Acquired amusia after a right middle cerebral artery infarction - a case study.

A 62-year-old musician-MM-developed amusia after a right middle-cerebral-artery infarction. Initially, MM showed melodic deficits while discriminating pitch-related differences in melodies, musical memory problems, and impaired sensitivity to tonal structures, but normal pitch discrimination and spectral resolution thresholds, and normal cognitive and language abilities. His rhythmic processing was intact when pitch variations were removed. After 3 months, MM showed a large improvement in his sensitivity to tonality, but persistent melodic deficits and a decline in perceiving the metric structure of rhythmic sequences. We also found visual cues aided melodic processing, which is novel and beneficial for future rehabilitation practice.

Focal Brain Lesions Causing Acquired Amusia Map to a Common Brain Network.

Music is a universal human attribute. The study of amusia, a neurologic music processing deficit, has increasingly elaborated our view on the neural organization of the musical brain. However, lesions causing amusia occur in multiple brain locations and often also cause aphasia, leaving the distinct neural networks for amusia unclear. Here, we utilized lesion network mapping to identify these networks. A systematic literature search was carried out to identify all published case reports of lesion-induced amusia. The reproducibility and specificity of the identified amusia network were then tested in an independent prospective cohort of 97 stroke patients (46 female and 51 male) with repeated structural brain imaging, specifically assessed for both music perception and language abilities. Lesion locations in the case reports were heterogeneous but connected to common brain regions, including bilateral temporoparietal and insular cortices, precentral gyrus, and cingulum. In the prospective cohort, lesions causing amusia mapped to a common brain network, centering on the right superior temporal cortex and clearly distinct from the network causally associated with aphasia. Lesion-induced longitudinal structural effects in the amusia circuit were confirmed as reduction of both gray and white matter volume, which correlated with the severity of amusia. We demonstrate that despite the heterogeneity of lesion locations disrupting music processing, there is a common brain network that is distinct from the language network. These results provide evidence for the distinct neural substrate of music processing, differentiating music-related functions from language, providing a testable target for noninvasive brain stimulation to treat amusia.

Music perception in acquired prosopagnosia.

BACKGROUND: Acquired prosopagnosia is often associated with other deficits such as dyschromatopsia and topographagnosia, from damage to adjacent perceptual networks. A recent study showed that some subjects with developmental prosopagnosia also have congenital amusia, but problems with music perception have not been described with the acquired variant. OBJECTIVE: Our goal was to determine if music perception was also impaired in subjects with acquired prosopagnosia, and if so, its anatomic correlate. METHOD: We studied eight subjects with acquired prosopagnosia, all of whom had extensive neuropsychological and neuroimaging testing. They performed a battery of tests evaluating pitch and rhythm processing, including the Montréal Battery for the Evaluation of Amusia. RESULTS: At the group level, subjects with anterior temporal lesions were impaired in pitch perception relative to the control group, but not those with occipitotemporal lesions. Three of eight subjects with acquired prosopagnosia had impaired musical pitch perception while rhythm perception was spared. Two of the three also showed reduced musical memory. These three reported alterations in their emotional experience of music: one reported music anhedonia and aversion, while the remaining two had changes consistent with musicophilia. The lesions of these three subjects affected the right or bilateral temporal poles as well as the right amygdala and insula. None of the three prosopagnosic subjects with lesions limited to the inferior occipitotemporal cortex exhibited impaired pitch perception or musical memory, or reported changes in music appreciation. CONCLUSION: Together with the results of our previous studies of voice recognition, these findings indicate an anterior ventral syndrome that can include the amnestic variant of prosopagnosia, phonagnosia, and various alterations in music perception, including acquired amusia, reduced musical memory, and subjective reports of altered emotional experience of music.

Central auditory processing in children after traumatic brain injury.

