1
|
Lemon R. The Corticospinal System and Amyotrophic Lateral Sclerosis: IFCN handbook chapter. Clin Neurophysiol 2024; 160:56-67. [PMID: 38401191 DOI: 10.1016/j.clinph.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/23/2023] [Accepted: 02/03/2024] [Indexed: 02/26/2024]
Abstract
Corticospinal neurons located in motor areas of the cerebral neocortex project corticospinal axons which synapse with the spinal network; a parallel corticobulbar system projects to the cranial motor network and to brainstem motor pathways. The primate corticospinal system has a widespread cortical origin and an extensive range of different fibre diameters, including thick, fast-conducting axons. Direct cortico-motoneuronal (CM) projections from the motor cortex to arm and hand alpha motoneurons are a recent evolutionary feature, that is well developed in dexterous primates and particularly in humans. Many of these projections originate from the caudal subdivision of area 4 ('new' M1: primary motor cortex). They arise from corticospinal neurons of varied soma size, including those with fast- and relatively slow-conducting axons. This CM system has been shown to be involved in the control of skilled movements, carried out with fractionation of the distal extremities and at low force levels. During movement, corticospinal neurons are activated quite differently from 'lower' motoneurons, and there is no simple or fixed functional relationship between a so-called 'upper' motoneuron and its target lower motoneuron. There are key differences in the organisation and function of the corticospinal and CM system in primates versus non-primates, such as rodents. These differences need to be recognized when making the choice of animal model for understanding disorders such as amyotrophic lateral sclerosis (ALS). In this neurodegenerative brain disease there is a selective loss of fast-conducting corticospinal axons, and their synaptic connections, and this is reflected in responses to non-invasive cortical stimuli and measures of cortico-muscular coherence. The loss of CM connections influencing distal limb muscles results in a differential loss of muscle strength or 'split-hand' phenotype. Importantly, there is also a unique impairment in the coordination of skilled hand tasks that require fractionation of digit movement. Scores on validated tests of skilled hand function could be used to assess disease progression.
Collapse
Affiliation(s)
- Roger Lemon
- Department of Clinical and Movement Sciences, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK.
| |
Collapse
|
2
|
Harris I, Niven EC, Griffin A, Scott SK. Is song processing distinct and special in the auditory cortex? Nat Rev Neurosci 2023; 24:711-722. [PMID: 37783820 DOI: 10.1038/s41583-023-00743-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2023] [Indexed: 10/04/2023]
Abstract
Is the singing voice processed distinctively in the human brain? In this Perspective, we discuss what might distinguish song processing from speech processing in light of recent work suggesting that some cortical neuronal populations respond selectively to song and we outline the implications for our understanding of auditory processing. We review the literature regarding the neural and physiological mechanisms of song production and perception and show that this provides evidence for key differences between song and speech processing. We conclude by discussing the significance of the notion that song processing is special in terms of how this might contribute to theories of the neurobiological origins of vocal communication and to our understanding of the neural circuitry underlying sound processing in the human cortex.
Collapse
Affiliation(s)
- Ilana Harris
- Institute of Cognitive Neuroscience, University College London, London, UK
| | - Efe C Niven
- Institute of Cognitive Neuroscience, University College London, London, UK
| | - Alex Griffin
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - Sophie K Scott
- Institute of Cognitive Neuroscience, University College London, London, UK.
| |
Collapse
|
3
|
Zhang Y, Zhou L, Zuo J, Wang S, Meng W. Analogies of human speech and bird song: From vocal learning behavior to its neural basis. Front Psychol 2023; 14:1100969. [PMID: 36910811 PMCID: PMC9992734 DOI: 10.3389/fpsyg.2023.1100969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Vocal learning is a complex acquired social behavior that has been found only in very few animals. The process of animal vocal learning requires the participation of sensorimotor function. By accepting external auditory input and cooperating with repeated vocal imitation practice, a stable pattern of vocal information output is eventually formed. In parallel evolutionary branches, humans and songbirds share striking similarities in vocal learning behavior. For example, their vocal learning processes involve auditory feedback, complex syntactic structures, and sensitive periods. At the same time, they have evolved the hierarchical structure of special forebrain regions related to vocal motor control and vocal learning, which are organized and closely associated to the auditory cortex. By comparing the location, function, genome, and transcriptome of vocal learning-related brain regions, it was confirmed that songbird singing and human language-related neural control pathways have certain analogy. These common characteristics make songbirds an ideal animal model for studying the neural mechanisms of vocal learning behavior. The neural process of human language learning may be explained through similar neural mechanisms, and it can provide important insights for the treatment of language disorders.
Collapse
Affiliation(s)
- Yutao Zhang
- Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China
| | - Lifang Zhou
- Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China
| | - Jiachun Zuo
- Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China
| | - Songhua Wang
- Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China
| | - Wei Meng
- Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China
| |
Collapse
|
4
|
Franken MK, Liu BC, Ostry DJ. Towards a somatosensory theory of speech perception. J Neurophysiol 2022; 128:1683-1695. [PMID: 36416451 PMCID: PMC9762980 DOI: 10.1152/jn.00381.2022] [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: 09/11/2022] [Revised: 11/19/2022] [Accepted: 11/19/2022] [Indexed: 11/24/2022] Open
Abstract
Speech perception is known to be a multimodal process, relying not only on auditory input but also on the visual system and possibly on the motor system as well. To date there has been little work on the potential involvement of the somatosensory system in speech perception. In the present review, we identify the somatosensory system as another contributor to speech perception. First, we argue that evidence in favor of a motor contribution to speech perception can just as easily be interpreted as showing somatosensory involvement. Second, physiological and neuroanatomical evidence for auditory-somatosensory interactions across the auditory hierarchy indicates the availability of a neural infrastructure that supports somatosensory involvement in auditory processing in general. Third, there is accumulating evidence for somatosensory involvement in the context of speech specifically. In particular, tactile stimulation modifies speech perception, and speech auditory input elicits activity in somatosensory cortical areas. Moreover, speech sounds can be decoded from activity in somatosensory cortex; lesions to this region affect perception, and vowels can be identified based on somatic input alone. We suggest that the somatosensory involvement in speech perception derives from the somatosensory-auditory pairing that occurs during speech production and learning. By bringing together findings from a set of studies that have not been previously linked, the present article identifies the somatosensory system as a presently unrecognized contributor to speech perception.
Collapse
Affiliation(s)
| | | | - David J Ostry
- McGill University, Montreal, Quebec, Canada
- Haskins Laboratories, New Haven, Connecticut
| |
Collapse
|
5
|
Del Tredici K, Braak H. Neuropathology and neuroanatomy of TDP-43 amyotrophic lateral sclerosis. Curr Opin Neurol 2022; 35:660-671. [PMID: 36069419 DOI: 10.1097/wco.0000000000001098] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE OF REVIEW Intracellular inclusions consisting of the abnormal TDP-43 protein and its nucleocytoplasmic mislocalization in selected cell types are hallmark pathological features of sALS. Descriptive (histological, morphological), anatomical, and molecular studies all have improved our understanding of the neuropathology of sporadic amyotrophic lateral sclerosis (sALS). This review highlights some of the latest developments in the field. RECENT FINDINGS Increasing evidence exists from experimental models for the prion-like nature of abnormal TDP-43, including a strain-effect, and with the help of neuroimaging-based studies, for spreading of disease along corticofugal connectivities in sALS. Progress has also been made with respect to finding and establishing reliable biomarkers (neurofilament levels, diffusor tensor imaging). SUMMARY The latest findings may help to elucidate the preclinical phase of sALS and to define possible mechanisms for delaying or halting disease development and progression.
Collapse
Affiliation(s)
- Kelly Del Tredici
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, University of Ulm, Ulm, Germany
| | | |
Collapse
|
6
|
Iwasaki SI, Yoshimura K, Asami T, Erdoğan S. Comparative morphology and physiology of the vocal production apparatus and the brain in the extant primates. Ann Anat 2022; 240:151887. [PMID: 35032565 DOI: 10.1016/j.aanat.2022.151887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/26/2021] [Accepted: 12/28/2021] [Indexed: 01/04/2023]
Abstract
Objective data mainly from the comparative anatomy of various organs related to human speech and language is considered to unearth clues about the mechanisms behind language development. The two organs of the larynx and hyoid bone are considered to have evolved towards suitable positions and forms in preparation for the occurrence of the large repertoire of vocalization necessary for human speech. However, some researchers have asserted that there is no significant difference of these organs between humans and non-human primates. Speech production is dependent on the voluntary control of the respiratory, laryngeal, and vocal tract musculature. Such control is fully present in humans but only partially so in non-human primates, which appear to be able to voluntarily control only supralaryngeal articulators. Both humans and non-human primates have direct cortical innervation of motor neurons controlling the supralaryngeal vocal tract but only human appear to have direct cortical innervation of motor neurons controlling the larynx. In this review, we investigate the comparative morphology and function of the wide range of components involved in vocal production, including the larynx, the hyoid bone, the tongue, and the vocal brain. We would like to emphasize the importance of the tongue in the primary development of human speech and language. It is now time to reconsider the possibility of the tongue playing a definitive role in the emergence of human speech.
