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Ekström AG, Gannon C, Edlund J, Moran S, Lameira AR. Chimpanzee utterances refute purported missing links for novel vocalizations and syllabic speech. Sci Rep 2024; 14:17135. [PMID: 39054330 PMCID: PMC11272771 DOI: 10.1038/s41598-024-67005-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Nonhuman great apes have been claimed to be unable to learn human words due to a lack of the necessary neural circuitry. We recovered original footage of two enculturated chimpanzees uttering the word "mama" and subjected recordings to phonetic analysis. Our analyses demonstrate that chimpanzees are capable of syllabic production, achieving consonant-to-vowel phonetic contrasts via the simultaneous recruitment and coupling of voice, jaw and lips. In an online experiment, human listeners naive to the recordings' origins reliably perceived chimpanzee utterances as syllabic utterances, primarily as "ma-ma", among foil syllables. Our findings demonstrate that in the absence of direct data-driven examination, great ape vocal production capacities have been underestimated. Chimpanzees possess the neural building blocks necessary for speech.
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Affiliation(s)
- Axel G Ekström
- Speech, Music & Hearing, KTH Royal Institute of Technology, Lindstedtsvägen 24, 118 28, Stockholm, Sweden.
| | | | - Jens Edlund
- Speech, Music & Hearing, KTH Royal Institute of Technology, Lindstedtsvägen 24, 118 28, Stockholm, Sweden
| | - Steven Moran
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Anthropology, University of Miami, Coral Gables, USA
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2
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Sclafani V, De Pascalis L, Bozicevic L, Sepe A, Ferrari PF, Murray L. Similarities and differences in the functional architecture of mother- infant communication in rhesus macaque and British mother-infant dyads. Sci Rep 2023; 13:13164. [PMID: 37574499 PMCID: PMC10423724 DOI: 10.1038/s41598-023-39623-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/27/2023] [Indexed: 08/15/2023] Open
Abstract
Similarly to humans, rhesus macaques engage in mother-infant face-to-face interactions. However, no previous studies have described the naturally occurring structure and development of mother-infant interactions in this population and used a comparative-developmental perspective to directly compare them to the ones reported in humans. Here, we investigate the development of infant communication, and maternal responsiveness in the two groups. We video-recorded mother-infant interactions in both groups in naturalistic settings and analysed them with the same micro-analytic coding scheme. Results show that infant social expressiveness and maternal responsiveness are similarly structured in humans and macaques. Both human and macaque mothers use specific mirroring responses to specific infant social behaviours (modified mirroring to communicative signals, enriched mirroring to affiliative gestures). However, important differences were identified in the development of infant social expressiveness, and in forms of maternal responsiveness, with vocal responses and marking behaviours being predominantly human. Results indicate a common functional architecture of mother-infant communication in humans and monkeys, and contribute to theories concerning the evolution of specific traits of human behaviour.
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Affiliation(s)
- V Sclafani
- Winnicott Research Unit, Department of Psychology, University of Reading, Reading, UK.
- College of Social Sciences, School of Psychology, University of Lincoln, Brayford Pool, Lincoln, LN6 7TS, UK.
| | - L De Pascalis
- Winnicott Research Unit, Department of Psychology, University of Reading, Reading, UK.
- Department of Psychology, Institute of Population Health, University of Liverpool, Liverpool, UK.
- Department of Psychology, University of Bologna, Bologna, Italy.
| | - L Bozicevic
- Winnicott Research Unit, Department of Psychology, University of Reading, Reading, UK
- Department of Primary Care & Mental Health, Institute of Population Health, University of Liverpool, Liverpool, Merseyside, UK
| | - A Sepe
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Laboratory of Neuro- and Psychophysiology, Department of Neurosciences, KU Leuven Medical School, Leuven, Belgium
| | - P F Ferrari
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Institut des Sciences Cognitives 'Marc Jeannerod', CNRS, Bron, and Université Claude Bernard Lyon 1, Lyon, France
| | - L Murray
- Winnicott Research Unit, Department of Psychology, University of Reading, Reading, UK
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3
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Ford A, Kovacs-Balint ZA, Wang A, Feczko E, Earl E, Miranda-Domínguez Ó, Li L, Styner M, Fair D, Jones W, Bachevalier J, Sánchez MM. Functional maturation in visual pathways predicts attention to the eyes in infant rhesus macaques: Effects of social status. Dev Cogn Neurosci 2023; 60:101213. [PMID: 36774827 PMCID: PMC9925610 DOI: 10.1016/j.dcn.2023.101213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
Differences in looking at the eyes of others are one of the earliest behavioral markers for social difficulties in neurodevelopmental disabilities, including autism. However, it is unknown how early visuo-social experiences relate to the maturation of infant brain networks that process visual social stimuli. We investigated functional connectivity (FC) within the ventral visual object pathway as a contributing neural system. Densely sampled, longitudinal eye-tracking and resting state fMRI (rs-fMRI) data were collected from infant rhesus macaques, an important model of human social development, from birth through 6 months of age. Mean trajectories were fit for both datasets and individual trajectories from subjects with both eye-tracking and rs-fMRI data were used to test for brain-behavior relationships. Exploratory findings showed infants with greater increases in FC between left V1 to V3 visual areas have an earlier increase in eye-looking before 2 months. This relationship was moderated by social status such that infants with low social status had a stronger association between left V1 to V3 connectivity and eye-looking than high status infants. Results indicated that maturation of the visual object pathway may provide an important neural substrate supporting adaptive transitions in social visual attention during infancy.