INTRODUCTION: Traumatic brain injury can impair the central auditory pathways and auditory cortex. Hence, individuals who suffered a traumatic brain injury may be at risk of central auditory processing disorders, which can be identified with behavioral tests that assess central auditory function. OBJECTIVE: To characterize and compare the performance of children and adolescents with and without a history of traumatic brain injury in behavioral tests that assess central auditory processing. METHOD: The sample comprised 8- to 18-year-old individuals of both sexes who suffered moderate or severe closed traumatic brain injury 3 to 24 months before their participation in the study and whose hearing thresholds were normal. These individuals were matched for sex and age with other subjects without a history of traumatic brain injury and submitted to behavioral assessment of the central auditory processing with special tests to assess hearing skills (namely, auditory closure, figure-ground, and temporal processing), selected according to their chronological age and response-ability. RESULTS: The study group performed statistically worse than the comparison group in auditory closure, figure-ground in verbal dichotic listening, and temporal ordering. The central auditory processing tests with abnormal results in the comparison group were different from those in the study group. CONCLUSION: Central auditory processing disorders were identified in all subjects of the study group, especially involving auditory closure and temporal processing skills, in comparison with subjects without a history of traumatic brain injury.

Music processing and amusia.

Music is a universal and important human trait, which is orchestrated by complex brain network centered in the temporal lobe but connecting broadly to multiple cortical and subcortical regions. In the human brain, music engages a widespread bilateral network of regions that govern auditory perception, syntactic and semantic processing, attention and memory, emotion and reward, and motor skills. The ability to perceive or produce music can be severely impaired either due to abnormal brain development or brain damage, leading to a condition called amusia. Modern neuroimaging studies of amusia have provided valuable knowledge about the structure and function of specific brain regions and white matter pathways that are crucial for music perception, highlighting the role of the right frontotemporal network in this process. In this chapter, we provide an overview on the neural basis of music processing in a healthy brain and review evidence obtained from the studies of congenital and acquired amusia.

Relación entre hiperacusia y desorden del procesamiento auditivo central: Una revisión de la literatura / Relationship between hyperacusis and auditory processing disorder: a literature review

Resumen La hiperacusia corresponde a la excesiva sensibilidad auditiva o intolerancia a ciertos sonidos cotidianos que para la mayoría de las personas parecerían habituales. Considerando los mecanismos fisiológicos involucrados en el origen de la hiperacusia, es lógico pensar que su presencia podría afectar algunas habilidades del procesamiento auditivo central, sin embargo, la evidencia en torno al tema es escasa y no existe actualmente una revisión de la literatura que agrupe las investigaciones sobre esta temática. Por ello, el presente estudio pretende identificar y analizar la evidencia científica disponible sobre la relación entre hiperacusia y desorden del procesamiento auditivo central. Se realizó una revisión de la literatura guiada por protocolo PRISMA en las bases de datos Proquest, Ebsco, Pubmed, ScienceDirect, Cochrane Library y Scielo de acuerdo con términos claves. Fueron incluidos artículos originales de investigación, revisiones sistemáticas y metaanálisis, publicados desde el año 2010, realizados en animales y humanos, escritos en idiomas inglés, español y portugués. Se encontraron 323 estudios relacionados con los términos claves utilizados, de los cuales 13 cumplieron con los criterios de inclusión y fueron analizados. Se puede concluir que la evidencia científica en torno al tema es escasa e incipiente. Estructuras de la vía auditiva central como núcleos cocleares, lemnisco lateral, colículos inferiores, cuerpo geniculado medial y corteza auditiva primaria estarían relacionadas con la hiperacusia, así como también habilidades de procesamiento auditivo de figura/fondo, ordenación temporal y transferencia interhemisférica se verían afectadas.

