Auditory Cortex In Patients Research Articles

Changes in Structure and Connectivity of Auditory Cortex in Patients with Unilateral Hearing Loss

The purpose of this study was to investigate cortical structural and connectivity changes in the auditory system due to the absence of unilateral input signals from the hearing-impaired ear in patients with unilateral hearing loss. Twenty-seven patients who have severe to profound unilateral hearing loss participated. T-1 images were acquired to calculate the normalized cortcial volume (nCV), and seed-based connectivity analysis was performed. It was shown that the nCV of Te 3.0 was decreased in the left unilateral hearing loss (LUHL). In LUHL group, a significant structural correlation was observed between region of interests (ROIs) within the auditory cortices of bilateral hemispheres, while right unilateral hearing loss (RUHL) group showed significant correlation between thalamus and auditory cortical regions. We proposed that cortical structural reorganization in unilateral hearing loss patients, that is different by deafness side. These results are expected to be related to individual binaural hearing performance in unilateral hearing loss.

Lateralization of cerebral blood flow in the auditory cortex of patients with idiopathic tinnitus and healthy controls: An arterial spin labeling study.

To assess the lateralization of cerebral blood flow (CBF) in the auditory cortex of idiopathic tinnitus patients and healthy controls (HCs) using 3D pseudocontinuous arterial spin labeling (pcASL). Thirty-six patients with idiopathic tinnitus and 43 sex- and age-matched HCs underwent 3D-pcASL scanning using a 3.0 T MRI system. For both groups, region of interest analysis was performed on the primary auditory cortex (PAC), auditory associative cortex (AAC), and secondary auditory cortex (SAC). The clinical data of all subjects were analyzed. In both tinnitus patients and HCs, CBF of the left PAC was significantly higher than that of the right (HCs: P = 0.02; patients: P = 0.043), but CBF of the right AAC and SAC was significantly higher than that of the left (AAC: HCs, P < 0.001; patients: P < 0.001. SAC: HCs, P < 0.001; patients: P = 0.001). Compared with HCs, tinnitus patients exhibited significantly higher CBF in the bilateral PAC (right: P = 0.008; left: P = 0.022). CBF in the left PAC was positively correlated with tinnitus severity (r = 0.399, P = 0.016). This study confirms the asymmetry of the auditory cortex and investigates the underlying neuropathology of idiopathic tinnitus in terms of CBF.

Elevation of EGR1/zif268, a Neural Activity Marker, in the Auditory Cortex of Patients with Schizophrenia and its Animal Model.

The family of epidermal growth factor (EGF) including neuregulin-1 are implicated in the neuropathology of schizophrenia. We established a rat model of schizophrenia by exposing perinatal rats to EGF and reported that the auditory pathophysiological traits of this modelsuch as prepulse inhibition, auditory steady-state response, and mismatch negativity are relevant to those of schizophrenia. We assessed the activation status of the auditory cortex in this model, as well as that in patients with schizophrenia, by monitoring the three neural activity-induced proteins: EGR1 (zif268), c-fos, and Arc. Among the activity markers, protein levels of EGR1 were significantly higher at the adult stage in EGF model rats than those in control rats. The group difference was observed despite an EGF model rat and a control rat being housed together, ruling out the contribution of rat vocalization effects. These changes in EGR1 levels were seen to be specific to the auditory cortex of this model. The increase in EGR1 levels were detectable at the juvenile stage and continued until old ages but displayed a peak immediately after puberty, whereas c-fos and Arc levels were nearly indistinguishable between groups at all ages with an exception of Arc decrease at the juvenile stage. A similar increase in EGR1 levels was observed in the postmortem superior temporal cortex of patients with schizophrenia. The commonality of the EGR1 increase indicates that the EGR1 elevation in the auditory cortex might be one of the molecular signatures of this animal model and schizophrenia associating with hallucination.

Changes of the Brain Causal Connectivity Networks in Patients With Long-Term Bilateral Hearing Loss.