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Affiliation(s)
- Aiden Ford
- Neuroscience Program, Emory University, Atlanta, GA, USA; Marcus Autism Center, USA.
| | | | - Arick Wang
- Emory Natl. Primate Res. Ctr., Emory Univ., Atlanta, GA, USA; Dept of Psychology, Emory University, Atlanta, GA, USA
| | - Eric Feczko
- Dept. of Pediatrics, University of Minnesota, Minneapolis, MN, USA; Masonic Institute of the Developing Brain, University of Minnesota, Minneapolis, MN, USA
| | - Eric Earl
- Data Science and Sharing Team, National Institute of Mental Health, NIH, DHHS, Bethesda, MD, USA
| | - Óscar Miranda-Domínguez
- Dept. of Pediatrics, University of Minnesota, Minneapolis, MN, USA; Masonic Institute of the Developing Brain, University of Minnesota, Minneapolis, MN, USA
| | - Longchuan Li
- Marcus Autism Center, USA; Children's Healthcare of Atlanta, GA, USA; Dept. of Pediatrics, Emory University, Sch. of Med., Atlanta, GA, USA
| | - Martin Styner
- Dept. of Psychiatry, Univ. of North Carolina, Chapel Hill, NC, USA
| | - Damien Fair
- Dept. of Pediatrics, University of Minnesota, Minneapolis, MN, USA; Masonic Institute of the Developing Brain, University of Minnesota, Minneapolis, MN, USA; Institute of Child Development, University of Minnesota, Minneapolis, MN, USA; Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, USA
| | - Warren Jones
- Marcus Autism Center, USA; Children's Healthcare of Atlanta, GA, USA; Dept. of Pediatrics, Emory University, Sch. of Med., Atlanta, GA, USA
| | - Jocelyne Bachevalier
- Emory Natl. Primate Res. Ctr., Emory Univ., Atlanta, GA, USA; Dept of Psychology, Emory University, Atlanta, GA, USA
| | - Mar M Sánchez
- Emory Natl. Primate Res. Ctr., Emory Univ., Atlanta, GA, USA; Dept. Psychiatry & Behavioral Sciences, Emory Univ., Sch. of Med., Atlanta, GA, USA
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4
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He L. Characterizing first and second language rhythm in English using spectral coherence between temporal envelope and mouth opening-closing movements. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 152:567. [PMID: 35931510 DOI: 10.1121/10.0012694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
This study investigated the rhythmic differences between first and second language English from 19 native speakers of American English and an equal number of native speakers of Mandarin. Speech rhythm was viewed from MacNeilage's frame/content theory. The spectral coherence between the temporal envelope and the mouth opening and closing kinematics was computed to operationalize the rhythmic frame. The spectral centroid, spread, rolloff, flatness, and entropy were calculated to reveal the frequency distribution patterns in the coherence. Using a binary logistic regression model, these measures were collectively found to be effective in characterizing rhythmic differences between native and non-native groups (A' = 0.71 and B″D = -0.06). Specifically, the native group was significantly higher than the non-native group in terms of spectral centroid and spread, whereas the native group was significantly lower than its non-native counterpart in terms of spectral flatness and entropy. Both groups were not significantly different in spectral rolloff. Possible explanations for the result as well as the efficacy of employing the aforesaid coherence in speech rhythm research in general were discussed.
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Affiliation(s)
- Lei He
- Department of Computational Linguistics, University of Zurich (UZH), Zurich-Oerlikon 8050, Switzerland
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5
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Michon M, Zamorano-Abramson J, Aboitiz F. Faces and Voices Processing in Human and Primate Brains: Rhythmic and Multimodal Mechanisms Underlying the Evolution and Development of Speech. Front Psychol 2022; 13:829083. [PMID: 35432052 PMCID: PMC9007199 DOI: 10.3389/fpsyg.2022.829083] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 03/07/2022] [Indexed: 11/24/2022] Open
Abstract
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 (i.e., the perception of a speaker's lips and tongue movements) 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.
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Affiliation(s)
- Maëva Michon
- Laboratory for Cognitive and Evolutionary Neuroscience, Department of Psychiatry, Faculty of Medicine, Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Estudios en Neurociencia Humana y Neuropsicología, Facultad de Psicología, Universidad Diego Portales, Santiago, Chile
| | - José Zamorano-Abramson
- Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Santiago, Chile
| | - Francisco Aboitiz
- Laboratory for Cognitive and Evolutionary Neuroscience, Department of Psychiatry, Faculty of Medicine, Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de Chile, Santiago, Chile
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6
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Turk AZ, SheikhBahaei S. Morphometric analysis of astrocytes in vocal production circuits of common marmoset (Callithrix jacchus). J Comp Neurol 2021; 530:574-589. [PMID: 34387357 PMCID: PMC8716418 DOI: 10.1002/cne.25230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/10/2022]
Abstract
Astrocytes, the star-shaped glial cells, are the most abundant non-neuronal cell population in the central nervous system. They play a key role in modulating activities of neural networks, including those involved in complex motor behaviors. Common marmosets (Callithrix jacchus), the most vocal non-human primate (NHP), have been used to study the physiology of vocalization and social vocal production. However, the neural circuitry involved in vocal production is not fully understood. In addition, even less is known about the involvement of astrocytes in this circuit. To understand the role, that astrocytes may play in the complex behavior of vocalization, the initial step may be to study their structural properties in the cortical and subcortical regions that are known to be involved in vocalization. Here, in the common marmoset, we identify all astrocytic subtypes seen in other primate's brains, including intralaminar astrocytes. In addition, we reveal detailed structural characteristics of astrocytes and perform morphometric analysis of astrocytes residing in the cortex and midbrain regions that are associated with vocal production. We found that cortical astrocytes in these regions illustrate a higher level of complexity when compared to those in the midbrain. We hypothesize that this complexity that is expressed in cortical astrocytes may reflect their functions to meet the metabolic/structural needs of these regions.
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Affiliation(s)
- Ariana Z Turk
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Shahriar SheikhBahaei
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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7
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Brown S, Yuan Y, Belyk M. Evolution of the speech-ready brain: The voice/jaw connection in the human motor cortex. J Comp Neurol 2020; 529:1018-1028. [PMID: 32720701 DOI: 10.1002/cne.24997] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/07/2020] [Accepted: 07/19/2020] [Indexed: 12/18/2022]
Abstract
A prominent model of the origins of speech, known as the "frame/content" theory, posits that oscillatory lowering and raising of the jaw provided an evolutionary scaffold for the development of syllable structure in speech. Because such oscillations are nonvocal in most nonhuman primates, the evolution of speech required the addition of vocalization onto this scaffold in order to turn such jaw oscillations into vocalized syllables. In the present functional MRI study, we demonstrate overlapping somatotopic representations between the larynx and the jaw muscles in the human primary motor cortex. This proximity between the larynx and jaw in the brain might support the coupling between vocalization and jaw oscillations to generate syllable structure. This model suggests that humans inherited voluntary control of jaw oscillations from ancestral species, but added voluntary control of vocalization onto this via the evolution of a new brain area that came to be situated near the jaw region in the human motor cortex.