Collapse
Affiliation(s)
- Shin-Ichi Iwasaki
- Faculty of Health Science, Gunma PAZ University, Takasaki, Japan; The Nippon Dental University, Tokyo and Niigata, Japan
| | - Ken Yoshimura
- Department of Anatomy, The Nippon Dental University School of Life Dentistry at Niigata, Niigata, Japan
| | - Tomoichiro Asami
- Faculty of Rehabilitation, Gunma Paz University, Takasaki, Japan
| | - Serkan Erdoğan
- Department of Anatomy, Faculty of Veterinary Medicine, Tekirdağ Namık Kemal University, Tekirdağ, Turkey.
| |
Collapse
|
7
|
Belyk M, Eichert N, McGettigan C. A dual larynx motor networks hypothesis. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200392. [PMID: 34719252 PMCID: PMC8558777 DOI: 10.1098/rstb.2020.0392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2021] [Indexed: 01/14/2023] Open
Abstract
Humans are vocal modulators par excellence. This ability is supported in part by the dual representation of the laryngeal muscles in the motor cortex. Movement, however, is not the product of motor cortex alone but of a broader motor network. This network consists of brain regions that contain somatotopic maps that parallel the organization in motor cortex. We therefore present a novel hypothesis that the dual laryngeal representation is repeated throughout the broader motor network. In support of the hypothesis, we review existing literature that demonstrates the existence of network-wide somatotopy and present initial evidence for the hypothesis' plausibility. Understanding how this uniquely human phenotype in motor cortex interacts with broader brain networks is an important step toward understanding how humans evolved the ability to speak. We further suggest that this system may provide a means to study how individual components of the nervous system evolved within the context of neuronal networks. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.
Collapse
Affiliation(s)
- Michel Belyk
- Department of Speech Hearing and Phonetic Sciences, University College London, London WC1N 1PJ, UK
- Department of Psychology, Edge Hill University, Ormskirk, L39 4QP, UK
| | - Nicole Eichert
- Wellcome Centre for Integrative Neuroimaging, Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Carolyn McGettigan
- Department of Speech Hearing and Phonetic Sciences, University College London, London WC1N 1PJ, UK
| |
Collapse
|
8
|
Waters S, Kanber E, Lavan N, Belyk M, Carey D, Cartei V, Lally C, Miquel M, McGettigan C. Singers show enhanced performance and neural representation of vocal imitation. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200399. [PMID: 34719245 PMCID: PMC8558773 DOI: 10.1098/rstb.2020.0399] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2021] [Indexed: 12/17/2022] Open
Abstract
Humans have a remarkable capacity to finely control the muscles of the larynx, via distinct patterns of cortical topography and innervation that may underpin our sophisticated vocal capabilities compared with non-human primates. Here, we investigated the behavioural and neural correlates of laryngeal control, and their relationship to vocal expertise, using an imitation task that required adjustments of larynx musculature during speech. Highly trained human singers and non-singer control participants modulated voice pitch and vocal tract length (VTL) to mimic auditory speech targets, while undergoing real-time anatomical scans of the vocal tract and functional scans of brain activity. Multivariate analyses of speech acoustics, larynx movements and brain activation data were used to quantify vocal modulation behaviour and to search for neural representations of the two modulated vocal parameters during the preparation and execution of speech. We found that singers showed more accurate task-relevant modulations of speech pitch and VTL (i.e. larynx height, as measured with vocal tract MRI) during speech imitation; this was accompanied by stronger representation of VTL within a region of the right somatosensory cortex. Our findings suggest a common neural basis for enhanced vocal control in speech and song. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.
Collapse
Affiliation(s)
- Sheena Waters
- Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, UK
- Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ, UK
| | - Elise Kanber
- Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, UK
- Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK
| | - Nadine Lavan
- Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK
- Department of Biological and Experimental Psychology, Queen Mary University of London, Mile End Road, Bethnal Green, London E1 4NS, UK
| | - Michel Belyk
- Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK
| | - Daniel Carey
- Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, UK
- Data & AI, Novartis Pharmaceuticals, Novartis Global Service Center, 203 Merrion Road, Dublin 4 D04 NN12, Ireland
| | - Valentina Cartei
- Equipe de Neuro-Ethologie Sensorielle (ENES), Centre de Recherche en Neurosciences de Lyon, Université de Lyon/Saint-Etienne, 21 rue du Docteur Paul Michelon, 42100 Saint-Etienne, France
- Department of Psychology, Institute of Education, Health and Social Sciences, University of Chichester, College Lane, Chichester, West Sussex PO19 6PE, UK
| | - Clare Lally
- Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, UK
- Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK
| | - Marc Miquel
- Department of Clinical Physics, Barts Health NHS Trust, London EC1A 7BE, UK
- William Harvey Research Institute, Queen Mary University of London, London EC1M 6BQ, UK
| | - Carolyn McGettigan
- Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, UK
- Speech, Hearing and Phonetic Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK
| |
Collapse
|
9
|
Human larynx motor cortices coordinate respiration for vocal-motor control. Neuroimage 2021; 239:118326. [PMID: 34216772 DOI: 10.1016/j.neuroimage.2021.118326] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/22/2021] [Accepted: 06/29/2021] [Indexed: 11/23/2022] Open
Abstract
Vocal flexibility is a hallmark of the human species, most particularly the capacity to speak and sing. This ability is supported in part by the evolution of a direct neural pathway linking the motor cortex to the brainstem nucleus that controls the larynx the primary sound source for communication. Early brain imaging studies demonstrated that larynx motor cortex at the dorsal end of the orofacial division of motor cortex (dLMC) integrated laryngeal and respiratory control, thereby coordinating two major muscular systems that are necessary for vocalization. Neurosurgical studies have since demonstrated the existence of a second larynx motor area at the ventral extent of the orofacial motor division (vLMC) of motor cortex. The vLMC has been presumed to be less relevant to speech motor control, but its functional role remains unknown. We employed a novel ultra-high field (7T) magnetic resonance imaging paradigm that combined singing and whistling simple melodies to localise the larynx motor cortices and test their involvement in respiratory motor control. Surprisingly, whistling activated both 'larynx areas' more strongly than singing despite the reduced involvement of the larynx during whistling. We provide further evidence for the existence of two larynx motor areas in the human brain, and the first evidence that laryngeal-respiratory integration is a shared property of both larynx motor areas. We outline explicit predictions about the descending motor pathways that give these cortical areas access to both the laryngeal and respiratory systems and discuss the implications for the evolution of speech.
Collapse
|
10
|
Lemon RN. The Cortical "Upper Motoneuron" in Health and Disease. Brain Sci 2021; 11:619. [PMID: 34066053 PMCID: PMC8151778 DOI: 10.3390/brainsci11050619] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 12/11/2022] Open
Abstract
Upper motoneurons (UMNs) in motor areas of the cerebral cortex influence spinal and cranial motor mechanisms through the corticospinal tract (CST) and through projections to brainstem motor pathways. The primate corticospinal system has a diverse cortical origin and a wide spectrum of fibre diameters, including large diameter fibres which are unique to humans and other large primates. Direct cortico-motoneuronal (CM) projections from the motor cortex to arm and hand motoneurons are a late evolutionary feature only present in dexterous primates and best developed in humans. CM projections are derived from a more restricted cortical territory ('new' M1, area 3a) and arise not only from corticospinal neurons with large, fast axons but also from those with relatively slow-conducting axons. During movement, corticospinal neurons are organised and recruited quite differently from 'lower' motoneurons. Accumulating evidence strongly implicates the corticospinal system in the early stages of ALS, with particular involvement of CM projections to distal limb muscles, but also to other muscle groups influenced by the CM system. There are important species differences in the organisation and function of the corticospinal system, and appropriate animal models are needed to understand disorders involving the human corticospinal system.
