How auditory temporal processing deficits relate to dyslexia

Abstract

Studies have shown that dyslexic children present a deficiency in the temporal processing of auditory stimuli applied in rapid succession. However, discussion continues concerning the way this deficiency can be influenced by temporal variables of auditory processing tests. Therefore, the purpose of the present study was to analyze by auditory temporal processing tests the effect of temporal variables such as interstimulus intervals, stimulus duration and type of task on dyslexic children compared to a control group. Of the 60 children evaluated, 33 were dyslexic (mean age = 10.5 years) and 27 were normal controls (mean age = 10.8 years). Auditory processing tests assess the abilities of discrimination and ordering of stimuli in relation to their duration and frequency. Results showed a significant difference in the average accuracy of control and dyslexic groups considering each variable (interstimulus intervals: 47.9 ± 5.5 vs 37.18 ± 6.0; stimulus duration: 61.4 ± 7.6 vs 50.9 ± 9.0; type of task: 59.9 ± 7.9 vs 46.5 ± 9.0) and the dyslexic group demonstrated significantly lower performance in all situations. Moreover, there was an interactive effect between the group and the duration of stimulus variables for the frequency-pattern tests, with the dyslexic group demonstrating significantly lower results for short durations (53.4 ± 8.2 vs 48.4 ± 11.1), as opposed to no difference in performance for the control group (62.2 ± 7.1 vs 60.6 ± 7.9). These results support the hypothesis that associates dyslexia with auditory temporal processing, identifying the stimulus-duration variable as the only one that unequally influenced the performance of the two groups.

Influence of memory, attention, IQ and age on auditory temporal processing tests: preliminary study

“…Currently, nonverbal auditory processing tests, such as Gaps-in-Noise (GIN) and Frequency Pattern, are widely used to evaluate the auditory temporal processing. The importance of using these tests is related to the hypothesis that attributes oral and/or written language disorders to a perceptual deficit, specifically to the auditory temporal processing (1)(2)(3)(4)(5)(6)(7) .…”

“…One of the issues considered when discussing the performance of children in auditory temporal processing tests is the variability of responses found (7,(8)(9)(10)(11)(12)(13)(14) . In a recently published study (14) , psychophysical tests involving frequency discrimination tasks were applied to groups of children without alterations, aged between 6 and 11 years.…”

Processamento auditivo (central) em crianças com dislexia: avaliação comportamental e eletrofisiológica

“…Despite the several researches corroborating the temporal processing theory (5)(6)(7)(8)(9) , there are controversies about these findings due to the difficulty in establishing a causal relation between the phonological processing and the auditory temporal processing (10,11) , besides the great individual variation in children's performance for this kind of auditory test (4,12,13) . Furthermore, there is the difficulty to evidence these disorders only by behavioral tests (14) .…”

Generalization of temporal order detection skill learning: two experimental studies of children with dyslexia

“…This hypothesis could explain the result of the studies conducted on children with dyslexia who did not show improvement of verbal skills (written language) after nonverbal auditory training in spite of improvement regarding the auditory tests applied (14)(15)(16)(17). This is due to the fact that there cannot be improvement of the verbal skills if there is no improvement of the perceptual skills related to auditory temporal processing, since this is considered to be the origin of reading problems detected in children with dyslexia (1)(2)(3)(4).…”

“…Published April 12, 2010. It has been shown that a deficit in temporal processing of auditory stimuli can be the basis for the reading problems of children with dyslexia (1)(2)(3)(4). More specifically, researchers have demonstrated a significantly worse performance in this group of children in a specific skill of auditory temporal processing, i.e., temporal order detection (4)(5)(6)(7). Temporal order detection skill refers to the processing of multiple auditory stimuli in their exact order of occurrence.…”