老年人整体运动敏感性降低的脑灰质体积变化基础

本研究使用多体素模式分析方法和随机点阵范式,首次探索了老年人整体运动敏感性（GMS）下降和其脑灰质体积下降间的关系。结果发现,老年人GMS显著低于年轻人,老年人V5/MT、V3和额顶等脑区灰质体积显著小于年轻人;V5/MT和V3区的灰质体积信号可以有效预测个体的GMS。结果提示,V5/MT区和V3区,特别是V3区的灰质体积下降可能是老年人GMS下降的主要原因;而基于“去分化假设”,全脑范围内其余脑区的灰质体积下降可能也在一定程度上与老年人GMS下降有关。     

整体运动知觉老化的方向不同步性及其总效应

采用随机点阵范式和实验内元分析技术,首次分离水平、垂直、旋转和径向运动形式下两两对立方向的运动一致性阈值,探究整体运动知觉(GMP)老化的方向不同步性及总效应。结果发现:四种运动形式下,老年组阈值均显著高于青年组,且元分析显示两组阈值之差的效应量大于0,表明相对于青年人,老年人的GMP存在显著下降。同时,老年组向右、向下、顺时针和外扩方向的阈值显著高于其对立方向及青年组,表明老年人这些方向的GMP衰退更加严重,提示GMP的老化存在方向不同步性。     

老年人整体运动知觉衰退的视觉机制——基于知觉模板模型

整体运动知觉存在年龄相关的衰退,然其老化的视觉机制仍不清楚。本研究分别招募34名青年人和老年人为研究对象,采用随机点阵范式,首次以动态速度为外部噪声考察了这一问题。结果发现,老年组整体运动一致性阈值显著高于青年组,且中等速度下的差异较小,证明整体运动知觉存在老化效应,且老化程度受到速度的影响。对两组数据进行知觉模板拟合发现,以青年组为基准,老年组表征内部加法噪声和排除外部噪声能力的 A_a 和 A_f 均大于1,且 A_a >> A_f ,提示老年人整体运动知觉的衰退可能源于其内部加法噪声的增强和排除外部噪声能力的减弱,其中内部加法噪声的增强更为显著。     

发展性阅读障碍的注意缺陷研究现状

近年来,发展性阅读障碍的注意缺陷研究逐渐受到重视.行为实验发现,阅读障碍者有多种注意缺陷现象,主要表现为“视野不对称性”和“注意转换延迟”.脑电研究表明,阅读障碍的注意缺陷与大脑后顶叶皮层功能异常有关.大细胞通路假设认为,阅读障碍的视知觉缺陷来源于视觉大细胞受损,大细胞通路所加工的信息主要投射到靠近颞枕顶联合区的V5MT区,这个脑区为后顶叶皮层提供大量投射.因此,阅读障碍的注意缺陷与大细胞通路受损存在一定关系.     

努力控制及其神经基础

本文对努力控制的概念、发展及其神经基础进行了归纳和总结。我们发现努力控制涉及的脑区主要包括背外侧和腹外侧前额叶,前扣带回,顶上和顶下小叶以及辅助运动皮层等。此外,通过分析对比后发现努力控制与执行功能之间在行为表现和神经基础上有密切关系：两者都与个体的学业成绩、情绪状态和攻击行为等有关;努力控制涉及的脑区有很大部分处于具有执行功能的突显网络和额顶控制网络。这些证据表明两者之间可能有共同的脑结构基础。     

运动习惯与社区老年人认知功能的关系

为评估社区老年人运动习惯与认知功能的关系,在北京市通过分层、方便取样的方法选取60岁以上的老年人732名,采用自编调查表收集一般人口学资料及运动习惯情况（包括有无运动习惯,运动频率,运动持续时间）,使用简明精神状态评估量表（MMSE）和北京版蒙特利尔认知评估量表（MoCA-BJ）评估认知功能。结果发现：（1）运动组整体认知功能及视空间定向能力得分均高于无运动组;（2）有无运动习惯可正向预测整体认知功能及视空间定向能力得分;（3）运动持续10年及以上组整体认知功能得分高于运动持续10年以下组。结果表明：相对于无运动习惯的社区老年人,有运动习惯的社区老年人的整体认知功能及视空间定向能力更好;运动持续年数较长,对社区老年人的认知功能起到促进作用。     