Collapse
Affiliation(s)
- Roger N Lemon
- Department of Clinical and Movement Sciences, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| |
Collapse
|
11
|
Eisen A. The Dying Forward Hypothesis of ALS: Tracing Its History. Brain Sci 2021; 11:brainsci11030300. [PMID: 33673524 PMCID: PMC7997258 DOI: 10.3390/brainsci11030300] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 02/25/2021] [Indexed: 01/15/2023] Open
Abstract
The site of origin of amyotrophic lateral sclerosis (ALS), although unsettled, is increasingly recognized as being cortico-fugal, which is a dying-forward process primarily starting in the corticomotoneuronal system. A variety of iterations of this concept date back to over 150 years. Recently, the hallmark TAR DNA-binding protein 43 (TDP-43) pathology, seen in >95% of patients with ALS, has been shown to be largely restricted to corticofugal projecting neurons (“dying forward”). Possibly, soluble but toxic cytoplasmic TDP-43 could enter the axoplasm of Betz cells, subsequently causing dysregulation of nuclear protein in the lower brainstem and spinal cord anterior horn cells. As the disease progresses, cortical involvement in ALS becomes widespread, including or starting with frontotemporal dementia, implying a broader view of ALS as a brain disease. The onset at the motor and premotor cortices should be considered a nidus at the edge of multiple cortical networks which eventually become disrupted, causing failure of a widespread cortical connectome.
Collapse
Affiliation(s)
- Andrew Eisen
- Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| |
Collapse
|
12
|
Téllez MJ, Mirallave-Pescador A, Seidel K, Urriza J, Shoakazemi A, Raabe A, Ghatan S, Deletis V, Ulkatan S. Neurophysiological monitoring of the laryngeal adductor reflex during cerebellar-pontine angle and brainstem surgery. Clin Neurophysiol 2020; 132:622-631. [PMID: 33272821 DOI: 10.1016/j.clinph.2020.10.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/09/2020] [Accepted: 10/06/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To correlate intraoperative changes of the laryngeal adductor reflex (LAR), alone or in combination with corticobulbar motor evoked potential of vocal muscles (vocal-CoMEPs), with postoperative laryngeal function after posterior fossa and brainstem surgery. METHODS We monitored 53 patients during cerebellar-pontine angle and brainstem surgeries. Vocal-CoMEPs and LAR were recorded from an endotracheal tube with imbedded electrodes or hook-wires electrodes. A LAR significant change (LAR-SC) defined as ≥ 50% amplitude decrement or loss, was classified as either transient or permanent injury to the vagus or medullary pathways by the end of the surgery. RESULTS All patients with permanent LAR loss (n = 5) or LAR-SC (n = 3), developed postoperative laryngeal dysfunction such as aspiration/pneumonia and permanent swallowing deficits (5.6%). Vocal-CoMEP findings refined postoperative vocal motor dysfunction. All seven patients with transient LAR-SC or loss, reverted by changing the surgical approach, did not present permanent deficits. CONCLUSIONS Permanent LAR-SCs or loss correlated with postoperative laryngeal dysfunction and predicted motor and sensory dysfunction of the vagus nerve and reflexive medullary pathways. In contrast, a LAR-SC or loss, averted by a timely surgical adjustment, prevented irreversible damage. SIGNIFICANCE Monitoring of the LAR, with vocal-CoMEPs, may enhance safety to resect complex posterior fossa and brainstem lesions.
Collapse
Affiliation(s)
- Maria J Téllez
- Department of Intraoperative Neurophysiology. Mount Sinai West Hospital. New York, NY, USA.
| | - Ana Mirallave-Pescador
- Department of Intraoperative Neurophysiology. Queen's Hospital. Barking, Havering, and Redbridge University Hospitals NHS Trust. London, UK
| | - Kathleen Seidel
- Department of Neurosurgery. Inselspital Bern University Hospital, Bern, Switzerland
| | - Javier Urriza
- Department of Clinical Neurophysiology. Complejo Hospitalario de Navarra, Pamplona, Spain
| | - Alireza Shoakazemi
- Department of Neurosurgery. Queen's Hospital. Barking, Havering, and Redbridge University Hospitals NHS Trust. London, UK
| | - Andreas Raabe
- Department of Neurosurgery. Inselspital Bern University Hospital, Bern, Switzerland
| | - Saadi Ghatan
- Department of Neurosurgery. Mount Sinai West Hospital. New York, NY, USA
| | - Vedran Deletis
- Albert Einstein College of Medicine, New York, NY, USA; Department of Neurosurgery, University Hospital Dubrava, Zagreb, Croatia
| | - Sedat Ulkatan
- Department of Intraoperative Neurophysiology. Mount Sinai West Hospital. New York, NY, USA
| |
Collapse
|
13
|
Schellino R, Boido M, Vercelli A. The Dual Nature of Onuf's Nucleus: Neuroanatomical Features and Peculiarities, in Health and Disease. Front Neuroanat 2020; 14:572013. [PMID: 33013330 PMCID: PMC7500142 DOI: 10.3389/fnana.2020.572013] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/19/2020] [Indexed: 12/13/2022] Open
Abstract
Onuf's nucleus is a small group of neurons located in the ventral horns of the sacral spinal cord. The motor neurons (MNs) of Onuf's nucleus innervate striated voluntary muscles of the pelvic floor and are histologically and biochemically comparable to the other somatic spinal MNs. However, curiously, these neurons also show some autonomic-like features as, for instance, they receive a strong peptidergic innervation. The review provides an overview of the histological, biochemical, metabolic, and gene expression peculiarities of Onuf's nucleus. Moreover, it describes the aging-related pathologies as well as several traumatic and neurodegenerative disorders in which its neurons are involved: indeed, Onuf's nucleus is affected in Parkinson's disease (PD) and Shy-Drager Syndrome (SDS), whereas it is spared in Amyotrophic Lateral Sclerosis (ALS), Spinal Muscular Atrophy (SMA), Duchenne Muscular Dystrophy (DMD). We summarize here the milestone studies that have contributed to clarifying the nature of Onuf's neurons and in understanding what makes them either vulnerable or resistant to damage. Altogether, these works can offer the possibility to develop new therapeutic strategies for counteracting neurodegeneration.
Collapse
Affiliation(s)
- Roberta Schellino
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy.,Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy
| | - Marina Boido
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy.,Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy.,National Institute of Neuroscience, Turin, Italy
| | - Alessandro Vercelli
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy.,Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Turin, Turin, Italy.,National Institute of Neuroscience, Turin, Italy
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Nieder A, Mooney R. The neurobiology of innate, volitional and learned vocalizations in mammals and birds. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190054. [PMID: 31735150 PMCID: PMC6895551 DOI: 10.1098/rstb.2019.0054] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2019] [Indexed: 11/12/2022] Open
Abstract
Vocalization is an ancient vertebrate trait essential to many forms of communication, ranging from courtship calls to free verse. Vocalizations may be entirely innate and evoked by sexual cues or emotional state, as with many types of calls made in primates, rodents and birds; volitional, as with innate calls that, following extensive training, can be evoked by arbitrary sensory cues in non-human primates and corvid songbirds; or learned, acoustically flexible and complex, as with human speech and the courtship songs of oscine songbirds. This review compares and contrasts the neural mechanisms underlying innate, volitional and learned vocalizations, with an emphasis on functional studies in primates, rodents and songbirds. This comparison reveals both highly conserved and convergent mechanisms of vocal production in these different groups, despite their often vast phylogenetic separation. This similarity of central mechanisms for different forms of vocal production presents experimentalists with useful avenues for gaining detailed mechanistic insight into how vocalizations are employed for social and sexual signalling, and how they can be modified through experience to yield new vocal repertoires customized to the individual's social group. This article is part of the theme issue 'What can animal communication teach us about human language?'
Collapse
Affiliation(s)
- Andreas Nieder
- Animal Physiology Unit, Institute of Neurobiology, University Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany
| | - Richard Mooney
- Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA
| |
Collapse
|
16
|
Vernes SC, Wilkinson GS. Behaviour, biology and evolution of vocal learning in bats. Philos Trans R Soc Lond B Biol Sci 2019; 375:20190061. [PMID: 31735153 DOI: 10.1098/rstb.2019.0061] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The comparative approach can provide insight into the evolution of human speech, language and social communication by studying relevant traits in animal systems. Bats are emerging as a model system with great potential to shed light on these processes given their learned vocalizations, close social interactions, and mammalian brains and physiology. A recent framework outlined the multiple levels of investigation needed to understand vocal learning across a broad range of non-human species, including cetaceans, pinnipeds, elephants, birds and bats. Here, we apply this framework to the current state-of-the-art in bat research. This encompasses our understanding of the abilities bats have displayed for vocal learning, what is known about the timing and social structure needed for such learning, and current knowledge about the prevalence of the trait across the order. It also addresses the biology (vocal tract morphology, neurobiology and genetics) and evolution of this trait. We conclude by highlighting some key questions that should be answered to advance our understanding of the biological encoding and evolution of speech and spoken communication. This article is part of the theme issue 'What can animal communication teach us about human language?'