Abstract Hyperacusis has been defined as the excessive auditory sensitivity or intolerance to certain everyday sounds that seem common for most people. Considering the underlying physiological mechanisms of hyperacusis, it is reasonable to think that it could affect some abilities involved in the central auditory processing. However, there is lack of evidence about this topic, and there is no literature review that gathers all the existing research. Therefore, the current study intends to identify and analyze the available scientific evidence regarding the relationship between hyperacusis and central auditory processing disorder. The review of the literature followed the PRISMA protocol, using key words in Proquest, Ebsco, Pubmed, ScienceDirect, Cochrane Library and Scielo databases. Original research articles, systematic reviews and meta-analyses of studies made with human and animals that have been published since 2010 in English, Spanish and Portuguese were included. Among them, 323 studies were related to the key terms, out of which 13 met the inclusion criteria and were analyzed. It is possible to conclude that there is little and incipient scientific evidence on the topic. Structures of the central auditory pathway such as cochlear nuclei, lateral lemniscus, inferior colliculi, medial geniculate body and primary auditory cortex seem to be related to hyperacusis; auditory processing skills such as figure/ground discrimination, temporal ordering and interhemispheric transfer appear to be affected as well.

Right ventral stream damage underlies both poststroke aprosodia and amusia.

BACKGROUND AND PURPOSE: This study was undertaken to determine and compare lesion patterns and structural dysconnectivity underlying poststroke aprosodia and amusia, using a data-driven multimodal neuroimaging approach. METHODS: Thirty-nine patients with right or left hemisphere stroke were enrolled in a cohort study and tested for linguistic and affective prosody perception and musical pitch and rhythm perception at subacute and 3-month poststroke stages. Participants listened to words spoken with different prosodic stress that changed their meaning, and to words spoken with six different emotions, and chose which meaning or emotion was expressed. In the music tasks, participants judged pairs of short melodies as the same or different in terms of pitch or rhythm. Structural magnetic resonance imaging data were acquired at both stages, and machine learning-based lesion-symptom mapping and deterministic tractography were used to identify lesion patterns and damaged white matter pathways giving rise to aprosodia and amusia. RESULTS: Both aprosodia and amusia were behaviorally strongly correlated and associated with similar lesion patterns in right frontoinsular and striatal areas. In multiple regression models, reduced fractional anisotropy and lower tract volume of the right inferior fronto-occipital fasciculus were the strongest predictors for both disorders, over time. CONCLUSIONS: These results highlight a common origin of aprosodia and amusia, both arising from damage and disconnection of the right ventral auditory stream integrating rhythmic-melodic acoustic information in prosody and music. Comorbidity of these disabilities may worsen the prognosis and affect rehabilitation success.

Achados clínicos fonoaudiológicos em adolescente com diabetes melittus tipo I: relato de caso / Speech-language pathology findings in adolescent with type I diabetes mellitus: a case report / Hallazgos de patología del habla y lenguaje en un adolescente con diabetes mellitus tipo I: reporte de un caso

Introdução: O diabetes mellitus tipo 1 (DM1) se caracteriza pela destruição das células beta das ilhotas pancreáticas, manifestando-se em hiperglicemia sintomática, devido a um déficit absoluto de insulina, gerando dependência vital de insulina exógena. É considerado típico em crianças e adolescentes; entretanto, pode se desenvolver em qualquer idade. Há inúmeros achados de alterações auditivas em pessoas com DM1, porém não há estudos em outras áreas da Fonoaudiologia. Objetivo: relatar o caso de um adolescente com diagnóstico recente de diabetes mellitus tipo I e alterações fonoaudiológicas na área da fala - desvio fonético no fonema /r/ - e de processamento auditivo. Apresentação do caso: Adolescente de 11 anos de idade vem encaminhado para Fonoaudiologia por não conseguir executar o /r/, com histórico de atendimento fonoaudiológico prévio. Logo após avaliação de fala e início do tratamento, realizou exame de processamento auditivo, que apontou alteração. Após 30 sessões de fonoterapia, o processamento auditivo foi tratado com sucesso. Discussão: Os achados do caso corroboram com o descrito na literatura consultada. Conclusão: O presente estudo se faz pertinente devido à escassez de estudos com mais participantes, com outras áreas da Fonoaudiologia que não somente a Audiologia.

