Comorbidity and cognitive overlap between developmental dyslexia and congenital amusia.

This study investigated whether there is a co-occurrence between developmental dyslexia and congenital amusia in adults. First, a database of online musical tests on 18,000 participants was analysed. Self-reported dyslexic participants performed significantly lower on melodic skills than matched controls, suggesting a possible link between reading and musical disorders. In order to test this relationship more directly, we evaluated 20 participants diagnosed with dyslexia, 16 participants diagnosed with amusia, and their matched controls, with a whole battery of literacy (reading, fluency, spelling), phonological (verbal working memory, phonological awareness) and musical tests (melody, rhythm and metre perception, incidental memory). Amusia was diagnosed in six (30%) dyslexic participants and reading difficulties were found in four (25%) amusic participants. Thus, the results point to a moderate comorbidity between amusia and dyslexia. Further research will be needed to determine what factors at the neural and/or cognitive levels are responsible for this co-occurrence.

Pitch-Responsive Cortical Regions in Congenital Amusia.

Congenital amusia is a lifelong deficit in music perception thought to reflect an underlying impairment in the perception and memory of pitch. The neural basis of amusic impairments is actively debated. Some prior studies have suggested that amusia stems from impaired connectivity between auditory and frontal cortex. However, it remains possible that impairments in pitch coding within auditory cortex also contribute to the disorder, in part because prior studies have not measured responses from the cortical regions most implicated in pitch perception in normal individuals. We addressed this question by measuring fMRI responses in 11 subjects with amusia and 11 age- and education-matched controls to a stimulus contrast that reliably identifies pitch-responsive regions in normal individuals: harmonic tones versus frequency-matched noise. Our findings demonstrate that amusic individuals with a substantial pitch perception deficit exhibit clusters of pitch-responsive voxels that are comparable in extent, selectivity, and anatomical location to those of control participants. We discuss possible explanations for why amusics might be impaired at perceiving pitch relations despite exhibiting normal fMRI responses to pitch in their auditory cortex: (1) individual neurons within the pitch-responsive region might exhibit abnormal tuning or temporal coding not detectable with fMRI, (2) anatomical tracts that link pitch-responsive regions to other brain areas (e.g., frontal cortex) might be altered, and (3) cortical regions outside of pitch-responsive cortex might be abnormal. The ability to identify pitch-responsive regions in individual amusic subjects will make it possible to ask more precise questions about their role in amusia in future work.

Auditory Processing in Children with Migraine: A Controlled Study.

Background This study aimed to investigate central auditory processing performance in children with migraine and compared with controls without headache. Methods Twenty-eight children of both sexes, aged between 8 and 12 years, diagnosed with migraine with and without aura, and a control group of the same age range and with no headache history, were included. Gaps-in-noise (GIN), duration pattern test (DPT), synthetic sentence identification (SSI) test, and nonverbal dichotic test (NVDT) were used to assess central auditory processing performance. Results Children with migraine performed significantly worse in DPT, SSI test, and NVDT when compared with controls without headache; however, no significant differences were found in the GIN test. Conclusions Children with migraine demonstrate impairment in the physiologic mechanism of temporal processing and selective auditory attention. In our short communication, migraine could be related to impaired central auditory processing in children.

Classifying song and speech: effects of focal temporal lesions and musical disorder.

Song and speech represent two auditory categories the brain usually classifies fairly easily. Functionally, this classification ability may depend to a great extent on characteristic features of pitch patterns present in song melody and speech prosody. Anatomically, the temporal lobe (TL) has been discussed as playing a prominent role in the processing of both. Here we tested individuals with congenital amusia and patients with unilateral left and right TL lesions in their ability to categorize song and speech. In a forced-choice paradigm, specifically designed auditory stimuli representing sung, spoken and "ambiguous" stimuli (being perceived as "halfway between" song and speech), had to be classified as either "song" or "speech". Congenital amusics and TL patients, contrary to controls, exhibited a surprising bias to classifying the ambiguous stimuli as "song" despite their apparent deficit to correctly process features typical for song. This response bias possibly reflects a strategy where, based on available context information (here: forced choice for either speech or song), classification of non-processable items may be achieved through elimination of processable classes. This speech-based strategy masks the pitch processing deficit in congenital amusics and TL lesion patients.

A long-term follow-up of children and adolescents referred for assessment of auditory processing disorder.

