Incidental Learning: A Systematic Review of Its Effect on Episodic Memory Performance in Older Age

Identifying the nature of episodic memory deficits in Major Depressive Disorder using a Real-World What-Where-When task

ABSTRACTDeficits in episodic memory have been reported in various psychiatric conditions, including Major Depressive Disorder (MDD). Many widely used episodic memory tests do not have the ability to distinguish between impaired memory of separate components of a real-life event (e.g., what happened, where it happened and when), and impaired binding of such real-life features. To address this issue, a naturalistic, real-world What-Where-When memory task was employed to assess the nature of episodic memory impairments in MDD. A validation study established that the task is sensitive to age-related episodic memory changes, and that intentional encoding does not invalidate the task. The main study then compared the performance of patients with depression and control participants on the intentionally encoded WWW task. Patients with MDD presented an overall episodic memory impairment arising from deficits in object memory and the ability to bind objects to temporal context. Taken together, our study confirms the episodic memory impairment in MDD, by providing evidence of deficient object memory and reduced ability to bind temporal context to objects in patients. Our naturalistic WWW task presents a promising approach for thorough identification of the nature of episodic memory impairments, under a real-world environment, in various conditions, including MDD.

Development and validation of an experimental verbal Episodic Memory task in Spanish

PURPOSE

To develop and validate an experimental verbal episodic memory task in Spanish.

METHODS

Six encoding blocks were elaborated, three deep and three superficial, each one with different demands of cognitive effort. The blocks were reviewed by four expert judges and tested in a pilot application. The agreement was assessed on whether the task allowed combined processing level and cognitive effort to be manipulated during incidental encoding of words, as well as clarity of instructions, examples, and workflow.

RESULTS

Variables such as lexical availability, metrics, and strength of association were useful to differentiate the cognitive effort between each block. The judges agreed that the processing blocks allowed a combined manipulation of the level of processing and cognitive effort and that the instructions are precise. After the pilot, the participants agreed that the instructions, examples, and way of working were easy to understand and perform.

CONCLUSION

The results provide evidence of validity related to the content for the proposed experimental task, thus becoming a viable alternative to consider in research aimed at identifying environmental factors that contribute to compensating the defects shown by episodic memory with age.

Memory impairment and its associated risk and protective factors among older adults in Indonesia

AIMS

This study aimed to evaluate the association between memory impairment and its risk and protective factors, focusing on demographic and health-related variables among older adults in Indonesia.

METHOD

The data analyzed were the Indonesian Family Life Survey-5 (IFLS-5) using cross-sectional variables of 4236 older adults aged 60 years and over included in the 2015 round. Memory impairment was assessed by immediate word list recall from the Telephone Interview for Cognitive Status (TICS). Sociodemographic factors and multiple health variables were included as predictors. Data were analyzed using frequency analyses bivariate and stepwise logistic regression tests.

RESULT

Among 4236 older adults, 49.7% were male and 50.3% were female. Stepwise backward analyses showed that memory impairment was independently associated with older age, being female, or not in a union (unmarried, separated, divorced, or widowed), having obtained low levels of education, living in a rural area, reporting low life satisfaction, low social capital, higher dependency, and having clinical depression. Only moderate (but not high or low) physical activity levels were associated with a lower risk. Being underweight increased the risk, but being overweight/obese (as assessed by BMI) protective factors for a lower immediate recall score.

CONCLUSION

Increasing education and continued engagement of older adults in psychosocial activities, including moderate physical activity, improving mental health, preventing weight loss, and maintaining functional ability to decrease dependency, are associated with increased episodic memory, especially in non-married and older women in rural areas of Indonesia.