Introduction: Type 1 diabetes mellitus (DM1) is characterized by the destruction of beta cells of pancreatic islets, manifesting in symptomatic hyperglycemia, due to an absolute insulin deficit, generating vital dependence on exogenous insulin. It is considered typical in children and adolescents; however, it can develop at any age. There are countless findings of auditory alterations in people with DM1, but there are no studies in other areas of Speech-Language Pathology. Objective: to report the case of an adolescent with a recent diagnosis of type I diabetes mellitus and Speech-Language Pathology disorders in the speech area - phonetic deviation in the phoneme /r/ - and auditory processing. Case report: An 11-year-old teenager arrives at the Speech-Language Pathology department for not being able to perform the /r/. Right after speech assessment and treatment initiation, he underwent an auditory processing exam, which showed changes. After 30 sessions of speech therapy, auditory processing was successfully treated. Discussion: The findings of the case corroborate with those described in the consulted literature. Conclusion: The present study is relevant due to the scarcity of studies with more participants, with other areas of Brazilian Speech-Language Pathology, other than only Audiology.

Introducción: la diabetes mellitus tipo 1 (DM1) se caracteriza por la destrucción de las células beta de los islotes pancreáticos, que se manifiestan en hiperglucemia sintomática, debido a un déficit absoluto de insulina, lo que genera una dependencia vital de la insulina exógena. Se considera típico en niños y adolescentes; sin embargo, puede desarrollarse a cualquier edad. Existen innumerables hallazgos de alteraciones auditivas en personas con DM1, pero no hay estudios en otras áreas de la Fonoaudiología. Objetivo: informar el caso de un adolescente con un diagnóstico reciente de diabetes mellitus tipo I y trastornos de fonoaudiología en el área del habla - desviación fonética en el fonema / r / - y procesamiento auditivo. Caso clínico: un adolescente de 11 años llega a Fonoaudiología por no poder realizar el /r/, con antecedentes de terapia del habla previa. Inmediatamente después de la evaluación del habla y el inicio del tratamiento, se sometió a un examen de procesamiento auditivo, que mostró cambios. Después de 30 sesiones de terapia del habla, el procesamiento auditivo se trató con éxito. Discusión: Los hallazgos del caso corroboran con los descritos en la literatura consultada. Conclusión: El presente estudio es relevante debido a la escasez de estudios con más participantes, con otras áreas de la Fonoaudiología brasileña además de la Audiología.

Central auditory processing: behavioral and electrophysiological assessment of children and adolescents diagnosed with stroke.

INTRODUCTION: Central auditory processing refers to the efficiency and effectiveness with which the central nervous system uses auditory information: it may be altered in neurological disorders and brain injuries, such as strokes. However, despite evidence of probable alterations in the pediatric population, functional abilities and post-stroke limitations are still not well documented in the literature. OBJECTIVE: To analyze the findings of the electrophysiological and behavioral evaluations of central auditory processing of children and adolescents diagnosed with stroke from a reference outpatient clinic, as well as to investigate possible associations with the variables: type and location of the stroke and age group. METHODS: The present study is characterized as comparative cross-sectional. The sample, for convenience, included individuals aged 7-18 years divided into two groups: study group, composed of individuals with a diagnosis of stroke, and control group, composed of individuals with typical development. The evaluation consisted of the following procedures: anamnesis, basic audiological evaluation, behavioral evaluation of the auditory processing disorder (dichotic digit test, dichotic consonant-vowel, synthetic sentence identification/pediatric speech intelligibility, gaps in noise, pitch pattern sequence, masking level difference), and electrophysiological evaluation (P300 and mismatch negativity). RESULTS: Nineteen children and adolescents were included in the study group. The control group was composed of 19 children and adolescents with typical development. In the comparison between the groups, a worse performance is observed for the study group in all the evaluated tests, behavioral and electrophysiological. In the behavioral evaluation of central auditory processing, there was a statistical difference for all tests, except for masking level difference and dichotic digit test, binaural separation step on the left. In the electrophysiological evaluation, there was a statistical difference in the latency of mismatch negativity and P300. No associations were found between the behavioral and electrophysiological findings and the location of the stroke and age group variables. CONCLUSION: Children and adolescents diagnosed with stroke present a worse performance in the electrophysiological and behavioral evaluations of central auditory processing when compared to a control group.

