Task-specific and task-unspecific long term effects of cognitive-motormultitask training

人类的多任务处理能力是有限的。尽管如此，有充分的证据表明，在各种认知和运动任务中的表现可以通过特定的单任务训练显着提高（SPP的可塑性观点），也可能转移到多任务的情况下。此外，研究表明，与单任务训练相比，多任务训练甚至可能导致练习任务以及转移到非练习任务中的更大绩效增量。在双重任务中，可以想象到三种可能的训练诱导的加工结构转变：a）减少至少一项任务的处理需求，B）智能整合独立的信息处理流，以及c）增加处理资源的数量。我们将研究这些问题，重点是运动-认知双任务训练，即，涉及足够复杂的连续运动任务的情况，如行走或其他姿势任务。这种类型的培训被广泛应用于老年人跌倒预防的背景下，并已受到具体的调查。它也受到了一些关注，可能对认知能力的有益影响。然而，这些训练效应的内在机制尚未得到明确的解释，训练效应的一个关键因素是不同任务的加工流在训练过程中如何相互干扰和调动资源。在第一个资助期，我们观察到不同的效果相比，一个更具有挑战性的力跟踪任务的“自动化”行走任务的水平上的结果表现在实践和转移任务，以及训练引起的加工结构的变化。在第二个资助期内，我们将更深入地调查这些任务引起的处理结构。我们将使用探测反应时间技术来揭示，在何种程度上参与处理的每一个任务，在不同的时刻。我们将联合收割机这项工作与进一步的训练研究相结合，在这些研究中，受试者练习选定的运动-认知双重任务组合数周。基于这些研究中收集的数据，我们将回顾现有的解释性概念，这些概念可以分为假设多任务处理过程中的固定限制或灵活限制处理。根据第一种观点，改进只能通过更有效地处理至少一项任务来解释，或者通过处理流的智能集成来解释。因此，长期的训练效果应限于至少涉及一项练习任务的情况。在某些情况下，极限概念允许更强的处理资源的招聘，因此，看到长期增加的可能性。这种可塑性，然后应观察到在性能的好处，在更广泛的转让情况。

Multi-tasking capacity of humans is limited. Nonetheless, there is ample evidence that perfor-mance in a variety of cognitive and motor tasks can significantly be improved (plasticity perspective of the SPP) by specific single-task training that might also transfer to multi-task situations. Moreo-ver, studies have demonstrated that multi-task training, compared to single-task training, may even lead to larger performance increments in the practiced tasks as well as in transfer to unpracticed tasks. Three possible training-induced transformations of the processing structure in dual tasks are conceivable: a) Reduction of processing demands of at least one of the tasks involved, b) smart integration of separate information processing streams, and c) increased quantity of processing resources.We will study these questions with a focus on motor-cognitive dual-task training, that is, situations in which a sufficiently complex continuous motor task is involved, like walking or other postural tasks. This type of training is widely applied in in the context of fall prevention in elderly and has been subject to specific investigations. It has also received some attention with respect to possible beneficial effects on cognitive performance. However, the mechanisms underlying these training effects have not been identified conclusively.A crucial factor for any resulting training effect is how processing streams of the different tasks in-terfere and recruit resources during practice. In the first funding period, we observed different effects for an "automatized" walking task compared to a more challenging force-tracking task at the level of the resulting performances in practiced and transfer tasks, and the training-induced altera-tions of the processing structure. In the second funding period, we will investigate the processing structure induced by these tasks in more depth. We will use a probe-reaction time technique to reveal, to which extent subjects are engaged in processing of each of the tasks at different moments in time. We combine this work with further training studies where subjects practice selected motor-cognitive dual-task combinations for several weeks. Based on the data collected in these studies, we will review existing explanatory concepts, which can be categorized as either assuming fixed-limit or flexible-limit processing during multitasking. According to the first, improvements can only be explained by more effective processing of at least one of the tasks, or by a smart integration of the processing streams. Accordingly, long-term training effects should be restricted to situations where at least one of the practiced tasks is involved. Flexible-limit concepts allow stronger recruitment of processing resources in certain contexts and, thus, see the possibility of long-term increases. This plasticity should then be observable in performance benefits in a broader range of transfer situations.