Reduced neutralization against Delta, Gamma, Mu, and Omicron BA.1 variants of SARS-CoV-2 from previous non-Omicron infection.

The understanding of the host immune response to SARS-CoV-2 variants of concern is critical for improving diagnostics, therapy development, and vaccines. Here, we analyzed the level of neutralizing antibodies against SARS-CoV-2 D614G, Delta, Gamma, Mu, and Omicron variants in D614G infected healthcare workers during a follow-up up to 6 months after recovery. We followed up 76 patients: 60.5% were women and 39.5% men. The 96.1% and 3.9% were symptomatic and asymptomatic, respectively. The most frequent symptoms were headache, myalgia, and cough. The 65.8%, 65.8%, and 92.1% of the infected individuals were positive for neutralizing antibodies against D614G variant at 2, 4, and 6 months of follow-up, respectively. The 26.3%, 48.7% and 65.8% of patients neutralized Delta variant, 19.7%, 32.9% and 52.6% of patients neutralized Gamma, 7.9%, 19.7% and 44.7% of patients neutralized Mu, and 4.0%, 9.2% and 15.8% of patients neutralized Omicron. Low neutralization against Gamma and Mu variants was observed during the follow-up, and very low against the Omicron variant was detected during the same period. The median of neutralizing antibody titers against D614G and Delta variants increased significantly during the follow-up. An association was observed between the levels of neutralizing antibodies against D614G and Delta variants and the severity of the disease. Our results suggest an immune escape from neutralizing antibodies with the Omicron variant because of the many mutations localized in the S protein.

Neutralization of alpha, gamma, and D614G SARS-CoV-2 variants by CoronaVac vaccine-induced antibodies.

Vaccination generates a neutralizing immune response against SARS-CoV-2. The genomic surveillance is showing the emergence of variants with mutations in spike, the main target of neutralizing antibodies. To understand the impact of these variants, we report the neutralization potency against alpha, gamma, and D614G SARS-CoV-2 variants in 44 individuals that received two doses of CoronaVac vaccine, an inactivated SARS-CoV-2 vaccine. Plasma samples collected at 60 days after the second dose of CoronaVac were analyzed by the reduction of cytopathic effect in Vero E6 cells with the three infectious variants of SARS-CoV-2. Plasma showed lower neutralization with alpha (geometric mean titer [GMT] = 18.5) and gamma (GMT = 10.0) variants than with D614G (GMT = 75.1) variant. Efficient neutralization against the alpha and gamma variants was not detected in 31.8% and 59.1% of plasma, respectively. These findings suggest the alpha and gamma variants could escape from neutralization by antibodies elicited by vaccination. Robust genomic and biological surveillance of viral variants could help to develop effective strategies for the control of SARS-CoV-2.

Cortical Processing of Vocal and Nonvocal Sounds in Cochlear-Implanted Children: An Electrophysiological Study.

OBJECTIVES: For prelingually deaf children, cochlear implants (CIs) can restore auditory input to the auditory cortex and the ability to acquire spoken language. Language development is strongly intertwined with voice perception. The aim of this electrophysiological study was to investigate human voice processing using measures of cortical auditory evoked potentials (AEPs) in pediatric CI users. DESIGN: Cortical AEPs were measured in 8 CI children (4 to 12 years old) with good auditory and language performance and 8 normal-hearing (NH) age-matched controls. The auditory stimuli were nonspeech vocal sounds (laughing, sighing, coughing) and environmental sounds (e.g., telephones, alarms, cars, bells, water, wind). Independent component analysis was used to minimize the CI artifact in cortical AEPs. RESULTS: Fronto-temporal positivity to vocal sounds was found in NH children, with a significant effect in the 140 to 240 msec latency range. In CI children, there was a positive response to vocal sounds in the 170 to 250 msec latency range, with a more diffuse and anterior distribution than in the NH children. CONCLUSIONS: Cortical responses to vocal sounds were recorded in CI children. The topography and latency of response to voice differed from that of NH children. The results suggest that cortical reorganization for processing vocal sounds may occur in congenitally deaf children fitted with a CI.

My voice or yours? An electrophysiological study.

