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Schizophrenia Bulletin Jan 2017Neuroimaging studies have demonstrated associations between smaller auditory cortex volume and auditory hallucinations (AH) in schizophrenia. Reduced cortical volume can...
BACKGROUND
Neuroimaging studies have demonstrated associations between smaller auditory cortex volume and auditory hallucinations (AH) in schizophrenia. Reduced cortical volume can result from a reduction of either cortical thickness or cortical surface area, which may reflect different neuropathology. We investigate for the first time how thickness and surface area of the auditory cortex relate to AH in a large sample of schizophrenia spectrum patients.
METHODS
Schizophrenia spectrum (n = 194) patients underwent magnetic resonance imaging. Mean cortical thickness and surface area in auditory cortex regions (Heschl's gyrus [HG], planum temporale [PT], and superior temporal gyrus [STG]) were compared between patients with (AH+, n = 145) and without (AH-, n = 49) a lifetime history of AH and 279 healthy controls.
RESULTS
AH+ patients showed significantly thinner cortex in the left HG compared to AH- patients (d = 0.43, P = .0096). There were no significant differences between AH+ and AH- patients in cortical thickness in the PT or STG, or in auditory cortex surface area in any of the regions investigated. Group differences in cortical thickness in the left HG was not affected by duration of illness or current antipsychotic medication.
CONCLUSIONS
AH in schizophrenia patients were related to thinner cortex, but not smaller surface area of the left HG, a region which includes the primary auditory cortex. The results support that structural abnormalities of the auditory cortex underlie AH in schizophrenia.
Topics: Adult; Auditory Cortex; Auditory Perception; Female; Hallucinations; Humans; Magnetic Resonance Imaging; Male; Psychotic Disorders; Schizophrenia; Young Adult
PubMed: 27605526
DOI: 10.1093/schbul/sbw130 -
Hearing Research Jan 2014For much of the past 30 years, investigations of auditory perception and language have been enhanced or even driven by the use of functional neuroimaging techniques that... (Review)
Review
For much of the past 30 years, investigations of auditory perception and language have been enhanced or even driven by the use of functional neuroimaging techniques that specialize in localization of central responses. Beginning with investigations using positron emission tomography (PET) and gradually shifting primarily to usage of functional magnetic resonance imaging (fMRI), auditory neuroimaging has greatly advanced our understanding of the organization and response properties of brain regions critical to the perception of and communication with the acoustic world in which we live. As the complexity of the questions being addressed has increased, the techniques, experiments and analyses applied have also become more nuanced and specialized. A brief review of the history of these investigations sets the stage for an overview and analysis of how these neuroimaging modalities are becoming ever more effective tools for understanding the auditory brain. We conclude with a brief discussion of open methodological issues as well as potential clinical applications for auditory neuroimaging. This article is part of a Special Issue entitled Human Auditory Neuroimaging.
Topics: Animals; Auditory Cortex; Auditory Pathways; Auditory Perception; Brain Mapping; Cerebrovascular Circulation; Hemodynamics; Humans; Magnetic Resonance Imaging; Positron-Emission Tomography
PubMed: 24076424
DOI: 10.1016/j.heares.2013.09.009 -
Hearing Research Apr 2011Cat auditory cortex (AC) receives input from many thalamic nuclei and cortical areas. Previous connectional studies often focused on one connectional system in... (Review)
Review
Cat auditory cortex (AC) receives input from many thalamic nuclei and cortical areas. Previous connectional studies often focused on one connectional system in isolation, limiting perspectives on AC computational processes. Here we review the convergent thalamic, commissural, and corticocortical projections to thirteen AC areas in the cat. Each input differs in strength and may thus serve unique roles. We compared the convergent intrinsic and extrinsic input to each area quantitatively. The intrinsic input was almost half the total. Among extrinsic projections, ipsilateral cortical sources contributed 75%, thalamic input contributed 15%, and contralateral sources contributed 10%. The patterns of distribution support the division of AC areas into families of tonotopic, non-tonotopic, multisensory, and limbic-related areas, each with convergent input arising primarily from within its group. The connections within these areal families suggest a form of processing in which convergence of input to an area could enable new forms of integration. In contrast, the lateral connections between families could subserve integration between categorical representations, allowing otherwise independent streams to communicate and thereby coordinating operations over wide spatial and functional scales. These patterns of serial and interfamilial cooperation challenge more classical models of organization that underestimate the diversity and complexity of AC connectivity.