锂盐对大鼠脑单胺类和氨基酸类神经介质含量的影响

本文以111只大鼠为材料,研究了锂盐重度中毒、血清锂达2.67±0.9meq/升,小脑锂达2.05±0.92meq/kg时,脑及各脑区六种单胺类和氨基酸,类物质含量的改变。结果表明,与正常动物相比,脑多巴胺(DA)和谷氨酸(GA)含量显著下降,5-羟色胺(5-HT),5-羟吲哚醋酸,(5-HIAA)和γ-氨基丁酸(GABA)显著增高,去甲基肾上腺素(NE)虽有下降却未达显著水平。就各脑区而言,端脑DA和GA含量显著下降,5-HIAA和GABA显著升高;间脑的NE显著下降,5-HT和GABA显著升高;脑干中除GABA增高外,其他五种测定物未发生显著改变。 这一结果似乎支持了情感活动和情感性精神病的单胺假说;但它并不是锂盐作用的唯一的和特异性机制,它也引起包括脑干在内的各脑区的GABA含量的增高。     

情景记忆成功年老化的神经机制

随着年龄的增长, 大部分老年人的情景记忆会出现衰退, 但也会有一部分老年人的情景记忆表现出成功的年老化, 即记忆成绩较好或随增龄的衰退程度较小。脑保持理论、神经去分化理论、认知储备理论以及神经补偿理论分别从不同角度解释了情景记忆成功年老化的神经机制。基于选择性优化与补偿模型对现有理论进行整合, 发现情景记忆成功年老化可能与个体的认知储备水平直接相关：高认知储备的老年人能够对情景记忆相关的脑区和脑网络进行优化且具备更强的神经补偿能力, 因而其脑功能(比如, 神经表征和神经加工通路的特异性)可能会保持地更好。未来研究需要更多地采用纵向设计来考察各理论之间的关系及其影响因素, 从而更好地解释记忆成功年老化的神经机制并为提升老年人的脑与认知健康提供支持。     

老年人日常人际问题解决中的悲伤情绪体验和情绪调节策略: 年龄和人格特质的作用

考察了日常人际问题解决中老年人的悲伤情绪体验和情绪调节策略与青年人的差异,以及年龄和人格特质的作用。共45名老年人和59名青年人接受半结构化访谈和人格特质测量。结果表明：（1）以教育水平为协变量的方差分析表明,老年人和青年人的悲伤情绪体验没有显著差异。老年人的被动情绪调节策略的使用和青年人存在显著差异;（2）老年人的被动情绪调节策略不但与年龄有关,而且与悲伤情绪体验有关。悲伤情绪体验可以显著预测其被动情绪调节策略使用;（3）老年人的悲伤情绪体验与人格特质神经质维度存在显著正相关;（4）老年人与年轻人的被动情绪调节策略都与悲伤情绪有关,但老年人的被动情绪调节策略不能由人格特质显著预测,而青年人的被动调节策略还可以由人格特质内外向维度显著预测。人格特质的内外向维度对老年人和青年人的前摄性情绪调节策略的预测效应是一致的。最后针对老年人的悲伤情绪体验和情绪调节策略的意义进行了讨论。     

皮层运动区和皮层下运动区在运动的认知控制中的作用

运动的认知控制是机体选择适合当前情境的运动的关键。皮层和皮层下运动区的不同脑区分别参与运动认知控制的不同方面, 同时又相互协作以确保各种运动的正确执行。运动前区(PMC)和初级运动区(M1)共同负责感觉与运动之间的转换, M1区、小脑和纹状体共同参与运动的学习和记忆, 辅助运动复合体(SMC)和M1区在运动的计划过程中发挥主导作用。基底神经节和前辅助运动区(pre-SMA)是对运动进行抑制的关键脑区。     