It remains poorly understood how brain causal connectivity networks change following hearing loss and their effects on cognition. In the current study, we investigated this issue. Twelve patients with long-term bilateral sensorineural hearing loss [mean age, 55.7 ± 2.0; range, 39–63 years; threshold of hearing level (HL): left ear, 49.0 ± 4.1 dB HL, range, 31.25–76.25 dB HL; right ear, 55.1 ± 7.1 dB HL, range, 35–115 dB HL; the duration of hearing loss, 16.67 ± 4.5, range, 3–55 years] and 12 matched normally hearing controls (mean age, 52.3 ± 1.8; range, 42–63 years; threshold of hearing level: left ear, 17.6 ± 1.3 dB HL, range, 11.25–26.25 dB HL; right ear, 19.7 ± 1.3 dB HL, range, 8.75–26.25 dB HL) participated in this experiment. We constructed and analyzed the causal connectivity networks based on functional magnetic resonance imaging data of these participants. Two-sample t-tests revealed significant changes of causal connections and nodal degrees in the right secondary visual cortex, associative visual cortex, right dorsolateral prefrontal cortex, left subgenual cortex, and the left cingulate cortex, as well as the shortest causal connectivity paths from the right secondary visual cortex to Broca’s area in hearing loss patients. Neuropsychological tests indicated that hearing loss patients presented significant cognitive decline. Pearson’s correlation analysis indicated that changes of nodal degrees and the shortest causal connectivity paths were significantly related with poor cognitive performances. We also found a cross-modal reorganization between associative visual cortex and auditory cortex in patients with hearing loss. Additionally, we noted that visual and auditory signals had different effects on neural activities of Broca’s area, respectively. These results suggest that changes in brain causal connectivity network are an important neuroimaging mark of cognitive decline. Our findings provide some implications for rehabilitation of hearing loss patients.

Abnormal auditory tonotopy in patients with schizophrenia

Auditory hallucinations are among the most prevalent and most distressing symptoms of schizophrenia. Despite significant progress, it is still unclear whether auditory hallucinations arise from abnormalities in primary sensory processing or whether they represent failures of higher-order functions. To address this knowledge gap, we capitalized on the increased spatial resolution afforded by ultra-high field imaging at 7 Tesla to investigate the tonotopic organization of the auditory cortex in patients with schizophrenia with a history of recurrent hallucinations. Tonotopy is a fundamental feature of the functional organization of the auditory cortex that is established very early in development and predates the onset of symptoms by decades. Compared to healthy participants, patients showed abnormally increased activation and altered tonotopic organization of the auditory cortex during a purely perceptual task, which involved passive listening to tones across a range of frequencies (88–8000 Hz). These findings suggest that the predisposition to auditory hallucinations is likely to be predicated on abnormalities in the functional organization of the auditory cortex and which may serve as a biomarker for the early identification of vulnerable individuals.

Differential Expression of Ribosomal Genes in Brain and Blood of Alzheimer's Disease Patients.

Changes in rRNA and rDNA expression have been associated with cellular and organism aging and have been linked to Alzheimer's disease (AD) pathogenesis. In this study, we investigated the mRNA expression of ribosomal genes (28S/18S) and β-amyloid precursor protein (APP) in different post mortem brain tissue regions (the entorhinal and auditory cortices and the hippocampus) of AD patients and elderly control subjects and also evaluated the extent of expression in peripheral blood from young, healthy, elderly, and Alzheimer's disease patients in order to investigate whether these individuals experienced the effects of aging. The comparative threshold cycle (CT) method via Real Time Polymerase Chain Reaction and the Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) were used to analyze gene expression and the Apolipoprotein E (APOE) genotype, respectively. When the brain areas were analyzed collectively, we observed a significant decrease in APP expression and a significant increase in levels of mRNA of 18S and 28S in Alzheimer's disease patients compared to healthy elderly individuals. Furthermore, there was a significant upregulation of 28SrRNA in the entorhinal cortex and hippocampus, but not in the auditory cortex of patients with AD. On the other hand, tests of blood samples verified a decreased expression of 28S rRNA in patients with AD. These results support the hypothesis that changes in rRNA are present in AD patients, are tissue-specific, and seem to occur independently and differently in each tissue. However, the next challenge is to discover the mechanisms responsible for the differences in expression observed in the blood and the brain in both healthy elderly individuals and Alzheimer's disease patients, as well as the impact of these genes on AD pathogenesis.

Spontaneous Gamma Activity in Schizophrenia.