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Affiliation(s)
- Steven Brown
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Ye Yuan
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Michel Belyk
- Department of Speech Hearing and Phonetic Sciences, University College London, London, UK
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8
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Bettle R, Rosati AG. The evolutionary origins of natural pedagogy: Rhesus monkeys show sustained attention following nonsocial cues versus social communicative signals. Dev Sci 2020; 24:e12987. [PMID: 32412163 DOI: 10.1111/desc.12987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/09/2020] [Accepted: 05/05/2020] [Indexed: 12/30/2022]
Abstract
The natural pedagogy hypothesis proposes that human infants preferentially attend to communicative signals from others, facilitating rapid cultural learning. In this view, sensitivity to such signals is a uniquely human adaptation and as such nonhuman animals should not produce or utilize these communicative signals. We test these evolutionary predictions by examining sensitivity to communicative cues in 206 rhesus monkeys (Macaca mulatta) using an expectancy looking time task modeled on prior work with infants. Monkeys observed a human actor who either made eye contact and vocalized to the monkey (social cue), or waved a fruit in front of her face and produced a tapping sound (nonsocial cue). The actor then either looked at an object (referential look) or looked toward empty space (look away). We found that, unlike human infants in analogous situations, rhesus monkeys looked longer at events following nonsocial cues, regardless of the demonstrator's subsequent looking behavior. Moreover younger and older monkeys showed similar patterns of responses across development. These results provide support for the natural pedagogy hypothesis, while also highlighting evolutionary changes in human sensitivity to communicative signals.
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Affiliation(s)
- Rosemary Bettle
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| | - Alexandra G Rosati
- Department of Psychology, University of Michigan, Ann Arbor, MI, USA.,Department of Anthropology, University of Michigan, Ann Arbor, MI, USA
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9
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Pereira AS, Kavanagh E, Hobaiter C, Slocombe KE, Lameira AR. Chimpanzee lip-smacks confirm primate continuity for speech-rhythm evolution. Biol Lett 2020; 16:20200232. [PMID: 32453963 DOI: 10.1098/rsbl.2020.0232] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Speech is a human hallmark, but its evolutionary origins continue to defy scientific explanation. Recently, the open-close mouth rhythm of 2-7 Hz (cycles/second) characteristic of all spoken languages has been identified in the orofacial signals of several nonhuman primate genera, including orangutans, but evidence from any of the African apes remained missing. Evolutionary continuity for the emergence of speech is, thus, still inconclusive. To address this empirical gap, we investigated the rhythm of chimpanzee lip-smacks across four populations (two captive and two wild). We found that lip-smacks exhibit a speech-like rhythm at approximately 4 Hz, closing a gap in the evidence for the evolution of speech-rhythm within the primate order. We observed sizeable rhythmic variation within and between chimpanzee populations, with differences of over 2 Hz at each level. This variation did not result, however, in systematic group differences within our sample. To further explore the phylogenetic and evolutionary perspective on this variability, inter-individual and inter-population analyses will be necessary across primate species producing mouth signals at speech-like rhythm. Our findings support the hypothesis that speech recruited ancient primate rhythmic signals and suggest that multi-site studies may still reveal new windows of understanding about these signals' use and production along the evolutionary timeline of speech.
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Affiliation(s)
- André S Pereira
- School of Psychology and Neuroscience, University of St Andrews, St Mary's Quad, South Street, St Andrews, KY16 9JP, UK.,School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Eithne Kavanagh
- Department of Psychology, University of York, Heslington, York, YO10 5DD, UK
| | - Catherine Hobaiter
- School of Psychology and Neuroscience, University of St Andrews, St Mary's Quad, South Street, St Andrews, KY16 9JP, UK
| | - Katie E Slocombe
- Department of Psychology, University of York, Heslington, York, YO10 5DD, UK
| | - Adriano R Lameira
- School of Psychology and Neuroscience, University of St Andrews, St Mary's Quad, South Street, St Andrews, KY16 9JP, UK.,Department of Psychology, University of Warwick, University Road, Coventry, CV4 7AL, UK
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10
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Wang A, Payne C, Moss S, Jones WR, Bachevalier J. Early developmental changes in visual social engagement in infant rhesus monkeys. Dev Cogn Neurosci 2020; 43:100778. [PMID: 32510341 PMCID: PMC7271941 DOI: 10.1016/j.dcn.2020.100778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/20/2020] [Accepted: 03/23/2020] [Indexed: 11/16/2022] Open
Abstract
Impairments in social interaction in Autism Spectrum Disorder (ASD) differ greatly across individuals and vary throughout an individual’s lifetime. Yet, an important marker of ASD in infancy is deviations in social-visual engagement, such as the reliably detectable early deviations in attention to the eyes or to biological movement (Klin et al., 2015). Given the critical nature of these early developmental periods, understanding its neurobehavioral underpinnings by means of a nonhuman primate model will be instrumental to understanding the pathophysiology of ASD. Like humans, rhesus macaques 1) develop in rich and complex social behaviors, 2) progressively develop social skills throughout infancy, and 3) have high similarities with humans in brain anatomy and cognitive functions (Machado and Bachevalier, 2003). In this study, male infant rhesus macaques living with their mothers in complex social groups were eye-tracked longitudinally from birth to 6 months while viewing full-faced videos of unfamiliar rhesus monkeys differing in age and sex. The results indicated a critical period for the refinement of social skills around 4–8 weeks of age in rhesus macaques. Specifically, infant monkeys’ fixation to the eyes shows an inflection in developmental trajectory, increasing from birth to 8 weeks, decreasing slowly to a trough between 14–18 weeks, before increasing again. These results parallel the developmental trajectory of social visual engagement published in human infants (Jones & Klin, 2013) and suggest the presence of a switch in the critical networks supporting these early developing social skills that is highly conserved between rhesus macaque and human infant development.