Resistance to noise-induced gap detection impairment in FVB mice is correlated with reduced neuroinflammatory response and parvalbumin-positive neuron loss.

Exposure to loud noises results in neuroinflammatory responses in the central auditory pathway. Noise-induced neuroinflammation is implicated in auditory processing deficits such as impairment in gap detection. In this study, we examined whether strain differences between the FVB and C57BL/6 mice in noise-induced impairment in gap detection are correlated with strain differences in neuroinflammatory responses. We found that noise induced more robust TNF-α expression in C57BL/6 than in FVB mice. Noise-induced microglial deramification was observed in C57BL/6 mice, but not in FVB mice. Furthermore, noise exposure resulted in a reduction in parvalbumin-positive (PV+) neuron density in the C57BL/6 mice, but not in FVB mice. These results suggest that neuroinflammatory responses and loss of PV+ neurons may contribute to strain differences in noise-induced impairment in gap detection.

Remediating spatial processing disorder in Aboriginal and Torres Strait Islander children.

OBJECTIVE: Australian Aboriginal and Torres Strait Islander children are much more likely than non-Indigenous children to experience early onset, chronic otitis media and associated hearing loss. This can result in the child developing spatial processing disorder (SPD). The aim of this study was to assess the efficacy of Sound Storm auditory training in remediating SPD in Aboriginal and Torres Strait Islander children at a regional school in Queensland, Australia. METHOD: Fifteen Aboriginal and Torres Strait Islander children (males = 8, females = 7, age range = 6-13 years, mean = 8 years; 6 months) with SPD were tested on audiometry, the Listening in Spatialized Noise - Sentences Test (LiSN-S), and Listening in Spatialized Noise - Universal Test (LiSN-U). Teachers completed the Listening Inventory for Education - Revised Teacher Questionnaire (LIFE-R) and Auditory Processing Domains Questionnaire (APDQ). These measures were taken pre- and post-training with Sound Storm. RESULTS: Children's Sound Storm noise-to-signal ratio improved significantly and was positively correlated with the number of games they played. Eight of the nine children who completed at least 40% of the training were retested on the LiSN-S, LiSN-U, LIFE-R, and APDQ post-training. SPD was remediated in seven children according to the LiSN-S. All five children who were retested on the LiSN-U post-training showed spatial advantage scores within the normal range. Questionnaire results were mixed with only some children showing improved scores on the LIFE-R and APDQ. CONCLUSIONS: Sound Storm auditory training can be used in school with Aboriginal and Torres Strait Islander children to remediate SPD, however, it has its challenges. Maintaining the child's motivation to complete the training can be difficult. Additionally, the impacts of school holidays, events, and absences must be managed, as well as the impacts of the program on the child's school day.

Processamento auditivo central em crianças com disfonia: avaliação comportamental e eletrofisiológica / Central auditory processing in children with dysphonia: behavioral and electrophysiological assessment / Procesamiento auditivo central en niños com disfonía: evaluación comportamental y electrofisiológica

Introdução: O transtorno do processamento auditivo central pode ocorrer em concomitância com outras alterações, assim como a disfonia. Objetivo: Analisar os resultados obtidos na avaliação do processamento auditivo central em crianças com disfonia. Método: Estudo comparativo e de coorte transversal, constituído por 16 crianças de oito a 11 anos reunidas em dois grupos: o Grupo Estudo composto por sete crianças com disfonia funcional ou organofuncional, e o Grupo Controle por nove crianças sem queixas e alterações vocais. Foram realizados os seguintes procedimentos: anamnese, gravação vocal, avaliação perceptivo-auditiva da voz, laringoscopia, avaliação audiológica básica, avaliação do processamento auditivo por meio de testes comportamentais e eletrofisiológicos. Resultados: Houve diferença estatisticamente significativa entre os grupos para as etapas de atenção direcionada no teste Dicótico não verbal, etapa de humming no Padrão de frequência, limiar de detecção de gap e porcentagem de acertos no Gaps in Noise e para a latência do P300. Conclusão: A partir da análise dos resultados verificou-se que o grupo com disfonia apresentou transtorno do processamento auditivo central com alteração nas habilidades auditivas de figura-fundo para sons não verbais, ordenação e resolução temporal e latência do P300 prolongada, sugerindo também um déficit no processamento cognitivo da informação acústica.