OBJECTIVE: This study investigated whether young adults (between 18 and 30 years at the time of the project) who were assessed for auditory processing disorder (APD) in childhood (between 7 and 16 years) experience persistence of listening and communication difficulties. DESIGN: Participants completed a mixed methods questionnaire focusing on common areas of complaint in APD and two open-ended questions exploring participants' past and present experiences with listening and communication difficulties. STUDY SAMPLE: Ninety-seven of the 722 potential participants returned completed questionnaires, of whom 66 had been diagnosed with APD (APD group) at the time of their auditory processing assessment and 31 had not met diagnostic criteria (NAPD group) at that time. RESULTS: Substantial commonality was noted in the reported listening and communication difficulties between the APD and NAPD participants. Volunteered comments aggregated into four major content themes which included: listening and communication difficulties; participants' sense of self; change; and participation. Members of the APD group reported greater communication difficulty than NAPD group members, irrespective of environmental listening conditions. CONCLUSIONS: Young adults with a prior referral for, and in some cases a diagnosis of, APD as children continue to experience auditory processing difficulties across a range of daily situations.

[Symptoms and diagnosis of auditory processing disorder]. / Symptome und Diagnosestellung auditiver Verarbeitungs- und Wahrnehmungsstörungen.

The definition of an auditory processing disorder (APD) is based on impairments of auditory functions. APDs are disturbances in processes central to hearing that cannot be explained by comorbidities such as attention deficit or language comprehension disorders. Symptoms include difficulties in differentiation and identification of changes in time, structure, frequency and intensity of sounds; problems with sound localization and lateralization, as well as poor speech comprehension in adverse listening environments and dichotic situations. According to the German definition of APD (as opposed to central auditory processing disorder, CAPD), peripheral hearing loss or cognitive impairment also exclude APD. The diagnostic methodology comprises auditory function tests and the required diagnosis of exclusion. APD is diagnosed if a patient's performance is two standard deviations below the normal mean in at least two areas of auditory processing. The treatment approach for an APD depends on the patient's particular deficits. Training, compensatory strategies and improvement of the listening conditions can all be effective.

What is the deficit in phonological processing deficits: auditory sensitivity, masking, or category formation?

Although children with language impairments, including those associated with reading, usually demonstrate deficits in phonological processing, there is minimal agreement as to the source of those deficits. This study examined two problems hypothesized to be possible sources: either poor auditory sensitivity to speech-relevant acoustic properties, mainly formant transitions, or enhanced masking of those properties. Adults and 8-year-olds with and without phonological processing deficits (PPD) participated. Children with PPD demonstrated weaker abilities than children with typical language development (TLD) in reading, sentence recall, and phonological awareness. Dependent measures were word recognition, discrimination of spectral glides, and phonetic judgments based on spectral and temporal cues. All tasks were conducted in quiet and in noise. Children with PPD showed neither poorer auditory sensitivity nor greater masking than adults and children with TLD, but they did demonstrate an unanticipated deficit in category formation for nonspeech sounds. These results suggest that these children may have an underlying deficit in perceptually organizing sensory information to form coherent categories.

Effect of nonlinguistic auditory training on phonological and reading skills.

OBJECTIVE: To analyze the effect of nonverbal auditory training on reading and phonological awareness tasks in children with dyslexia and the effect of age in relation to post-training learning considering the ages from 7 to 14. METHODS: In experiment 1, one group with dyslexia (total = 12) was trained and compared with a group of untrained dyslexic subjects (total = 28). In experiment 2, the performance of the trained dyslexic group (total = 18) was compared at three different moments: 2 months before, at the beginning, and at the end of training. Training was carried out for 2 months using a computer program responsible for training discrimination skills. RESULTS: The group receiving nonverbal auditory training demonstrated significant improvements (mainly for the group from 7 to 10 years old), not only in the nonverbal auditory skills trained (p < 0.001), but also in phonological awareness syllable tasks (synthesis, segmentation, manipulation and syllable transposition) in experiment 1 (p < 0.003), and phonemic tasks (p < 0.001) and text reading (p < 0.001) in experiment 2. CONCLUSION: The results suggest a link between verbal and nonverbal skills, in addition to corroborating studies regarding the existence of a critical learning period.

Electrophysiological Evidence of Auditory and Cognitive Processing Deficits in Parkinson Disease.