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Affiliation(s)
- Arick Wang
- Yerkes National Primate Research Ctr., Emory University, Atlanta, GA, 30329, United States; Dept. of Psychology, Emory University, Atlanta, GA, 30322, United States.
| | - Christa Payne
- Yerkes National Primate Research Ctr., Emory University, Atlanta, GA, 30329, United States
| | - Shannon Moss
- Yerkes National Primate Research Ctr., Emory University, Atlanta, GA, 30329, United States
| | - Warren R Jones
- Dept. of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, United States; Marcus Autism Center, Atlanta, GA, 30329, United States
| | - Jocelyne Bachevalier
- Yerkes National Primate Research Ctr., Emory University, Atlanta, GA, 30329, United States; Dept. of Psychology, Emory University, Atlanta, GA, 30322, United States
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Prieur J, Barbu S, Blois‐Heulin C, Lemasson A. The origins of gestures and language: history, current advances and proposed theories. Biol Rev Camb Philos Soc 2019; 95:531-554. [DOI: 10.1111/brv.12576] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 11/30/2019] [Accepted: 12/03/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Jacques Prieur
- Department of Education and PsychologyComparative Developmental Psychology, Freie Universität Berlin Berlin Germany
- Univ Rennes, Normandie Univ, CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 F‐35380 Paimpont France
| | - Stéphanie Barbu
- Univ Rennes, Normandie Univ, CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 F‐35380 Paimpont France
| | - Catherine Blois‐Heulin
- Univ Rennes, Normandie Univ, CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 F‐35380 Paimpont France
| | - Alban Lemasson
- Univ Rennes, Normandie Univ, CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 F‐35380 Paimpont France
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12
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Ravignani A, Dalla Bella S, Falk S, Kello CT, Noriega F, Kotz SA. Rhythm in speech and animal vocalizations: a cross-species perspective. Ann N Y Acad Sci 2019; 1453:79-98. [PMID: 31237365 PMCID: PMC6851814 DOI: 10.1111/nyas.14166] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/14/2019] [Accepted: 05/24/2019] [Indexed: 12/31/2022]
Abstract
Why does human speech have rhythm? As we cannot travel back in time to witness how speech developed its rhythmic properties and why humans have the cognitive skills to process them, we rely on alternative methods to find out. One powerful tool is the comparative approach: studying the presence or absence of cognitive/behavioral traits in other species to determine which traits are shared between species and which are recent human inventions. Vocalizations of many species exhibit temporal structure, but little is known about how these rhythmic structures evolved, are perceived and produced, their biological and developmental bases, and communicative functions. We review the literature on rhythm in speech and animal vocalizations as a first step toward understanding similarities and differences across species. We extend this review to quantitative techniques that are useful for computing rhythmic structure in acoustic sequences and hence facilitate cross-species research. We report links between vocal perception and motor coordination and the differentiation of rhythm based on hierarchical temporal structure. While still far from a complete cross-species perspective of speech rhythm, our review puts some pieces of the puzzle together.
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Affiliation(s)
- Andrea Ravignani
- Artificial Intelligence LaboratoryVrije Universiteit BrusselBrusselsBelgium
- Institute for Advanced StudyUniversity of AmsterdamAmsterdamthe Netherlands
| | - Simone Dalla Bella
- International Laboratory for BrainMusic and Sound Research (BRAMS)MontréalQuebecCanada
- Department of PsychologyUniversity of MontrealMontréalQuebecCanada
- Department of Cognitive PsychologyWarsawPoland
| | - Simone Falk
- International Laboratory for BrainMusic and Sound Research (BRAMS)MontréalQuebecCanada
- Laboratoire de Phonétique et Phonologie, UMR 7018, CNRS/Université Sorbonne Nouvelle Paris‐3Institut de Linguistique et Phonétique générales et appliquéesParisFrance
| | | | - Florencia Noriega
- Chair for Network DynamicsCenter for Advancing Electronics Dresden (CFAED), TU DresdenDresdenGermany
- CODE University of Applied SciencesBerlinGermany
| | - Sonja A. Kotz
- International Laboratory for BrainMusic and Sound Research (BRAMS)MontréalQuebecCanada
- Basic and Applied NeuroDynamics Laboratory, Faculty of Psychology and Neuroscience, Department of Neuropsychology and PsychopharmacologyMaastricht UniversityMaastrichtthe Netherlands
- Department of NeuropsychologyMax‐Planck Institute for Human Cognitive and Brain SciencesLeipzigGermany
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14
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15
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Koda H, Kunieda T, Nishimura T. From hand to mouth: monkeys require greater effort in motor preparation for voluntary control of vocalization than for manual actions. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180879. [PMID: 30564395 PMCID: PMC6281949 DOI: 10.1098/rsos.180879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/30/2018] [Indexed: 05/21/2023]
Abstract
Voluntary control of vocal production is an essential component of the language faculty, which is thought to distinguish humans from other primates. Recent experiments have begun to reveal the capability of non-human primates to perform vocal control; however, the mechanisms underlying this ability remain unclear. Here, we revealed that Japanese macaque monkeys can learn to vocalize voluntarily through a different mechanism than that used for manual actions. The monkeys rapidly learned to touch a computer monitor when a visual stimulus was presented and showed a capacity for flexible adaptation, such that they reacted when the visual stimulus was shown at an unexpected time. By contrast, successful vocal training required additional time, and the monkeys exhibited difficulty with vocal execution when the visual stimulus appeared earlier than expected; this occurred regardless of extensive training. Thus, motor preparation before execution of an action may be a key factor in distinguishing vocalization from manual actions in monkeys; they do not exhibit a similar ability to perform motor preparation in the vocal domains. By performing direct comparisons, this study provides novel evidence regarding differences in motor control abilities between vocal and manual actions. Our findings support the suggestion that the functional expansion from hand to mouth might be a critical evolutionary event for the acquisition of voluntary control of vocalizations.
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Affiliation(s)
- Hiroki Koda
- Primate Research Institute, Kyoto University, Kyoto, Japan
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16
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Rosati AG, Arre AM, Platt ML, Santos LR. Developmental shifts in social cognition: socio-emotional biases across the lifespan in rhesus monkeys. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2573-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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17
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Alexandrou AM, Saarinen T, Kujala J, Salmelin R. Cortical Tracking of Global and Local Variations of Speech Rhythm during Connected Natural Speech Perception. J Cogn Neurosci 2018; 30:1704-1719. [PMID: 29916785 DOI: 10.1162/jocn_a_01295] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
During natural speech perception, listeners must track the global speaking rate, that is, the overall rate of incoming linguistic information, as well as transient, local speaking rate variations occurring within the global speaking rate. Here, we address the hypothesis that this tracking mechanism is achieved through coupling of cortical signals to the amplitude envelope of the perceived acoustic speech signals. Cortical signals were recorded with magnetoencephalography (MEG) while participants perceived spontaneously produced speech stimuli at three global speaking rates (slow, normal/habitual, and fast). Inherently to spontaneously produced speech, these stimuli also featured local variations in speaking rate. The coupling between cortical and acoustic speech signals was evaluated using audio-MEG coherence. Modulations in audio-MEG coherence spatially differentiated between tracking of global speaking rate, highlighting the temporal cortex bilaterally and the right parietal cortex, and sensitivity to local speaking rate variations, emphasizing the left parietal cortex. Cortical tuning to the temporal structure of natural connected speech thus seems to require the joint contribution of both auditory and parietal regions. These findings suggest that cortical tuning to speech rhythm operates on two functionally distinct levels: one encoding the global rhythmic structure of speech and the other associated with online, rapidly evolving temporal predictions. Thus, it may be proposed that speech perception is shaped by evolutionary tuning, a preference for certain speaking rates, and predictive tuning, associated with cortical tracking of the constantly changing-rate of linguistic information in a speech stream.