Collapse
Affiliation(s)
- Sonja C Vernes
- Neurogenetics of Vocal Communication Group, Max Planck Institute for Psycholinguistics, PO Box 310, Nijmegen 6500 AH, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Kapittelweg 29, Nijmegen 6525 EN, The Netherlands
| | - Gerald S Wilkinson
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
17
|
Abstract
Although language, and therefore spoken language or speech, is often considered unique to humans, the past several decades have seen a surge in nonhuman animal studies that inform us about human spoken language. Here, I present a modern, evolution-based synthesis of these studies, from behavioral to molecular levels of analyses. Among the key concepts drawn are that components of spoken language are continuous between species, and that the vocal learning component is the most specialized and rarest and evolved by brain pathway duplication from an ancient motor learning pathway. These concepts have important implications for understanding brain mechanisms and disorders of spoken language.
Collapse
Affiliation(s)
- Erich D Jarvis
- Laboratory of Neurogenetics of Language, The Rockefeller University, New York, NY, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| |
Collapse
|
18
|
Unforeseen clinical outcome for laryngeal adductor reflex loss during intraaxial brainstem surgery. Clin Neurophysiol 2019; 130:2001-2002. [DOI: 10.1016/j.clinph.2019.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 06/29/2019] [Accepted: 07/02/2019] [Indexed: 11/19/2022]
|
19
|
Lieberman P. The antiquity and evolution of the neural bases of rhythmic activity. Ann N Y Acad Sci 2019; 1453:114-124. [PMID: 31368158 DOI: 10.1111/nyas.14199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/10/2019] [Accepted: 07/02/2019] [Indexed: 11/30/2022]
Abstract
The evolution of the anatomy and neural circuits that regulate the rhythm of speech can be traced back to the Devonian age, 400 million years ago. Epigenetic processes 100 million years later modified these circuits. Natural selection on similar genetic processes occurred during the evolution of archaic hominins and humans. The lungs and larynx-anatomy that produces the rhythmic fundamental frequency patterns of speech-have a deep evolutionary history. Neural circuits linking the cortex, basal ganglia, and other subcortical structures plan, sequence, and execute motor as well as cognitive acts. These neural circuits generate the rhythm of speech, singing, and chanting. The human form of the transcription factor FOXP2 increased synaptic connectivity and plasticity in basal ganglia circuits, enhancing motor control and cognitive and linguistic capabilities in humans as well as Neanderthals. The archeological record also suggests that Neanderthals passed spoken language. Homologous circuits existed in amphibians. In songbirds, the avian form of FOXP2 acted on similar neural circuits allowing birds to learn and produce new songs. Current studies point to natural selection on genetic events enhancing these and other neural circuits to yield fully human rhythmic speech, and motor, cognitive, and linguistic capabilities, rather than the saltation proposed by Noam Chomsky.
Collapse
Affiliation(s)
- Philip Lieberman
- Department of Cognitive, Linguistic, and Psychological Sciences, Brown University, Providence, Rhode Island
| |
Collapse
|
20
|
Guiry S, Worthley A, Simonyan K. A separation of innate and learned vocal behaviors defines the symptomatology of spasmodic dysphonia. Laryngoscope 2018; 129:1627-1633. [PMID: 30582159 DOI: 10.1002/lary.27617] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/17/2018] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Spasmodic dysphonia (SD) is a neurological disorder characterized by involuntary spasms in the laryngeal muscles. It is thought to selectively affect speaking; other vocal behaviors remain intact. However, the patients' own perspective on their symptoms is largely missing, leading to partial understanding of the full spectrum of voice alterations in SD. METHODS A cohort of 178 SD patients rated their symptoms on the visual analog scale based on the level of effort required for speaking, singing, shouting, whispering, crying, laughing, and yawning. Statistical differences between the effort for speaking and the effort for other vocal behaviors were assessed using nonparametric Wilcoxon rank-sum tests within the overall SD cohort as well as within different subgroups of SD. RESULTS Speech production was found to be the most impaired behavior, ranking as the most effortful type of voice production in all SD patients. In addition, singing required nearly similar effort as speaking, ranking as the second most altered vocal behavior. Shouting showed a range of variability in its alterations, being especially difficult to produce for patients with adductor form, co-occurring voice tremor, late onset of disorder, and familial history of dystonia. Other vocal behaviors, such as crying, laughing, whispering, and yawning, were within the normal ranges across all SD patients. CONCLUSION Our findings widen the symptomatology of SD, which has predominantly been focused on selective speech impairments. We suggest that a separation of SD symptoms is rooted in selective aberrations of the neural circuitry controlling learned but not innate vocal behaviors. LEVEL OF EVIDENCE 4 Laryngoscope, 129:1627-1633, 2019.
Collapse
Affiliation(s)
- Samantha Guiry
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A
| | - Alexis Worthley
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A
| | - Kristina Simonyan
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.,Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.,Harvard Medical School, Boston, Massachusetts, U.S.A
| |
Collapse
|
21
|
Dunn JC, Smaers JB. Neural Correlates of Vocal Repertoire in Primates. Front Neurosci 2018; 12:534. [PMID: 30140202 PMCID: PMC6095195 DOI: 10.3389/fnins.2018.00534] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/16/2018] [Indexed: 01/07/2023] Open
Abstract
Understanding the nature of the relationship between vocal complexity and brain architecture across non-human primates may help elucidate some of the key elements underlying the evolution of human speech. Here, we report a positive correlation between vocal repertoire size and the relative size of cortical association areas (governing voluntary control over behavioural output) in non-human primates. We further demonstrate that a hominid grade shift in the relative volume of cortical association areas coincides with a similar grade shift in the hypoglossal nucleus (which is associated with the cranial nerve that innervates the muscles of the tongue). Our results support a qualitative continuity in the neural correlates of vocal repertoire, but a quantitative discontinuity in the extent to which the neural system supporting speech is innervated by cortical association areas in great apes and humans.
Collapse
Affiliation(s)
- Jacob C Dunn
- Behavioural Ecology Research Group, Department of Biology, Anglia Ruskin University, Cambridge, United Kingdom.,Biological Anthropology, Department of Archaeology, University of Cambridge, Cambridge, United Kingdom
| | - Jeroen B Smaers
- Department of Anthropology, Stony Brook University, Stony Brook, NY, United States
| |
Collapse
|
22
|
Belyk M, Lee YS, Brown S. How does human motor cortex regulate vocal pitch in singers? ROYAL SOCIETY OPEN SCIENCE 2018; 5:172208. [PMID: 30224990 PMCID: PMC6124115 DOI: 10.1098/rsos.172208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
Vocal pitch is used as an important communicative device by humans, as found in the melodic dimension of both speech and song. Vocal pitch is determined by the degree of tension in the vocal folds of the larynx, which itself is influenced by complex and nonlinear interactions among the laryngeal muscles. The relationship between these muscles and vocal pitch has been described by a mathematical model in the form of a set of 'control rules'. We searched for the biological implementation of these control rules in the larynx motor cortex of the human brain. We scanned choral singers with functional magnetic resonance imaging as they produced discrete pitches at four different levels across their vocal range. While the locations of the larynx motor activations varied across singers, the activation peaks for the four pitch levels were highly consistent within each individual singer. This result was corroborated using multi-voxel pattern analysis, which demonstrated an absence of patterned activations differentiating any pairing of pitch levels. The complex and nonlinear relationships between the multiple laryngeal muscles that control vocal pitch may obscure the neural encoding of vocal pitch in the brain.
Collapse
Affiliation(s)
- Michel Belyk
- Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Yune S. Lee
- Department of Speech and Hearing Sciences and Center for Brain Injury, The Ohio State University, Columbus, OH, USA
| | - Steven Brown
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
23
|
Turner MR, Eisen A, Kiernan MC, Ravits J, Swash M. Kinnier Wilson's puzzling features of amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2018; 89:657-666. [PMID: 29122933 DOI: 10.1136/jnnp-2017-317217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 11/03/2022]
Affiliation(s)
- Martin R Turner
- Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, UK
| | - Andrew Eisen
- Department of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew C Kiernan
- Brain and Mind Centre, Sydney Medical School, The University of Sydney; Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - John Ravits
- Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | | |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Molecular specification of facial branchial motor neurons in vertebrates. Dev Biol 2018; 436:5-13. [PMID: 29391164 DOI: 10.1016/j.ydbio.2018.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/27/2018] [Accepted: 01/28/2018] [Indexed: 02/02/2023]
Abstract
Orofacial muscles are critical for life-sustaining behaviors, such as feeding and breathing. Centuries of work by neuroanatomists and surgeons resulted in the mapping of bulbar motor neurons in the brainstem and the course of the cranial nerves that carry their axons. Despite the sophisticated understanding of the anatomy of the region, the molecular mechanisms that dictate the development and maturation of facial motor neurons remain poorly understood. This fundamental problem has been recently revisited by physiologists with novel techniques of studying the rhythmic contraction of orofacial muscles in relationship to breathing. The molecular understanding of facial motor neuron development will not only lead to the comprehension of the neural basis of facial expression but may also unlock new avenues to generate stem cell-derived replacements. This review summarizes the current understanding of molecular programs involved in facial motor neuron generation, migration, and maturation, including neural circuit assembly.