Topics: Animals; Auditory Cortex; Auditory Pathways; Auditory Perception; Brain Mapping; Cats; Cerebral Cortex; Hearing; Limbic System; Neurology; Thalamus
PubMed: 20576491
DOI: 10.1016/j.heares.2010.05.008 -
NeuroImage. Clinical 2018The exact neurophysiological basis of chronic tinnitus, which affects 10-15% of the population, remains unknown and is controversial at many levels. It is an open...
UNLABELLED
The exact neurophysiological basis of chronic tinnitus, which affects 10-15% of the population, remains unknown and is controversial at many levels. It is an open question whether phantom sound perception results from increased central neural gain or not, a crucial question for any future therapeutic intervention strategies for tinnitus. We performed a comprehensive study of mild hearing-impaired participants with and without tinnitus, excluding participants with co-occurrences of hyperacusis. A right-hemisphere correlation between tinnitus loudness and auditory perceptual difficulty was observed in the tinnitus group, independent of differences in hearing thresholds. This correlation was linked to reduced and delayed sound-induced suprathreshold auditory brain responses (ABR wave V) in the tinnitus group, suggesting subsided rather than exaggerated central neural responsiveness. When anatomically predefined auditory regions of interest were analysed for altered sound-evoked BOLD fMRI activity, it became evident that subcortical and cortical auditory regions and regions involved in sound detection (posterior insula, hippocampus), responded with reduced BOLD activity in the tinnitus group, emphasizing reduced, rather than increased, central neural gain. Regarding previous findings of evoked BOLD activity being linked to positive connectivities at rest, we additionally analysed r-fcMRI responses in anatomically predefined auditory regions and regions associated with sound detection. A profound reduction in positive interhemispheric connections of homologous auditory brain regions and a decline in the positive connectivities between lower auditory brainstem regions and regions involved in sound detection (hippocampus, posterior insula) were observed in the tinnitus group. The finding went hand-in-hand with the emotional (amygdala, anterior insula) and temporofrontal/stress-regulating regions (prefrontal cortex, inferior frontal gyrus) that were no longer positively connected with auditory cortex regions in the tinnitus group but were instead positively connected to lower-level auditory brainstem regions. Delayed sound processing, reduced sound-evoked BOLD fMRI activity and altered r-fcMRI in the auditory midbrain correlated in the tinnitus group and showed right hemisphere dominance as did tinnitus loudness and perceptual difficulty. The findings suggest that reduced central neural gain in the auditory stream may lead to phantom perception through a failure to energize attentional/stress-regulating networks for contextualization of auditory-specific information. Reduced auditory-specific information flow in tinnitus has until now escaped detection in humans, as low-level auditory brain regions were previously omitted from neuroimaging studies.
TRIAL REGISTRATION
German Clinical Trials Register DRKS0006332.
Topics: Acoustic Stimulation; Auditory Cortex; Evoked Potentials, Auditory; Female; Humans; Magnetic Resonance Imaging; Male; Nerve Net; Prefrontal Cortex; Rest; Tinnitus
PubMed: 30202725
DOI: 10.1016/j.nicl.2018.08.029 -
The Journal of Neuroscience : the... Jun 2022The brain areas that mediate the formation of auditory threat memory and perceptual decisions remain uncertain to date. Candidates include the primary (A1) and secondary...
Frequency-Dependent Plasticity in the Temporal Association Cortex Originates from the Primary Auditory Cortex, and Is Modified by the Secondary Auditory Cortex and the Medial Geniculate Body.
The brain areas that mediate the formation of auditory threat memory and perceptual decisions remain uncertain to date. Candidates include the primary (A1) and secondary (A2) auditory cortex, the medial division of the medial geniculate body (MGm), amygdala, and the temporal association cortex. We used chemogenetic and optogenetic manipulations with and patch-clamp recordings to assess the roles of these brain regions in threat memory learning in female mice. We found that conditioned sound (CS) frequency-dependent plasticity resulted in the formation of auditory threat memory in the temporal association cortex. This neural correlated auditory threat memory depended on CS frequency information from A1 glutamatergic subthreshold monosynaptic inputs, CS lateral inhibition from A2 glutamatergic disynaptic inputs, and non-frequency-specific facilitation from MGm glutamatergic monosynaptic inputs. These results indicate that the A2 and MGm work together in an inhibitory-facilitative role. The ability to recognize specific sounds to avoid predators or seek prey is a useful survival tool. Improving this ability through experiential learning is an added advantage requiring neural plasticity. As an example, humans must learn to distinguish the sound of a car horn, and thus avoid oncoming traffic. Our research discovered that the temporal association cortex can encode this kind of auditory information through tonal receptive field plasticity. In addition, the results revealed the underlying synaptic mechanisms of this process. These results extended our understanding of how meaningful auditory information is processed in an animal's brain.
