to be specialized for dynamics aspects of social perceptions such as eye-gaze, facial expression and crucially for audio-visual integration of speech. Here, we review empirical studies addressing an understudied but crucial aspect of speech and communication, namely the processing of visual orofacial cues and its integration with vocal auditory cues. Along this review, we offer new insights from our understanding of speech as the product of evolution and development of a rhythmic and multimodal organization of sensorimotor brain networks, supporting volitional motor control of the upper vocal tract and audio-visual voices-faces integration. (shrink)

A perception-action system may underlie the mechanisms by which human speech exchange in social interaction is managed, as well as the evolutionary precursors of these mechanisms in closely related species. Some phenomena of interaction well-studied by sociologists are suggested as a point of departure for further research.

This paper and its subsequent parts (Part II and Part III) build on an earlier publication (McKenna 1986). They suggest that important clinical data on the relationship between infantile constitutional deficits and microenvironmental factors relevant to SIDS can be acquired by examining the physiological regulatory effects (well documented among nonhuman primates) that parents assert on their infants when they sleep together.I attempt to show why access to parental sensory cues (movement, touch, smell, sound) that induce arousals in infants while they (...) sleep could possibly help one of many different subclasses of infants either to override certain kinds of sleep-induced breathing control errors suspected to be involved in SIDS or to avoid them altogether. I do not suggest that solitary nocturnal sleep “causes” SIDS, that all parents should sleep with their infants, or that traditional SIDS research strategies should be abandoned. However, using evolutionary data, I do suggest that an adaptive fit exists between parent-infant sleep contact and the natural physiological vulnerabilities of the neurologically immature human infant, whose breathing system is more complex than that of other mammals owing to its speech-breathing abilities. This “fit” is best understood, it is argued, in terms of the 4–5 million years of human evolution in which parent-infant contact was almost certainly continuous during at least the first year of an infant’s life. Thus, to dismiss the idea that solitary sleep has no physiological consequences for infants does not accord with scientific facts. (shrink)

Charmed by Corballis's presentation, we challenge the use of mirror neurons as a supporting platform for the gestural theory of language, the link between vocalization and cerebral specialization, and the relationship between gesture and language as two separate albeit coupled systems of communication. We revive an alternative explanation of lateralization of language and handedness.

There is evidence of reciprocal connectivity, similarity of oscillatory responses to stimulation of multiple motor and somatosensory cortices, whole system oscillation, and short- latency responses to behavioral perturbation. These suggest that frame/content may be instantiated by overlapping neural populations, and that the genesis of frame oscillations may be profitably thought of as an emergent property of a distributed neural system.