UNIROUEN, CRFDP (EA 7475), Normandie University , Rouen, France.
CNRS, LNC, Laboratoire de Neurosciences Cognitives, Aix Marseille University , Marseille, France.
Neuropsychol Dev Cogn B Aging Neuropsychol Cogn. 2020 Sep;27(5):729-747. doi: 10.1080/13825585.2019.1674773. Epub 2019 Oct 9.
While imitation of meaningless gestures is a gold standard in the assessment of apraxia in patients with either stroke or neurodegenerative diseases, little is known about potential age-related effects on this measure. A significant body of literature has indicated that different mechanisms (i.e., executive functioning, visuospatial skills, sensory integration, body knowledge, categorical apprehension) may underlie the performance depending on imitation conditions (i.e., finger/hand, uni-/bimanual, symmetric/asymmetric, crossed/uncrossed configurations). However, neither the effects of these conditions on performance, nor the contribution of the abovementioned mechanisms to imitation have been explored in normal aging. The aim of the present study was to fill this gap. To do so, healthy adults ( = 103) aged 50 to 89 were asked to imitate 45 meaningless gestures. The authors controlled for general cognitive function, motor function, visual-spatial skills, executive function, sensory integration, body knowledge, and mechanical problem-solving skills. The results showed that asymmetry, body-midline crossing and, to a lesser extent, bimanual activity added an additional layer of difficulty to imitation tasks. After controlling for motor speed and cognitive function, age had an effect on imitation skills after 70 years old. This may reflect a decline in body knowledge, sensory integration, and executive functions. In contrast, the visuospatial and mechanical problem-solving hypotheses were ruled out. An additional motor simulation hypothesis is proposed. These findings may prove useful for clinicians working in memory clinics by providing insights on how to interpret imitation deficits. Lower performance after 70 years old should not be considered abnormal in a systematic manner.
虽然模仿无意义的手势是评估中风或神经退行性疾病患者失用症的金标准，但对于这种测量方法潜在的年龄相关影响知之甚少。大量文献表明，不同的机制（即执行功能、视空间技能、感觉整合、身体知识、范畴理解）可能是根据模仿条件（即手指/手、单手/双手、对称/不对称、交叉/非交叉配置）来解释模仿行为。然而，无论是这些条件对表现的影响，还是上述机制对模仿的贡献，在正常衰老中都没有得到探索。本研究旨在填补这一空白。为此，要求 50 至 89 岁的健康成年人模仿 45 个无意义的手势。作者控制了一般认知功能、运动功能、视空间技能、执行功能、感觉整合、身体知识和机械问题解决技能。结果表明，不对称、身体中线交叉，以及在较小程度上的双手活动，给模仿任务增加了额外的难度。在控制运动速度和认知功能后，70 岁以后，年龄对模仿技能有影响。这可能反映了身体知识、感觉整合和执行功能的下降。相比之下，视空间和机械问题解决的假设被排除。提出了一个额外的运动模拟假设。这些发现可能对记忆诊所的临床医生有用，为他们提供如何解释模仿缺陷的见解。70 岁以后的表现下降不应被系统地视为异常。
