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J Bartling

Publications and source records attributed to J Bartling.

4 recordsLinked to original sources

Pre-attentive processing of auditory patterns in dyslexic human subjects.

It has been hypothesized that auditory temporal processing plays a major role in the aetiology of dyslexia. Event-related brain potentials (mismatch negativity, MMN) of auditory temporal processing were assessed in 15 dyslectic adults and 20 controls. A complex tonal pattern was used where the difference between standard and deviant stimuli was the temporal, not the frequency structure. Dyslexics had a significantly smaller MMN in the time window of 225-600 ms. This result shows that dyslexics have a significant pre-attentive deficit in processing of rapid temporal patterns suggesting that it may be the temporal information embedded in speech sounds, rather than phonetic information per se, that resulted in the attenuated MMN found in dyslexics in previous studies. MMN scalp topographies were similar for both groups, showing a maximum over fronto-central leads.

Acoustic Stimulation

Attenuated hemispheric lateralization in dyslexia: evidence of a visual processing deficit.

There is controversial evidence that deficits in the processing of low contrast and low spatial frequency stimuli are of importance in the pathogenesis of dyslexia. Fifteen adult dyslexics and 19 controls were examined using visual evoked potentials (VEP) at varying spatial frequencies (2 and 11.33 cpd) and contrasts (0.2, 0.4, 0.6, 0.8). Our results show that the amplitude of VEPs following different spatial frequencies and contrasts did not differentiate between dyslexics and controls. Further, we found significantly higher amplitudes of the P1 and P2 over the right occipital cortex. For the P2, this hemispheric asymmetry was not found in the dyslexic group suggesting a specific low level visual processing deficit in the right occipital region in dyslexia.

Adult

Auditory processing and dyslexia: evidence for a specific speech processing deficit.

In order to investigate the relationship between dyslexia and central auditory processing, 19 children with spelling disability and 15 controls at grades 5 and 6 were examined using a passive oddball paradigm. Mismatch negativity (MMN) was determined for tone and speech stimuli. While there were no group differences for the tone stimuli, we found a significantly attenuated MMN in the dyslexic group for the speech stimuli. This finding leads to the conclusion that dyslexics have a specific speech processing deficit at the sensory level which could be used to identify children at risk at an early age.

Acoustic Stimulation

Role of auditory temporal processing for reading and spelling disability.

The role of auditory temporal processing in reading and spelling was investigated in a sample of 30 children and one of 31 adults, using a gap-detection task with nonspeech stimuli. There was no evidence for a relationship between reading and spelling disability (dyslexia) and the gap-detection threshold. The results were discussed regarding the relevance for the popular hypothesis of an auditory temporal processing deficit underlying dyslexia.

Acoustic Stimulation