This study examined the neural processes underlying own voice discrimination using electrophysiological methods. Event-related potentials were recorded while healthy subjects (n = 17) heard passively three oddball sequences composed of recordings of the French vowel/a/pronounced either by the participant her/himself or by two unknown persons. The results indicated that, although the mismatch negativity (MMN) displayed similar peak latency and amplitude in both conditions, the subsequent P3a clearly distinguished the two conditions since its amplitude was significantly smaller for own voice discrimination than for that of unknown voices. Moreover, the own voice discriminative response was associated with an early pre-MMN response. This early response involved a left inferior frontal component, the activity of which lasted throughout the time course of the discriminative response, which included both MMN and P3a.

Dynamics of anticipatory mechanisms during predictive context processing.

We employed an electroencephalography paradigm manipulating predictive context to dissociate the neural dynamics of anticipatory mechanisms. Subjects either detected random targets or targets preceded by a predictive sequence of three distinct stimuli. The last stimulus in the three-stimulus sequence (decisive stimulus) did not require any motor response but 100% predicted a subsequent target event. We showed that predictive context optimises target processing via the deployment of distinct anticipatory mechanisms at different times of the predictive sequence. Prior to the occurrence of the decisive stimulus, enhanced attentional preparation was manifested by reductions in the alpha oscillatory activities over the visual cortices, resulting in facilitation of processing of the decisive stimulus. Conversely, the subsequent 100% predictable target event did not reveal the deployment of attentional preparation in the visual cortices, but elicited enhanced motor preparation mechanisms, indexed by an increased contingent negative variation and reduced mu oscillatory activities over the motor cortices before movement onset. The present results provide evidence that anticipation operates via different attentional and motor preparation mechanisms by selectively pre-activating task-dependent brain areas as the predictability gradually increases.

Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners.

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, <100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.

Recognition of Variants of Concern by Antibodies and T Cells Induced by a SARS-CoV-2 Inactivated Vaccine.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible of the current pandemic ongoing all around the world. Since its discovery in 2019, several circulating variants have emerged and some of them are associated with increased infections and death rate. Despite the genetic differences among these variants, vaccines approved for human use have shown a good immunogenic and protective response against them. In Chile, over 70% of the vaccinated population is immunized with CoronaVac, an inactivated SARS-CoV-2 vaccine. The immune response elicited by this vaccine has been described against the first SARS-CoV-2 strain isolated from Wuhan, China and the D614G strain (lineage B). To date, four SARS-CoV-2 variants of concern described have circulated worldwide. Here, we describe the neutralizing capacities of antibodies secreted by volunteers in the Chilean population immunized with CoronaVac against variants of concern Alpha (B.1.1.7), Beta (B.1.351) Gamma (P.1) and Delta (B.617.2). Methods: Volunteers enrolled in a phase 3 clinical trial were vaccinated with two doses of CoronaVac in 0-14 or 0-28 immunization schedules. Sera samples were used to evaluate the capacity of antibodies induced by the vaccine to block the binding between Receptor Binding Domain (RBD) from variants of concern and the human ACE2 receptor by an in-house ELISA. Further, conventional microneutralization assays were used to test neutralization of SARS-CoV-2 infection. Moreover, interferon-γ-secreting T cells against Spike from variants of concern were evaluated in PBMCs from vaccinated subjects using ELISPOT. Results: CoronaVac promotes the secretion of antibodies able to block the RBD of all the SARS-CoV-2 variants studied. Seropositivity rates of neutralizing antibodies in the population evaluated were over 97% for the lineage B strain, over 80% for Alpha and Gamma variants, over 75% for Delta variant and over 60% for the Beta variant. Geometric means titers of blocking antibodies were reduced when tested against SARS-CoV-2 variants as compared to ancestral strain. We also observed that antibodies from vaccinated subjects were able to neutralize the infection of variants D614G, Alpha, Gamma and Delta in a conventional microneutralization assay. Importantly, after SARS-CoV-2 infection, we observed that the blocking capacity of antibodies from vaccinated volunteers increased up to ten times for all the variants tested. We compared the number of interferon-γ-secreting T cells specific for SARS-CoV-2 Spike WT and variants of concern from vaccinated subjects and we did not detect significant differences. Conclusion: Immunization with CoronaVac in either immunization schedule promotes the secretion of antibodies able to block SARS-CoV-2 variants of concern and partially neutralizes SARS-CoV-2 infection. In addition, it stimulates cellular responses against all variants of concern.