Topics: Acoustic Stimulation; Amygdala; Animals; Auditory Cortex; Conditioning, Classical; Female; Geniculate Bodies; Mice; Neuronal Plasticity
PubMed: 35613891
DOI: 10.1523/JNEUROSCI.1481-21.2022 -
Hearing Research Jul 2007Despite extensive subcortical processing, the auditory cortex is believed to be essential for normal sound localization. However, we still have a poor understanding of... (Review)
Review
Despite extensive subcortical processing, the auditory cortex is believed to be essential for normal sound localization. However, we still have a poor understanding of how auditory spatial information is encoded in the cortex and of the relative contribution of different cortical areas to spatial hearing. We investigated the behavioral consequences of inactivating ferret primary auditory cortex (A1) on auditory localization by implanting a sustained release polymer containing the GABA(A) agonist muscimol bilaterally over A1. Silencing A1 led to a reversible deficit in the localization of brief noise bursts in both the horizontal and vertical planes. In other ferrets, large bilateral lesions of the auditory cortex, which extended beyond A1, produced more severe and persistent localization deficits. To investigate the processing of spatial information by high-frequency A1 neurons, we measured their binaural-level functions and used individualized virtual acoustic space stimuli to record their spatial receptive fields (SRFs) in anesthetized ferrets. We observed the existence of a continuum of response properties, with most neurons preferring contralateral sound locations. In many cases, the SRFs could be explained by a simple linear interaction between the acoustical properties of the head and external ears and the binaural frequency tuning of the neurons. Azimuth response profiles recorded in awake ferrets were very similar and further analysis suggested that the slopes of these functions and location-dependent variations in spike timing are the main information-bearing parameters. Studies of sensory plasticity can also provide valuable insights into the role of different brain areas and the way in which information is represented within them. For example, stimulus-specific training allows accurate auditory localization by adult ferrets to be relearned after manipulating binaural cues by occluding one ear. Reversible inactivation of A1 resulted in slower and less complete adaptation than in normal controls, whereas selective lesions of the descending cortico collicular pathway prevented any improvement in performance. These results reveal a role for auditory cortex in training-induced plasticity of auditory localization, which could be mediated by descending cortical pathways.
Topics: Acoustic Stimulation; Animals; Auditory Cortex; Ferrets; Neuronal Plasticity; Sound Localization
PubMed: 17314017
DOI: 10.1016/j.heares.2007.01.001 -
Scientific Reports Sep 2016Visual information can alter auditory perception. This is clearly illustrated by the well-known McGurk illusion, where an auditory/aba/ and a visual /aga/ are merged to...
Visual information can alter auditory perception. This is clearly illustrated by the well-known McGurk illusion, where an auditory/aba/ and a visual /aga/ are merged to the percept of 'ada'. It is less clear however whether such a change in perception may recalibrate subsequent perception. Here we asked whether the altered auditory perception due to the McGurk illusion affects subsequent auditory perception, i.e. whether this process of fusion may cause a recalibration of the auditory boundaries between phonemes. Participants categorized auditory and audiovisual speech stimuli as /aba/, /ada/ or /aga/ while activity patterns in their auditory cortices were recorded using fMRI. Interestingly, following a McGurk illusion, an auditory /aba/ was more often misperceived as 'ada'. Furthermore, we observed a neural counterpart of this recalibration in the early auditory cortex. When the auditory input /aba/ was perceived as 'ada', activity patterns bore stronger resemblance to activity patterns elicited by /ada/ sounds than when they were correctly perceived as /aba/. Our results suggest that upon experiencing the McGurk illusion, the brain shifts the neural representation of an /aba/ sound towards /ada/, culminating in a recalibration in perception of subsequent auditory input.
