Eira Jansson-Verkasalo

Deficient auditory processing in children with Asperger Syndrome, as indexed by event-related potentials.

Asperger Syndrome (AS) is characterized by normal language development but deficient understanding and use of the intonation and prosody of speech. While individuals with AS report difficulties in auditory perception, there are no studies addressing auditory processing at the sensory level. In this study, event-related potentials (ERP) were recorded for syllables and tones in children with AS and in their control counterparts. Children with AS displayed abnormalities in transient sound-feature encoding, as indexed by the obligatory ERPs, and in sound discrimination, as indexed by the mismatch negativity. These deficits were more severe for the tone stimuli than for the syllables. These results indicate that auditory sensory processing is deficient in children with AS, and that these deficits might be implicated in the perceptual problems encountered by children with AS.

Neurophysiologic correlates of deficient phonological representations and object naming in prematurely born children.

OBJECTIVE The aim of this follow-up study was to evaluate the development of object naming ability and auditory processing in prematurely born children. Furthermore, we investigated whether the mismatch negativity (MMN) parameters at the age of 4 years correlate with the MMN parameters and naming ability at the age of 6 years. METHODS Twelve very low birth weight (VLBW) preterm children (mean age 5 years 7 months) and matched controls were studied. Object naming was measured by the Boston naming test. Auditory event-related potentials (ERPs), especially the MMN, were recorded for Finnish syllables (standard /taa/; deviants /ta/ and /kaa/) in an oddball paradigm. RESULTS VLBW preterm children scored significantly lower in the object naming test than their controls. The MMN amplitude for consonant change was significantly smaller in the preterm group compared to the controls. The MMN amplitude at the age of 4 years correlated with the MMN amplitude at the age of 6 years. Furthermore, absence of the MMN at the age of 4 years predicted naming difficulties at the age of 6 years. CONCLUSIONS VLBW preterm children with a difficulty to preattentively discriminate changes in syllables, as indexed by the diminished change detection response, MMN, seem to have sustained naming difficulty. Therefore, it is reasonable to record the MMN along with the language development from infancy, in order to identify the children at risk for language deficiencies and to provide appropriate rehabilitation.

Atypical pattern of discriminating sound features in adults with Asperger syndrome as reflected by the mismatch negativity.

Asperger syndrome, which belongs to the autistic spectrum of disorders, is characterized by deficits of social interaction and abnormal perception, like hypo- or hypersensitivity in reacting to sounds and discriminating certain sound features. We determined auditory feature discrimination in adults with Asperger syndrome with the mismatch negativity (MMN), a neural response which is an index of cortical change detection. We recorded MMN for five different sound features (duration, frequency, intensity, location, and gap). Our results suggest hypersensitive auditory change detection in Asperger syndrome, as reflected in the enhanced MMN for deviant sounds with a gap or shorter duration, and speeded MMN elicitation for frequency changes.

Atypical perceptual narrowing in prematurely born infants is associated with compromised language acquisition at 2 years of age

BackgroundEarly auditory experiences are a prerequisite for speech and language acquisition. In healthy children, phoneme discrimination abilities improve for native and degrade for unfamiliar, socially irrelevant phoneme contrasts between 6 and 12 months of age as the brain tunes itself to, and specializes in the native spoken language. This process is known as perceptual narrowing, and has been found to predict normal native language acquisition. Prematurely born infants are known to be at an elevated risk for later language problems, but it remains unclear whether these problems relate to early perceptual narrowing. To address this question, we investigated early neurophysiological phoneme discrimination abilities and later language skills in prematurely born infants and in healthy, full-term infants.ResultsOur follow-up study shows for the first time that perceptual narrowing for non-native phoneme contrasts found in the healthy controls at 12 months was not observed in very prematurely born infants. An electric mismatch response of the brain indicated that whereas full-term infants gradually lost their ability to discriminate non-native phonemes from 6 to 12 months of age, prematurely born infants kept on this ability. Language performance tested at the age of 2 years showed a significant delay in the prematurely born group. Moreover, those infants who did not become specialized in native phonemes at the age of one year, performed worse in the communicative language test (MacArthur Communicative Development Inventories) at the age of two years. Thus, decline in sensitivity to non-native phonemes served as a predictor for further language development.ConclusionOur data suggest that detrimental effects of prematurity on language skills are based on the low degree of specialization to native language early in development. Moreover, delayed or atypical perceptual narrowing was associated with slower language acquisition. The results hence suggest that language problems related to prematurity may partially originate already from this early tuning stage of language acquisition.

Language abilities of children with Asperger syndrome.

