scholarly journals Auditory and Language Contributions to Neural Encoding of Speech Features in Noisy Environments

2018 ◽  
Author(s):  
Jiajie Zou ◽  
Jun Feng ◽  
Tianyong Xu ◽  
Peiqing Jin ◽  
Cheng Luo ◽  
...  
Keyword(s):  
Language Processing ◽  
Noise Intensity ◽  
Gain Control ◽  
Neural Representation ◽  
Noisy Environments ◽  
Envelope Tracking ◽  
Neural Basis ◽  
Speech Envelope ◽  
Noise Robust ◽  
Temporal Profiles

AbstractRecognizing speech in noisy environments is a challenging task that involves both auditory and language mechanisms. Previous studies have demonstrated noise-robust neural tracking of the speech envelope, i.e., fluctuations in sound intensity, in human auditory cortex, which provides a plausible neural basis for noise-robust speech recognition. The current study aims at teasing apart auditory and language contributions to noise-robust envelope tracking by comparing 2 groups of listeners, i.e., native listeners of the testing language and foreign listeners who do not understand the testing language. In the experiment, speech is mixed with spectrally matched stationary noise at 4 intensity levels and the neural responses are recorded using electroencephalography (EEG). When the noise intensity increases, an increase in neural response gain is observed for both groups of listeners, demonstrating auditory gain control mechanisms. Language comprehension creates no overall boost in the response gain or the envelope-tracking precision but instead modulates the spatial and temporal profiles of envelope-tracking activity. Based on the spatio-temporal dynamics of envelope-tracking activity, the 2 groups of listeners and the 4 levels of noise intensity can be jointly decoded by a linear classifier. All together, the results show that without feedback from language processing, auditory mechanisms such as gain control can lead to a noise-robust speech representation. High-level language processing, however, further modulates the spatial-temporal profiles of the neural representation of the speech envelope.

scholarly journals Age-related decreases of cortical visuo-phonological transformation of unheard spectral fine-details

2021 ◽  
Author(s):  
Nina Suess ◽  
Anne Hauswald ◽  
Patrick Reisinger ◽  
Sebastian Rösch ◽  
Anne Keitel ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Fundamental Frequency ◽  
Visual Information ◽  
Visual Speech ◽  
Phonological Information ◽  
Noisy Environments ◽  
Neural Basis ◽  
Resonant Frequencies ◽  
Acoustic Information ◽  
Speech Envelope

AbstractThe integration of visual and auditory cues is crucial for successful processing of speech, especially under adverse conditions. Recent reports have shown that when participants watch muted videos of speakers, the phonological information about the acoustic speech envelope is tracked by the visual cortex. However, the speech signal also carries much richer acoustic details, e.g. about the fundamental frequency and the resonant frequencies, whose visuo-phonological transformation could aid speech processing. Here, we investigated the neural basis of the visuo-phonological transformation processes of these more fine-grained acoustic details and assessed how they change with ageing. We recorded whole-head magnetoencephalography (MEG) data while participants watched silent intelligible and unintelligible videos of a speaker. We found that the visual cortex is able to track the unheard intelligible modulations of resonant frequencies and the pitch linked to lip movements. Importantly, only the processing of intelligible unheard formants decreases significantly with age in the visual and also in the cingulate cortex. This is not the case for the processing of the unheard speech envelope, the fundamental frequency or the purely visual information carried by lip movements. These results show that unheard spectral fine-details (along with the unheard acoustic envelope) are transformed from a mere visual to a phonological representation. Aging affects especially the ability to derive spectral dynamics at formant frequencies. Since listening in noisy environments should capitalize on the ability to track spectral fine-details, our results provide a novel focus on compensatory processes in such challenging situations.Significance statementThe multisensory integration of speech cues from visual and auditory modalities is crucial for optimal speech perception in noisy environments or for elderly individuals with progressive hearing loss. It has already been shown that the visual cortex is able to extract global acoustic information like amplitude modulations from silent visual speech, but whether this extends to fine-detailed spectral acoustic information remains unclear. Here, we demonstrate that the visual cortex is indeed able to extract fine-detailed phonological cues just from watching silent lip movements. Furthermore, this tracking of acoustic fine-details is deteriorating with age. These results suggest that the human brain is able to transform visual information into useful phonological information, and this process might be crucially affected in ageing individuals.