The role of motion direction selective extrastriate regions in reading: a transcranial magnetic stimulation study

Why reading ability is correlated with motion processing ability is perplexing. Activity in motion direction processing regions (Area V5/MT+) was perturbed by means of repetitive transcranial magnetic stimulation (rTMS) to examine its effect on reading. A functional probe (significant shortening of the motion aftereffect) was used to identify Area V5/MT+. Right-handed participants (8 m, 8 f) received three 7.5 min blocks of rTMS, after which two phonological and one orthographic reading tasks were administered. Application of rTMS to Area V5/MT+ (as compared to a non-rTMS baseline) significantly decreased performance only during non-word naming. The pattern of naming errors and the absence of deficits on the second phonological task were not consistent with a role for Area V5/MT+ in phonological decoding. Instead, its role in reading may be limited to image stabilization and/or letter localization.     

Validating age-related functional imaging changes in verbal working memory with acute stroke

Functional imaging studies consistently find that older adults recruit bilateral brain regions in cognitive tasks that are strongly lateralized in younger adults, a characterization known as the Hemispheric Asymmetry Reduction in Older Adults model. While functional imaging displays what brain areas are active during tasks, it cannot demonstrate what brain regions are necessary for task performance. We used behavioral data from acute stroke patients to test the hypothesis that older adults need both hemispheres for a verbal working memory task that is predominantly left-lateralized in younger adults. Right-handed younger (age ? 50, n = 7) and older adults (age > 50, n =21) with acute unilateral stroke, as well as younger (n =6) and older (n =13) transient ischemic attack (TIA) patients, performed a self-paced verbal item-recognition task. Older patients with stroke to either hemisphere had a higher frequency of deficits in the verbal working memory task compared to older TIA patients. Additionally, the deficits in older stroke patients were mainly in retrieval time while the deficits in younger stroke patients were mainly in accuracy. These data suggest that bihemispheric activity is necessary for older adults to successfully perform a verbal working memory task.     

Attenuated audiovisual integration in middle-aged adults in a discrimination task

Numerous studies have focused on the diversity of audiovisual integration between younger and older adults. However, consecutive trends in audiovisual integration throughout life are still unclear. In the present study, to clarify audiovisual integration characteristics in middle-aged adults, we instructed younger and middle-aged adults to conduct an auditory/visual stimuli discrimination experiment. Randomized streams of unimodal auditory (A), unimodal visual (V) or audiovisual stimuli were presented on the left or right hemispace of the central fixation point, and subjects were instructed to respond to the target stimuli rapidly and accurately. Our results demonstrated that the responses of middle-aged adults to all unimodal and bimodal stimuli were significantly slower than those of younger adults (p < 0.05). Audiovisual integration was markedly delayed (onset time 360 ms) and weaker (peak 3.97%) in middle-aged adults than in younger adults (onset time 260 ms, peak 11.86%). The results suggested that audiovisual integration was attenuated in middle-aged adults and further confirmed age-related decline in information processing.     

Compensatory processing during rule-based category learning in older adults

Healthy older adults typically perform worse than younger adults at rule-based category learning, but better than patients with Alzheimer’s or Parkinson’s disease. To further investigate aging’s effect on rule-based category learning, we monitored event-related potentials (ERPs) while younger and neuropsychologically typical older adults performed a visual category-learning task with a rule-based category structure and trial-by-trial feedback. Using these procedures, we previously identified ERPs sensitive to categorization strategy and accuracy in young participants. In addition, previous studies have demonstrated the importance of neural processing in the prefrontal cortex and the medial temporal lobe for this task. In this study, older adults showed lower accuracy and longer response times than younger adults, but there were two distinct subgroups of older adults. One subgroup showed near-chance performance throughout the procedure, never categorizing accurately. The other subgroup reached asymptotic accuracy that was equivalent to that in younger adults, although they categorized more slowly. These two subgroups were further distinguished via ERPs. Consistent with the compensation theory of cognitive aging, older adults who successfully learned showed larger frontal ERPs when compared with younger adults. Recruitment of prefrontal resources may have improved performance while slowing response times. Additionally, correlations of feedback-locked P300 amplitudes with category-learning accuracy differentiated successful younger and older adults. Overall, the results suggest that the ability to adapt one’s behavior in response to feedback during learning varies across older individuals, and that the failure of some to adapt their behavior may reflect inadequate engagement of prefrontal cortex.     