Current diagnostic taxonomies (ICD-10, DSM-IV) emphasize normal acquisition of language in Asperger syndrome (AS). Although many linguistic sub-skills may be fairly normal in AS there are also contradictory findings. There are only few studies examining language skills of children with AS in detail. The aim of this study was to study language performance in children with AS and their age, sex and IQ matched controls. Children with AS had significantly lower scores in the subtest of Comprehension of Instructions. Results showed that although many linguistic skills may develop normally, comprehension of language may be affected in children with AS. The results suggest that receptive language processes should be studied in detail in children with AS.

Speech-feature discrimination in children with Asperger syndrome as determined with the multi-feature mismatch negativity paradigm

OBJECTIVE Asperger syndrome, belonging to the autistic spectrum of disorders, involves deficits in social interaction and prosodic use of language but normal development of formal language abilities. Auditory processing involves both hyper- and hypoactive reactivity to acoustic changes. METHODS Responses composed of mismatch negativity (MMN) and obligatory components were recorded for five types of deviations in syllables (vowel, vowel duration, consonant, syllable frequency, syllable intensity) with the multi-feature paradigm from 8-12-year old children with Asperger syndrome. RESULTS Children with Asperger syndrome had larger MMNs for intensity and smaller MMNs for frequency changes than typically developing children, whereas no MMN group differences were found for the other deviant stimuli. Furthermore, children with Asperger syndrome performed more poorly than controls in Comprehension of Instructions subtest of a language test battery. CONCLUSIONS Cortical speech-sound discrimination is aberrant in children with Asperger syndrome. This is evident both as hypersensitive and depressed neural reactions to speech-sound changes, and is associated with features (frequency, intensity) which are relevant for prosodic processing. SIGNIFICANCE The multi-feature MMN paradigm, which includes variation and thereby resembles natural speech hearing circumstances, suggests abnormal pattern of speech discrimination in Asperger syndrome, including both hypo- and hypersensitive responses for speech features.

Similarities in the phenotype of the auditory neural substrate in children with Asperger syndrome and their parents

Asperger syndrome (AS) is a developmental disorder of brain function characterized by deficits in social interaction including difficulties in understanding emotional expressions. Children with AS share some of the behavioural characteristics with their parents and AS seems to run particularly in the male members of the same families. The aim of the present study was to determine whether similarities could be found between children with AS and their parents at central auditory processing. It was found that in children with AS the sound encoding, as reflected by the exogenous components of event‐related potentials, was similarly abnormal as in both their mothers and fathers. However, their abnormal cortical auditory discrimination, as indexed by the prolonged latency of the mismatch negativity, resembled that of their fathers but not that of their mothers. The present results suggest that complex genetic mechanisms may contribute to auditory abnormalities encountered in children with AS.

Deficient speech-sound processing, as shown by the electrophysiologic brain mismatch negativity response, and naming ability in prematurely born children

Very low birth weight (VLBW, <1500 g) preterm birth has been associated with anatomic abnormalities in brain development and cognitive and language disorders. We examined object naming ability, and an electrophysiologic index of auditory sensory discrimination of speech sounds (the mismatch negativity, MMN) in 4-year-old VLBW prematurely born children. We found that half of the VLBW children were inferior to their controls in the object naming ability. Also the MMN amplitudes were smaller in the preterm group as compared with the controls. Further, the MMN amplitude varied as a function of childrens performance on object naming, such that the weaker object-naming performance of the preterm group was paralleled by the diminished MMN amplitudes. Therefore, difficulties in auditory discrimination seem to be implicated in language difficulties encountered in VLBW prematurely born children.

Auditory stream segregation in children with Asperger syndrome

Individuals with Asperger syndrome (AS) often have difficulties in perceiving speech in noisy environments. The present study investigated whether this might be explained by deficient auditory stream segregation ability, that is, by a more basic difficulty in separating simultaneous sound sources from each other. To this end, auditory event-related brain potentials were recorded from a group of school-aged children with AS and a group of age-matched controls using a paradigm specifically developed for studying stream segregation. Differences in the amplitudes of ERP components were found between groups only in the stream segregation conditions and not for simple feature discrimination. The results indicated that children with AS have difficulties in segregating concurrent sound streams, which ultimately may contribute to the difficulties in speech-in-noise perception.

Corrigendum to "Auditory stream segregation in children with Asperger syndrome" [Biol. Psychol. 82 (2009) 301-307]

Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, P.O. Box 9, Helsinki FIN-00014, Finland Department of Child Neurology, Helsinki University Central Hospital, Finland Department of Neuroscience, Albert Einstein College of Medicine, USA Faculty of Humanities, Logopedics, University of Oulu, Finland Department of Clinical Neurophysiology, Oulu University Hospital, Finland Neuropsychiatric Rehabilitation and Medical Centre NeuroMental, Helsinki, Finland