A major goal of translational neuroscience is to identify neural circuit abnormalities in neuropsychiatric disorders that can be studied in animal models to facilitate the development of new treatments. Oscillations in the gamma band (30-100 Hz) of the electroencephalogram have received considerable interest as the basic mechanisms underlying these oscillations are understood, and gamma abnormalities have been found in schizophrenia (SZ). Animal models of SZ based on hypofunction of the N-methyl-d-aspartate receptor (NMDAR) demonstrate increased spontaneous broadband gamma power, but this phenomenon has not been identified clearly in patients with SZ. To examine spontaneous gamma power and its relationship to evoked gamma oscillations in the auditory cortex of patients with SZ. We performed a cross-sectional study including 24 patients with chronic SZ and 24 matched healthy control participants at the Veterans Affairs Boston Healthcare System from January 1, 2009, through December 31, 2012. Electroencephalograms were obtained during auditory steady-state stimulation at multiple frequencies (20, 30, and 40 Hz) and during a resting state in 18 participants in each group. Electroencephalographic activity in the auditory cortex was estimated using dipole source localization. Auditory steady-state response (ASSR) measures included the phase-locking factor and evoked power. Spontaneous gamma power was measured as induced (non-phase-locked) gamma power in the ASSR data and as total gamma power in the resting-state data. The ASSR phase-locking factor was reduced significantly in patients with SZ compared with controls for the 40-Hz stimulation (mean [SD], 0.075 [0.028] vs 0.113 [0.065]; F1,46 = 6.79 [P = .012]) but not the 20- or the 30-Hz stimulation (0.042 [0.038] vs 0.043 [0.034]; F1,46 = 0.006 [P = .938] and 0.084 [0.040] vs 0.098 [0.050]; F1,46 = 1.605 [P = .212], respectively), repeating previous findings. The mean [SD] broadband-induced (30-100 Hz) gamma power was increased in patients with SZ compared with controls during steady-state stimulation (6.579 [3.783] vs 3.984 [1.843]; F1,46 = 9.128 [P = .004]; d = 0.87) but not during rest (0.006 [0.003] vs 0.005 [0.002]; F1,34 = 1.067 [P = .309]; d = 0.35). Induced gamma power in the left hemisphere of the patients with SZ during the 40-Hz stimulation was positively correlated with auditory hallucination symptoms (tangential, ρ = 0.587 [P = .031]; radial, ρ = 0.593 [P = .024]) and negatively correlated with the ASSR phase-locking factor (baseline: ρ = -0.572 [P = .024]; ASSR: ρ = -0.568 [P = .032]). Spontaneous gamma activity is increased during auditory steady-state stimulation in SZ, reflecting a disruption in the normal balance of excitation and inhibition. This phenomenon interacts with evoked oscillations, possibly contributing to the gamma ASSR deficit found in SZ. The similarity of increased spontaneous gamma power in SZ to the findings of increased spontaneous gamma power in animal models of NMDAR hypofunction suggests that spontaneous gamma power could serve as a biomarker for the integrity of NMDARs on parvalbumin-expressing inhibitory interneurons in humans and in animal models of neuropsychiatric disorders.

Functional Connectivity in Patients With Sensorineural Hearing Loss Using Resting-State MRI.

This study was undertaken to evaluate whole-brain functional connectivity changes related to auditory cortex in patients with left-sided sensorineural hearing loss (SNHL) using resting-state functional connectivity magnetic resonance imaging. Imaging was performed in 19 patients with left-sided SNHL and 35 individuals in the control group without SNHL. Data were collected and analyzed to map functional connectivity using the left/right primary auditory cortex as the region of interest to identify global differences between patients with SNHL and the control group. In comparison to the control group, the SNHL group was found to have significant functional connectivity changes in the auditory system, recognition network, visual cortex, and language network. These findings suggest that functional brain alterations in unilateral SNHL patients may indicate reorganizations that occur in response to auditory deficits.