Introduction

2001 ◽  
Vol 4 (2) ◽  
pp. 101-103
Author(s):  
David W. Green
Keyword(s):  
Language Processing ◽  
Neural Activity ◽  
Neural Representation ◽  
Special Issue ◽  
Neural Basis ◽  
And Control ◽  
The Brain ◽  
Electrophysiological Methods ◽  
Neuroimaging Techniques ◽  
Do So

The papers in this Special Issue focus on the use of neuroimaging techniques to answer questions about the neural representation, processing and control of two languages. Neuropsychological data from bilingual aphasics remain vital if we are to establish the neural basis of language (see Paradis, 1995) but lesion-deficit studies alone cannot tell us how neural activity relates to ongoing language processing. Modern neuroimaging methods provide a means to do so. There are two broad classes of such methods: electrophysiological methods allow us to answer questions about when a particular process occurs whereas haemodynamic methods allow us to answer the complementary question of where in the brain such a process is carried out. Before giving a thumb-nail sketch of the papers in this Special Issue, I briefly discuss each class of method.

Meta-analysis of the neural representation of first language and second language

2011 ◽  
Vol 32 (4) ◽  
pp. 799-819 ◽  
Author(s):  
RAJANI SEBASTIAN ◽  
ANGELA R. LAIRD ◽  
SWATHI KIRAN
Keyword(s):  
Second Language ◽  
Language Proficiency ◽  
Language Processing ◽  
Functional Neuroimaging ◽  
Meta Analysis ◽  
First Language ◽  
Likelihood Estimation ◽  
Neural Representation ◽  
Second Language Processing ◽  
Meta Analyses

ABSTRACTThis study reports an activation likelihood estimation meta-analysis of published functional neuroimaging studies of bilingualism. Four parallel meta-analyses were conducted by taking into account the proficiency of participants reported in the studies. The results of the meta-analyses suggest differences in the probabilities of activation patterns between high proficiency and moderate/low proficiency bilinguals. The Talairach coordinates of activation in first language processing were very similar to that of second language processing in the high proficient bilinguals. However, in the low proficient group, the activation clusters were generally smaller and distributed over wider areas in both the hemispheres than the clusters identified in the ALE maps from the high proficient group. These findings draw attention to the importance of language proficiency in bilingual neural representation.

Neural Basis of Rhythm Perception

2018 ◽  
pp. 164-186
Author(s):  
Christina M. Vanden Bosch der Nederlanden ◽  
J. Eric T. Taylor ◽  
Jessica A. Grahn
Keyword(s):  
Language Processing ◽  
Mirror Neurons ◽  
Auditory Information ◽  
Language Outcomes ◽  
Rhythm Perception ◽  
Neural Basis ◽  
Oscillatory Dynamics ◽  
Motor Excitability ◽  
Neural Underpinnings

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.

scholarly journals Neural envelope tracking as a measure of speech understanding in cochlear implant users

2018 ◽  
Author(s):  
Eline Verschueren ◽  
Ben Somers ◽  
Tom Francart
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Closed Loop ◽  
Objective Measure ◽  
Speech Understanding ◽  
Envelope Tracking ◽  
Actual Speech ◽  
Speech Envelope ◽  
Electroencephalogram Eeg ◽  
Automatic Fitting

ABSTRACTThe speech envelope is essential for speech understanding and can be reconstructed from the electroencephalogram (EEG) recorded while listening to running speech. This so-called neural envelope tracking has been shown to relate to speech understanding in normal hearing listeners, but has barely been investigated in persons wearing cochlear implants (CI). We investigated the relation between speech understanding and neural envelope tracking in CI users.EEG was recorded in 8 CI users while they listened to a story. Speech understanding was varied by changing the intensity of the presented speech. The speech envelope was reconstructed from the EEG using a linear decoder and then correlated with the envelope of the speech stimulus as a measure of neural envelope tracking which was compared to actual speech understanding.This study showed that neural envelope tracking increased with increasing speech understanding in every participant. Furthermore behaviorally measured speech understanding was correlated with participant specific neural envelope tracking results indicating the potential of neural envelope tracking as an objective measure of speech understanding in CI users. This could enable objective and automatic fitting of CIs and pave the way towards closed-loop CIs that adjust continuously and automatically to individual CI users.

