Faculty of Education, Bar-Ilan University, Ramat-Gan, Israel.
Department of Psychology and Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Centre, Bar-Ilan University, Ramat-Gan, Israel.
J Appl Res Intellect Disabil. 2023 Jul;36(4):796-811. doi: 10.1111/jar.13096. Epub 2023 Mar 15.
Life expectancy is on rise and the intriguing question is: When does cognitive decline occur among adults with intellectual disability, compared to adults with typical development? This cross-sectional study examined cognitive performance of crystallised/fluid intelligence, working and long-term memory of adults with intellectual disability of etiologies other than Down syndrome (IQ 50-68) and adults with typical development (IQ 85-114) in four age cohorts (30-39; 40-49; 50-59; 60-69).
The WAIS III and the Rey-AVLT were administered to both groups.
Four patterns of cognitive performance were found: (a) Vocabulary (crystallised intelligence), Spatial Span Forward and Retention yielded similar scores across all four age cohorts in participants with typical development and with intellectual disability. (b) Similarities, Raven and Digit Span Backward exhibit lower scores only in 50-59 or 60-69 compared to the 30-39 age cohort in both groups, (c) Digit Span Forward, Spatial Span Backward and Total Leaning (LTM) yielded lower scores in the 50-59 or 60-69 age cohorts in the typical group, but similar scores in participants with intellectual disability along the age cohorts, (d) Block Design (fluid intelligence) yielded a lower score in the 50-59 cohort versus lower scores only at ages 60-69 in participants with typical development.
Our findings suggest a possible parallel trajectory in age-related cognitive performance for individuals with and without intellectual disability in six measures, and a possible more preserved trajectory in fluid intelligence and some memory measures in adults with intellectual disability compared to their peers. Caution should be exercised regarding Digit and Spatial Span Backwards, which yielded a floor effect in participants with intellectual disability. The Cognitive Reserve Theory, the Safeguard Hypothesis and late maturation might serve as explanations for these findings.
预期寿命在上升，一个有趣的问题是：与具有典型发育的成年人相比，智力障碍成年人的认知能力下降发生在何时？本横断面研究检查了其他病因（非唐氏综合征）智力障碍成年人（智商 50-68）和具有典型发育的成年人（智商 85-114）的晶体/流体智力、工作记忆和长时记忆的认知表现，分为四个年龄组（30-39；40-49；50-59；60-69）。
对两组参与者均进行了韦氏智力测验第三版（WAIS III）和 Rey 听觉词语学习测验（Rey-AVLT）。
发现了四种认知表现模式：（a）词汇（晶体智力）、空间广度向前和保留在具有典型发育和智力障碍的参与者中在所有四个年龄组中均获得相似的分数。（b）相似性、瑞文和数字广度倒序在两组中仅在 50-59 或 60-69 岁时的分数低于 30-39 岁年龄组。（c）数字广度向前、空间广度倒序和总学习（LTM）在典型组中在 50-59 或 60-69 岁年龄组中得分较低，但在智力障碍参与者中随着年龄组的变化得分相似。（d）积木设计（流体智力）在典型组中 50-59 岁年龄组的得分较低，而在参与者中仅在 60-69 岁时的得分较低。
我们的研究结果表明，在六个测量指标中，智力障碍个体和无智力障碍个体的认知表现可能存在平行轨迹，而在流体智力和某些记忆测量指标中，智力障碍个体的认知表现可能更为保留。对于具有智力障碍的参与者，数字广度和空间广度倒序可能会出现下限效应，因此应该谨慎使用这些测量指标。认知储备理论、保护假说和晚熟可能是这些发现的解释。