Collapse
|
26
|
|
27
|
A cortical circuit for voluntary laryngeal control: Implications for the evolution language. Psychon Bull Rev 2017; 24:56-63. [PMID: 27368637 DOI: 10.3758/s13423-016-1100-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The development of voluntary laryngeal control has been argued to be a key innovation in the evolution of language. Part of the evidence for this hypothesis comes from neuroscience. For example, comparative research has shown that humans have direct cortical innervation of motor neurons controlling the larynx, whereas nonhuman primates do not. Research on cortical motor control circuits has shown that the frontal lobe cortical motor system does not work alone; it is dependent on sensory feedback control circuits. Thus, the human brain must have evolved not only the required efferent motor pathway but also the cortical circuit for controlling those efferent signals. To fill this gap, I propose a link between the evolution of laryngeal control and neuroscience research on the human dorsal auditory-motor speech stream. Specifically, I argue that the dorsal stream Spt (Sylvian parietal-temporal) circuit evolved in step with the direct cortico-laryngeal control pathway and together represented a key advance in the evolution of speech. I suggest that a cortical laryngeal control circuit may play an important role in language by providing a prosodic frame for speech planning.
Collapse
|
28
|
Eisen A, Braak H, Del Tredici K, Lemon R, Ludolph AC, Kiernan MC. Cortical influences drive amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2017; 88:917-924. [PMID: 28710326 DOI: 10.1136/jnnp-2017-315573] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/26/2017] [Accepted: 05/02/2017] [Indexed: 11/04/2022]
Abstract
The early motor manifestations of sporadic amyotrophic lateral sclerosis (ALS), while rarely documented, reflect failure of adaptive complex motor skills. The development of these skills correlates with progressive evolution of a direct corticomotoneuronal system that is unique to primates and markedly enhanced in humans. The failure of this system in ALS may translate into the split hand presentation, gait disturbance, split leg syndrome and bulbar symptomatology related to vocalisation and breathing, and possibly diffuse fasciculation, characteristic of ALS. Clinical neurophysiology of the brain employing transcranial magnetic stimulation has convincingly demonstrated a presymptomatic reduction or absence of short interval intracortical inhibition, accompanied by increased intracortical facilitation, indicating cortical hyperexcitability. The hallmark of the TDP-43 pathological signature of sporadic ALS is restricted to cortical areas as well as to subcortical nuclei that are under the direct control of corticofugal projections. This provides anatomical support that the origins of the TDP-43 pathology reside in the cerebral cortex itself, secondarily in corticofugal fibres and the subcortical targets with which they make monosynaptic connections. The latter feature explains the multisystem degeneration that characterises ALS. Consideration of ALS as a primary neurodegenerative disorder of the human brain may incorporate concepts of prion-like spread at synaptic terminals of corticofugal axons. Further, such a concept could explain the recognised widespread imaging abnormalities of the ALS neocortex and the accepted relationship between ALS and frontotemporal dementia.
Collapse
Affiliation(s)
- Andrew Eisen
- Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Heiko Braak
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, University of Ulm, Ulm, Baden-Württemberg, Germany
| | - Kelly Del Tredici
- Clinical Neuroanatomy Section, Department of Neurology, Center for Biomedical Research, University of Ulm, Ulm, Baden-Württemberg, Germany
| | - Roger Lemon
- Sobell Department of Motor Neuroscience and Movement Disorders, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK
| | | | - Matthew C Kiernan
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
29
|
The origins of the vocal brain in humans. Neurosci Biobehav Rev 2017; 77:177-193. [DOI: 10.1016/j.neubiorev.2017.03.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/15/2017] [Accepted: 03/22/2017] [Indexed: 01/13/2023]
|
30
|
Nakajima T, Tazoe T, Sakamoto M, Endoh T, Shibuya S, Elias LA, Mezzarane RA, Komiyama T, Ohki Y. Reassessment of Non-Monosynaptic Excitation from the Motor Cortex to Motoneurons in Single Motor Units of the Human Biceps Brachii. Front Hum Neurosci 2017; 11:19. [PMID: 28194103 PMCID: PMC5276998 DOI: 10.3389/fnhum.2017.00019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/10/2017] [Indexed: 12/05/2022] Open
Abstract
Corticospinal excitation is mediated by polysynaptic pathways in several vertebrates, including dexterous monkeys. However, indirect non-monosynaptic excitation has not been clearly observed following transcranial electrical stimulation (TES) or cervicomedullary stimulation (CMS) in humans. The present study evaluated indirect motor pathways in normal human subjects by recording the activities of single motor units (MUs) in the biceps brachii (BB) muscle. The pyramidal tract was stimulated with weak TES, CMS, and transcranial magnetic stimulation (TMS) contralateral to the recording side. During tasks involving weak co-contraction of the BB and hand muscles, all stimulation methods activated MUs with short latencies. Peristimulus time histograms (PSTHs) showed that responses with similar durations were induced by TES (1.9 ± 1.4 ms) and CMS (2.0 ± 1.4 ms), and these responses often showed multiple peaks with the PSTH peak having a long duration (65.3% and 44.9%, respectively). Such long-duration excitatory responses with multiple peaks were rarely observed in the finger muscles following TES or in the BB following stimulation of the Ia fibers. The responses obtained with TES were compared in the same 14 BB MUs during the co-contraction and isolated BB contraction tasks. Eleven and three units, respectively, exhibited activation with multiple peaks during the two tasks. In order to determine the dispersion effects on the axon conduction velocities (CVs) and synaptic noise, a simulation study that was comparable to the TES experiments was performed with a biologically plausible neuromuscular model. When the model included the monosynaptic-pyramidal tract, multiple peaks were obtained in about 34.5% of the motoneurons (MNs). The experimental and simulation results indicated the existence of task-dependent disparate inputs from the pyramidal tract to the MNs of the upper limb. These results suggested that intercalated interneurons are present in the spinal cord and that these interneurons might be equivalent to those identified in animal experiments.
Collapse
Affiliation(s)
- Tsuyoshi Nakajima
- Division of Sports and Health Science, Chiba UniversityChiba, Japan; Department of Integrative Physiology, Kyorin University School of MedicineTokyo, Japan
| | - Toshiki Tazoe
- Division of Sports and Health Science, Chiba UniversityChiba, Japan; Department of Physical Medicine and Rehabilitation, Center for the Neural Basis of Cognition, Systems Neuroscience Institute, University of PittsburghPittsburgh, PA, USA
| | - Masanori Sakamoto
- Division of Sports and Health Science, Chiba UniversityChiba, Japan; Faculty of Education, Department of Physical Education, Kumamoto UniversityKumamoto, Japan
| | - Takashi Endoh
- Division of Sports and Health Science, Chiba UniversityChiba, Japan; Faculty of Child Development and Education, Uekusa Gakuen UniversityChiba, Japan
| | - Satoshi Shibuya
- Department of Integrative Physiology, Kyorin University School of Medicine Tokyo, Japan
| | - Leonardo A Elias
- Neural Engineering Research Laboratory, Department of Biomedical Engineering, School of Electrical and Computer Engineering, University of CampinasCampinas, Brazil; Biomedical Engineering Laboratory, Escola Politecnica, Departamento de Engenharia de Telecomunicações e Controle (PTC), University of Sao PauloSao Paulo, Brazil
| | - Rinaldo A Mezzarane
- Division of Sports and Health Science, Chiba UniversityChiba, Japan; Biomedical Engineering Laboratory, Escola Politecnica, Departamento de Engenharia de Telecomunicações e Controle (PTC), University of Sao PauloSao Paulo, Brazil; Laboratory of Signal Processing and Motor Control, College of Physical Education, University of BrasíliaBrasília, Brazil
| | | | - Yukari Ohki
- Department of Integrative Physiology, Kyorin University School of Medicine Tokyo, Japan
| |
Collapse
|
31
|
Structural Organization of the Laryngeal Motor Cortical Network and Its Implication for Evolution of Speech Production. J Neurosci 2016; 36:4170-81. [PMID: 27076417 DOI: 10.1523/jneurosci.3914-15.2016] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/28/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The laryngeal motor cortex (LMC) is essential for the production of learned vocal behaviors because bilateral damage to this area renders humans unable to speak but has no apparent effect on innate vocalizations such as human laughing and crying or monkey calls. Several hypotheses have been put forward attempting to explain the evolutionary changes from monkeys to humans that potentially led to enhanced LMC functionality for finer motor control of speech production. These views, however, remain limited to the position of the larynx area within the motor cortex, as well as its connections with the phonatory brainstem regions responsible for the direct control of laryngeal muscles. Using probabilistic diffusion tractography in healthy humans and rhesus monkeys, we show that, whereas the LMC structural network is largely comparable in both species, the LMC establishes nearly 7-fold stronger connectivity with the somatosensory and inferior parietal cortices in humans than in macaques. These findings suggest that important "hard-wired" components of the human LMC network controlling the laryngeal component of speech motor output evolved from an already existing, similar network in nonhuman primates. However, the evolution of enhanced LMC-parietal connections likely allowed for more complex synchrony of higher-order sensorimotor coordination, proprioceptive and tactile feedback, and modulation of learned voice for speech production. SIGNIFICANCE STATEMENT The role of the primary motor cortex in the formation of a comprehensive network controlling speech and language has been long underestimated and poorly studied. Here, we provide comparative and quantitative evidence for the significance of this region in the control of a highly learned and uniquely human behavior: speech production. From the viewpoint of structural network organization, we discuss potential evolutionary advances of enhanced temporoparietal cortical connections with the laryngeal motor cortex in humans compared with nonhuman primates that may have contributed to the development of finer vocal motor control necessary for speech production.