Follicle-stimulating hormone promotes nerve growth factor and vascular endothelial growth factor expression in epithelial ovarian cells.

Ovarian cancer is the first cause of death for gynecological malignances in developed countries and around 80% correspond to Epithelial Ovarian Cancer (EOC). Overexpression of Nerve Growth Factor (NGF) and its high affinity receptor TRKA are involved in EOC progression, modulating several oncogenic processes such as angiogenesis by the increase of Vascular Endothelial Growth Factor (VEGF). FSH receptors (FSH-R) are present in EOC, but their changes and contribution during EOC progression are still not thoroughly known. The aims of this study were to evaluate the abundance of FSH receptors during EOC differentiation and to determine whether FSH modulates oncoproteins such as NGF and VEGF in ovarian cells. FSH-R expression in EOC tissues and cell lines (A2780, poorly differentiated EOC cells and HOSE, non-tumoral ovarian surface epithelial cells) were measured by RT-PCR and laser capture of epithelial cells from EOC samples by qPCR. FSH-R protein levels were evaluated by immunohisto/cytochemistry. Additionally, ovarian explants and ovarian cell lines were stimulated with FSH and/or FSH-R inhibitor to assess NGF and VEGF mRNA and protein levels. The results showed that FSH-R levels decreased during EOC progression, nevertheless these receptors are still present in poorly differentiated EOC. FSH increased NGF expression in ovarian cells, which was prevented using a FSH-R inhibitor. Similarly, in ovarian cancer explants, FSH increased NGF and VEGF mRNA, as well as NGF protein levels. These results suggest that FSH would display a key role not only in initial stages of EOC, but also in late stages of this disease, by modulation of NGF and VEGF levels in EOC cells.

Metformin Reduces NGF-Induced Tumour Promoter Effects in Epithelial Ovarian Cancer Cells.

Epithelial ovarian cancer (EOC) is a lethal gynaecological neoplasm characterized by rapid growth and angiogenesis. Nerve growth factor (NGF) and its high affinity receptor tropomyosin receptor kinase A (TRKA) contribute to EOC progression by increasing the expression of c-MYC, survivin and vascular endothelial growth factor (VEGF) along with a decrease in microRNAs (miR) 23b and 145. We previously reported that metformin prevents NGF-induced proliferation and angiogenic potential of EOC cells. In this study, we sought to obtain a better understanding of the mechanism(s) by which metformin blocks these NGF-induced effects in EOC cells. Human ovarian surface epithelial (HOSE) and EOC (A2780/SKOV3) cells were stimulated with NGF and/or metformin to assess the expression of c-MYC, ß-catenin, survivin and VEGF and the abundance of the tumor suppressor miRs 23b and 145. Metformin decreased the NGF-induced transcriptional activity of MYC and ß-catenin/T-cell factor/lymphoid enhancer-binding factor (TCF-Lef), as well as the expression of c-MYC, survivin and VEGF in EOC cells, while it increased miR-23b and miR-145 levels. The preliminary analysis of ovarian biopsies from women users or non-users of metformin was consistent with these in vitro results. Our observations shed light on the mechanisms by which metformin may suppress tumour growth in EOC and suggest that metformin should be considered as a possible complementary therapy in EOC treatment.

Topography of syllable change-detection electrophysiological indices in children and adults with reading disabilities.

INTRODUCTION: Developmental dyslexia (DD) is a frequent language-based learning disorder. The predominant etiological view postulates that reading problems originate from a phonological impairment. METHOD: We studied mismatch negativity (MMN) and Late Discriminative Negativity (LDN) to syllables change in both children (n=12; 8-12 years) and young adults (n=15; 14-23 years) with DD compared with controls. RESULTS/DISCUSSION: The present study confirmed abnormal automatic discrimination of syllable changes in both children and adults with developmental dyslexia. MMN topographic, amplitude and latency group differences were evidenced, suggesting different brain mechanisms involved in elementary auditory stimulus change-detection in DD, especially in the left hemisphere. The LDN results demonstrated that the auditory disorder of temporal processing in DD children becomes more serious at late stages of information processing and that the apparent cerebral hypo reactivity to speech changes in DD actually may correspond to additional processes. The age-related differences observed in both MMN and LDN topographies, amplitudes and latency between subjects with DD and controls could indicate different developmental courses in the neural representation of basic speech sounds in good and poor readers, with a tendency to normalization with increasing age. CONCLUSION: Our results showing atypical electrophysiological concomitants of speech auditory perception in DD strongly support the hypothesis of deviant cortical organization in DD.

