scholarly journals Relations between hemispheric asymmetries of grey matter and auditory processing of spoken syllables in 281 healthy adults

2021 ◽  
Author(s):  
Tulio Guadalupe ◽  
Xiang-Zhen Kong ◽  
Sophie E. A. Akkermans ◽  
Simon E. Fisher ◽  
Clyde Francks
Keyword(s):  
Auditory Cortex ◽  
Speech Processing ◽  
Auditory Processing ◽  
Dichotic Listening ◽  
Grey Matter ◽  
Magnetic Resonance Images ◽  
Hemispheric Dominance ◽  
Subcortical Structures ◽  
Hemispheric Asymmetries ◽  
Ear Advantage

AbstractMost people have a right-ear advantage for the perception of spoken syllables, consistent with left hemisphere dominance for speech processing. However, there is considerable variation, with some people showing left-ear advantage. The extent to which this variation is reflected in brain structure remains unclear. We tested for relations between hemispheric asymmetries of auditory processing and of grey matter in 281 adults, using dichotic listening and voxel-based morphometry. This was the largest study of this issue to date. Per-voxel asymmetry indexes were derived for each participant following registration of brain magnetic resonance images to a template that was symmetrized. The asymmetry index derived from dichotic listening was related to grey matter asymmetry in clusters of voxels corresponding to the amygdala and cerebellum lobule VI. There was also a smaller, non-significant cluster in the posterior superior temporal gyrus, a region of auditory cortex. These findings contribute to the mapping of asymmetrical structure–function links in the human brain and suggest that subcortical structures should be investigated in relation to hemispheric dominance for speech processing, in addition to auditory cortex.

scholarly journals Relations between hemispheric asymmetries of grey matter and auditory processing of spoken syllables in 281 healthy adults

2020 ◽  
Author(s):  
Tulio Guadalupe ◽  
Xiang-Zhen Kong ◽  
Sophie E. A. Akkermans ◽  
Simon E. Fisher ◽  
Clyde Francks
Keyword(s):  
Auditory Cortex ◽  
Speech Processing ◽  
Auditory Processing ◽  
Dichotic Listening ◽  
Grey Matter ◽  
Magnetic Resonance Images ◽  
Hemispheric Dominance ◽  
Subcortical Structures ◽  
Hemispheric Asymmetries ◽  
Ear Advantage

AbstractMost people have a right-ear advantage for the perception of spoken syllables, consistent with left hemisphere dominance for speech processing. However, there is considerable variation, with some people showing left-ear advantage. The extent to which this variation is reflected in brain structure remains unclear. We tested for relations between hemispheric asymmetries of auditory processing and of grey matter in 281 adults, using dichotic listening and voxel-based morphometry. This was the largest study of this issue to date. Per-voxel asymmetry indexes were derived for each participant following registration of brain magnetic resonance images to a template that was symmetrized. The asymmetry index derived from dichotic listening was related to grey matter asymmetry in clusters of voxels corresponding to the amygdala and cerebellum lobule VI. There was also a smaller, non-significant cluster in the posterior superior temporal gyrus, a region of auditory cortex. These findings contribute to the mapping of asymmetrical structure-function links in the human brain, and suggest that subcortical structures should be investigated in relation to hemispheric dominance for speech processing, in addition to auditory cortex.

scholarly journals Asymmetric sampling in human auditory cortex reveals spectral processing hierarchy

2019 ◽  
Author(s):  
Jérémy Giroud ◽  
Agnès Trébuchon ◽  
Daniele Schön ◽  
Patrick Marquis ◽  
Catherine Liegeois-Chauvel ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Auditory System ◽  
Speech Processing ◽  
Auditory Processing ◽  
Differential Sensitivity ◽  
Processing Mode ◽  
Cortical Hierarchy ◽  
Processing Modes ◽  
Left And Right ◽  
Cortical Auditory Processing