Introduction: Central auditory processing disorder may occur in parallel with other dysfunctions, such as dysphonia. Objective: To investigate auditory processing results in children with dysphonia. Methods: Comparative and cross-sectional study of 16 children aged 8 to 11 years old, who were divided into two groups: a study group of 7 children with functional or organic and functional dysphonia; and a control group of 9 children with no vocal complaints or disorders. After clinical assessment voices were recorded and children underwent perceptive voice evaluation, audiogram, and auditory processing with behavioral and electrophysiological tests. Results: A statistically significant difference was found between the groups with regard to dichotic nonverbal listening tests, humming in the frequency pattern test, and gap detection threshold, in addition to the percentage of correct answers in gap-in-noise test and for the P300 latency. Conclusion: Children with dysphonia had central auditory processing disorder with changes in listening skills for figure-ground to nonverbal sounds, ordering and temporal resolution and P300 latency suggesting a concomitant impairment in cognitive processing of acoustic information.

Introducción: El trastorno de procesamiento auditivo central puede estar en comorbilidad con otras alteraciones como la disfonía. Objetivo: Analizar los resultados obtenidos en la evaluación del procesamiento auditivo central en niños con disfonía. Métodos: Estudio comparativo y de corte transversal, constituido por 16 niños entre 8 y 11 años de edad reunidos en dos grupos: el Grupo de Estudio compuesto por siete niños con disfonía funcional u orgánico funcional y el Grupo Control compuesto por nueve niños sin quejas ni alteraciones vocales. Fueron realizados los siguientes procedimientos: Anamnesis, grabación vocal, evaluación perceptivo auditiva de la voz, laringoscopia, evaluación audiológica básica, evaluación del procesamiento auditivo por medio de tests comportamentales y electrofisiológicos. Resultados: Hubo diferencia estadísticamente significativa entre los grupos para las etapas de atención direccionada en el test Dicótico no verbal, etapa de humming en el Patrón de frecuencia, limiar de detección de gap y porcentaje de aciertos en el Gaps in Noise y para la latencia del P300. Conclusión: A partir del análisis de los resultados se verificó que el grupo con disfonía presentó trastorno de procesamiento auditivo central con alteración en las habilidades auditivas de figura-fondo para los sonidos no verbales, ordenamiento, resolución temporal y latencia del P300 prolongada; sugiriendo también un déficit en el procesamiento cognitivo de la información acústica.

Abnormal development of auditory responses in the inferior colliculus of a mouse model of Fragile X Syndrome.