BACKGROUND: Parkinson's disease (PD) patients are at increased risk for central auditory processing (CAP) deficits and cognitive dysfunction. However, behavioral assessments of CAP and cognitive processing used in a previous study by our research team found few significant differences in performance between early-stage PD patients and age-matched control subjects. The objective of this study is to use auditory event-related potentials (AERPs) to compare CAP and cognitive functions in a population of PD patients with a group of age-matched control subjects. METHODS: AERPs in response to tonal and speech stimuli were recorded from 35 adults who had a medical diagnosis of PD (23 males and 12 females; mean age = 66.9 ± s.d.11.2 years), and 35 age-matched control subjects who did not have PD or any other neurological disorders (31 males and 4 females; mean age = 65.4 ± s.d.12.3 years). Auditory stimuli included pure tones (500 and 1000 Hz) to elicit the P300 response and a dichotic digits paradigm to elicit the N200 processing negativity. RESULTS: Compared to control subjects, PD patients exhibited significantly longer latencies of P300 and N200 components and smaller amplitude N200 components. Latency and amplitude of the N200 component were significantly correlated with participants' age. N200 amplitude was correlated with results from the Rey Auditory Verbal Learning Test (RAVLT) of cognitive ability. Latency of the P300 and amplitude of the N200 components were significantly correlated with results from the Spatial Release From Masking (SRM) behavioral CAP assessment. CONCLUSIONS: AERP assessments used in this study appear to be sensitive indicators of CAP and cognitive deficits exhibited by early-stage PD patients. While few significant differences in performance on behavioral CAP and cognitive tests were previously observed between this population of PD patients and age-matched control subjects, N200 and P300 components recorded in the present study revealed impaired neural processing by the PD group.

Biological changes in auditory function following training in children with autism spectrum disorders.

BACKGROUND: Children with pervasive developmental disorders (PDD), such as children with autism spectrum disorders (ASD), often show auditory processing deficits related to their overarching language impairment. Auditory training programs such as Fast ForWord Language may potentially alleviate these deficits through training-induced improvements in auditory processing. METHODS: To assess the impact of auditory training on auditory function in children with ASD, brainstem and cortical responses to speech sounds presented in quiet and noise were collected from five children with ASD who completed Fast ForWord training. RESULTS: Relative to six control children with ASD who did not complete Fast ForWord, training-related changes were found in brainstem response timing (three children) and pitch-tracking (one child), and cortical response timing (all five children) after Fast ForWord use. CONCLUSIONS: These results provide an objective indication of the benefit of training on auditory function for some children with ASD.

Paradoxical and labile medial olivocochlear functioning as a potential marker of auditory processing disorder in a child with learning disabilities.

INTRODUCTION: The medial olivocochlear system (MOCS) is composed of fibres projecting directly onto outer hair cells and plays a role in improving the signal-to-noise ratio. The MOCS can be evaluated by measuring suppression of the otoacoustic emissions evoked by contralateral acoustic stimulation. Dyslexic children present an increased probability of auditory processing disorder (APD). These children may present paradoxical MOCS dysfunction. CASE REPORT: We report the case of a dyslexic child with APD, who was severely disabled in a noisy environment. Audiometric tests were normal, and the central auditory assessment showed labile MOCS functioning that was not only ineffective, but also potentially deleterious, possibly accounting for this child's hearing impairment in a noisy environment. DISCUSSION: This case illustrates the importance of audiological assessment and objective investigation of MOCS function in children with a learning disability, especially with hearing difficulties in the presence of noise, in whom auditory training can be beneficial.

[Congenital amusia and its effects on non-musical skills]. / Amusia congénita y sus efectos en habilidades no musicales.

INTRODUCTION: Congenital amusia is a specific condition in which the individual is unable to recognise tonal variations in a piece of musical. This cannot be explained by a previous brain injury, hearing loss, cognitive deficit, socio-affective disorder or lack of environmental stimulation. The current estimated prevalence is 1.5% of the world population, with a significant genetic component among those who suffer from it. It has been claimed that certain cognitive abilities in the emotional, spatial and language fields may be affected in people with amusia. AIM: To review the literature describing the effects on non-musical skills that may coexist in individuals with congenital amusia. DEVELOPMENT: Several neuroimaging studies have observed morphological and functional changes in the temporal lobe, as well as in the white matter connections between the superior temporal gyrus and the inferior frontal gyrus. From these affected regions, there may be a deficit in cognitive skills related to adjacent areas. CONCLUSIONS: Congenital amusia has been associated with poor performance in different non-musical cognitive skills, such as visuospatial processing, language processing, reading difficulties, face recognition and emotional aspects.