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18
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He L. Development of speech rhythm in first language: The role of syllable intensity variability. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:EL463. [PMID: 29960429 DOI: 10.1121/1.5042083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The opening-closing alternations of the mouth were viewed as the articulatory basis of speech rhythm. Such articulatory cycles have been observed to highly correlate with the intensity curve of the speech signal. Analysis of the intensity variability in English monolingual children and adults revealed that (1) adults showed significantly smaller intensity variability than children, and (2) intensity variability decreased from intermediate-aged children to older children. Maturation of articulatory motor control is likely to be the main reason for the reduced variability in articulatory cycles, and hence smaller intensity variability in adults and older children.
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Affiliation(s)
- Lei He
- Department of Linguistics, University of Tübingen, Wilhelmstraße 19-23, DE-72074, Tübingen, Germany
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19
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Belyk M, Johnson JF, Kotz SA. Poor neuro-motor tuning of the human larynx: a comparison of sung and whistled pitch imitation. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171544. [PMID: 29765635 PMCID: PMC5936900 DOI: 10.1098/rsos.171544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/13/2018] [Indexed: 06/08/2023]
Abstract
Vocal imitation is a hallmark of human communication that underlies the capacity to learn to speak and sing. Even so, poor vocal imitation abilities are surprisingly common in the general population and even expert vocalists cannot match the precision of a musical instrument. Although humans have evolved a greater degree of control over the laryngeal muscles that govern voice production, this ability may be underdeveloped compared with control over the articulatory muscles, such as the tongue and lips, volitional control of which emerged earlier in primate evolution. Human participants imitated simple melodies by either singing (i.e. producing pitch with the larynx) or whistling (i.e. producing pitch with the lips and tongue). Sung notes were systematically biased towards each individual's habitual pitch, which we hypothesize may act to conserve muscular effort. Furthermore, while participants who sung more precisely also whistled more precisely, sung imitations were less precise than whistled imitations. The laryngeal muscles that control voice production are under less precise control than the oral muscles that are involved in whistling. This imprecision may be due to the relatively recent evolution of volitional laryngeal-motor control in humans, which may be tuned just well enough for the coarse modulation of vocal-pitch in speech.
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Affiliation(s)
- Michel Belyk
- Bloorview Research Institute, 150 Kilgour Road, Toronto, CanadaM4G 1R8
- Faculty of Psychology and Neuroscience, University of Maastricht, Maastricht, The Netherlands
| | - Joseph F. Johnson
- Faculty of Psychology and Neuroscience, University of Maastricht, Maastricht, The Netherlands
| | - Sonja A. Kotz
- Faculty of Psychology and Neuroscience, University of Maastricht, Maastricht, The Netherlands
- Department of Neuropsychology, Max Planck Institute for Human and Cognitive Sciences, Leipzig, Germany
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20
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Aboitiz F. A Brain for Speech. Evolutionary Continuity in Primate and Human Auditory-Vocal Processing. Front Neurosci 2018; 12:174. [PMID: 29636657 PMCID: PMC5880940 DOI: 10.3389/fnins.2018.00174] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/05/2018] [Indexed: 12/27/2022] Open
Abstract
In this review article, I propose a continuous evolution from the auditory-vocal apparatus and its mechanisms of neural control in non-human primates, to the peripheral organs and the neural control of human speech. Although there is an overall conservatism both in peripheral systems and in central neural circuits, a few changes were critical for the expansion of vocal plasticity and the elaboration of proto-speech in early humans. Two of the most relevant changes were the acquisition of direct cortical control of the vocal fold musculature and the consolidation of an auditory-vocal articulatory circuit, encompassing auditory areas in the temporoparietal junction and prefrontal and motor areas in the frontal cortex. This articulatory loop, also referred to as the phonological loop, enhanced vocal working memory capacity, enabling early humans to learn increasingly complex utterances. The auditory-vocal circuit became progressively coupled to multimodal systems conveying information about objects and events, which gradually led to the acquisition of modern speech. Gestural communication accompanies the development of vocal communication since very early in human evolution, and although both systems co-evolved tightly in the beginning, at some point speech became the main channel of communication.
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Affiliation(s)
- Francisco Aboitiz
- Centro Interdisciplinario de Neurociencias, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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21
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Dahlhaus R. Of Men and Mice: Modeling the Fragile X Syndrome. Front Mol Neurosci 2018; 11:41. [PMID: 29599705 PMCID: PMC5862809 DOI: 10.3389/fnmol.2018.00041] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/31/2018] [Indexed: 12/26/2022] Open
Abstract
The Fragile X Syndrome (FXS) is one of the most common forms of inherited intellectual disability in all human societies. Caused by the transcriptional silencing of a single gene, the fragile x mental retardation gene FMR1, FXS is characterized by a variety of symptoms, which range from mental disabilities to autism and epilepsy. More than 20 years ago, a first animal model was described, the Fmr1 knock-out mouse. Several other models have been developed since then, including conditional knock-out mice, knock-out rats, a zebrafish and a drosophila model. Using these model systems, various targets for potential pharmaceutical treatments have been identified and many treatments have been shown to be efficient in preclinical studies. However, all attempts to turn these findings into a therapy for patients have failed thus far. In this review, I will discuss underlying difficulties and address potential alternatives for our future research.