AbstractSpeech perception is mediated by both left and right auditory cortices, but with differential sensitivity to specific acoustic information contained in the speech signal. A detailed description of this functional asymmetry is missing, and the underlying models are widely debated. We analyzed cortical responses from 96 epilepsy patients with electrode implantation in left or right primary, secondary, and/or association auditory cortex. We presented short acoustic transients to reveal the stereotyped spectro-spatial oscillatory response profile of the auditory cortical hierarchy. We show remarkably similar bimodal spectral response profiles in left and right primary and secondary regions, with preferred processing modes in the theta (∼4-8 Hz) and low gamma (∼25-50 Hz) ranges. These results highlight that the human auditory system employs a two-timescale processing mode. Beyond these first cortical levels of auditory processing, a hemispheric asymmetry emerged, with delta and beta band (∼3/15 Hz) responsivity prevailing in the right hemisphere and theta and gamma band (∼6/40 Hz) activity in the left. These intracranial data provide a more fine-grained and nuanced characterization of cortical auditory processing in the two hemispheres, shedding light on the neural dynamics that potentially shape auditory and speech processing at different levels of the cortical hierarchy.Author summarySpeech processing is now known to be distributed across the two hemispheres, but the origin and function of lateralization continues to be vigorously debated. The asymmetric sampling in time (AST) hypothesis predicts that (1) the auditory system employs a two-timescales processing mode, (2) present in both hemispheres but with a different ratio of fast and slow timescales, (3) that emerges outside of primary cortical regions. Capitalizing on intracranial data from 96 epileptic patients we sensitively validated each of these predictions and provide a precise estimate of the processing timescales. In particular, we reveal that asymmetric sampling in associative areas is subtended by distinct two-timescales processing modes. Overall, our results shed light on the neurofunctional architecture of cortical auditory processing.

Different pattern of auditory processing lateralization in musicians and non-musicians

2021 ◽  
Vol 19 (1) ◽  
pp. 105-119
Author(s):  
Anna Krzyżak
Keyword(s):  
Speech Processing ◽  
Auditory Processing ◽  
Dichotic Listening ◽  
Similar Rate ◽  
Focused Attention ◽  
Binaural Processing ◽  
Left And Right ◽  
The Difference ◽  
The Right ◽  
External Stimuli

The aim of the study was an evaluation of different pattern of auditory processing lateralization in musicians and non-musicians. 41 people aged 20-46 participated in the experiment, from which two research groups were selected: musicians ‒ instrumentalists professionally active (N: 21) and non-musicians (N: 20). All of them were right-handed. The dichotic listening test (Kurkowski 2007) was used to assess the laterality of external stimuli. The examination showed the superiority of right-ear perception or binaural speech processing. In the study of non-focused attention, musicians achieved a similar rate of correct responses for the left and right ear, which indicates binaural processing, where they gave more correct responses for the left ear and fewer correct responses for the right ear than non-musicians. The difference between the groups is statistically significant. In the study focused on the right ear, both groups obtained similar high scores. In the left-ear study the musicians gave more correct responses from the perception of stimuli to the left ear than non-musicians. This research confirmed different pattern of auditory processing lateralization in musicians and non-musicians.

scholarly journals Neurophysiological Evaluation of Right-Ear Advantage During Dichotic Listening

2021 ◽  
Vol 12 ◽  
Author(s):  
Keita Tanaka ◽  
Bernhard Ross ◽  
Shinya Kuriki ◽  
Tsuneo Harashima ◽  
Chie Obuchi ◽  
...  
Keyword(s):  
Steady State ◽  
Auditory Cortex ◽  
Dichotic Listening ◽  
Steady State Response ◽  
State Response ◽  
Auditory Steady State Response ◽  
Left And Right ◽  
Ear Advantage ◽  
Right Ear Advantage ◽  
The Right

Right-ear advantage refers to the observation that when two different speech stimuli are simultaneously presented to both ears, listeners report stimuli more correctly from the right ear than the left. It is assumed to result from prominent projection along the auditory pathways to the contralateral hemisphere and the dominance of the left auditory cortex for the perception of speech elements. Our study aimed to investigate the role of attention in the right-ear advantage. We recorded magnetoencephalography data while participants listened to pairs of Japanese two-syllable words (namely, “/ta/ /ko/” or “/i/ /ka/”). The amplitudes of the stimuli were modulated at 35 Hz in one ear and 45 Hz in the other. Such frequency-tagging allowed the selective quantification of left and right auditory cortex responses to left and right ear stimuli. Behavioral tests confirmed the right-ear advantage, with higher accuracy for stimuli presented to the right ear than to the left. The amplitude of the auditory steady-state response was larger when attending to the stimuli compared to passive listening. We detected a correlation between the attention-related increase in the amplitude of the auditory steady-state response and the laterality index of behavioral accuracy. The right-ear advantage in the free-response dichotic listening was also found in neural activities in the left auditory cortex, suggesting that it was related to the allocation of attention to both ears.