(1)H-MRS study of auditory cortex in patients with presbycusis

To study the metabolic changes of auditory cortex in patients with presbycusis by using proton magnetic resonance spectroscopy ((1)H-MRS). Ten normal hearing volunteers (youth group), 10 normal hearing of elderly (aged group) and 8 patients with presbycusis (presbycusis group) were checked with proton magnetic resonance spectroscopy. N-acetylaspartic acid (NAA), creatine (Cr), choline (Cho), γ-aminobutyric acid (GABA), glutamic acid (Glu) compound were measured. The differences between the groups were semi-quantitatively analyzed. When compared with youth group, reduced NAA/Cr, increased Cho/Cr were found in the aged group and presbycusis group (P < 0.05). GABA/Cr ratio and Glu/Cr ratio were significant difference between presbycusis group and youth group (P < 0.05). There were no significant difference in the GABA/Cr and Glu/Cr ratios in the bilateral auditory cortex between the youth group and the aged group (P > 0.05). When compared with aged group, the metabolic changes of auditory cortex in patients with presbycusis were remarkable (P < 0.05). (1)H-MRS is a noninvasive technique that can provide useful information concerning the metabolic changes of auditory cortex in human. In comparison to the aged group and the youth group, the changes of NAA, GABA, Cho and Glu is found in auditory cortex in patients with presbycusis.

FUNCTIONAL MAGNETIC RESONANCE IMAGING OF AUDITORY CORTEX IN PARTIAL DEAFNESS TREATMENT

BackgroundRecently, there has been a surge of interest in neuroimaging techniques that might help to objectively evaluate the residual hearing abilities of patients with hearing abilities of patients considered for partial deafness treatment (PDT). Such an evaluation might allow a wider range of PD candidates to benefit from cochlear implantation (CI). Although existing studies suggest that functional magnetic resonance (fMRI) may help predict the benefits of CI for hearing-impaired patients, little is known about the activity of the primary auditory cortex in patients with partial deafness. This study is the first to apply fMRI to examine BOLD signal changes in the auditory cortex induced by chirp stimulation in patients with partial deafnessMaterial and MethodTen patients considered for partial deafness treatment with electro-acoustic stimulation (PDT-EAS) and 10 patients considered for electrical complement treatment (PDT-EC) according to Skarżyński’s categorization of partial deafness treatment (PDT) participated in the study. fMRI measurements were performed in a 3T Siemens Magnetom Trio scanner at the Bioimaging Research Center (BRC) of the Institute of Physiology and Pathology of Hearing in Kajetany, Poland. During the fMRI study, subjects were presented with a chirp of two different bandwidths: 50–950 Hz (middle frequency 500 Hz) and 3000–5000 Hz (middle frequency 4000 Hz) at 90 dB(C) via MRI-compatible earphones. A sparse paradigm was used and the data was analyzed using the SPM8 package (Statistical Parametric Mapping, http://www.fil.ion.ucl.ac.uk/spm/). Standard preprocessing was followed by a second-level analysis for contrast of low and high frequencies.ResultsAs expected, bilateral activation in the auditory cortex was observed in response to stimulation by 500 Hz chirps in PDT-EAS and PDT-EC candidates. Activation in response to 4000 Hz chirps were found only in the PDT-EAS group but less strongly than for 500 Hz chirps.ConclusionsfMRI can be used as an objective way of assessing residual hearing in the auditory cortex of patients with partial deafness.

The “paradoxical” engagement of the primary auditory cortex in patients with auditory verbal hallucinations: A meta-analysis of functional neuroimaging studies

The existing literature on neuroimaging studies of auditory verbal hallucinations (AVHs) in patients with schizophrenia contains an apparent “paradox” in that the same areas in the auditory cortex seem to be both activated and deactivated in relation to AVHs, depending on whether an external auditory stimulus is present or not. We performed meta-analyses of neuroimaging studies examining patients with schizophrenia during the processing of auditory stimuli and in individuals experiencing hallucinations in the absence of auditory stimuli to examine whether the auditory cortex shows the paradoxical decrease/increase pattern across studies. Databases PubMed and ISI Web of Knowledge were queried with the combination of the keywords “auditory verbal hallucinations”, “auditory hallucinations”, “fMRI”, “PET”, “imaging”, yielding 11 studies involving comparison between schizophrenia and control group during external auditory stimulation, and 12 studies of hallucinating subjects experiencing AVHs and resting in the absence of auditory stimulation. The data were analyzed using Activation Likelihood Estimation method. The results showed overlapping increased activation in the absence of an external stimulus, and decreased activation in the presence of an external auditory stimulus in the left primary auditory cortex and in the right rostral prefrontal cortex, confirming the “paradoxical” brain activation in relation to AVHs. It is suggested that the “paradox” may be caused by an attentional bias towards internally generated information and failure of down- and up-regulation of the default mode and auditory processing networks, respectively, with the consequence that the spontaneous activation in the absence of an external stimulus shuts down the perceptual apparatus for further processing.