Left temporal impairment of auditory information processing in prematurely born 9-year-old children: an electrophysiological study.

Children born preterm more than average display cognitive difficulties that are significant enough to prevent normal schooling. The aim of our study was to provide better understanding of the long-term neuropathological processes associated with preterm injury, through the hypothesis that mild cognitive disorders might be related to slight deficits in primary functions such as attention and perception. Assessment of auditory pre-attentive processes was performed by recording the obligatory sensory response (N250) and the change-detection response (Mismatch Negativity, MMN). Topographic study of these responses was performed in fifteen 9-year-old children born preterm (27-33 weeks gestational age) matched to fifteen control children born at term. The auditory stimulus sequence consisted of 1000 Hz standard and 1100 Hz deviant tones (15%) delivered binaurally with an interstimulus interval of 700 ms. The results showed that MMN was similar in both groups. Analysis of the responses to standard repetitive tones demonstrated significantly smaller N250 wave amplitude in children born preterm. Scalp current density maps showed that this reduction in amplitude was associated with lower activity of both frontal and left supratemporal generators. Although the functional significance of the N250 wave in children remains to be clarified, our results indicate a disorder of auditory processes related to prematurity that might have consequences on the development of higher-level processes.

Atypical sound discrimination in children with ASD as indicated by cortical ERPs.

BACKGROUND: Individuals with autism spectrum disorder (ASD) show a relative indifference to the human voice. Accordingly, and contrarily to their typically developed peers, adults with autism do not show a preferential response to voices in the superior temporal sulcus; this lack of voice-specific response was previously linked to atypical processing of voices. In electroencephalography, a slow event-related potential (ERP) called the fronto-temporal positivity to voice (FTPV) is larger for vocal than for non-vocal sounds, resulting in a voice-sensitive response over right fronto-temporal sites. Here, we investigated the neurophysiological correlates of voice perception in children with and without ASD. METHODS: Sixteen children with autism and 16 age-matched typically developing children heard vocal (speech and non-speech) and non-vocal sounds while their electroencephalographic activity was recorded; overall IQ was smaller in the group of children with ASD. ERP amplitudes were compared using non-parametric statistical tests at each electrode and in successive 20-ms time windows. Within each group, differences between conditions were assessed using a non-parametric Quade test between 0 and 400 ms post-stimulus. Inter-group comparisons of ERP amplitudes were performed using non-paired Kruskal-Wallis tests between 140 and 180 ms post-stimulus. RESULTS: Typically developing children showed the classical voice-sensitive response over right fronto-temporal electrodes, for both speech and non-speech vocal sounds. Children with ASD did not show a preferential response to vocal sounds. Inter-group analysis showed no difference in the processing of vocal sounds, both speech and non-speech, but significant differences in the processing of non-vocal sounds over right fronto-temporal sites. CONCLUSIONS: Our results demonstrate a lack of voice-preferential response in children with autism spectrum disorders. In contrast to observations in adults with ASD, the lack of voice-preferential response was attributed to an atypical response to non-vocal sounds, which was overall more similar to the event-related potentials evoked by vocal sounds in both groups. This result suggests atypical maturation processes in ASD impeding the specialization of temporal regions in voice processing.

Interactions Between Trypanosoma cruzi the Chagas Disease Parasite and Naturally Infected Wild Mepraia Vectors of Chile.