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Affiliation(s)
- Regina Dahlhaus
- Institute for Biochemistry, Emil-Fischer Centre, University of Erlangen-Nürnberg, Erlangen, Germany
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22
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Bidding evidence for primate vocal learning and the cultural substrates for speech evolution. Neurosci Biobehav Rev 2017; 83:429-439. [DOI: 10.1016/j.neubiorev.2017.09.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 10/18/2022]
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23
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Toyoda A, Maruhashi T, Malaivijitnond S, Koda H. Speech‐like orofacial oscillations in stump‐tailed macaque (
Macaca arctoides
) facial and vocal signals. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2017; 164:435-439. [DOI: 10.1002/ajpa.23276] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 06/17/2017] [Accepted: 06/23/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Aru Toyoda
- Primate Research Institute, Kyoto UniversityInuyama Aichi484‐8506 Japan
| | - Tamaki Maruhashi
- Faculty of Humanities, Musashi University, Nerima, Tokyo 176-8534 Japan
| | - Suchinda Malaivijitnond
- Department of Biology, Faculty of ScienceChulalongkorn UniversityBangkok10330 Thailand
- National Primate Research Center of ThailandChulalongkorn UniversitySaraburi Thailand
| | - Hiroki Koda
- Primate Research Institute, Kyoto UniversityInuyama Aichi484‐8506 Japan
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24
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Warlaumont AS, Finnegan MK. Learning to Produce Syllabic Speech Sounds via Reward-Modulated Neural Plasticity. PLoS One 2016; 11:e0145096. [PMID: 26808148 PMCID: PMC4726623 DOI: 10.1371/journal.pone.0145096] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/29/2015] [Indexed: 11/19/2022] Open
Abstract
At around 7 months of age, human infants begin to reliably produce well-formed syllables containing both consonants and vowels, a behavior called canonical babbling. Over subsequent months, the frequency of canonical babbling continues to increase. How the infant's nervous system supports the acquisition of this ability is unknown. Here we present a computational model that combines a spiking neural network, reinforcement-modulated spike-timing-dependent plasticity, and a human-like vocal tract to simulate the acquisition of canonical babbling. Like human infants, the model's frequency of canonical babbling gradually increases. The model is rewarded when it produces a sound that is more auditorily salient than sounds it has previously produced. This is consistent with data from human infants indicating that contingent adult responses shape infant behavior and with data from deaf and tracheostomized infants indicating that hearing, including hearing one's own vocalizations, is critical for canonical babbling development. Reward receipt increases the level of dopamine in the neural network. The neural network contains a reservoir with recurrent connections and two motor neuron groups, one agonist and one antagonist, which control the masseter and orbicularis oris muscles, promoting or inhibiting mouth closure. The model learns to increase the number of salient, syllabic sounds it produces by adjusting the base level of muscle activation and increasing their range of activity. Our results support the possibility that through dopamine-modulated spike-timing-dependent plasticity, the motor cortex learns to harness its natural oscillations in activity in order to produce syllabic sounds. It thus suggests that learning to produce rhythmic mouth movements for speech production may be supported by general cortical learning mechanisms. The model makes several testable predictions and has implications for our understanding not only of how syllabic vocalizations develop in infancy but also for our understanding of how they may have evolved.
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Affiliation(s)
- Anne S. Warlaumont
- Cognitive and Information Sciences, University of California, Merced, Merced, CA, United States of America
| | - Megan K. Finnegan
- Speech & Hearing Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States of America
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25
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Plummer AR, Beckman ME. Framing a socio-indexical basis for the emergence and cultural transmission of phonological systems. JOURNAL OF PHONETICS 2015; 53:66-78. [PMID: 26834297 PMCID: PMC4730900 DOI: 10.1016/j.wocn.2015.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Moulin-Frier et al. (2016) proffer a conceptual framework and computational modeling architecture for the investigation of the emergence of phonological universals for spoken languages. They validate the framework and architecture by testing to see whether universals such as the prevalence of triangular vowel systems that show adequate dispersion in the F1-F2-F3 space can fall out of simulations of referential communication between social agents, without building principles such as dispersion directly into the model. In this paper, we examine the assumptions underlying the framework, beginning with the assumption that it is such substantive universals that are in need of explanation rather than the rich diversity of phonological systems observed across human cultures and the compositional ("prosodic") structure that characterizes signed as well as spoken languages. Also, when emergence is construed at the time-scales of the biological evolution of the species and of the cultural evolution of distinct speech communities, it is the affiliative or affective rather than the referential function that has the greater significance for our understanding of how phonological systems can emerge de novo in ontogeny.
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Affiliation(s)
- Andrew R. Plummer
- Department of Computer Science and Engineering, The Ohio State University
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26
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Vocal communication is multi-sensorimotor coordination within and between individuals. Behav Brain Sci 2015; 37:572-3; discussion 577-604. [PMID: 25514962 DOI: 10.1017/s0140525x13004202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Speech is an exquisitely coordinated interaction among effectors both within and between individuals. No account of human communication evolution that ignores its foundational multisensory characteristics and cooperative nature will be satisfactory. Here, we describe two additional capacities - rhythmic audiovisual speech and cooperative communication - and suggest that they may utilize the very same or similar circuits as those proposed for vocal learning.
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27
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Ghazanfar AA, Takahashi DY. The evolution of speech: vision, rhythm, cooperation. Trends Cogn Sci 2014; 18:543-53. [PMID: 25048821 PMCID: PMC4177957 DOI: 10.1016/j.tics.2014.06.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 06/11/2014] [Accepted: 06/16/2014] [Indexed: 10/25/2022]
Abstract
A full account of human speech evolution must consider its multisensory, rhythmic, and cooperative characteristics. Humans, apes, and monkeys recognize the correspondence between vocalizations and their associated facial postures, and gain behavioral benefits from them. Some monkey vocalizations even have a speech-like acoustic rhythmicity but lack the concomitant rhythmic facial motion that speech exhibits. We review data showing that rhythmic facial expressions such as lip-smacking may have been linked to vocal output to produce an ancestral form of rhythmic audiovisual speech. Finally, we argue that human vocal cooperation (turn-taking) may have arisen through a combination of volubility and prosociality, and provide comparative evidence from one species to support this hypothesis.
