Speech Perception

Author(s):  
David Poeppel ◽  
Gregory B. Cogan ◽  
Ido Davidesco ◽  
Adeen Flinker

Speech perception can be thought of as the set of operations that take as input the continuously varying acoustic waveforms available at the auditory periphery (vibrations in the ear) and that generate as output those representations (abstractions in the head) that constitute the basis for the subsequent operations that mediate language comprehension (which can, of course, be fed by audition, vision, or touch). The neural basis of speech perception proper has been studied experimentally by every available neural recording and stimulation technique. The interpretation of the findings and the development of a comprehensive mechanistic theory are complicated by the fact that very different protocols are used: studies range from the identification and categorization of single vowels and syllables to decisions on single spoken words to intelligibility judgments on connected speech. Within this broader context, three topics have received considerable attention: the hemispheric lateralization of speech perception, the role of the motor system, and the potential contribution of neural oscillations to perceptual analysis. This chapter discusses each of these areas in turn.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Joao Castelhano ◽  
Isabel C. Duarte ◽  
Joao Duraes ◽  
Henrique Madeira ◽  
Miguel Castelo-Branco

Software programming is a modern activity that poses strong challenges to the human brain. The neural mechanisms that support this novel cognitive faculty are still unknown. On the other hand, reading and calculation abilities represent slightly less recent human activities, in which neural correlates are relatively well understood. We hypothesize that calculus and reading brain networks provide joint underpinnings with distinctly weighted contributions which concern programming tasks, in particular concerning error identification. Based on a meta-analysis of the core regions involved in both reading and math and recent experimental evidence on the neural basis of programming tasks, we provide a theoretical account that integrates the role of these networks in program understanding. In this connectivity-based framework, error-monitoring processing regions in the frontal cortex influence the insula, which is a pivotal hub within the salience network, leading into efficient causal modulation of parietal networks involved in reading and mathematical operations. The core role of the anterior insula and anterior midcingulate cortex is illuminated by their relation to performance in error processing and novelty. The larger similarity that we observed between the networks underlying calculus and programming skills does not exclude a more limited but clear overlap with the reading network, albeit with differences in hemispheric lateralization when compared with prose reading. Future work should further elucidate whether other features of computer program understanding also use distinct weights of phylogenetically “older systems” for this recent human activity, based on the adjusting influence of fronto-insular networks. By unraveling the neural correlates of program understanding and bug detection, this work provides a framework to understand error monitoring in this novel complex faculty.


2021 ◽  
Vol 3 (1) ◽  
pp. 41-58
Author(s):  
Caroline Nallet ◽  
Judit Gervain

Neonates show broad-based, universal speech perception abilities, allowing them to acquire any language. Moreover, an increasing body of research shows that prenatal experience with speech, which is a low-pass signal mainly preserving prosody, already shapes those abilities. In this review, we first provide a summary of the empirical evidence available today on newborns’ universal and experience-modulated speech perception abilities. We then interpret these findings in a new framework, focusing on the role of the prenatal prosodic experience in speech perception development. We argue that the chronological sequence of infants’ experience with speech, starting before birth with a low-pass filtered signal and continuing with the full-band signal after birth, sets up the prosodic hierarchy and a cascade of embedded neural oscillations as its brain correlate, laying the foundations for language acquisition. Prosody, constituting infants’ very first experience with language, may thus play a fundamental role in speech perception and language development.


2020 ◽  
Vol 27 (31) ◽  
pp. 5119-5136 ◽  
Author(s):  
Barbara Carpita ◽  
Donatella Marazziti ◽  
Lionella Palego ◽  
Gino Giannaccini ◽  
Laura Betti ◽  
...  

Background: Autism Spectrum Disorder (ASD) is a condition strongly associated with genetic predisposition and familial aggregation. Among ASD patients, different levels of symptoms severity are detectable, while the presence of intermediate autism phenotypes in close relatives of ASD probands is also known in literature. Recently, increasing attention has been paid to environmental factors that might play a role in modulating the relationship between genomic risk and development and severity of ASD. Within this framework, an increasing body of evidence has stressed a possible role of both gut microbiota and inflammation in the pathophysiology of neurodevelopment. The aim of this paper is to review findings about the link between microbiota dysbiosis, inflammation and ASD. Methods: Articles ranging from 1990 to 2018 were identified on PUBMED and Google Scholar databases, with keyword combinations as: microbiota, immune system, inflammation, ASD, autism, broad autism phenotype, adult. Results: Recent evidence suggests that microbiota alterations, immune system and neurodevelopment may be deeply intertwined, shaping each other during early life. However, results from both animal models and human samples are still heterogeneous, while few studies focused on adult patients and ASD intermediate phenotypes. Conclusion: A better understanding of these pathways, within an integrative framework between central and peripheral systems, might not only shed more light on neural basis of ASD symptoms, clarifying brain pathophysiology, but it may also allow to develop new therapeutic strategies for these disorders, still poorly responsive to available treatments.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2036
Author(s):  
Luigi Marongiu ◽  
Markus Burkard ◽  
Sascha Venturelli ◽  
Heike Allgayer

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.