Chagas disease, which ranks among the world's most neglected diseases, is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. Mepraia species are the wild vectors of this parasite in Chile. Host-parasite interactions can occur at several levels, such as co-speciation and ecological host fitting, among others. Thus, we are exploring the interactions between T. cruzi circulating in naturally infected Mepraia species in all areas endemic of Chile. We evaluated T. cruzi infection rates of 27 different haplotypes of the wild Mepraia species and identified their parasite genotypes using minicircle PCR amplification and hybridization tests with genotype-specific DNA probes. Infection rates were lower in northern Chile where Mepraia gajardoi circulates (10-35%); in central Chile, Mepraia spinolai is most abundant, and infection rates varied in space and time (0-55%). T. cruzi discrete typing units (DTUs) TcI, TcII, TcV, and Tc VI were detected. Mixed infections with two or more DTUs are frequently found in highly infected insects. T. cruzi DTUs have distinct, but not exclusive, ecological and epidemiological associations with their hosts. T. cruzi infection rates of M. spinolai were higher than in M. gajardoi, but the presence of mixed infection with more than one T. cruzi DTU was the same. The same T. cruzi DTUs (TcI, TcII, TcV, and TcVI) were found circulating in both vector species, even though TcI was not equally distributed. These results suggest that T. cruzi DTUs are not associated with any of the two genetically related vector species nor with the geographic area. The T. cruzi vectors interactions are discussed in terms of old and recent events. By exploring T. cruzi DTUs present in Mepraia haplotypes and species from northern to central Chile, we open the analysis on these invertebrate host-parasite interactions.

Auditory evoked potentials to tones and syllables in adults: evidence of specific influence on N250 wave.

Late auditory evoked potentials were recorded in eight adults according to stimulus duration (50ms versus 250ms) and to speech nature of the stimulus (tones versus syllables). The main effect of these parameters concerned the negative fronto-central wave, which occurs beyond 200ms termed N250 in this paper; it had a greater amplitude and a longer latency when tone duration increased from 50 to 250ms and a longer latency, a greater amplitude and a longer time-course in response to syllables compared to tones. Moreover, this wave was inversed in polarity at the mastoid sites, indicating the involvement of generators of the N250 wave in the supratemporal auditory cortex. These results showing the sensitivity of the N250 wave to tone duration and to speech stimuli indicated that this electrophysiological index might allow further assessment of cortical activity involved in speech stimuli processing.

Is my voice just a familiar voice? An electrophysiological study.

It is not clear whether self-stimuli are processed by the brain as highly familiar overlearned stimuli or as self-specific stimuli. This study examined the neural processes underlying discrimination of one's own voice (OV) compared with a familiar voice (FV) using electrophysiological methods. Event-related potentials were recorded while healthy subjects (n = 15) listened passively to oddball sequences composed of recordings of the French vowel /a/ pronounced either by the participant her/himself, or by a familiar person or an unknown person. The results indicated that, although mismatch negativity displayed similar peak latency and amplitude in both conditions, the amplitude of the subsequent P3a was significantly smaller in response to OV compared with a FV. This study therefore indicated that fewer pre-attentional processes are involved in the discrimination of one's OV than in the discrimination of FVs.

Asymmetry of temporal auditory T-complex: right ear-left hemisphere advantage in Tb timing in children.

OBJECTIVE: To investigate brain asymmetry of the temporal auditory evoked potentials (T-complex) in response to monaural stimulation in children compared to adults. METHODS: Ten children (7 to 9 years) and ten young adults participated in the study. All were right-handed. The auditory stimuli used were tones (1100 Hz, 70 dB SPL, 50 ms duration) delivered monaurally (right, left ear) at four different levels of stimulus onset asynchrony (700-1100-1500-3000 ms). Latency and amplitude of responses were measured at left and right temporal sites according to the ear stimulated. RESULTS: Peaks of the three successive deflections (Na-Ta-Tb) of the T-complex were greater in amplitude and better defined in children than in adults. Amplitude measurements in children indicated that Na culminates on the left hemisphere whatever the ear stimulated whereas Ta and Tb culminate on the right hemisphere but for left ear stimuli only. Peak latency displayed different patterns of asymmetry. Na and Ta displayed shorter latencies for contralateral stimulation. The original finding was that Tb peak latency was the shortest at the left temporal site for right ear stimulation in children. Amplitude increased and/or peak latency decreased with increasing SOA, however no interaction effect was found with recording site or with ear stimulated. CONCLUSION: Our main original result indicates a right ear-left hemisphere timing advantage for Tb peak in children. The Tb peak would therefore be a good candidate as an electrophysiological marker of ear advantage effects during dichotic stimulation and of functional inter-hemisphere interactions and connectivity in children.

Increased perception of loudness in autism.