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Affiliation(s)
- Asif A Ghazanfar
- Princeton Neuroscience Institute, Departments of Psychology and Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Daniel Y Takahashi
- Princeton Neuroscience Institute, Department of Psychology, Princeton University, Princeton, NJ 08544, USA
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28
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Mendoza G, Merchant H. Motor system evolution and the emergence of high cognitive functions. Prog Neurobiol 2014; 122:73-93. [PMID: 25224031 DOI: 10.1016/j.pneurobio.2014.09.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 08/15/2014] [Accepted: 09/05/2014] [Indexed: 11/26/2022]
Abstract
In human and nonhuman primates, the cortical motor system comprises a collection of brain areas primarily related to motor control. Existing evidence suggests that no other mammalian group has the number, extension, and complexity of motor-related areas observed in the frontal lobe of primates. Such diversity is probably related to the wide behavioral flexibility that primates display. Indeed, recent comparative anatomical, psychophysical, and neurophysiological studies suggest that the evolution of the motor cortical areas closely correlates with the emergence of high cognitive abilities. Advances in understanding the cortical motor system have shown that these areas are also related to functions previously linked to higher-order associative areas. In addition, experimental observations have shown that the classical distinction between perceptual and motor functions is not strictly followed across cortical areas. In this paper, we review evidence suggesting that evolution of the motor system had a role in the shaping of different cognitive functions in primates. We argue that the increase in the complexity of the motor system has contributed to the emergence of new abilities observed in human and nonhuman primates, including the recognition and imitation of the actions of others, speech perception and production, and the execution and appreciation of the rhythmic structure of music.
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Affiliation(s)
- Germán Mendoza
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
| | - Hugo Merchant
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
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29
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García RR, Zamorano F, Aboitiz F. From imitation to meaning: circuit plasticity and the acquisition of a conventionalized semantics. Front Hum Neurosci 2014; 8:605. [PMID: 25152726 PMCID: PMC4126550 DOI: 10.3389/fnhum.2014.00605] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 07/20/2014] [Indexed: 12/04/2022] Open
Abstract
The capacity for language is arguably the most remarkable innovation of the human brain. A relatively recent interpretation prescribes that part of the language-related circuits were co-opted from circuitry involved in hand control-the mirror neuron system (MNS), involved both in the perception and in the execution of voluntary grasping actions. A less radical view is that in early humans, communication was opportunistic and multimodal, using signs, vocalizations or whatever means available to transmit social information. However, one point that is not yet clear under either perspective is how learned communication acquired a semantic property thereby allowing us to name objects and eventually describe our surrounding environment. Here we suggest a scenario involving both manual gestures and learned vocalizations that led to the development of a primitive form of conventionalized reference. This proposal is based on comparative evidence gathered from other species and on neurolinguistic evidence in humans, which points to a crucial role for vocal learning in the early development of language. Firstly, the capacity to direct the attention of others to a common object may have been crucial for developing a consensual referential system. Pointing, which is a ritualized grasping gesture, may have been crucial to this end. Vocalizations also served to generate joint attention among conversants, especially when combined with gaze direction. Another contributing element was the development of pantomimic actions resembling events or animals. In conjunction with this mimicry, the development of plastic neural circuits that support complex, learned vocalizations was probably a significant factor in the evolution of conventionalized semantics in our species. Thus, vocal imitations of sounds, as in onomatopoeias (words whose sound resembles their meaning), are possibly supported by mirror system circuits, and may have been relevant in the acquisition of early meanings.
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Affiliation(s)
- Ricardo R. García
- Centro de Estudios Cognitivos, Facultad de Filosofía y Humanidades, Universidad de ChileSantiago, Chile
| | - Francisco Zamorano
- División de Neurociencia, Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del DesarrolloSantiago, Chile
| | - Francisco Aboitiz
- Departamento de Psiquiatría, Escuela de Medicina, y Centro Interdisciplinario de Neurociencia, Pontificia Universidad Católica de ChileSantiago, Chile
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30
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Paukner A, Simpson EA, Ferrari PF, Mrozek T, Suomi SJ. Neonatal imitation predicts how infants engage with faces. Dev Sci 2014; 17:833-40. [PMID: 24995706 DOI: 10.1111/desc.12207] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 05/02/2014] [Indexed: 11/29/2022]
Abstract
In human infants, neonatal imitation and preferences for eyes are both associated with later social and communicative skills, yet the relationship between these abilities remains unexplored. Here we investigated whether neonatal imitation predicts facial viewing patterns in infant rhesus macaques. We first assessed infant macaques for lipsmacking (a core affiliative gesture) and tongue protrusion imitation in the first week of life. When infants were 10-28 days old, we presented them with an animated macaque avatar displaying a still face followed by lipsmacking or tongue protrusion movements. Using eye tracking technology, we found that macaque infants generally looked equally at the eyes and mouth during gesture presentation, but only lipsmacking-imitators showed significantly more looking at the eyes of the neutral still face. These results suggest that neonatal imitation performance may be an early measure of social attention biases and might potentially facilitate the identification of infants at risk for atypical social development.
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Affiliation(s)
- Annika Paukner
- Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Poolesville, MD, USA
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31
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Abstract
In primates, different vocalizations are produced, at least in part, by making different facial expressions. Not surprisingly, humans, apes, and monkeys all recognize the correspondence between vocalizations and the facial postures associated with them. However, one major dissimilarity between monkey vocalizations and human speech is that, in the latter, the acoustic output and associated movements of the mouth are both rhythmic (in the 3- to 8-Hz range) and tightly correlated, whereas monkey vocalizations have a similar acoustic rhythmicity but lack the concommitant rhythmic facial motion. This raises the question of how we evolved from a presumptive ancestral acoustic-only vocal rhythm to the one that is audiovisual with improved perceptual sensitivity. According to one hypothesis, this bisensory speech rhythm evolved through the rhythmic facial expressions of ancestral primates. If this hypothesis has any validity, we expect that the extant nonhuman primates produce at least some facial expressions with a speech-like rhythm in the 3- to 8-Hz frequency range. Lip smacking, an affiliative signal observed in many genera of primates, satisfies this criterion. We review a series of studies using developmental, x-ray cineradiographic, EMG, and perceptual approaches with macaque monkeys producing lip smacks to further investigate this hypothesis. We then explore its putative neural basis and remark on important differences between lip smacking and speech production. Overall, the data support the hypothesis that lip smacking may have been an ancestral expression that was linked to vocal output to produce the original rhythmic audiovisual speech-like utterances in the human lineage.