2017 ◽  
Vol 31 (7/8) ◽  
pp. 730-745 ◽  
Author(s):  
Jorge Cegarra-Sanchez ◽  
Juan-Gabriel Cegarra-Navarro ◽  
Anthony Wensley ◽  
Jose Diaz Manzano

Purpose Knowledge acquired from sources of unverified information such as gossip, partial truths or lies, in this paper it is termed as “counter-knowledge.” The purpose of this paper is to explore this topic through an exploration of the links between a Hospital-in-the-Home Units (HHUs) learning process (LP), counter-knowledge, and the utilization of communication technologies. The following two questions are addressed: Does the reduction of counter-knowledge result in the utilization of communication technologies? Does the development of counter-knowledge hinder the LP? Design/methodology/approach This paper examines the relevance of communication technologies to the exploration and exploitation of knowledge for 252 patients of a (HHU) within a Spanish regional hospital. The data collected was analyzed using the PLS-Graph. Findings To HHU managers, this study offers a set of guidelines to assist in their gaining an understanding of the role of counter-knowledge in organizational LPs and the potential contribution of communication technologies. Our findings support the proposition that the negative effects of counter-knowledge can be mitigated by using communication technologies. Originality/value It is argued in this paper that counter-knowledge may play a variety of different roles in the implementation of LPs. Specifically, the assignment of communication technologies to homecare units has given them the means to filter counter-knowledge and prevent users from any possible problems caused by such counter-knowledge.


2017 ◽  
Vol 13 (7) ◽  
pp. P1197
Author(s):  
Suvarna Alladi ◽  
Shailaja Mekala ◽  
Vani K. Kasyap ◽  
Suneel Kumar Bagadi ◽  
Sireesha Jala ◽  
...  

Brain ◽  
2006 ◽  
Vol 129 (4) ◽  
pp. 932-943 ◽  
Author(s):  
A. Ting Wang ◽  
Susan S. Lee ◽  
Marian Sigman ◽  
Mirella Dapretto

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mieko Oka ◽  
Nobuhiko Ohno ◽  
Takakazu Kawamata ◽  
Tomohiro Aoki

Introduction: Intracranial aneurysm (IA) affects 1 to 5 % in general public and becomes the primary cause of subarachnoid hemorrhage, the most severe form of stroke. However, currently, no drug therapy is available for IAs to prevent progression and rupture of lesions. Elucidation of mechanisms underlying the disease is thus mandatory. Considering the important role of vascular smooth muscle cells (SMCs) in the maintenance of stiffness of arterial walls and also in the pathogenesis of atherosclerosis via mediating inflammatory responses, we in the present study analyzed morphological or phenotypical changes of SMCs during the disease development in the lesions. Methods: We subjected rats to an IA model in which lesions are induced by increase of hemodynamic force loading on intracranial arterial bifurcations and performed histopathological analyses of induced lesions including the electron microscopic examination. We then immunostained specimens from induced lesions to explore factors responsible for dedifferentiation or migration of SMCs. In vitro study was also done to examine effect of some candidate factors on dedifferentiation or migration of cultured SMCs. Results: We first found the accumulation of SMCs underneath the endothelial cell layer mainly at the neck portion of the lesion. These cells was positive for the embryonic form of myosin heavy chain, a marker for the dedifferentiated SMCs, and the expression of pro-inflammatory factors like TNF-α. In immunostaining to explore the potential factor regulating the dedifferentiation of SMCs, we found that Platelet-derived growth factor-BB (PDGF-BB) was expressed in endothelial cells at the neck portion of IA walls. Consistently, recombinant PDGF-BB could promote the dedifferentiate of SMCs and chemo-attracted them in in vitro. Finally, in the stenosis model of the carotid artery, PDGF-BB expression was induced in endothelial cells in which high wall shear stress was loaded and the dedifferentiation of SMCs occurred there. Conclusions: The findings from the present study imply the role of dedifferentiated SMCs partially recruited by PDGF-BB from endothelial cells in the formation of inflammatory microenvironment at the neck portion of IA walls, leading to the progression of the disease.


Author(s):  
Christina M. Vanden Bosch der Nederlanden ◽  
J. Eric T. Taylor ◽  
Jessica A. Grahn

To understand and enjoy music, it is important to be able to hear the beat and move your body to the rhythm. However, impaired rhythm processing has a broader impact on perception and cognition beyond music-specific tasks. We also experience rhythms in our everyday interactions, through the lip and jaw movements of watching someone speak, the syllabic structure of words on the radio, and in the movements of our limbs when we walk. Impairments in the ability to perceive and produce rhythms are related to poor language outcomes, such as dyslexia, and they can provide an index of a primary symptom in movement disorders, such as Parkinson’s disease. The chapter summarizes a growing body of literature examining the neural underpinnings of rhythm perception and production. It highlights the importance of auditory-motor relationships in finding and producing a beat in music by reviewing evidence from a number of methodologies. These approaches illustrate how rhythmic auditory information capitalizes on auditory-motor interactions to influence motor excitability, and how beat perception emerges as a function of nonlinear oscillatory dynamics of the brain. Together these studies highlight the important role of rhythm in human development, evolutionary comparisons, multi-modal perception, mirror neurons, language processing, and music.


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