Word recognition in aphasia

2007 ◽  
pp. 140-156
Author(s):  
Sheila Blumstein
Keyword(s):  
Word Recognition ◽  
Language Processing ◽  
Speech Processing ◽  
Current Knowledge ◽  
Recognition System ◽  
Speech And Language ◽  
Neural Basis ◽  
Sentential Context ◽  
The Face ◽  
Speech And Language Processing

This article reviews current knowledge about the nature of auditory word recognition deficits in aphasia. It assumes that the language functioning of adults with aphasia was normal prior to sustaining brain injury, and that their word recognition system was intact. As a consequence, the study of aphasia provides insight into how damage to particular areas of the brain affects speech and language processing, and thus provides a crucial step in mapping out the neural systems underlying speech and language processing. To this end, much of the discussion focuses on word recognition deficits in Broca's and Wernicke's aphasics, two clinical syndromes that have provided the basis for much of the study of the neural basis of language. Clinically, Broca's aphasics have a profound expressive impairment in the face of relatively good auditory language comprehension. This article also considers deficits in processing the sound structure of language, graded activation of the lexicon, lexical competition, influence of word recognition on speech processing, and influence of sentential context on word recognition.

The Structural Language Network

2017 ◽  
Author(s):  
Angela D. Friederici ◽  
Noam Chomsky
Keyword(s):  
White Matter ◽  
Language Processing ◽  
Sentence Processing ◽  
Information Transfer ◽  
Right Hemisphere ◽  
Brain Regions ◽  
Neural Basis ◽  
Fiber Tracts ◽  
White Matter Fiber Tracts ◽  
The Right

An adequate description of the neural basis of language processing must consider the entire network both with respect to its structural white matter connections and the functional connectivities between the different brain regions as the information has to be sent between different language-related regions distributed across the temporal and frontal cortex. This chapter discusses the white matter fiber bundles that connect the language-relevant regions. The chapter is broken into three sections. In the first, we look at the white matter fiber tracts connecting the language-relevant regions in the frontal and temporal cortices; in the second, the ventral and dorsal pathways in the right hemisphere that connect temporal and frontal regions; and finally in the third, the two syntax-relevant and (at least) one semantic-relevant neuroanatomically-defined networks that sentence processing is based on. From this discussion, it becomes clear that online language processing requires information transfer via the long-range white matter fiber pathways that connect the language-relevant brain regions within each hemisphere and between hemispheres.

scholarly journals Audio-tactile enhancement of cortical speech-envelope tracking

NeuroImage ◽  
2019 ◽  
Vol 202 ◽  
pp. 116134 ◽  
Author(s):  
Lars Riecke ◽  
Sophia Snipes ◽  
Sander van Bree ◽  
Amanda Kaas ◽  
Lars Hausfeld
Keyword(s):  
Envelope Tracking ◽  
Speech Envelope ◽  
Tactile Enhancement

scholarly journals The neural representation of facial-emotion categories reflects conceptual structure

2019 ◽  
Vol 116 (32) ◽  
pp. 15861-15870 ◽  
Author(s):  
Jeffrey A. Brooks ◽  
Junichi Chikazoe ◽  
Norihiro Sadato ◽  
Jonathan B. Freeman
Keyword(s):  
Individual Differences ◽  
Emotion Perception ◽  
Conceptual Structure ◽  
Neural Representation ◽  
Facial Emotion ◽  
Neural Basis ◽  
Concept Knowledge ◽  
Cross Cultural Differences ◽  
Specific Emotion ◽  
The Right

Humans reliably categorize configurations of facial actions into specific emotion categories, leading some to argue that this process is invariant between individuals and cultures. However, growing behavioral evidence suggests that factors such as emotion-concept knowledge may shape the way emotions are visually perceived, leading to variability—rather than universality—in facial-emotion perception. Understanding variability in emotion perception is only emerging, and the neural basis of any impact from the structure of emotion-concept knowledge remains unknown. In a neuroimaging study, we used a representational similarity analysis (RSA) approach to measure the correspondence between the conceptual, perceptual, and neural representational structures of the six emotion categories Anger, Disgust, Fear, Happiness, Sadness, and Surprise. We found that subjects exhibited individual differences in their conceptual structure of emotions, which predicted their own unique perceptual structure. When viewing faces, the representational structure of multivoxel patterns in the right fusiform gyrus was significantly predicted by a subject’s unique conceptual structure, even when controlling for potential physical similarity in the faces themselves. Finally, cross-cultural differences in emotion perception were also observed, which could be explained by individual differences in conceptual structure. Our results suggest that the representational structure of emotion expressions in visual face-processing regions may be shaped by idiosyncratic conceptual understanding of emotion categories.

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