Collapse
|
32
|
Chankaew E, Srirabheebhat P, Manochiopinig S, Witthiwej T, Benjamin I. Bulbar dysfunction in normal pressure hydrocephalus: a prospective study. Neurosurg Focus 2016; 41:E15. [PMID: 27581311 DOI: 10.3171/2016.6.focus16183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Normal pressure hydrocephalus (NPH) is clinically characterized by gait disturbance, cognitive impairment, and urinary incontinence, as well as enlargement of the ventricles. To the best of the authors' knowledge, there have been no previous publications regarding the correlation between bulbar dysfunction and NPH. The primary objective of this study was to compare preoperative and postoperative prevalence of bulbar dysfunction in patients with NPH. Secondary objectives included assessing the results of surgery for swallowing, speech, gait, cognition, and urination, and evaluating the correlation between bulbar dysfunction and triad symptoms. METHODS Fifty-three patients with NPH who underwent shunt placement surgery at Siriraj Hospital were included in the study. Patients were evaluated for gait, cognition, urination, swallowing, and speech before and 6 months after shunt placement. Triad symptoms were assessed using standard methods. Bulbar dysfunctions were assessed using the Swallowing Problem Questionnaire, Thai Articulation Test, Resonation Screening Test (RST), and Thai Nasality Test. The Thai Speech Assessment Program and nasometer were used for objective speech measurement. RESULTS Preoperatively, 86% (43/50) of patients had swallowing problems and 75% (37/49) had speech problems, as measured by the RST. Postoperatively, there was significant improvement in swallowing (p < 0.001), speech problems by RST (p = 0.008), and voice volume (p = 0.009), but no significant change in the nasometer test. All triad symptoms were improved. There were significant correlations between swallowing impairment and gait disturbance (r = 0.358, p = 0.009), and RST and cognitive impairment (r = -0.502, p < 0.001). CONCLUSIONS This is the first study of bulbar dysfunction in patients with NPH. The results showed that the prevalence of bulbar dysfunction is very high. The correlation between bulbar dysfunction and the classic NPH triad has been documented and published. These bulbar symptoms also significantly improved after surgery. As such, bulbar dysfunction should be regarded as a core symptom that should be considered along with the classic triad in the clinical diagnosis and management of NPH.
Collapse
Affiliation(s)
| | | | - Sriwimon Manochiopinig
- Division of Speech-Language Therapy, Department of Rehabilitation Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | | |
Collapse
|
33
|
Abstract
This review of the central nervous control systems for voice and swallowing has suggested that the traditional concepts of a separation between cortical and limbic and brain stem control should be refined and be more integrative. For voice production, a separation of the nonhuman vocalization system from the human learned voice production system has been posited based primarily on studies of nonhuman primates. However, recent humans studies of emotionally based vocalizations and human volitional voice production have shown more integration between these two systems than previously proposed. Recent human studies have shown that reflexive vocalization as well as learned voice production not involving speech involve a common integrative system. However, recent studies of nonhuman primates have provided evidence that some cortical activity vocalization and cortical changes occur with training during vocal behavior. For swallowing, evidence from the macaque and functional brain imaging in humans indicates that the control for the pharyngeal phase of swallowing is not primarily under brain stem mechanisms as previously proposed. Studies suggest that the initiation and patterning of swallowing for the pharyngeal phase is also under active cortical control for both spontaneous as well as volitional swallowing in awake humans and nonhuman primates.
Collapse
|
34
|
Marinovic W, Tresilian JR. Triggering prepared actions by sudden sounds: reassessing the evidence for a single mechanism. Acta Physiol (Oxf) 2016; 217:13-32. [PMID: 26548462 DOI: 10.1111/apha.12627] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 10/13/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022]
Abstract
Loud acoustic stimuli can unintentionally elicit volitional acts when a person is in a state of readiness to execute them (the StartReact effect). It has been assumed that the same subcortical pathways and brain regions underlie all instances of the StartReact effect. They are proposed to involve the startle reflex pathways, and the eliciting mechanism is distinct from other ways in which sound can affect the motor system. We present an integrative review which shows that there is no evidence to support these assumptions. We argue that motor command generation for learned, volitional orofacial, laryngeal and distal limb movements is cortical and the StartReact effect for such movements involves transcortical pathways. In contrast, command generation for saccades, locomotor corrections and postural adjustments is subcortical and subcortical pathways are implicated in the StartReact effect for these cases. We conclude that the StartReact effect is not a special phenomenon mediated by startle reflex pathways, but rather is a particular manifestation of the excitatory effects of intense stimulation on the central nervous system.
Collapse
Affiliation(s)
- W. Marinovic
- School of Health & Rehabilitation Sciences; The University of Queensland; Brisbane Qld Australia
- Centre for Sensorimotor Performance; School of Human Movement and Nutrition Sciences; The University of Queensland; Brisbane Qld Australia
| | - J. R. Tresilian
- Department of Psychology; University of Warwick; Coventry UK
| |
Collapse
|
35
|
Belyk M, Pfordresher PQ, Liotti M, Brown S. The Neural Basis of Vocal Pitch Imitation in Humans. J Cogn Neurosci 2015; 28:621-35. [PMID: 26696298 DOI: 10.1162/jocn_a_00914] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Vocal imitation is a phenotype that is unique to humans among all primate species, and so an understanding of its neural basis is critical in explaining the emergence of both speech and song in human evolution. Two principal neural models of vocal imitation have emerged from a consideration of nonhuman animals. One hypothesis suggests that putative mirror neurons in the inferior frontal gyrus pars opercularis of Broca's area may be important for imitation. An alternative hypothesis derived from the study of songbirds suggests that the corticostriate motor pathway performs sensorimotor processes that are specific to vocal imitation. Using fMRI with a sparse event-related sampling design, we investigated the neural basis of vocal imitation in humans by comparing imitative vocal production of pitch sequences with both nonimitative vocal production and pitch discrimination. The strongest difference between these tasks was found in the putamen bilaterally, providing a striking parallel to the role of the analogous region in songbirds. Other areas preferentially activated during imitation included the orofacial motor cortex, Rolandic operculum, and SMA, which together outline the corticostriate motor loop. No differences were seen in the inferior frontal gyrus. The corticostriate system thus appears to be the central pathway for vocal imitation in humans, as predicted from an analogy with songbirds.