scholarly journals Lateralization of Auditory Processing of Silbo Gomero

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1183
Author(s):  
Pamela Villar González ◽  
Onur Güntürkün ◽  
Sebastian Ocklenburg
Keyword(s):  
Language Processing ◽  
Auditory Processing ◽  
Dichotic Listening ◽  
Relative Increase ◽  
Control Group ◽  
Language Lateralization ◽  
Ear Advantage ◽  
Listening Task ◽  
Right Ear Advantage ◽  
The Right

Left-hemispheric language dominance is a well-known characteristic of the human language system. However, it has been shown that leftward language lateralization decreases dramatically when people communicate using whistles. Whistled languages present a transformation of a spoken language into whistles, facilitating communication over great distances. In order to investigate the laterality of Silbo Gomero, a form of whistled Spanish, we used a vocal and a whistled dichotic listening task in a sample of 75 healthy Spanish speakers. Both individuals that were able to whistle and to understand Silbo Gomero and a non-whistling control group showed a clear right-ear advantage for vocal dichotic listening. For whistled dichotic listening, the control group did not show any hemispheric asymmetries. In contrast, the whistlers’ group showed a right-ear advantage for whistled stimuli. This right-ear advantage was, however, smaller compared to the right-ear advantage found for vocal dichotic listening. In line with a previous study on language lateralization of whistled Turkish, these findings suggest that whistled language processing is associated with a decrease in left and a relative increase in right hemispheric processing. This shows that bihemispheric processing of whistled language stimuli occurs independent of language.

scholarly journals Sensitivity to temporal modulation rate and spectral bandwidth in the human auditory system: fMRI evidence

2012 ◽  
Vol 107 (8) ◽  
pp. 2042-2056 ◽  
Author(s):  
Tobias Overath ◽  
Yue Zhang ◽  
Dan H. Sanes ◽  
David Poeppel
Keyword(s):  
Auditory Cortex ◽  
Auditory Processing ◽  
Hierarchical Models ◽  
Primary Auditory Cortex ◽  
Auditory Pathway ◽  
Spectral Bandwidth ◽  
Temporal Modulation ◽  
Subcortical Structures ◽  
Modulation Rate ◽  
Slow Modulation

Hierarchical models of auditory processing often posit that optimal stimuli, i.e., those eliciting a maximal neural response, will increase in bandwidth and decrease in modulation rate as one ascends the auditory neuraxis. Here, we tested how bandwidth and modulation rate interact at several loci along the human central auditory pathway using functional MRI in a cardiac-gated, sparse acquisition design. Participants listened passively to both narrowband (NB) and broadband (BB) carriers (1/4- or 4-octave pink noise), which were jittered about a mean sinusoidal amplitude modulation rate of 0, 3, 29, or 57 Hz. The jittering was introduced to minimize stimulus-specific adaptation. The results revealed a clear difference between spectral bandwidth and temporal modulation rate: sensitivity to bandwidth (BB > NB) decreased from subcortical structures to nonprimary auditory cortex, whereas sensitivity to slow modulation rates was largest in nonprimary auditory cortex and largely absent in subcortical structures. Furthermore, there was no parametric interaction between bandwidth and modulation rate. These results challenge simple hierarchical models, in that BB stimuli evoked stronger responses in primary auditory cortex (and subcortical structures) rather than nonprimary cortex. Furthermore, the strong preference for slow modulation rates in nonprimary cortex demonstrates the compelling global sensitivity of auditory cortex to modulation rates that are dominant in the principal signals that we process, e.g., speech.

scholarly journals Dichotic listening deficits in amblyaudia are characterized by aberrant neural oscillations in auditory cortex

2020 ◽  
Author(s):  
Sara Momtaz ◽  
Deborah W. Moncrieff ◽  
Gavin M. Bidelman
Keyword(s):  
Functional Connectivity ◽  
Auditory Cortex ◽  
Language Learning ◽  
Auditory Processing ◽  
Dichotic Listening ◽  
Neural Oscillations ◽  
Complex Sounds ◽  
Time Frequency ◽  
Right Ear Advantage ◽  
The Right