Invariance of firing rate and field potential dynamics to stimulus modulation rate in human auditory cortex

The effect of stimulus modulation rate on the underlying neural activity in human auditory cortex is not clear. Human studies (using both invasive and noninvasive techniques) have demonstrated that at the population level, auditory cortex follows stimulus envelope. Here we examined the effect of stimulus modulation rate by using a rare opportunity to record both spiking activity and local field potentials (LFP) in auditory cortex of patients during repeated presentations of an audio-visual movie clip presented at normal, double, and quadruple speeds. Mean firing rate during evoked activity remained the same across speeds and the temporal response profile of firing rate modulations at increased stimulus speeds was a linearly scaled version of the response during slower speeds. Additionally, stimulus induced power modulation of local field potentials in the high gamma band (64-128 Hz) exhibited similar temporal scaling as the neuronal firing rate modulations. Our data confirm and extend previous studies in humans and anesthetized animals, supporting a model in which both firing rate, and high-gamma LFP power modulations in auditory cortex follow the temporal envelope of the stimulus across different modulation rates.

Paired-Pulse Inhibition in the Auditory Cortex in Parkinson's Disease and Its Dependence on Clinical Characteristics of the Patients

We aimed to determine the value of the paired-pulse inhibition (PPI) in the auditory cortex in patients with Parkinson's disease (PD) and analyze its dependence on clinical characteristics of the patients. The central (Cz) auditory evoked potentials were recorded in 58 patients with PD and 22 age-matched healthy subjects. PPI of the N1/P2 component was significantly (P < .001) reduced for interstimulus intervals 500, 700, and 900 ms in patients with PD compared to control subjects. The value of PPI correlated negatively with the age of the PD patients (P < .05), age of disease onset (P < .05), body bradykinesia score (P < .01), and positively with the Mini Mental State Examination (MMSE) cognitive score (P < .01). Negative correlation between value of PPI and the age of the healthy subjects (P < .05) was also observed. Thus, results show that cortical inhibitory processes are deficient in PD patients and that the brain's ability to carry out the postexcitatory inhibition is age-dependent.

Long-range synchrony of gamma oscillations and auditory hallucination symptoms in schizophrenia

Phase locking in the gamma-band range has been shown to be diminished in patients with schizophrenia. Moreover, there have been reports of positive correlations between phase locking in the gamma-band range and positive symptoms, especially hallucinations. The aim of the present study was to use a new methodological approach in order to investigate gamma-band phase synchronization between the left and right auditory cortex in patients with schizophrenia and its relationship to auditory hallucinations. Subjects were 18 patients with chronic schizophrenia (SZ) and 16 healthy control (HC) subjects. Auditory hallucination symptom scores were obtained using the Scale for the Assessment of Positive Symptoms. Stimuli were 40-Hz binaural click trains. The generators of the 40 Hz-ASSR were localized using eLORETA and based on the computed intracranial signals lagged interhemispheric phase locking between primary and secondary auditory cortices was analyzed. Current source density of the 40 ASSR response was significantly diminished in SZ in comparison to HC in the right superior and middle temporal gyrus (p < 0.05). Interhemispheric phase locking was reduced in SZ in comparison to HC for the primary auditory cortices (p < 0.05) but not in the secondary auditory cortices. A significant positive correlation was found between auditory hallucination symptom scores and phase synchronization between the primary auditory cortices (p < 0.05, corrected for multiple testing) but not for the secondary auditory cortices. These results suggest that long-range synchrony of gamma oscillations is disturbed in schizophrenia and that this deficit is related to clinical symptoms such as auditory hallucinations.

BOLD-fMRI study of auditory cortex in patients with tinnitus

ObjectiveBlood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) was used to study activation signals in the brain cortex evoked by tone stimulation in patients with tinnitus for its potential utility as an objective indicator of tinnitus. MethodsBOLD-fMRI examination was conducted in 7 patients with chronic tinnitus and 15 control subjects. The activation signal in the brain cortex was recorded. ResultsSignificant activation was found in temporal lobe in control subjects, with greater signal volume and intensity on the contralateral than ipsilateral auditory cortex (P<0.01). However, there was no discernable patterns in the anatomical location, volume and intensity of cortical activation signals in patients with chronic tinnitus. ConclusionsPatients with chronic tinnitus may have abnormal neural activities in the auditory cortex.