Collapse
|
36
|
Abstract
ABSTRACT:In recognition of the 100th anniversary of Charcot’s death we have reviewed possible pathogenic mechanisms in amyotrophic lateral sclerosis (ALS). Advances in the last 5 years in molecular biology and genetics have identified mutations in the cytosolic dismutase (SODI) gene in some patients with familial ALS raising the possibility that oxidative stress may be involved in the pathogenesis. An excitotoxic pathogenesis has been implicated based on elevated plasma and CSF levels of amino acids and altered contents of amino acids in the nervous system of ALS patients and changes in the number of excitatory amino acid receptors. ALS sera containing antibodies to L-type calcium channels and the development of immune mediated lower and upper and lower motor neuron models have revitalized research efforts focusing on an immune basis for ALS. Other pathogenic mechanisms which have been the subject of recent research include elemental toxicity, apoptosis and programmed cell death and possibly a deficiency or abnormality in growth factors. Pathogenic processes for ALS must account for an increasing incidence of ALS, male preponderance, and the selective vulnerability of the corticomotoneuronal system.
Collapse
|
37
|
Belyk M, Brown S. Pitch underlies activation of the vocal system during affective vocalization. Soc Cogn Affect Neurosci 2015; 11:1078-88. [PMID: 26078385 DOI: 10.1093/scan/nsv074] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/04/2015] [Indexed: 11/12/2022] Open
Abstract
Affective prosody is that aspect of speech that conveys a speaker's emotional state through modulations in various vocal parameters, most prominently pitch. While a large body of research implicates the cingulate vocalization area in controlling affective vocalizations in monkeys, no systematic test of functional homology for this area has yet been reported in humans. In this study, we used functional magnetic resonance imaging to compare brain activations when subjects produced affective vocalizations in the form of exclamations vs non-affective vocalizations with similar pitch contours. We also examined the perception of affective vocalizations by having participants make judgments about either the emotions being conveyed by recorded affective vocalizations or the pitch contours of the same vocalizations. Production of affective vocalizations and matched pitch contours activated a highly overlapping set of brain areas, including the larynx-phonation area of the primary motor cortex and a region of the anterior cingulate cortex that is consistent with the macro-anatomical position of the cingulate vocalization area. This overlap contradicts the dominant view that these areas form two distinct vocal pathways with dissociable functions. Instead, we propose that these brain areas are nodes in a single vocal network, with an emphasis on pitch modulation as a vehicle for affective expression.
Collapse
Affiliation(s)
- Michel Belyk
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Steven Brown
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
38
|
de Oliveira-Souza R. Damage to the pyramidal tracts is necessary and sufficient for the production of the pyramidal syndrome in man. Med Hypotheses 2015; 85:99-110. [PMID: 25959865 DOI: 10.1016/j.mehy.2015.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 10/23/2022]
Abstract
The causal role played by damage to the pyramidal tracts in the production of spastic hemiplegia in man has been hotly debated over the past hundred years. Two broad streams of thought have emerged from this dispute. The first, which is grounded on the clinicopathological schools of Jean-Martin Charcot (1825-1893) and Paul Flechsig (1847-1929), claimed that the four cardinal signs of hemiplegia, namely (i) paralysis, (ii) spasticity, (iii) hyperactive phasic muscle reflexes ("tendon jerks") and (iv) the sign of Babinski, are caused by injury or dysfunction of the pyramidal tracts. The second school, championed by John Farquhar Fulton (1899-1960) and Derek Denny-Brown (1901-1981), reflects the increasing influence of experimental neurology on clinicopathological concepts after World War II. According to this school, most elements of the pyramidal syndrome are caused by the added release or injury of extrapyramidal structures at different levels of the forebrain and brainstem. Most symptoms of spastic hemiplegia were thus interpreted as signs of extrapyramidal (e.g., reticulospinal) release or damage. However, consensus on which symptoms of spastic hemiplegia were due to pyramidal or extrapyramidal changes was never reached. To add to this uncertainty, a number of clinicopathological cases that supported the old view were sporadically published over the same period. The purpose of the present essay is to provide clinicoanatomic perspective to the neurological literature in support of the hypothesis that damage to the pyramidal tracts is a necessary and sufficient condition for the production of the complete pyramidal syndrome in man.
Collapse
Affiliation(s)
- Ricardo de Oliveira-Souza
- D'Or Institute for Research & Education (IDOR), Brazil; Federal University of the State of Rio de Janeiro, Brazil.
| |
Collapse
|
39
|
Abstract
The faith that "comparative analysis of the behaviour of modern primates, in conjunction with an accurate phylogenetic tree of relatedness, has the power to chart the early history of human cognitive evolution" (Byrne 2000 p. 543) runs afoul of the fact that no other primate besides humans is capable of vocal production learning. This basic enabling adaptation for articulate speech bears crucially on the reconstruction of language origins.
Collapse
|
40
|
Why we can talk, debate, and change our minds: neural circuits, basal ganglia operations, and transcriptional factors. Behav Brain Sci 2014; 37:561-2; discussion 577-604. [PMID: 25514951 DOI: 10.1017/s0140525x13004093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ackermann et al. disregard attested knowledge concerning aphasia, Parkinson disease, cortical-to-striatal circuits, basal ganglia, laryngeal phonation, and other matters. Their dual-pathway model cannot account for "what is special about the human brain." Their human cortical-to-laryngeal neural circuit does not exist. Basal ganglia operations, enhanced by mutations on FOXP2, confer human motor-control, linguistic, and cognitive capabilities.
Collapse
|
41
|
Simonyan K. The laryngeal motor cortex: its organization and connectivity. Curr Opin Neurobiol 2014; 28:15-21. [PMID: 24929930 PMCID: PMC4177508 DOI: 10.1016/j.conb.2014.05.006] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 05/18/2014] [Accepted: 05/19/2014] [Indexed: 10/25/2022]
Abstract
Our ability to learn and control the motor aspects of complex laryngeal behaviors, such as speech and song, is modulated by the laryngeal motor cortex (LMC), which is situated in the area 4 of the primary motor cortex and establishes both direct and indirect connections with laryngeal motoneurons. In contrast, the LMC in monkeys is located in the area 6 of the premotor cortex, projects only indirectly to laryngeal motoneurons and its destruction has essentially no effect on production of species-specific calls. These differences in cytoarchitectonic location and connectivity may be a result of hominid evolution that led to the LMC shift from the phylogenetically 'old' to 'new' motor cortex in order to fulfill its paramount function, that is, voluntary motor control of human speech and song production.
Collapse
Affiliation(s)
- Kristina Simonyan
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States; Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| |
Collapse
|
42
|
Brainard MS, Fitch WT. Editorial overview: Communication and language: Animal communication and human language. Curr Opin Neurobiol 2014; 28:v-viii. [DOI: 10.1016/j.conb.2014.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
43
|
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.
Collapse
Affiliation(s)
- Germán Mendoza
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
| | - Hugo Merchant
- Instituto de Neurobiología, UNAM, Campus Juriquilla, Mexico.
| |
Collapse
|
44
|
Kato M, Okanoya K, Koike T, Sasaki E, Okano H, Watanabe S, Iriki A. Human speech- and reading-related genes display partially overlapping expression patterns in the marmoset brain. BRAIN AND LANGUAGE 2014; 133:26-38. [PMID: 24769279 DOI: 10.1016/j.bandl.2014.03.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 03/02/2014] [Accepted: 03/22/2014] [Indexed: 06/03/2023]
Abstract
Language is a characteristic feature of human communication. Several familial language impairments have been identified, and candidate genes for language impairments already isolated. Studies comparing expression patterns of these genes in human brain are necessary to further understanding of these genes. However, it is difficult to examine gene expression in human brain. In this study, we used a non-human primate (common marmoset; Callithrix jacchus) as a biological model of the human brain to investigate expression patterns of human speech- and reading-related genes. Expression patterns of speech disorder- (FoxP2, FoxP1, CNTNAP2, and CMIP) and dyslexia- (ROBO1, DCDC2, and KIAA0319) related genes were analyzed. We found the genes displayed overlapping expression patterns in the ocular, auditory, and motor systems. Our results enhance understanding of the molecular mechanisms underlying language impairments.