Topics: Adult; Auditory Cortex; Auditory Perception; Female; Humans; Illusions; Magnetic Resonance Imaging; Male; Young Adult
PubMed: 27611960
DOI: 10.1038/srep32891 -
Frontiers in Neural Circuits 2014The auditory lemniscal thalamocortical (TC) pathway conveys information from the ventral division of the medial geniculate body to the primary auditory cortex (A1).... (Review)
Review
The auditory lemniscal thalamocortical (TC) pathway conveys information from the ventral division of the medial geniculate body to the primary auditory cortex (A1). Although their general topographic organization has been well characterized, functional transformations at the lemniscal TC synapse still remain incompletely codified, largely due to the need for integration of functional anatomical results with the variability observed with various animal models and experimental techniques. In this review, we discuss these issues with classical approaches, such as in vivo extracellular recordings and tracer injections to physiologically identified areas in A1, and then compare these studies with modern approaches, such as in vivo two-photon calcium imaging, in vivo whole-cell recordings, optogenetic methods, and in vitro methods using slice preparations. A surprising finding from a comparison of classical and modern approaches is the similar degree of convergence from thalamic neurons to single A1 neurons and clusters of A1 neurons, although, thalamic convergence to single A1 neurons is more restricted from areas within putative thalamic frequency lamina. These comparisons suggest that frequency convergence from thalamic input to A1 is functionally limited. Finally, we consider synaptic organization of TC projections and future directions for research.
Topics: Animals; Auditory Cortex; Auditory Pathways; Humans; Models, Neurological; Thalamus
PubMed: 25071456
DOI: 10.3389/fncir.2014.00075 -
Cerebral Cortex (New York, N.Y. : 1991) Feb 2023Voice signaling is integral to human communication, and a cortical voice area seemed to support the discrimination of voices from other auditory objects. This large...
Voice signaling is integral to human communication, and a cortical voice area seemed to support the discrimination of voices from other auditory objects. This large cortical voice area in the auditory cortex (AC) was suggested to process voices selectively, but its functional differentiation remained elusive. We used neuroimaging while humans processed voices and nonvoice sounds, and artificial sounds that mimicked certain voice sound features. First and surprisingly, specific auditory cortical voice processing beyond basic acoustic sound analyses is only supported by a very small portion of the originally described voice area in higher-order AC located centrally in superior Te3. Second, besides this core voice processing area, large parts of the remaining voice area in low- and higher-order AC only accessorily process voices and might primarily pick up nonspecific psychoacoustic differences between voices and nonvoices. Third, a specific subfield of low-order AC seems to specifically decode acoustic sound features that are relevant but not exclusive for voice detection. Taken together, the previously defined voice area might have been overestimated since cortical support for human voice processing seems rather restricted. Cortical voice processing also seems to be functionally more diverse and embedded in broader functional principles of the human auditory system.
Topics: Humans; Auditory Cortex; Acoustic Stimulation; Auditory Perception; Voice; Sound; Magnetic Resonance Imaging
PubMed: 35348635
DOI: 10.1093/cercor/bhac128 -
Brain and Cognition Feb 2018Auditory-sensorimotor coupling is critical for musical performance, during which auditory and somatosensory feedback signals are used to ensure desired outputs. Previous...
Auditory-sensorimotor coupling is critical for musical performance, during which auditory and somatosensory feedback signals are used to ensure desired outputs. Previous studies reported opercular activation in subjects performing or listening to music. A functional connectivity analysis suggested the parietal operculum (PO) as a connector hub that links auditory, somatosensory, and motor cortical areas. We therefore examined whether this PO network differs between musicians and non-musicians. We analyzed resting-state PO functional connectivity with Heschl's gyrus (HG), the planum temporale (PT), the precentral gyrus (preCG), and the postcentral gyrus (postCG) in 35 musicians and 35 non-musicians. In musicians, the left PO exhibited increased functional connectivity with the ipsilateral HG, PT, preCG, and postCG, whereas the right PO exhibited enhanced functional connectivity with the contralateral HG, preCG, and postCG and the ipsilateral postCG. Direct functional connectivity between an auditory area (the HG or PT) and a sensorimotor area (the preCG or postCG) did not significantly differ between the groups. The PO's functional connectivity with auditory and sensorimotor areas is enhanced in musicians relative to non-musicians. We propose that the PO network facilitates musical performance by mediating multimodal integration for modulating auditory-sensorimotor control.
Topics: Adolescent; Adult; Auditory Cortex; Connectome; Female; Humans; Magnetic Resonance Imaging; Male; Motor Cortex; Music; Nerve Net; Somatosensory Cortex; Young Adult
PubMed: 29122368
DOI: 10.1016/j.bandc.2017.11.001