Reduced connectivity of the auditory cortex in patients with auditory hallucinations: a resting state functional magnetic resonance imaging study

Previous research has reported auditory processing deficits that are specific to schizophrenia patients with a history of auditory hallucinations (AH). One explanation for these findings is that there are abnormalities in the interhemispheric connectivity of auditory cortex pathways in AH patients; as yet this explanation has not been experimentally investigated. We assessed the interhemispheric connectivity of both primary (A1) and secondary (A2) auditory cortices in n=13 AH patients, n=13 schizophrenia patients without auditory hallucinations (non-AH) and n=16 healthy controls using functional connectivity measures from functional magnetic resonance imaging (fMRI) data. Functional connectivity was estimated from resting state fMRI data using regions of interest defined for each participant based on functional activation maps in response to passive listening to words. Additionally, stimulus-induced responses were regressed out of the stimulus data and the functional connectivity was estimated for the same regions to investigate the reliability of the estimates. AH patients had significantly reduced interhemispheric connectivity in both A1 and A2 when compared with non-AH patients and healthy controls. The latter two groups did not show any differences in functional connectivity. Further, this pattern of findings was similar across the two datasets, indicating the reliability of our estimates. These data have identified a trait deficit specific to AH patients. Since this deficit was characterized within both A1 and A2 it is expected to result in the disruption of multiple auditory functions, for example, the integration of basic auditory information between hemispheres (via A1) and higher-order language processing abilities (via A2).

Direct Electrical Stimulation of Heschl's Gyrus for Tinnitus Treatment

The purpose of the study was to determine the effect of electrical stimulation of the auditory cortex in patients with tinnitus. Nonrandomized clinical trial. Two patients with debilitating tinnitus refractory to conventional therapies were treated. Patients were evaluated with validated questionnaires and psychoacoustic measures to determine the frequency and pitch of their tinnitus. Tones at these frequencies were then presented to the first patient (RP) under magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) to determine the tonotopic map for these frequencies in Heschl's gyrus. These tonotopic sites were targeted for implant with a quadripolar electrode. In the second patient (MV), only the fMRI tonotopic map was performed. These fMRI results detected an area of increased activity, which was selected as the site for the implanted bipolar electrode. Patient RP (bilateral tinnitus for 2 years) has experienced a sustained reduction to near elimination of tinnitus with intracerebral implanted electrodes, whereas patient MV (unilateral tinnitus for 7 years) had an unsustained reduction in her tinnitus. These findings suggest that the perception and annoyance of tinnitus may be modulated or reduced through electrical stimulation of the auditory cortex. These unsustained effects for patient MV may have been influenced by the longstanding nature of her tinnitus or by another reason as yet undetermined.

The Auditory Cortex in Schizophrenia

The Auditory Cortex in Schizophrenia

A recovery from enhancement of activation in auditory cortex of patients with idiopathic sudden sensorineural hearing loss

Objective We previously reported enhanced activation of auditory cortex in patients with bilateral chronic inner-ear hearing loss. To determine whether this enhancement can exhibit a short-term alteration, we measured auditory evoked magnetic fields (AEFs) in patients with idiopathic sudden sensorineural hearing loss (ISSHL) in the acute phase (AP) and recovery phases (RPs). Methods We recorded AEFs in two unilateral ISSHL patients at three time points (AP, RP1, and RP2) using a whole-head neuromagnetometer. Tone bursts of 1 kHz were presented monaurally to the affected and healthy ear at four different intensities (40–70 dB HL). Results Both patients showed the enhancement of N100 m moment at AP and not at RPs in response to the affected ear stimulation, and stronger N100 m moment in ipsilateral than contralateral hemisphere in response to the healthy ear stimulation at AP. Conclusions Enhancement of N100 m amplitude occurs in ISSHL patients and disappears on the scale of days. Enhancement of activity in the auditory cortex derived from inner-ear hearing loss can thus exhibit short-term change. Significance The results of this study provide first evidence for a recovery from enhancement of activation in the auditory cortex following injury of peripheral hearing organ.

A dissociation of structure and function in the auditory cortex of patients with schizophrenia

A dissociation of structure and function in the auditory cortex of patients with schizophrenia