Collapse
Affiliation(s)
- Masaki Kato
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Center for Advanced Research on Logic and Sensibility (CARLS), Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan.
| | - Kazuo Okanoya
- Laboratory for Biolinguistics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Taku Koike
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Erika Sasaki
- Department of Applied Developmental Biology, Central Institute for Experimental Animals, 3-25-12 Tonomachi, Kawasaki, Kanagawa 210-0821, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; KEIO-RIKEN Research Center for Human Cognition, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; KEIO-RIKEN Research Center for Human Cognition, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan; Keio University Joint Research Laboratory, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Shigeru Watanabe
- KEIO-RIKEN Research Center for Human Cognition, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan; Center for Advanced Research on Logic and Sensibility (CARLS), Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan
| | - Atsushi Iriki
- Laboratory for Symbolic Cognitive Development, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; KEIO-RIKEN Research Center for Human Cognition, Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan; Center for Advanced Research on Logic and Sensibility (CARLS), Keio University, 2-15-45 Mita, Minato-ku, Tokyo 108-8345, Japan.
| |
Collapse
|
45
|
Brain mechanisms of acoustic communication in humans and nonhuman primates: An evolutionary perspective. Behav Brain Sci 2014; 37:529-46. [DOI: 10.1017/s0140525x13003099] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
AbstractAny account of “what is special about the human brain” (Passingham 2008) must specify the neural basis of our unique ability to produce speech and delineate how these remarkable motor capabilities could have emerged in our hominin ancestors. Clinical data suggest that the basal ganglia provide a platform for the integration of primate-general mechanisms of acoustic communication with the faculty of articulate speech in humans. Furthermore, neurobiological and paleoanthropological data point at a two-stage model of the phylogenetic evolution of this crucial prerequisite of spoken language: (i) monosynaptic refinement of the projections of motor cortex to the brainstem nuclei that steer laryngeal muscles, presumably, as part of a “phylogenetic trend” associated with increasing brain size during hominin evolution; (ii) subsequent vocal-laryngeal elaboration of cortico-basal ganglia circuitries, driven by human-specificFOXP2mutations.;>This concept implies vocal continuity of spoken language evolution at the motor level, elucidating the deep entrenchment of articulate speech into a “nonverbal matrix” (Ingold 1994), which is not accounted for by gestural-origin theories. Moreover, it provides a solution to the question for the adaptive value of the “first word” (Bickerton 2009) since even the earliest and most simple verbal utterances must have increased the versatility of vocal displays afforded by the preceding elaboration of monosynaptic corticobulbar tracts, giving rise to enhanced social cooperation and prestige. At the ontogenetic level, the proposed model assumes age-dependent interactions between the basal ganglia and their cortical targets, similar to vocal learning in some songbirds. In this view, the emergence of articulate speech builds on the “renaissance” of an ancient organizational principle and, hence, may represent an example of “evolutionary tinkering” (Jacob 1977).
Collapse
|
46
|
Arriaga G, Jarvis ED. Mouse vocal communication system: are ultrasounds learned or innate? BRAIN AND LANGUAGE 2013; 124:96-116. [PMID: 23295209 PMCID: PMC3886250 DOI: 10.1016/j.bandl.2012.10.002] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 10/05/2012] [Accepted: 10/08/2012] [Indexed: 05/20/2023]
Abstract
Mouse ultrasonic vocalizations (USVs) are often used as behavioral readouts of internal states, to measure effects of social and pharmacological manipulations, and for behavioral phenotyping of mouse models for neuropsychiatric and neurodegenerative disorders. However, little is known about the neurobiological mechanisms of rodent USV production. Here we discuss the available data to assess whether male mouse song behavior and the supporting brain circuits resemble those of known vocal non-learning or vocal learning species. Recent neurobiology studies have demonstrated that the mouse USV brain system includes motor cortex and striatal regions, and that the vocal motor cortex sends a direct sparse projection to the brainstem vocal motor nucleus ambiguous, a projection previously thought be unique to humans among mammals. Recent behavioral studies have reported opposing conclusions on mouse vocal plasticity, including vocal ontogeny changes in USVs over early development that might not be explained by innate maturation processes, evidence for and against a role for auditory feedback in developing and maintaining normal mouse USVs, and evidence for and against limited vocal imitation of song pitch. To reconcile these findings, we suggest that the trait of vocal learning may not be dichotomous but encompass a broad spectrum of behavioral and neural traits we call the continuum hypothesis, and that mice possess some of the traits associated with a capacity for limited vocal learning.
Collapse
Affiliation(s)
- Gustavo Arriaga
- Department of Neurobiology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA.
| | | |
Collapse
|
47
|
de Oliveira-Souza R. The human extrapyramidal system. Med Hypotheses 2012; 79:843-52. [DOI: 10.1016/j.mehy.2012.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/28/2012] [Accepted: 09/07/2012] [Indexed: 12/11/2022]
|
48
|
Of mice, birds, and men: the mouse ultrasonic song system has some features similar to humans and song-learning birds. PLoS One 2012; 7:e46610. [PMID: 23071596 PMCID: PMC3468587 DOI: 10.1371/journal.pone.0046610] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 09/06/2012] [Indexed: 11/28/2022] Open
Abstract
Humans and song-learning birds communicate acoustically using learned vocalizations. The characteristic features of this social communication behavior include vocal control by forebrain motor areas, a direct cortical projection to brainstem vocal motor neurons, and dependence on auditory feedback to develop and maintain learned vocalizations. These features have so far not been found in closely related primate and avian species that do not learn vocalizations. Male mice produce courtship ultrasonic vocalizations with acoustic features similar to songs of song-learning birds. However, it is assumed that mice lack a forebrain system for vocal modification and that their ultrasonic vocalizations are innate. Here we investigated the mouse song system and discovered that it includes a motor cortex region active during singing, that projects directly to brainstem vocal motor neurons and is necessary for keeping song more stereotyped and on pitch. We also discovered that male mice depend on auditory feedback to maintain some ultrasonic song features, and that sub-strains with differences in their songs can match each other's pitch when cross-housed under competitive social conditions. We conclude that male mice have some limited vocal modification abilities with at least some neuroanatomical features thought to be unique to humans and song-learning birds. To explain our findings, we propose a continuum hypothesis of vocal learning.
Collapse
|
49
|
Simonyan K, Horwitz B, Jarvis ED. Dopamine regulation of human speech and bird song: a critical review. BRAIN AND LANGUAGE 2012; 122:142-50. [PMID: 22284300 PMCID: PMC3362661 DOI: 10.1016/j.bandl.2011.12.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 12/11/2011] [Accepted: 12/12/2011] [Indexed: 05/23/2023]
Abstract
To understand the neural basis of human speech control, extensive research has been done using a variety of methodologies in a range of experimental models. Nevertheless, several critical questions about learned vocal motor control still remain open. One of them is the mechanism(s) by which neurotransmitters, such as dopamine, modulate speech and song production. In this review, we bring together the two fields of investigations of dopamine action on voice control in humans and songbirds, who share similar behavioral and neural mechanisms for speech and song production. While human studies investigating the role of dopamine in speech control are limited to reports in neurological patients, research on dopaminergic modulation of bird song control has recently expanded our views on how this system might be organized. We discuss the parallels between bird song and human speech from the perspective of dopaminergic control as well as outline important differences between these species.
Collapse
Affiliation(s)
- Kristina Simonyan
- Department of Neurology, Mount Sinai School of Medicine, New York, NY, United States.
| | | | | |
Collapse
|
50
|
Petkov CI, Jarvis ED. Birds, primates, and spoken language origins: behavioral phenotypes and neurobiological substrates. FRONTIERS IN EVOLUTIONARY NEUROSCIENCE 2012; 4:12. [PMID: 22912615 PMCID: PMC3419981 DOI: 10.3389/fnevo.2012.00012] [Citation(s) in RCA: 225] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 07/20/2012] [Indexed: 11/18/2022]
Abstract
Vocal learners such as humans and songbirds can learn to produce elaborate patterns of structurally organized vocalizations, whereas many other vertebrates such as non-human primates and most other bird groups either cannot or do so to a very limited degree. To explain the similarities among humans and vocal-learning birds and the differences with other species, various theories have been proposed. One set of theories are motor theories, which underscore the role of the motor system as an evolutionary substrate for vocal production learning. For instance, the motor theory of speech and song perception proposes enhanced auditory perceptual learning of speech in humans and song in birds, which suggests a considerable level of neurobiological specialization. Another, a motor theory of vocal learning origin, proposes that the brain pathways that control the learning and production of song and speech were derived from adjacent motor brain pathways. Another set of theories are cognitive theories, which address the interface between cognition and the auditory-vocal domains to support language learning in humans. Here we critically review the behavioral and neurobiological evidence for parallels and differences between the so-called vocal learners and vocal non-learners in the context of motor and cognitive theories. In doing so, we note that behaviorally vocal-production learning abilities are more distributed than categorical, as are the auditory-learning abilities of animals. We propose testable hypotheses on the extent of the specializations and cross-species correspondences suggested by motor and cognitive theories. We believe that determining how spoken language evolved is likely to become clearer with concerted efforts in testing comparative data from many non-human animal species.
Collapse
Affiliation(s)
- Christopher I. Petkov
- Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, UK
- Centre for Behavior and Evolution, Newcastle UniversityNewcastle upon Tyne, UK
| | - Erich D. Jarvis
- Department of Neurobiology, Howard Hughes Medical Institute, Duke UniversityDurham, NC, USA
| |
Collapse
|