Temporal and contextual binding in episodic memory in younger and older adults

Episodic memory (EM) is a subsystem responsible for storing and recalling information about the basic elements of an event in a binding manner. Some approaches consider the temporal element to be one of the basic components of EM (WWWhen paradigm), while others consider that the contextual component is able in practice to better represent this cognitive ability (WWWhich paradigm). The relationship of both paradigms simultaneously with other instruments for measuring EM has not been investigated in healthy older adults. Thus, the present study examined the performance of young and older adults on questions based on the WWWhen and WWWhich paradigms, investigating the relationship of these questions with episodic (Remember) and non-episodic (Know) strategies. The results showed that for the younger adults both the questions demonstrated to only be significantly related with the "remember" strategy. On the other hand, older adults presented a response pattern in which the "WWWhich" questions used only episodic strategies for their correct resolution. Aging appears to promote a substantial reduction in both "Remember" and "Know" strategies, mainly those associated with solving tasks based on the temporal element of EM.

Consideration of different scoring approaches for a verbal incidental learning measure from the WAIS-IV using hippocampal volumes

Objective: While Spencer's verbal incidental learning (IL) task-from Vocabulary and Similarities subtests of the WAIS-has been validated relative to traditional memory measures and Alzheimer's disease (AD) pathology, the effectiveness of the particular scoring method used has not been assessed relative to alternative scoring weightings. The purpose of this study was to compare original and alternative scoring methods of this IL task by using an AD biomarker-benchmark to arrive at an optimal approach. Methods: Fifty-five memory-clinic patients aged 59-87 received neuropsychological assessment, measures of IL, and quantitative brain imaging. Partial correlation coefficients with total hippocampal volume-controlling for age, sex, and intracranial volume-were assessed across several IL scoring methods, and partial correlations with measures of memory were examined to evaluate convergent validity.Results: IL scoring methods maximizing the contribution of paired-associate-recall-performance were significantly correlated with both hippocampal volumes and traditional memory measures, whereas discrimination-emphasized scoring methods were not.Conclusions: IL scoring methods emphasizing memory paired-associate recall appeared to be preferable to those emphasizing memory discrimination. Administration of the IL- Similarities subtest alone, without IL- Vocabulary, may strike a balance between strength of relationships with both hippocampal volumes and standard memory measures, while also limiting administration time.

Learning by Insight-Like Sudden Comprehension as a Potential Strategy to Improve Memory Encoding in Older Adults

Several cognitive functions show a decline with advanced age, most prominently episodic memory. Problem-solving by insight represents a special associative form of problem-solving that has previously been shown to facilitate long-term memory formation. Recent neuroimaging evidence suggests that the encoding network involved in insight-based memory formation is largely hippocampus-independent. This may represent a potential advantage in older adults, as the hippocampus is one of the earliest brain structures to show age-related volume loss and functional impairment. Here, we investigated the potential beneficial effects of learning by insight in healthy older (60-79 years) compared to young adults (19-28 years). To this end, we compared later memory performance for verbal riddles encoded incidentally via induced insight-like sudden comprehension in both age groups. We employed a variant of the Compound Remote Associate Task (CRAT) for incidental encoding, during which participants were instructed to judge the solvability of items. In a 24-h delayed surprise memory test, participants attempted to solve previously encountered items and additionally performed a recognition memory test. During this test, older adults correctly solved an equal proportion of new CRA items compared to young adults and both age groups reported a similar frequency of Aha! experiences. While overall memory performance was better in young participants (higher proportion of correctly solved and correctly recognized old CRA items), older participants exhibited a stronger beneficial effect of insight-like sudden comprehension on later recognition memory for CRA items. Our results suggest that learning via insight might constitute a promising approach to improve memory function in old age.

The Functional Foundations of Episodic Memory Remain Stable Throughout the Lifespan

It has been suggested that specific forms of cognition in older age rely largely on late-life specific mechanisms. Here instead, we tested using task-fMRI (n = 540, age 6–82 years) whether the functional foundations of successful episodic memory encoding adhere to a principle of lifespan continuity, shaped by developmental, structural, and evolutionary influences. We clustered regions of the cerebral cortex according to the shape of the lifespan trajectory of memory activity in each region so that regions showing the same pattern were clustered together. The results revealed that lifespan trajectories of memory encoding function showed a continuity through life but no evidence of age-specific mechanisms such as compensatory patterns. Encoding activity was related to general cognitive abilities and variations of grey matter as captured by a multi-modal independent component analysis, variables reflecting core aspects of cognitive and structural change throughout the lifespan. Furthermore, memory encoding activity aligned to fundamental aspects of brain organization, such as large-scale connectivity and evolutionary cortical expansion gradients. Altogether, we provide novel support for a perspective on memory aging in which maintenance and decay of episodic memory in older age needs to be understood from a comprehensive life-long perspective rather than as a late-life phenomenon only.

