Univ. Lille, ULR 4072 - PSITEC - Psychologie : Interactions, Temps, Emotions, Cognition, 59000, Lille, France.
Clinique du Val de Lys (Groupe Ramsay), 167 rue Nationale, 59200, Tourcoing, France.
Psychol Res. 2024 Mar;88(2):670-677. doi: 10.1007/s00426-023-01872-2. Epub 2023 Sep 28.
Grabbing a phone from a table or stepping over an obstacle on the ground are daily activities that require the brain to take account of both object and the body's parameters. Research has shown that a person's estimated maximum reach is temporarily overestimated after using a tool, even when the tool is no longer in hand. This tool effect reflects the high plasticity of the perceptual-motor system (e.g., body schema updating)-at least in young individuals. The objective of the present study was to determine whether the tool effect is smaller in older adults. Forty-four young adults, 37 older adults without cognitive impairment and 30 older adults with cognitive impairment took part in the experiment. The task consisted in visually estimating the ability to reach (using the index finger) a target positioned at different locations on a table, both before and after using a rake. We observed a strong after-effect of tool use in the young adults only. Conversely, a tool effect was similarly absent in the older adults without and with cognitive impairment. Moreover, even before the tool was used, the maximum reach was overestimated in each of the three groups, although the overestimation was greatest in the two groups of older adults. In summary, we showed that the tool effect, observed in young adults, was absent in older adults; this finding suggests that with advancing age, the perceptual-motor system is less able to adapt to novel sensorimotor contexts. This lack of adaptation might explain (at least in part) the overestimation of motor skills often reported in the elderly.
从桌子上抓起电话或跨过地面上的障碍物是日常生活中需要大脑同时考虑物体和身体参数的活动。研究表明，即使工具不再手中，使用工具后，人对自己最大伸展距离的预估会暂时增加。这种工具效应反映了感知运动系统的高度可塑性（例如，身体图式更新），至少在年轻人中是如此。本研究的目的是确定在老年人中，工具效应是否较小。44 名年轻人、37 名无认知障碍的老年人和 30 名有认知障碍的老年人参加了实验。任务包括使用食指在桌子上的不同位置目测目标，在使用耙子前后进行估计。我们只在年轻人中观察到了强烈的工具使用后效。相反，在无认知障碍和认知障碍的老年人中，工具效应也同样不存在。此外，即使在使用工具之前，每个组的最大伸展距离都被高估了，尽管高估程度在两个老年组中最大。总之，我们表明，在年轻人中观察到的工具效应在老年人中不存在；这一发现表明，随着年龄的增长，感知运动系统适应新的感觉运动环境的能力降低。这种适应能力的缺乏可能解释了老年人经常报告的运动技能高估的原因（至少部分解释）。
