Southern Illinois University Carbondale, Department of Psychology, Carbondale, IL 62091, USA.
Child Neuropsychol. 2009 Sep;15(5):485-506. doi: 10.1080/09297040902748218.
Prior research has put forth at least four possible contributors to the verbal short-term memory (VSTM) deficit in children with developmental reading disabilities (RD): poor phonological awareness that affects phonological coding into VSTM, a less effective phonological store, slow articulation rate, and fewer/poorer quality long-term memory (LTM) representations. This project is among the first to test the four suppositions in one study. Participants included 18 children with RD and 18 controls. VSTM was assessed using Baddeley's model of the phonological loop. Findings suggest all four suppositions are correct, depending upon the type of material utilized. Children with RD performed comparably to controls in VSTM for common words but worse for less frequent words and nonwords. Furthermore, only articulation rate predicted VSTM for common words, whereas Verbal IQ and articulation rate predicted VSTM for less frequent words, and phonological awareness and articulation rate predicted VSTM for nonwords. Overall, findings suggest that the mechanism(s) used to code and store items by their meaning is intact in RD, and the deficit in VSTM for less frequent words may be a result of fewer/poorer quality LTM representations for these words. In contrast, phonological awareness and the phonological store are impaired, affecting VSTM for items that are coded phonetically. Slow articulation rate likely affects VSTM for most material when present. When assessing reading performance, VSTM predicted decoding skill but not word identification after controlling Verbal IQ and phonological awareness. Thus, VSTM likely contributes to reading ability when words are novel and must be decoded.
先前的研究提出了至少四个可能导致发育性阅读障碍（RD）儿童的言语短期记忆（VSTM）缺陷的因素：影响 VSTM 中语音编码的语音感知能力差、语音存储效果较差、发音速度较慢以及长期记忆（LTM）的表示形式较少/较差。本项目是第一个在一项研究中检验这四个假设的项目之一。参与者包括 18 名 RD 儿童和 18 名对照组。使用 Baddeley 的语音环路模型评估 VSTM。研究结果表明，这四个假设都是正确的，这取决于所使用的材料类型。对于常见单词，RD 儿童在 VSTM 中的表现与对照组相当，但对于较少见的单词和非单词，表现则较差。此外，只有发音速度可以预测常见单词的 VSTM，而言语智商和发音速度可以预测较少见单词的 VSTM，而语音感知和发音速度可以预测非单词的 VSTM。总体而言，研究结果表明，在 RD 中，用于通过意义对项目进行编码和存储的机制完好无损，并且对于较少见单词的 VSTM 缺陷可能是由于这些单词的 LTM 表示形式较少/较差。相比之下，语音感知和语音存储受到损害，影响了通过语音编码的项目的 VSTM。发音速度较慢很可能会在大多数情况下影响 VSTM。在评估阅读表现时，在控制言语智商和语音感知后，VSTM 预测解码技能，但不预测单词识别。因此，当单词较新且必须进行解码时，VSTM 可能有助于阅读能力。