Sensory processing abnormalities are frequently associated with autism spectrum disorders, but the underlying mechanisms are unclear. Here we studied auditory processing in a mouse model of Fragile X Syndrome (FXS), a leading known genetic cause of autism and intellectual disability. Both humans with FXS and the Fragile X mental retardation gene (Fmr1) knockout (KO) mouse model show auditory hypersensitivity, with the latter showing a strong propensity for audiogenic seizures (AGS) early in development. Because midbrain abnormalities cause AGS, we investigated whether the inferior colliculus (IC) of the Fmr1 KO mice shows abnormal auditory processing compared with wild-type (WT) controls at specific developmental time points. Using antibodies against neural activity marker c-Fos, we found increased density of c-Fos+ neurons in the IC, but not auditory cortex, of Fmr1 KO mice at P21 and P34 following sound presentation. In vivo single-unit recordings showed that IC neurons of Fmr1 KO mice are hyperresponsive to tone bursts and amplitude-modulated tones during development and show broader frequency tuning curves. There were no differences in rate-level responses or phase locking to amplitude-modulated tones in IC neurons between genotypes. Taken together, these data provide evidence for the development of auditory hyperresponsiveness in the IC of Fmr1 KO mice. Although most human and mouse work in autism and sensory processing has centered on the forebrain, our new findings, along with recent work on the lower brainstem, suggest that abnormal subcortical responses may underlie auditory hypersensitivity in autism spectrum disorders.NEW & NOTEWORTHY Autism spectrum disorders (ASD) are commonly associated with sensory sensitivity issues, but the underlying mechanisms are unclear. This study presents novel evidence for neural correlates of auditory hypersensitivity in the developing inferior colliculus (IC) in Fmr1 knockout (KO) mouse, a mouse model of Fragile X Syndrome (FXS), a leading genetic cause of ASD. Responses begin to show genotype differences between postnatal days 14 and 21, suggesting an early developmental treatment window.

Binaural interaction component of the auditory brainstem response in children with autism spectrum disorder.

INTRODUCTION: There is ample evidence that auditory dysfunction is a common feature of autism spectrum disorder (ASD). Binaural interaction component (BIC) manifests binaural interaction and is valid and proven response which reflects ongoing binaural processing. OBJECTIVES: To investigate the differences in binaural interaction component of auditory brainstem response (ABR-BIC) between children with autism spectrum disorder (ASD) and normal peers and to correlate between ABR-BIC amplitudes and the acquired communication skills in ASD children. METHODS: ASD was diagnosed according to the criteria of 5th edition of diagnostic and statistical manual of mental disorders (DSM-V) and all children with ASD underwent test of acquired communication skills (TACS). Click evoked ABRs were elicited by left monaural, right monaural and binaural stimulation at intensity of 65 dBnHL in all participants. ABR-BIC was then calculated as the difference between the binaurally evoked ABR waveform and a predicted binaural waveform created by algebraically summing the left and right monaurally evoked ABRs. The difference in amplitudes that gives rise to ABR-BIC is at IV-VI waves. RESULTS: ABR-BIC amplitudes were demonstrated to be significantly reduced in the ASD group compared to the control group. There was significant positive correlation between ABR-BIC amplitude and the language and social scores in TACS. CONCLUSION: This study provided an objective evidence of binaural processing disorder in children with ASD.

Association between prism adaptation and auditory cues on spatial navigation in individuals with unilateral neglect.

BACKGROUND: Unilateral neglect is common among right-hemispheric stroke individuals and also concerns the auditory modality. Prism adaptation can improve auditory extinction during a dichotic listening task, but its effect during an ecological task has not been studied. OBJECTIVE: The main objective was to evaluate whether lateralized cueing before and after prism adaptation improved virtual spatial navigation of stroke individuals with visual and auditory unilateral neglect. Secondary objectives were to assess spatial memory and obtain a better understanding of the mechanism of the cueing treatment by using an eye-tracker. METHODS: We included 22 stroke individuals with left visual and auditory neglect, 14 individuals without neglect, and 12 healthy controls. After a familiarization task, participants underwent 3 evaluation sessions. Participants were first passively shown a path that they had then to actively reproduce by using a joystick. A path with lateralized beeping sounds indicating direction and a path without any sounds were followed in a randomized order. After prism adaptation, the participants followed a third path with lateralized beeping sounds. The time of navigation and number of trajectory mistakes were recorded. After navigation, spatial memory was assessed. Additionally, an eye-tracker was used during the navigation period. RESULTS: The navigational performance of participants with neglect was significantly better with than without auditory cues, especially after prism adaptation. With auditory cues, participants without neglect reached the navigational performance of healthy controls. The spatial memory of individuals with neglect was significantly lower with auditory cues. Eye-tracking analyses showed that participants with neglect made more saccades and looked longer at the right-square angles in the absence of auditory cues. CONCLUSIONS: This study demonstrates the positive effect of auditory cues in virtual spatial navigation of individuals with visual and auditory neglect and the potentiation of the help of cues after prism adaptation.

