Langhanns Christine, Müller Hermann
Institute of Sport Science, Justus Liebig University Giessen, DE.
Nemolab, Justus Liebig University Giessen, DE.
J Cogn. 2020 Sep 30;3(1):33. doi: 10.5334/joc.122.
Continuous motor tasks like walking have the potential to allow a dynamic allocation of processing resources when interrupted by intermittent cognitive tasks. The degree to which a successful interleaving of processing streams of both tasks is possible may depend on the temporal regularity of events. Fifteen subjects participated in an experiment where we systematically manipulated the regularity of stimulus onsets in a 2-back task relative to the step cycle. We tested three conditions where stimulus onset was always synchronous to a defined event in the stride (right heel strike, left heel strike, and midway between two heel strikes) and two conditions where the temporal location of the stimulus shifted from stride to stride. In order to test for potential effects of task difficulty, we also manipulated walking speed. We measured reaction times, accuracy of the reactions and several measures describing motor performance. There was no sign of task interference in these measures when stimuli always appeared at the same relative location within the step cycle. However, we observed prolonged reaction times when the stimulus came up earlier than expected. Surprisingly, in the other non-regular regime, where the stimulus appeared later than expected, reaction times were fastest. We interpret this result in the light of a prescheduled allocation of processing resources that is linked to the cyclic profile of processing requirements of the motor task.
像行走这样的连续运动任务在被间歇性认知任务打断时，有可能实现处理资源的动态分配。两项任务的处理流成功交织的程度可能取决于事件的时间规律性。15名受试者参与了一项实验，在该实验中，我们相对于步幅周期系统地操纵了2-back任务中刺激开始的规律性。我们测试了三种条件，即刺激开始总是与步幅中的特定事件（右足跟触地、左足跟触地以及两次足跟触地之间的中点）同步，以及两种条件，即刺激的时间位置在步幅之间变化。为了测试任务难度的潜在影响，我们还操纵了步行速度。我们测量了反应时间、反应准确性以及描述运动表现的多项指标。当刺激总是出现在步幅周期内相同的相对位置时，这些指标中没有任务干扰的迹象。然而，当刺激出现得比预期早时，我们观察到反应时间延长。令人惊讶的是，在另一种不规则情况下，即刺激出现得比预期晚时，反应时间最快。我们根据与运动任务处理需求的循环特征相关联的处理资源预定分配来解释这一结果。