Neural correlates of age-related reduction in visual motion priming

Previously we reported that priming of visual motion perception is reduced in older adults compared to younger adults (Jiang, Greenwood, & Parasuraman, 1999, Psychology and Aging, 14(4), 619; Jiang, Luo, & Parasuraman, 2002b, Neuropsychology, 16(2), 140). To examine the neural mechanisms underlying this age-related effect, event-related brain potentials (ERPs) were recorded during perceptual judgments of motion directions by younger and older adults in two experiments. When judging single-step motion, both younger and older adults evoked significantly larger ERP late positive component (LPC) responses to unambiguous motion compared to LPC responses elicited by ambiguous motion. In contrast, compared to the younger adults, the older adults evoked comparable but delayed ERP responses to single motion steps. In the second experiment the younger and older groups judged the directions of two successive motion-steps (either motion priming or motion reversals). Under short (200-400 ms) stimulus onset asynchrony (SOA), the difference between the ERP responses to priming and reversal conditions was significantly larger for the younger than for the older adults. This study provides the first electrophysiological evidence that brain aging leads to delayed processing of single motion direction and visual motion priming as early as 100 ms in the early visual cortex. Age-related changes in strength and temporal characteristics of neural responses in temporal-parietal regions were particularly pronounced in older adults when successive motion signals are placed closely in time, within 400 ms.     

时间知觉在老年人跨期选择中的作用

随着人口老龄化速度的加快,老年人的跨期选择问题受到越来越多的关注。时间知觉是影响跨期选择的重要因素之一。然而,目前从时间知觉的角度来探讨老年人跨期选择的研究比较有限。本文在总结国内外相关研究的基础之上,试图分析时间知觉的随龄变化如何影响老年人的跨期选择。具体而言,本文从时间长度知觉、时间成本知觉以及时间知觉相关心理动机三个方面进行探讨,并指出了时间知觉视角的局限性及今后的研究方向。     

Prevalence and correlates of psychological distress of middle-aged and older women living with HIV

The aims of this study were to examine the prevalence and correlates of psychological distress among older women living with HIV in comparison to their male counterparts and younger women and to identify the sociodemographic and disease-related factors associated with psychological distress. The sample consisted of 508 HIV-infected patients (65 older women, 323 women aged below 50 years, and 120 older men) recruited from 10 Portuguese hospitals. Data regarding psychological distress were collected using the Brief Symptom Inventory (BSI). Seven older women (10.8%), eight older men (6.7%), and 61 younger women (18.9%) reported a T-score ≥ 63 for global severity index (GSI), indicative of a need for further psychological evaluation. Overall, younger women reported significantly higher psychological distress than older men. The odds of having clinically significant psychological distress score were significantly lower for older women reporting sexual transmission, while for younger women, having other co-infections was a significant correlate of higher psychological distress. Younger women were 2.67 (95% CI: 1.22–5.84) times more likely to report psychological distress than were older men. The odds were not significantly different from older women. This study shows that older women do not differ substantially from younger women and older men in terms of psychological distress. The results reinforce, however, that mental health interventions should be tailored to reflect individuals’ circumstances as well as developmental contexts. Moreover, they draw attention to the importance of examining resilience characteristics in older adults to understand the mechanisms behind ‘successful ageing’ while living with HIV.