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32
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Boeckx C, Benítez-Burraco A. The shape of the human language-ready brain. Front Psychol 2014; 5:282. [PMID: 24772099 PMCID: PMC3983487 DOI: 10.3389/fpsyg.2014.00282] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 03/17/2014] [Indexed: 12/14/2022] Open
Abstract
Our core hypothesis is that the emergence of our species-specific language-ready brain ought to be understood in light of the developmental changes expressed at the levels of brain morphology and neural connectivity that occurred in our species after the split from Neanderthals–Denisovans and that gave us a more globular braincase configuration. In addition to changes at the cortical level, we hypothesize that the anatomical shift that led to globularity also entailed significant changes at the subcortical level. We claim that the functional consequences of such changes must also be taken into account to gain a fuller understanding of our linguistic capacity. Here we focus on the thalamus, which we argue is central to language and human cognition, as it modulates fronto-parietal activity. With this new neurobiological perspective in place, we examine its possible molecular basis. We construct a candidate gene set whose members are involved in the development and connectivity of the thalamus, in the evolution of the human head, and are known to give rise to language-associated cognitive disorders. We submit that the new gene candidate set opens up new windows into our understanding of the genetic basis of our linguistic capacity. Thus, our hypothesis aims at generating new testing grounds concerning core aspects of language ontogeny and phylogeny.
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Affiliation(s)
- Cedric Boeckx
- Catalan Institute for Advanced Studies and Research (ICREA) Barcelona, Spain ; Department of Linguistics, Universitat de Barcelona Barcelona, Spain
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33
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Ghazanfar AA. Multisensory vocal communication in primates and the evolution of rhythmic speech. Behav Ecol Sociobiol 2013; 67. [PMID: 24222931 DOI: 10.1007/s00265-013-1491-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The integration of the visual and auditory modalities during human speech perception is the default mode of speech processing. That is, visual speech perception is not a capacity that is "piggybacked" on to auditory-only speech perception. Visual information from the mouth and other parts of the face is used by all perceivers to enhance auditory speech. This integration is ubiquitous and automatic and is similar across all individuals across all cultures. The two modalities seem to be integrated even at the earliest stages of human cognitive development. If multisensory speech is the default mode of perception, then this should be reflected in the evolution of vocal communication. The purpose of this review is to describe the data that reveal that human speech is not uniquely multisensory. In fact, the default mode of communication is multisensory in nonhuman primates as well but perhaps emerging with a different developmental trajectory. Speech production, however, exhibits a unique bimodal rhythmic structure in that both the acoustic output and the movements of the mouth are rhythmic and tightly correlated. This structure is absent in most monkey vocalizations. One hypothesis is that the bimodal speech rhythm may have evolved through the rhythmic facial expressions of ancestral primates, as indicated by mounting comparative evidence focusing on the lip-smacking gesture.
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Affiliation(s)
- Asif A Ghazanfar
- Neuroscience Institute, Princeton University, Princeton NJ 08540, USA ; Department of Psychology, Princeton University, Princeton NJ 08540, USA ; Department of Ecology & Evolutionary Biology, Princeton University, Princeton NJ 08540, USA
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34
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Monkeys are perceptually tuned to facial expressions that exhibit a theta-like speech rhythm. Proc Natl Acad Sci U S A 2013; 110:1959-63. [PMID: 23319616 DOI: 10.1073/pnas.1214956110] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human speech universally exhibits a 3- to 8-Hz rhythm, corresponding to the rate of syllable production, which is reflected in both the sound envelope and the visual mouth movements. Artificial perturbation of the speech rhythm outside the natural range reduces speech intelligibility, demonstrating a perceptual tuning to this frequency band. One theory posits that the mouth movements at the core of this speech rhythm evolved through modification of ancestral primate facial expressions. Recent evidence shows that one such communicative gesture in macaque monkeys, lip-smacking, has motor parallels with speech in its rhythmicity, its developmental trajectory, and the coordination of vocal tract structures. Whether monkeys also exhibit a perceptual tuning to the natural rhythms of lip-smacking is unknown. To investigate this, we tested rhesus monkeys in a preferential-looking procedure, measuring the time spent looking at each of two side-by-side computer-generated monkey avatars lip-smacking at natural versus sped-up or slowed-down rhythms. Monkeys showed an overall preference for the natural rhythm compared with the perturbed rhythms. This lends behavioral support for the hypothesis that perceptual processes in monkeys are similarly tuned to the natural frequencies of communication signals as they are in humans. Our data provide perceptual evidence for the theory that speech may have evolved from ancestral primate rhythmic facial expressions.
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35
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Ghazanfar AA, Takahashi DY, Mathur N, Fitch WT. Cineradiography of monkey lip-smacking reveals putative precursors of speech dynamics. Curr Biol 2012; 22:1176-82. [PMID: 22658603 PMCID: PMC3569518 DOI: 10.1016/j.cub.2012.04.055] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 03/14/2012] [Accepted: 04/17/2012] [Indexed: 11/18/2022]
Abstract
A key feature of speech is its stereotypical 5 Hz rhythm. One theory posits that this rhythm evolved through the modification of rhythmic facial movements in ancestral primates. If the hypothesis has any validity, then a comparative approach may shed some light. We tested this idea by using cineradiography (X-ray movies) to characterize and quantify the internal dynamics of the macaque monkey vocal tract during lip-smacking (a rhythmic facial expression) versus chewing. Previous human studies showed that speech movements are faster than chewing movements, and the functional coordination between vocal tract structures is different between the two behaviors. If rhythmic speech evolved through a rhythmic ancestral facial movement, then one hypothesis is that monkey lip-smacking versus chewing should also exhibit these differences. We found that the lips, tongue, and hyoid move with a speech-like 5 Hz rhythm during lip-smacking, but not during chewing. Most importantly, the functional coordination between these structures was distinct for each behavior. These data provide empirical support for the idea that the human speech rhythm evolved from the rhythmic facial expressions of ancestral primates.
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Affiliation(s)
- Asif A. Ghazanfar
- Neuroscience Institute
- Departments of Ecology and Evolutionary Biology
- Departments of Psychology Princeton University, Princeton, NJ 08540, USA
| | - Daniel Y. Takahashi
- Neuroscience Institute
- Departments of Psychology Princeton University, Princeton, NJ 08540, USA
| | - Neil Mathur
- Neuroscience Institute
- Departments of Ecology and Evolutionary Biology
| | - W. Tecumseh Fitch
- Department of Cognitive Biology, Faculty of Life Sciences, University of Vienna, 14 Althanstrasse, A-1090 Vienna, Austria
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