Laures-Gore Jacqueline, Marshall Rebecca Shisler, Verner Erin
Communication Disorders Program, Georgia State University.
Aphasiology. 2011 Jan 14;25(1):43-56. doi: 10.1080/02687031003714426.
Working memory (WM) limitations have been suggested as a significant source of the linguistic processing deficits observed in individuals with aphasia (IWA). Digits forward (DF) and digits backward (DB) span tasks are frequently used to study WM in both healthy and clinical populations. Unfortunately, only a handful of studies have explored digit span in IWA. AIMS: The purpose of the current study is to measure the DF and DB spans of IWA and compare their digit spans to a group with right brain damage, but no aphasia (RBD). Additionally, DF and DB span is compared within each group to determine if there is indeed a performance differential that may support the idea that DB is a more difficult WM task in these populations. METHODS AND PROCEDURES: Seventeen IWA and 14 individuals with RBD participated in a DF and DB span task. Modifications to the span tasks were implemented to accommodate language deficits. A series of two digits were orally presented to each participant continuing to a maximum of eight digits. There were seven trials per digit series. Participants were asked to point to the correct order of digits on a written 1-9 digit list provided on individual note cards or verbally repeat the numbers if the participant was able to do so. OUTCOMES AND RESULTS: IWA demonstrated shorter digit spans than the RBD group. Both groups performed worse on the DB span tasks than the DF span tasks. CONCLUSIONS: The results are consistent with previous studies suggesting that DB span is shorter than DF span in other populations and that there are differences in performance on digit span tasks between the two groups. The differences between RBD group and IWA may be explained by decreased attentional capacity or inefficient resource allocation in IWA, or alternatively, a deficient phonological loop. Future studies should explore these possibilities.
工作记忆（WM）限制被认为是失语症患者（IWA）语言加工缺陷的一个重要来源。顺背数字（DF）和倒背数字（DB）广度任务常用于研究健康人群和临床人群的工作记忆。不幸的是，只有少数研究探讨了失语症患者的数字广度。目的：本研究的目的是测量失语症患者的顺背数字和倒背数字广度，并将他们的数字广度与右脑损伤但无失语症（RBD）的组进行比较。此外，还比较了每组内的顺背数字和倒背数字广度，以确定是否确实存在表现差异，这可能支持倒背数字在这些人群中是更困难的工作记忆任务这一观点。方法和程序：17名失语症患者和14名右脑损伤患者参与了顺背数字和倒背数字广度任务。对广度任务进行了修改，以适应语言缺陷。向每位参与者口头呈现一系列两个数字，最多持续到八个数字。每个数字系列有七次试验。要求参与者在个人便签卡上提供的1-9数字书面列表中指出数字的正确顺序，或者如果参与者能够做到，则口头重复这些数字。结果：失语症患者的数字广度比右脑损伤组短。两组在倒背数字广度任务上的表现均比顺背数字广度任务差。结论：结果与先前的研究一致，表明在其他人群中倒背数字广度比顺背数字广度短，并且两组在数字广度任务上的表现存在差异。右脑损伤组和失语症患者之间的差异可能是由于失语症患者注意力容量下降或资源分配效率低下，或者是由于语音回路缺陷。未来的研究应该探索这些可能性。