TITLE: Amusia congénita y sus efectos en habilidades no musicales.Introducción. La amusia congénita es una condición específica en la que el individuo afectado es incapaz de reconocer variaciones tonales en las piezas musicales. Esto no puede explicarse por una lesión encefálica previa, una pérdida auditiva, un déficit cognitivo, un trastorno socioafectivo o una falta de estimulación ambiental. Actualmente se estima una prevalencia del 1,5% de la población mundial, con un importante componente genético entre los afectados. Se ha descrito que en las personas con amusia puede haber afectación de ciertas habilidades cognitivas en el campo emocional, espacial y del lenguaje. Objetivo. Revisar la bibliografía donde se describen los efectos en las habilidades no musicales que pueden coexistir en individuos con amusia congénita. Desarrollo. Varios estudios de neuroimagen han permitido observar cambios morfológicos y funcionales en el lóbulo temporal, así como en las conexiones de la sustancia blanca entre el giro temporal superior y el giro frontal inferior. Partiendo de estas regiones afectadas, podría existir un déficit en habilidades cognitivas relacionadas con áreas adyacentes. Conclusiones. La amusia congénita se ha relacionado con un pobre desempeño en diferentes habilidades cognitivas no musicales, como el procesamiento visuoespacial, el procesamiento del lenguaje, alteraciones de la lectura, el reconocimiento de rostros y aspectos emocionales.

Screening signs of auditory processing problem: does it distinguish attention deficit hyperactivity disorder subtypes in a clinical sample of children?

OBJECTIVES: The aim of this study is to survey parental report of screening signs of auditory processing problem in attention deficit hyperactivity disorder (ADHD) children and its association with gender and co-morbidity with oppositional defiant disorder (ODD) and separation anxiety (SAD). METHODS: 104 children and adolescents referrals to the child and adolescent psychiatry clinic were interviewed. The auditory processing problem checklist asked parents to indicate their child's reaction to sounds. It screens signs of two aspects of auditory processing problem including hypersensitivity to sounds (HES) (or auditory defensiveness) and hyposensitivity to sound (HOS) (under-registers). RESULTS: The mean age of the children was 8.5 (SD=1.8). Children with ODD had significantly higher HES, HOS and the whole checklist mean scores. Subtypes of ADHD were not associated with the auditory processing problems. CONCLUSIONS: ADHD children with ODD are likely to be at a significant risk for manifesting both of the auditory processing problem including defensiveness and auditory hyposensitivity to sounds. Auditory processing problems do not differentiate different subtypes of ADHD.

Central auditory processing development in adolescents with and without learning disabilities.

Auditory processing deficit (APD) is estimated to affect 5% of school-age children and adolescents, and 30-50% of those diagnosed with learning problems. The diagnosis and indeed the existence of APD, however, remain controversial. One reason for this controversy is that the factors contributing to normal variations in auditory processing and its development are poorly understood. To address the developmental issue, we compared the performance of younger (14 yr/o) and older (18 yr/o) adolescents on frequency discrimination, backward masking detection and gap detection using an oddball paradigm. Older adolescents had lower backward masking thresholds compared with younger adolescents, but the prolonged development of thresholds was not accompanied by a corresponding increase in performance consistency. The distribution of thresholds on all three tasks did not differ between typically developing adolescents and those diagnosed with learning disabilities. A questionnaire designed to tap difficulties in daily listening situations also failed to differentiate the two groups. These findings suggest that basing the diagnosis of APD on tests conducted with the oddball procedure requires the establishment of norms from large and age specific samples. They also suggest that the development of auditory sensory acuity in the general population is longer than typically assumed.

[Clinical characteristics and LGI1 gene mutation analysis on an autosomal dominant lateral temporal lobe epilepsy].

OBJECTIVE: To report the clinical and genetic study of a new Chinese family with autosomal dominant lateral temporal lobe epilepsy (ADLTE). METHODS: The living affected members underwent a full clinical, neurophysiological, electroencephalogram (EEG), and magnetic resonance imaging (MRI) study. Genetic analysis was performed by LGI1 DNA sequence analysis. RESULTS: The clinical feature of the patients was coincidence wall with the definition of ADLTE by International League Against Epilepsy in 2001. The living affected members had an adult or children onset of drug-responsive tonic-clonic seizures or complex partial seizures constantly preceded by auditory or visionary aura. Routine EEG revealed no focal abnormalities over both temporal regions. MRI detected no structural abnormality. Analysis of LGI1 gene showed no mutation in all affected members. CONCLUSION: This kindred has typical clinical manifestations of ADLTE. The pathogenesis has no association with mutation of the exons of LGI1 gene.

The co-occurrence of pitch and rhythm disorders in congenital amusia.

The most studied form of congenital amusia is characterized by a difficulty with detecting pitch anomalies in melodies, also referred to as pitch deafness. Here, we tested for the presence of associated deficits in rhythm processing, beat in particular, in pitch deafness. In Experiment 1, participants performed beat perception and production tasks with musical excerpts of various genres. The results show a beat finding disorder in six of the ten assessed pitch-deaf participants. In order to remove a putative interference of pitch variations with beat extraction, the same participants were tested with percussive rhythms in Experiment 2 and showed a similar impairment. Furthermore, musical pitch and beat processing abilities were correlated. These new results highlight the tight connection between melody and rhythm in music processing that can nevertheless dissociate in some individuals.