Clinical reports on autism describe abnormal responses to auditory stimuli such as intolerance to sounds. The present study assessed subjective perception of loudness in subjects with autism compared to healthy controls, using two psychoacoustic tests. First, the auditory dynamic range was evaluated at six different tone frequencies. Secondly, loudness growth as a function of the intensity level of a 1 kHz tone was estimated. Verbal responses from a group of 11 children and adolescents with autism were compared to responses of 11 age- and gender- matched healthy controls. Smaller auditory dynamic ranges were found in the autistic group than in the control group, as well as increased perception of loudness, indicating hyperacusis in subjects with autism.

Cortical auditory processing and communication in children with autism: electrophysiological/behavioral relations.

The purpose of the present study was to investigate the relations between late auditory evoked potentials (AEPs) recorded at temporal sites (the N1c wave or Tb) and verbal and non-verbal abilities in children with autism. The study was performed in 26 mentally retarded children with autism (AUT) aged 4-8 years (mean age +/- S.E.M. = 71 +/- 2 months; mean verbal and non-verbal developmental quotient +/- S.E.M. = 36 +/- 4 and 48 +/- 3). The stimuli used were 750 Hz tone bursts of 200 ms duration delivered binaurally at different intensity levels (50, 60, 70, 80 dB SPL) with 3-5 s interstimulus intervals. Temporal AEPs were first compared to those of a group of 16 normal children (NOR) in the same age range (mean age +/- S.E.M. = 69 +/- 3 months). We then focused on the AUT group and considered relations between temporal AEPs and the severity of disorders of verbal and non-verbal communication assessed using a behavior rating scale. AEPs recorded on left and right temporal sites were of smaller amplitude in the AUT group than in the NOR group. Increasing intensity-related amplitude was observed on both sides in NOR and only on the right side in AUT. The lack of intensity effect on the left side resulted in a particular pattern of asymmetry at the highest level of intensity (80 dB SPL) with greater N1c amplitude on the right than on the left side (the reverse was found in the NOR group). Electro-clinical correlations indicated that the greater the amplitude of the right temporal N1c responses, the higher the verbal and non-verbal communication abilities. This suggests a developmental reorganization of left-right hemisphere functions in autism, with preferential activation of the right hemisphere for functions usually allocated to the left hemisphere, particularly those involving the secondary auditory areas situated on the lateral surface of the superior temporal gyrus where the N1c/Tb wave is generated.

Cortical electrophysiological markers of language abilities in children with hearing AIDS: a pilot study.

OBJECTIVE: To investigate cortical auditory evoked potentials (CAEPs) in pediatric hearing aid (HA) users, with and without language impairment. DESIGN: CAEPs were measured in 11 pediatric HA users (age: 8-12 years) with moderate bilateral sensorineural hearing loss (HL); participants were classified according to language ability. CAEPs were also measured for a control group of 11 age-matched, normal-hearing (NH) children. RESULTS: HL children without language impairment exhibited normal CAEPs. HL children with language impairment exhibited atypical temporal CAEPs, characterized by the absence of N1c; frontocentral responses displayed normal age-related patterns. CONCLUSION: Results suggest that abnormal temporal brain function may underlie language impairment in pediatric HA users with moderate sensorineural HL.

Hallucinations and negative symptoms differentially revealed by frontal and temporal responses to speech in schizophrenia.

BACKGROUND: Auditory verbal hallucinations (AVH) in schizophrenia may arise because of aberrant speech perception. We used an electroencephalography method to examine the neural processes underlying speech perception in schizophrenic patients with hallucinations. METHODS: Cortical event-related potentials (ERPs) were analyzed topographically (scalp potential and scalp current density (SCD) mapping) in response to the vowel /a/ using a passive paradigm in 26 patients with schizophrenia. RESULTS: From the SCD distribution of the P1 peak, we showed that, whereas the hallucination score (PSYRATS) was negatively correlated with the amplitude of the frontal currents, the PANSS negative symptom score was negatively correlated with the amplitude of the temporal currents in patients with schizophrenia. CONCLUSIONS: These results provide evidence that AVH and negative symptoms are associated with abnormal early processing of speech. Whereas AVH are related to decreased early frontal activation, negative symptoms are associated with a reduced early temporal response.