Aix-Marseille Université & CNRS, ISM UMR 7287, Faculté des Sciences du Sport, Institut des Sciences du Mouvement, 163 Route de Luminy, BP 910, 13288, Marseille cedex 09, France.
Exp Brain Res. 2013 Jul;228(1):105-16. doi: 10.1007/s00221-013-3542-0. Epub 2013 May 7.
Though age-related decrease in information-processing capacities is hypothesized to be a prominent cause of behavioral slowing, it has been scarcely systematically studied in goal-directed motor tasks. The present study investigated how the decrease in information processing affects the sensorimotor processes underlying the control of a discrete Fitts' task. The index of difficulty (ID) of the task was manipulated using changes in either target distance (D) or target width (W). In each manipulation, movement (MTs), acceleration (ATs) and deceleration times (DTs) of young and older participants were compared across eight ID levels. They were analyzed with efficiency functions, state traces and Brinley plots. Our results showed that older participants were always slower. However, in both age groups, MTs were longer in D manipulation, which resulted from a slowing of both ATs and DTs, while W manipulation affected mainly DTs. In D manipulation, equivalent age-related slowing ratios were observed for AT and DT (1.3). In W manipulation, ATs of older participants were additively slower than those of young participants. Conversely, DTs presented a multiplicative slowing ratio of 1.3. These findings showed that ID manipulations differentially loaded information processing in the nervous system and that age-related slowing of multisensory control processes was independent of the manipulated dimension. Nevertheless, ID manipulations revealed different age-related adaptations to task constraints, suggesting that D and W manipulations are complementary means to assess age-related slowing of the processes involved in target-directed rapid-aiming tasks, with D scaling being more specific to capture the slowing of force-impulse control.
虽然人们假设与年龄相关的信息处理能力下降是行为迟缓的一个主要原因，但在目标导向的运动任务中，这一现象很少被系统地研究。本研究调查了信息处理能力下降如何影响离散菲茨任务控制的感觉运动过程。通过改变目标距离（D）或目标宽度（W）来操纵任务的难度指数（ID）。在每种操作中，比较了年轻和年长参与者在八个 ID 水平下的运动（MTs）、加速度（ATs）和减速时间（DTs）。它们用效率函数、状态轨迹和 Brinley 图进行分析。我们的结果表明，年长参与者总是更慢。然而，在两个年龄组中，D 操作的 MTs 更长，这是由于 ATs 和 DTs 的减速所致，而 W 操作主要影响 DTs。在 D 操作中，观察到 AT 和 DT 的等效年龄相关减速比为 1.3。在 W 操作中，年长参与者的 ATs 比年轻参与者的 ATs 减速更明显。相反，DTs 的减速比为 1.3。这些发现表明，ID 操作以不同的方式在神经系统中加载信息处理，并且多感觉控制过程的与年龄相关的减速与操作维度无关。然而，ID 操作揭示了对任务约束的不同年龄相关适应，这表明 D 和 W 操作是评估目标导向快速瞄准任务中涉及的过程与年龄相关减速的互补手段，D 标度更具体地捕捉力脉冲控制的减速。