ABSTRACTChildren diagnosed with auditory processing disorder (APD) show deficits in processing complex sounds that are associated with difficulties in higher-order language, learning, cognitive, and communicative functions. Amblyaudia (AMB) is a subcategory of APD characterized by abnormally large ear asymmetries in dichotic listening tasks. Here, we examined frequency-specific neural oscillations and functional connectivity via high-density EEG in children with and without AMB during passive listening of nonspeech stimuli. Time-frequency maps of these “brain rhythms” revealed stronger phase-locked beta-gamma (∼35 Hz) oscillations in AMB participants within bilateral auditory cortex for sounds presented to the right ear, suggesting a hypersynchronization and imbalance of auditory neural activity. Brain-behavior correlations revealed neural asymmetries in cortical responses predicted the larger than normal right-ear advantage seen in participants with AMB. Additionally, we found weaker functional connectivity in the AMB group from right to left auditory cortex, despite their stronger neural responses overall. Our results reveal abnormally large auditory sensory encoding and an imbalance in communication between cerebral hemispheres (ipsi-to -contralateral signaling) in AMB. These neurophysiological changes might lead to the functionally poorer behavioral capacity to integrate information between the two ears in children with AMB.

scholarly journals The impact of music on auditory and speech processing

2019 ◽  
Author(s):  
Abdollah Moossavi ◽  
Nasrin Gohari
Keyword(s):  
Speech Perception ◽  
Auditory Cortex ◽  
Auditory System ◽  
Speech Processing ◽  
Auditory Processing ◽  
Cognitive Skills ◽  
Large Area ◽  
Music Training ◽  
The Impact ◽  
The Brain

Background and Aim: Researchers in the fields of psychoacoustic and electrophysiology are mostly focused on demonstrating the better and different neurophysiological performance of musicians. The present study explores the imp­act of music upon the auditory system, the non-auditory system as well as the improvement of language and cognitive skills following listening to music or receiving music training. Recent Findings: Studies indicate the impact of music upon the auditory processing from the cochlea to secondary auditory cortex and other parts of the brain. Besides, the impact of music on speech perception and other cognitive proce­ssing is demonstrated. Some papers point to the bottom-up and some others to the top-down pro­cessing, which is explained in detail. Conclusion: Listening to music and receiving music training, in the long run, creates plasticity from the cochlea to the auditory cortex. Since the auditory path of musical sounds overlaps functionally with that of speech path, music hel­ps better speech perception, too. Both percep­tual and cognitive functions are involved in this process. Music engages a large area of the brain, so music can be used as a supplement in rehabi­litation programs and helps the improvement of speech and language skills.

scholarly journals Role of the Thalamus in Basal Forebrain Regulation of Neural Activity in the Primary Auditory Cortex

2020 ◽  
Vol 30 (8) ◽  
pp. 4481-4495
Author(s):  
H Azimi ◽  
A-L Klaassen ◽  
K Thomas ◽  
M A Harvey ◽  
G Rainer
Keyword(s):  
Auditory Cortex ◽  
Auditory Processing ◽  
Basal Forebrain ◽  
Primary Auditory Cortex ◽  
Strong Relationship ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Subcortical Structures ◽  
Medial Geniculate ◽  
Sensory Encoding

Abstract Many studies have implicated the basal forebrain (BF) as a potent regulator of sensory encoding even at the earliest stages of or cortical processing. The source of this regulation involves the well-documented corticopetal cholinergic projections from BF to primary cortical areas. However, the BF also projects to subcortical structures, including the thalamic reticular nucleus (TRN), which has abundant reciprocal connections with sensory thalamus. Here we present naturalistic auditory stimuli to the anesthetized rat while making simultaneous single-unit recordings from the ventral medial geniculate nucleus (MGN) and primary auditory cortex (A1) during electrical stimulation of the BF. Like primary visual cortex, we find that BF stimulation increases the trial-to-trial reliability of A1 neurons, and we relate these results to change in the response properties of MGN neurons. We discuss several lines of evidence that implicate the BF to thalamus pathway in the manifestation of BF-induced changes to cortical sensory processing and support our conclusions with supplementary TRN recordings, as well as studies in awake animals showing a strong relationship between endogenous BF activity and A1 reliability. Our findings suggest that the BF subcortical projections that modulate MGN play an important role in auditory processing.

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