The Relationship of Cardiometabolic Risk and Auditory Processing among African Americans: The Jackson Heart Study.

OBJECTIVES: There is limited research in population-based studies on auditory processing. The purpose of this work is to determine the prevalence of auditory processing impairment in the Jackson Heart Study cohort and to identify potential relationships with cardiometabolic risk factors. STUDY DESIGN: Cross-sectional study. SETTING: Jackson Heart Study in Jackson, Mississippi. SUBJECTS: Participants of an all-African American cardiovascular study cohort (n = 1314). METHODS: The Quick Speech-in-Noise and Dichotic Digits, Double Pairs tests were used to assess auditory processing. Logistic regression and multinomial logistic regression models were used to examine how participants' cardiometabolic risk factors and audiologic characteristics were associated with speech perception in noise and binaural integration. RESULTS: Quick Speech-in-Noise and Dichotic Digits, Double Pairs testing showed a prevalence of auditory processing impairment in 69% and 71% of the cohort, respectively, which was significantly related to age, hearing thresholds, sex, and education level. With covariate adjustment in statistical models for age, sex, pure tone average, and education level, waist circumference, systolic blood pressure, and hypertension were statistically predictive of auditory processing impairment ( P < .05). CONCLUSION: The results suggest a high prevalence of auditory processing deficits in the Jackson Heart Study cohort. In addition, cardiometabolic and audiologic factors show a statistically significant independent relationship with auditory impairment measures.

Morphological features of the medial superior olive in autism.

Autism is a psychosocial disorder clinically characterized by social difficulties, impairment in communication skills and repetitive behavioral patterns. Despite the increasing reported incidence of autism, the neurobiology of this disorder is poorly understood. However, researchers have uncovered numerous structural anomalies in the brainstem, cerebellum and forebrain of autistic individuals and there is substantial support for the association of hearing deficits with autism. In an effort to discover an anatomical correlate for the functional auditory deficits found in autism, we examined the SOC, a group of brainstem nuclei that function in sound source localization, in post-mortem brain tissue from autistic individuals. The neurons of the medial superior olive (MSO), an SOC nucleus, display a precise geometric organization essential for detection of timing differences between the two ears. We examined the architecture of the MSO in five autistic brains (ages 8 to 32 years) and two age-matched controls (ages 26 and 29 years) and found a significant disruption in the morphology of MSO neurons in autistic brains, involving cell body shape and orientation. The results from this study provide evidence on the cellular level that may help to explain the hearing difficulties associated with autism.

Olanzapine improves deficient sensory inhibition in DBA/2 mice.

Most schizophrenia patients do not inhibit their P50 auditory evoked potential to the second of duplicate auditory stimuli, reflecting a failure to inhibit responses to irrelevant sensory input. Typical antipsychotic drugs do not improve this deficit while some atypical antipsychotics do. A previous study using an animal model, deficient P20-N40 (which corresponds to the human P50) inhibitory processing in DBA/2 mice found that sensory inhibition was improved by clozapine, the prototypical atypical antipsychotic, but not by haloperidol, a typical antipsychotic. The improvement after clozapine was mediated by alpha7 nicotinic receptors. The present study addresses whether another atypical antipsychotic, olanzapine, will also improve sensory inhibition deficits in the mouse model. In vivo electrophysiological recordings of the P20-N40 auditory evoked potential in anesthetized DBA/2 mice, which spontaneously exhibit a schizophrenia-like inhibitory processing deficit, were obtained after olanzapine alone (0.01, 0.033, 0.1, 0.33 mg/kg, IP) and the efficacious dose of olanzapine (0.033 mg/kg, IP) in combination with either the alpha7 nicotinic receptor antagonist alpha-bungarotoxin or the alpha4beta2 nicotinic receptor antagonist di-hydro-beta-erythroidine. All doses of olanzapine produced improved P20-N40 inhibitory processing in DBA/2 mice. The normalization observed after the 0.033 mg/kg dose of olanzapine was due to a selective decrease in response to the second auditory stimulus indicating an increase in inhibitory processing. This improvement was blocked by pre-administration of alpha-bungarotoxin but not di-hydro-beta-erythroidine. Like clozapine, olanzapine acts via alpha7 nicotinic receptors to elicit improved inhibitory processing of auditory stimuli.