Kray Jutta, Fehér Balázs
Department of Psychology, Saarland University Saarbruecken, Germany.
Front Psychol. 2017 Mar 17;8:410. doi: 10.3389/fpsyg.2017.00410. eCollection 2017.
Recent aging studies on training in task switching found that older adults showed larger improvements to an untrained switching task as younger adults do. However, less clear is what type of cognitive control processes can explain these training gains as participants were trained with a particular type of switching task including bivalent stimuli, requiring high inhibition demands, and no task cues helping them keeping track of the task sequence, and by this, requiring high working-memory (WM) demands. The aims of this study were first to specify whether inhibition, WM, or switching demands are critical for the occurrence of transfer and whether this transfer depends on the degree of overlap between training and transfer situation; and second to assess whether practiced-induced gains in task switching can be maintained over a longer period of time. To this end, we created five training conditions that varied in switching (switching vs. single task training), inhibition (switching training with bivalent or univalent stimuli), and WM demands (switching training with or without task cues). We investigated 81 younger adults and 82 older adults with a pretest-training-posttest design and a follow-up measurement after 6 months. Results indicated that all training and age groups showed improvements in task switching and a differential effect of training condition on improvements to an untrained switching task in younger and older adults. For younger adults, we found larger improvements in task switching for the switching groups than the single-task training group independently of inhibition and WM demands, suggesting that practice in switching is most critical. However, these benefits disappeared after 6 months. In contrast, for older adults training groups practicing task switching under high inhibition demands showed larger improvements to untrained switching tasks than the other groups. Moreover, these benefits were maintained over time. We also found that the transfer of benefits in task switching was larger with greater overlap between training and transfer situation. However, results revealed no evidence for transfer to other untrained cognitive task. Overall, the findings suggest that training in resolving interference while switching between two tasks is most critical for the occurrence of transfer in the elderly.
最近关于任务切换训练的衰老研究发现，与年轻人相比，老年人在未经训练的切换任务上表现出更大的进步。然而，尚不清楚哪种类型的认知控制过程可以解释这些训练成果，因为参与者接受的是特定类型的切换任务训练，包括二价刺激，需要较高的抑制需求，且没有任务线索帮助他们跟踪任务顺序，因此需要较高的工作记忆（WM）需求。本研究的目的首先是确定抑制、WM还是切换需求对迁移的发生至关重要，以及这种迁移是否取决于训练与迁移情境之间的重叠程度；其次是评估练习诱导的任务切换增益是否能在较长时间内保持。为此，我们创建了五种训练条件，这些条件在切换（切换训练与单任务训练）、抑制（使用二价或单价刺激的切换训练）和WM需求（有或没有任务线索的切换训练）方面有所不同。我们采用前测-训练-后测设计，并在6个月后进行随访测量，对81名年轻人和82名老年人进行了研究。结果表明，所有训练组和年龄组在任务切换方面都有改善，并且训练条件对年轻人和老年人未经训练的切换任务改善有不同影响。对于年轻人，我们发现切换组在任务切换方面的改善比单任务训练组更大，与抑制和WM需求无关，这表明切换练习最为关键。然而，这些益处6个月后消失了。相比之下，对于老年人，在高抑制需求下练习任务切换的训练组在未经训练的切换任务上比其他组有更大的改善。此外，这些益处随着时间的推移得以保持。我们还发现，训练与迁移情境之间的重叠越大，任务切换中的益处迁移就越大。然而，结果没有显示出向其他未经训练的认知任务迁移的证据。总体而言，研究结果表明，在两项任务之间切换时解决干扰的训练对老年人迁移的发生最为关键。