Systematic Audiological Assessment of Auditory Functioning in Patients With Parkinson's Disease.

Purpose Alterations in primary auditory functioning have been reported in patients with Parkinson's disease (PD). Despite the current findings, the pathophysiological mechanisms underlying these alterations remain unclear, and the effect of dopaminergic medication on auditory functioning in PD has been explored insufficiently. Therefore, this study aimed to systematically investigate primary auditory functioning in patients with PD by using both subjective and objective audiological measurements. Method In this case-control study, 25 patients with PD and 25 age-, gender-, and education-matched healthy controls underwent an audiological test battery consisting of tonal audiometry, short increment sensitivity index, otoacoustic emissions (OAEs), and speech audiometry. Patients with PD were tested in the on- and off-medication states. Results Increased OAE amplitudes were found when patients with PD were tested without dopaminergic medication. In addition, speech audiometry in silence and multitalker babble noise demonstrated higher phoneme scores for patients with PD in the off-medication condition. The results showed no differences in auditory functioning between patients with PD in the on-medication condition and healthy controls. No effect of disease stage or motor score was evident. Conclusions This study provides evidence for a top-down involvement in auditory processing in PD at both central and peripheral levels. Most important, the increase in OAE amplitude in the off-medication condition in PD is hypothesized to be linked to a dysfunction of the olivocochlear efferent system, which is known to have an inhibitory effect on outer hair cell functioning. Future studies may clarify whether OAEs may facilitate an early diagnosis of PD.

Neural architectures of music - Insights from acquired amusia.

The ability to perceive and produce music is a quintessential element of human life, present in all known cultures. Modern functional neuroimaging has revealed that music listening activates a large-scale bilateral network of cortical and subcortical regions in the healthy brain. Even the most accurate structural studies do not reveal which brain areas are critical and causally linked to music processing. Such questions may be answered by analysing the effects of focal brain lesions in patients´ ability to perceive music. In this sense, acquired amusia after stroke provides a unique opportunity to investigate the neural architectures crucial for normal music processing. Based on the first large-scale longitudinal studies on stroke-induced amusia using modern multi-modal magnetic resonance imaging (MRI) techniques, such as advanced lesion-symptom mapping, grey and white matter morphometry, tractography and functional connectivity, we discuss neural structures critical for music processing, consider music processing in light of the dual-stream model in the right hemisphere, and propose a neural model for acquired amusia.

Are basic auditory processes involved in source-monitoring deficits in patients with schizophrenia?

Patients with schizophrenia (SZ) display deficits in both basic non-verbal auditory processing and source-monitoring of speech. To date, the contributions of basic auditory deficits to higher-order cognitive impairments, such as source-monitoring, and to clinical symptoms have yet to be elucidated. The aim of this study was to investigate the deficits and relationships between basic auditory functions, source-monitoring performances, and clinical symptom severity in SZ. Auditory processing of 4 psychoacoustic features (pitch, intensity, amplitude, length) and 2 types of source-monitoring (internal and reality monitoring) performances were assessed in 29 SZ and 29 healthy controls. Clinical symptoms were evaluated in patients with the Positive And Negative Syndrome Scale. Compared to the controls, SZ individuals in showed significant reductions in both global basic auditory processing (p < .0005, d = 1.16) and source-monitoring (p < .0005, d = 1.24) abilities. Both deficits correlated significantly in patients and across groups (all p < .05). Pitch processing skills were negatively correlated with positive symptom severity (r = -0.4, p < .05). A step-wise regression analysis showed that pitch discrimination was a significant predictor of source-monitoring performance. These results suggest that cognitive mechanisms associated with the discrimination of basic auditory features are most compromised in patients with source-monitoring disability. Basic auditory processing may index pathophysiological processes that are critical for optimal source-monitoring in schizophrenia and that are involved in positive symptoms.