Afshar Mohamad Reza, Ghorbani Ali, Rashedi Vahid, Jalilevand Nahid, Kamali Mohamad
Department of Speech Therapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran; Department of Speech Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
Department of Speech Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
Int J Pediatr Otorhinolaryngol. 2017 Oct;101:117-122. doi: 10.1016/j.ijporl.2017.07.034. Epub 2017 Jul 27.
The aim of this study was to compare working memory span in Persian-speaking preschool children with speech sound disorder (SSD) and their typically speaking peers. Additionally, the study aimed to examine Non-Word Repetition (NWR), Forward Digit Span (FDS) and Backward Digit Span (BDS) in four groups of children with varying severity levels of SSD.
The participants in this study comprised 35 children with SSD and 35 typically developing (TD) children -matched for age and sex-as a control group. The participants were between the age range of 48 and 72 months. Two components of working memory including phonological loop and central executive were compared between two groups. We used two tasks (NWR and FDS) to assess phonological loop component, and one task (BDS) to assess central executive component. Percentage of correct consonants (PCC) was used to calculate the severity of SSD.
Significant differences were observed between the two groups in all tasks that assess working memory (p < 0.001). In addition, the comparison of the phonological loop of working memory between the various severity groups indicated significant differences between different severities of both NWR and FDS tasks among the SSD children (p < 0.001). Nevertheless, comparison of the central executive between various severity groups, which was assessed with the BDS task, did not show any significant differences (p > 0.05). The result showed that PCC scores in TD children were associated with NWR (p < 0.001), FDS (p = 0.001), and BDS (p < 0.001). Furthermore, PCC scores in SSD children were associated with NWR and FDS (p < 0.001), but not with BDS (p > 0.05).
The working memory skills were weaker in SSD children, in comparison to TD children. In addition, children with varying levels of severity of SSD differed in terms of NWR and FSD, but not BDS.
本研究旨在比较患有语音障碍（SSD）的波斯语学龄前儿童与其正常说话的同龄人之间的工作记忆广度。此外，该研究旨在考察四组不同SSD严重程度的儿童的非词重复（NWR）、顺背数字广度（FDS）和倒背数字广度（BDS）。
本研究的参与者包括35名患有SSD的儿童和35名年龄和性别匹配的正常发育（TD）儿童作为对照组。参与者年龄在48至72个月之间。比较了两组之间工作记忆的两个组成部分，即语音回路和中央执行系统。我们使用两项任务（NWR和FDS）来评估语音回路组成部分，以及一项任务（BDS）来评估中央执行系统组成部分。使用正确辅音百分比（PCC）来计算SSD的严重程度。
在所有评估工作记忆的任务中，两组之间均观察到显著差异（p < 0.001）。此外，不同严重程度组之间工作记忆的语音回路比较表明，SSD儿童中NWR和FDS任务的不同严重程度之间存在显著差异（p < 0.001）。然而，用BDS任务评估的不同严重程度组之间的中央执行系统比较未显示任何显著差异（p > 0.05）。结果表明，TD儿童的PCC分数与NWR（p < 0.001）、FDS（p = 0.001）和BDS（p < 0.001）相关。此外，SSD儿童的PCC分数与NWR和FDS相关（p < 0.001），但与BDS无关（p > 0.05）。
与TD儿童相比，SSD儿童的工作记忆技能较弱。此外，不同SSD严重程度的儿童在NWR和FSD方面存在差异，但在BDS方面没有差异。
