Auditory processing and combination of distinctive features in speech acquisition in children with phonological disorders
CONCLUSION: The results obtained in the SSW and Dichotic Listening Test showed a deficit in the abilities of complex temporal order and figure-ground, as well as lagged sensorial memory. These deficits might jeopardize the acquisition of the features described.
The cognition of nonverbal sounds in dementia has been relatively little explored. Here we undertook a systematic study of nonverbal sound processing in patient groups with canonical dementia syndromes comprising clinically diagnosed typical amnestic Alzheimer’s disease (AD; n = 21), progressive nonfluent aphasia (PNFA; n = 5), logopenic progressive aphasia (LPA; n = 7) and aphasia in association with a progranulin gene mutation (GAA; n = 1), and in healthy age-matched controls (n = 20). Based on a cognitive framework treating complex sounds as ‘auditory objects’, we designed a novel neuropsychological battery to probe auditory object cognition at early perceptual (sub-object), object representational (apperceptive) and semantic levels. All patients had assessments of peripheral hearing and general neuropsychological functions in addition to the experimental auditory battery. Whilst a number of aspects of auditory object analysis were impaired across patient groups and were influenced by general executive (working memory) capacity, certain auditory deficits had some specificity for particular dementia syndromes. Patients with AD had a disproportionate deficit of auditory apperception but preserved timbre processing. Patients with PNFA had salient deficits of timbre and auditory semantic processing, but intact auditory size and apperceptive processing. Patients with LPA had a generalised auditory deficit that was influenced by working memory function. In contrast, the patient with GAA showed substantial preservation of auditory function, but a mild deficit of pitch direction processing and a more severe deficit of auditory apperception. The findings provide evidence for separable stages of auditory object analysis and separable profiles of impaired auditory object cognition in different dementia syndromes.
N1, P2 and T-complex of the auditory brain event-related potentials to tones with varying rise times in adults with and without dyslexia
Dyslexia is a learning difficulty affecting the acquisition of fluent reading and spelling skills due to poor phonological processing. Underlying deficits in processing sound rise time have also been found in children and adults with dyslexia. However, the neural basis for these deficits is unknown. In the present study event-related potentials were used to index neural processing and examine the effect of rise time manipulation on the obligatory N1, T-complex and P2 responses in English speaking adults with and without dyslexia. The Tb wave of the T-complex showed differences between groups, with the amplitudes for Tb becoming less negative with increased rise time for the participants with dyslexia only. Frontocentral N1 and P2 did not show group effects. Enhanced Tb amplitude that is modulated by rise time could indicate altered neural networks at the lateral surface of the superior temporal gyrus in adults with dyslexia.
Conclusion: Children with GJB2-related deafness benefit from cochlear implantation to the same extent as those with non-GJB2-related deafness.
from the Journal of Laryngology and Otology
CONCLUSION: The CAP tests used in this study indicated their reliability through the test-retest.
Speech processing skills go through intensive development during mid-childhood, providing basis also for literacy acquisition. The sequence of auditory cortical processing of speech has been characterized in adults, but very little is known about the neural representation of speech sound perception in the developing brain. We used whole-head magnetoencephalography (MEG) to record neural responses to speech and nonspeech sounds in first-graders (7-8-year-old) and compared the activation sequence to that in adults. In children, the general location of neural activity in the superior temporal cortex was similar to that in adults, but in the time domain the sequence of activation was strikingly different. Cortical differentiation between sound types emerged in a prolonged response pattern at about 250 ms after sound onset, in both hemispheres, clearly later than the corresponding effect at about 100 ms in adults that was detected specifically in the left hemisphere. Better reading skills were linked with shorter-lasting neural activation, speaking for interdependence of the maturing neural processes of auditory perception and developing linguistic skills. This study uniquely utilized the potential of MEG in comparing both spatial and temporal characteristics of neural activation between adults and children. Besides depicting the group-typical features in cortical auditory processing, the results revealed marked interindividual variability in children
from Human Brain Mapping
The patients in our sample showed changes in overall severity, strain, loudness, and instability values, and reductions in F0 and its variability. On comparing the variation of results between the groups, we were able to prove in our study that implant recipients postlingually deaf adults (experimental group), without specific vocal rehabilitation, differed from nonrecipients (control group) in loudness and F0 variability sustained vowel /a/ in male participants.
from the Journal of Voice
Phonological Short term memory in deaf children fitted with a cochlear implant: effects of phonological similarity, word lenght and lipreading cues
Phonological short-term memory (pSTM), or the ability to hold information in mind for a few seconds, is investigated in deaf children fitted with a cochlear implant (CI children) before the age of 3 years, in the framework of Baddeley’s model. Results show that, compared to their age-matched hearing controls, CI children are delayed in the development of their pSTM capacity, and exhibit reduced effect of phonological similarity (PSE) and word length (WLE). However, when CI children are matched for pSTM capacity with younger NH children, the difference regarding PSE and WLE disappear. The CI children do not produce more order errors than NH children. Taken together, the results indicate normal resources of functioning of pSTM. The reasons for the shorter pSTM span in CI children are discussed.
CONCLUSION: subjects from the dyslexic group presented different patterns of (central) auditory processing disorder, with greater alteration in the tests that evaluate the temporal processing when compared to the tests that evaluate other auditory abilities.
What models of verbal working memory can learn from phonological theory: Decomposing the phonological similarity effect
Despite developments in phonology over the last few decades, models of verbal working memory make reference to phoneme-sized phonological units, rather than to the features of which they are composed. This study investigates the influence on short-term retention of such features by comparing the serial recall of lists of syllables with varying types and levels of similarity in their onset consonants. Lists are (a) dissimilar (/fa–na–ga/) (b) acoustically similar (/pa-ta-ka/) or (c) articulatorily similar (/da–la–za/). When no overt articulation is required, we find no decrease in performance for articulatorily similar items as compared to the dissimilar list. However, we are able to show that acoustic similarity clearly impairs recall. It is only when participants recall the lists orally, that performance is impaired for both types of similar lists. These results have implications for accounts of the phonological similarity effect in particular and of verbal working memory in general.
from the Journal of Memory and Language
The aim of this study was to present the results obtained in the auditory processing evaluation of a patient with neurofibromatosis type 1. Although the patient presented normal peripheral hearing, auditory processing deficits were identified in several abilities. This finding, described for the first time in neurofibromatosis, might help to explain the cognitive and learning disabilities broadly described for this common genetic disorder.
CONCLUSION: The presence of hearing loss increased the gap detection thresholds and lowered the percentage of correct responses on the Gaps-in-Noise test.
CONCLUSION: the GIN test identified deficit in the hearing skill of temporal resolution in patients with tinnitus. In the studied age group (21 to 45 years) there was no correlation between age and the results obtained in the GIN test.
CONCLUSION: prior basic knowledge of English did not enhance general learning (improvement in pronunciation) of the second language, however, it improved the ability of temporal processing in the used test.
CONCLUSION: adolescents exposed to metallic mercury presented a lower performance on most of the auditory processing tests when compared to those who had no history of exposure to mercury. The main deficit found in the study was related to difficulty in distinguishing successive brief sounds.