Crossley Margaret, Hiscock Merrill, Foreman Jeanette Beckie
Department of Psychology, University of Saskatchewan, 9 Campus Drive, Saskatoon, Sask., Canada S7N 5A5.
J Clin Exp Neuropsychol. 2004 May;26(3):332-46. doi: 10.1080/13803390490510068.
Attentional functions of individuals with early stage Alzheimer's disease (AD) and normal older adults (NC) were studied using a concurrent-task paradigm. Fourteen patients (5 men, 9 women) and 14 age- and sex-matched normal adults engaged in speeded unimanual tapping and speaking tasks during single- and dual-task trials. Speaking tasks were either relatively automatized (Speech Repetition) or relatively effortful (Speech Fluency). As single-task tapping rates were slower for the AD participants than for the NC participants, a proportional decrement score was used as an index of interference in the dual-task conditions. Interference during concurrent-task performance was greater when the cognitive task was effortful for both the NC and the AD groups. Although AD patients suffered higher levels of interference than NC participants while performing the effortful speech task, the two groups showed equivalent small changes in tapping speed while combining the automatized speaking and tapping tasks. Results suggest that a general-purpose attentional processing resource declines in the early stages of AD but dual-task performance is well-maintained when the component tasks are relatively automatized.
使用并发任务范式研究了早期阿尔茨海默病（AD）患者和正常老年人（NC）的注意力功能。14名患者（5名男性，9名女性）和14名年龄及性别匹配的正常成年人在单任务和双任务试验中进行了快速单手敲击和言语任务。言语任务要么是相对自动化的（言语重复），要么是相对费力的（言语流畅性）。由于AD参与者的单任务敲击速度比NC参与者慢，比例递减分数被用作双任务条件下干扰的指标。当认知任务对NC组和AD组都很费力时，并发任务执行期间的干扰更大。尽管AD患者在执行费力的言语任务时比NC参与者受到更高水平的干扰，但在将自动化言语和敲击任务结合起来时，两组的敲击速度变化相当小。结果表明，在AD的早期阶段，通用的注意力处理资源会下降，但当组成任务相对自动化时，双任务表现能得到很好的维持。