What Employees Do Today Because of Their Experience Yesterday: How Incidental Learning Influences Train Driver Behavior and Safety Margins (A Big Data Analysis)

Employee behavior plays an important role in the occurrence and prevention of incidents, affecting safety margins. In this study, we examine the potential impact of incidental learning on human behavior in the presence of variation in task design. Incidental learning is the day-to-day on-the-job learning that occurs unintentionally. This learning influences which behavior (schema) is more likely to be activated in the employee’s brain. We posit that an incorrect schema can be activated and lead to undesired behavior if the employee is often exposed to (visually) similar tasks that require different behavior. In rail transport, there is a risk of trains passing through red signals. The train driver’s behavior plays an important role in preventing these signal passed at danger (SPAD) incidents. In this study we used speed and location data to analyze train driver deceleration behavior during red signal approaches in the Netherlands. The Dutch rail system showed variation in yellow signal aspects and signal distance. An analysis using 19 months of empirical data indicated changes in behavior when the employee had been previously exposed to different behavior requirements in the same location with a similar yellow signal. These results imply that task design can be improved by taking into consideration what an employee is exposed to during other moments of the shift, and not just during the execution of the specific task.

Older Adults Encode Task-Irrelevant Stimuli, but Can This Side-Effect be Useful to Them?

We studied whether, due to deteriorating inhibitory functions, older people are more likely to process irrelevant stimuli; and if so, could they later use this information better than young adults. In the study phase of our experiment, a Posner-type gaze-cued version of a Simon task was performed in which we presented task-irrelevant cues, where faces or patches with either left- or right-looking dots for the pupil of the eye preceded the task to press a button congruent or incongruent with the presentation side of the target stimulus. In the follow-up test phase, participants completed an unexpected facial recognition test. In the study phase not only a decreased P1, but also an increased N170 amplitude of the event-related potentials (ERPs) were found in older, compared to younger adults, and also for faces compared to patches. Even though in the test phase both age-groups could recognize the faces better than statistically by chance, neither the older nor the younger participants could discriminate them effectively. The late positive component (LPC)—the ERP correlates of the old/new effect, being the higher amplitude for the earlier presented stimuli when compared with the unseen stimuli during the recognition test—was not evolved in the older group, while a reversed old/new effect was seen in younger participants: higher amplitude was found in New-Right and Old-Wrong conditions (for faces they did not recognize independent of seeing them before) compared to Old-Right and New-Wrong conditions (for faces they thought they recognized from the study phase). In conclusion, although older adults showed enhanced processing of task-irrelevant stimuli compared to younger adults, as indicated by the N170 amplitude, however, they were not able to utilize this information in a later task, as was suggested by the recognition rate and LPC amplitude results.

Examining the Relationship between a Verbal Incidental Learning Measure from the WAIS-IV and Neuroimaging Biomarkers for Alzheimer's Pathology

Convergent validation of a verbal incidental learning (IL) task from the WAIS-IV using neuroimaging biomarkers is warranted to understand its sensitivity to Alzheimer's disease (AD) pathology. Fifty-five memory clinic patients aged 59 to 87 years received neuropsychological assessment, and measures of IL and quantitative brain imaging. Worse IL-Total Score and IL-Similarities performances were significantly associated with smaller hemispheric hippocampal volumes. IL measures were not significantly correlated with cerebral β-amyloid burden, though a trend was present and effect sizes were mild. These hippocampal volume results suggest that this IL task may be sensitive to AD pathology along the AD continuum.