Decision-making competence in younger and older adults: which cognitive abilities contribute to the application of decision rules?

Older adults perform worse than younger adults when applying decision rules to choose between options that vary along multiple attributes. Although previous studies have shown that general fluid cognitive abilities contribute to the accurate application of decision rules, relatively little is known about which specific cognitive abilities play the most important role. We examined the independent roles of working memory, verbal fluency, semantic knowledge, and components of executive functioning. We found that age-related decline in applying decision rules was statistically mediated by age-related decline in working memory and verbal fluency. Our results have implications for theories of aging and decision-making.     

从整合的角度看联结记忆中的项目再认

联结记忆由三种成分构成：项目1, 项目2以及项目1-项目2之间的联结, 其中, 对项目1和项目2的再认称之为项目再认, 而对项目1-项目2之间联结的再认称之为联结再认。双加工理论认为项目再认可以由熟悉性和回想加工来完成, 而联结再认只能由回想加工来完成。但近期有大量的研究发现：当要学习的项目对被整合为一个新的整体表征时, 熟悉性也能够支持联结再认。而关于整合对联结记忆中项目再认的研究较少, 总结已有研究提出两种观点：一种是“只有受益”观点(benefits-only)认为整合在增加联结再认的同时不影响项目再认; 另一种是“收支平衡”观点(costs and benefits)认为整合增加联结再认是以牺牲项目再认为代价的。未来研究应该关注整合对联结记忆中项目再认的影响及其神经机制, 了解整合对联结再认和项目再认的具体作用, 有助于针对具体记忆任务选择合适的编码方式来提高记忆表现。     

增龄性联结记忆损伤及其影响因素

老年人的联结记忆随年龄增长而出现普遍损伤, 这种增龄性联结记忆损伤究竟是因捆绑功能受损导致的特定损伤还是因整体认知机能受损导致的信息表征能力的整体损伤, 还存有争论。以Naveh-Benjamin (2000)的联结损伤假说(ADH)为代表的特定损伤观认为, 增龄性联结记忆损伤与老年人捆绑不同项目和提取这些捆绑的特定加工过程的损伤有关; 而以Benjamin (2010)的DRYAD模型为代表的整体损伤观则认为, 增龄性联结记忆损伤与老年人因老化而导致的记忆保持精度的整体损伤有关。二者在基本观点、实验支持及存在问题上各有侧重。此外, 影响增龄性联结损伤的因素还可大致分为刺激信息特性、被试主体特点两方面。同时强调未来研究不仅要关注老年人联结损伤的认知机制和影响因素, 更应关注其实际应用和临床指导价值。     

Explicit and implicit motor sequence learning in children and adults; the role of age and visual working memory

This study investigated explicit and implicit motor learning, and the influence of visual working memory (VWM) and age. Sixty children and 28 adults learned a nine-button sequence task explicitly and implicitly. Performance in explicit and implicit learning improved with age. Learning curves were similar across ages for implicit learning. In explicit learning, learning curves differed across ages: younger children started slower, but their learning rate was higher compared to older children. Learning curves were similar across VWM scores, but performance in explicit learning was positively influenced by VWM scores. Further research and implications for education and rehabilitation are discussed.     

The propensity to perceive meaningful coincidences is associated with increased posterior alpha power during retention of information in a modified Sternberg paradigm

There are ample inter-individual differences in the frequency with which people perceive meaningful coincidences. Previous research has identified increased proactive interference, that is a reduced working memory capacity, as one possible mechanism associated with this phenomenon. The present study aimed at extending this finding into the domain of neuroscience, (1) by assessing EEG alpha oscillations during the retention of information, (2) by replicating the behavioral link between meaningful coincidences and proactive interference. In a sample of 52 participants, the behavioral replication was successful. Furthermore, participants who perceived more meaningful coincidences showed higher alpha power increases at parietal-occipital sites, and at the same time, displayed lower alpha power increases at frontal areas, during retention of information. This neurophysiological activation pattern further underlines the assumption that participants who perceive more meaningful coincidences show lower working memory capacities, since increased alpha power at parietal areas reflects a higher load on working memory demands.     

Not all information in visual working memory is forgotten equally

To improve maintenance of task-relevant information in visual working memory (VWM), previously encoded, but no longer relevant, information can be suppressed or forgotten. However, it is unclear whether a cue directing attention to a subset of stimuli leads to complete forgetting for non-cued stimuli. The current study utilized a novel method of testing to-be forgotten information to determine if the effectiveness of forgetting differs depending on the type of encoded stimuli. Participants performed a directed forgetting change detection task, and importantly, the changed stimulus could be a novel stimulus or a to-be-forgotten stimulus. Stimulus type (colors, objects, or shapes) was manipulated across two experiments. Results suggest that a cue benefits memory for to-be-remembered information, but performance is not equivalent to never encoding to-be-forgotten information. Furthermore, the type of encoded information impacts the extent of forgetting.     

Strategic value-directed learning and memory in Alzheimer's disease and behavioural-variant frontotemporal dementia

In healthy adults, the ability to prioritize learning of highly valued information is supported by executive functions and enhances subsequent memory retrieval for this information. In Alzheimer's disease (AD) and behavioural-variant frontotemporal dementia (bvFTD), marked deficits are evident in learning and memory, presenting in the context of executive dysfunction. It is unclear whether these patients show a typical memory bias for higher valued stimuli. We administered a value-directed word-list learning task to AD (n = 10) and bvFTD (n = 21) patients and age-matched healthy controls (n = 22). Each word was assigned a low, medium or high point value, and participants were instructed to maximize the number of points earned across three learning trials. Participants’ memory for the words was assessed on a delayed recall trial, followed by a recognition test for the words and corresponding point values. Relative to controls, both patient groups showed poorer overall learning, delayed recall and recognition. Despite these impairments, patients with AD preferentially recalled high-value words on learning trials and showed significant value-directed enhancement of recognition memory for the words and points. Conversely, bvFTD patients did not prioritize recall of high-value words during learning trials, and this reduced selectivity was related to inhibitory dysfunction. Nonetheless, bvFTD patients showed value-directed enhancement of recognition memory for the point values, suggesting a mismatch between memory of high-value information and the ability to apply this in a motivationally salient context. Our findings demonstrate that value-directed enhancement of memory may persist to some degree in patients with dementia, despite pronounced deficits in learning and memory.     

创伤个体注意控制、焦虑及情绪对闯入记忆的影响

以往研究认为认知控制在闯入记忆的发展中起一定作用。研究以83名大学生本科生为被试,采用创伤电影范式和问卷调查结合的方式,旨在考察创伤个体注意控制、焦虑及情绪对闯入记忆的影响。结果显示,注意控制、焦虑和情绪与闯入记忆相关;注意控制和观看创伤电影前的消极情绪对闯入记忆有一定的预测作用;注意控制与焦虑、情绪相关;高低注意控制组分别在焦虑、情绪上差异显著。注意控制、焦虑、创伤前负性情绪与闯入记忆相关;注意控制、创伤前负性情绪显著影响闯入记忆。 关键词：闯入记忆;注意控制;焦虑;情绪;创伤