Kray Jutta, Lucenet Joanna, Blaye Agnès
Development of Language, Learning, and Action, Department of Psychology, Saarland University Saarbrücken, Germany.
Front Aging Neurosci. 2010 Nov 16;2:147. doi: 10.3389/fnagi.2010.00147. eCollection 2010.
In this study we examined (a) whether verbal self-instructions can enhance task-switching performance in younger and older adults, and (b) whether verbal self-instruction benefits on task switching are smaller when memory demands on keeping track of the task sequence are reduced by spatial task cueing. Task-switching ability was measured as the difference in performance between single-task and mixed-task blocks (termed mixing costs), in which participants switched between two tasks A and B. One group of participants performed the switching tasks with spatial task cues, indicating which of the two tasks has to be performed, thereby reducing demands on the endogenous control of serial task order (low task-sequencing load). The other group switched between tasks without external task cues (high task-sequencing load). To investigate the influence of verbal self-instructions on task switching, participants either named aloud the next task during task preparation (task-naming condition) or they did not verbalize (control condition). Results indicated that age differences in verbalization benefits on mixing costs depend on early learning whereby benefits were generally larger when subjects had some prior practice in task switching alone, and that verbalization benefits did not differ between the two task-sequencing load conditions. These findings suggest that task naming is a suitable cognitive intervention for enhancing the control of task switching in younger and older adults, even if memory load is reduced, and that for the efficient application of this strategy it first has to be coordinated with task switching, which is easier when task switching is already practiced.
在本研究中，我们考察了：（a）言语自我指令是否能提高年轻人和老年人的任务切换表现；以及（b）当通过空间任务提示减少追踪任务序列的记忆需求时，言语自我指令对任务切换的益处是否会减小。任务切换能力通过单任务块和混合任务块之间的表现差异（称为混合成本）来衡量，其中参与者在两项任务A和B之间进行切换。一组参与者在有空间任务提示的情况下执行切换任务，提示表明必须执行两项任务中的哪一项，从而减少对串行任务顺序的内源性控制的需求（低任务序列负荷）。另一组在没有外部任务提示的情况下进行任务切换（高任务序列负荷）。为了研究言语自我指令对任务切换的影响，参与者在任务准备期间要么大声说出下一个任务（任务命名条件），要么不发声（对照条件）。结果表明，言语化对混合成本的益处的年龄差异取决于早期学习，即当受试者单独进行过一些任务切换的前期练习时，益处通常更大，并且言语化的益处在两种任务序列负荷条件之间没有差异。这些发现表明，任务命名是一种适合的认知干预措施，可用于增强年轻人和老年人对任务切换的控制，即使记忆负荷降低，并且为了有效应用该策略，它首先必须与任务切换相协调，当已经练习过任务切换时这更容易做到。
