Impact of working memory capacity on predominance of parietal over frontal P300 amplitude.

Working memory-related neural activity varies with task load, and these neural variations can be constrained by working memory capacity (WMC). For instance, some studies suggest that parietal and frontal P300 amplitudes, reflecting working memory functioning, vary differentially with task load and WMC. The present study explored whether the predominance of parietal over frontal P300 amplitude is related to WMC, and whether this relationship varies according to task load. Thirty-one adults aged 20-40 years performed a Sternberg task with two set sizes (2 vs. 6 items), during which event-related potentials were recorded. This allowed us to explore the P300 and estimate the magnitude of its parietal over frontal predominance, calculated as a parietal over frontal predominance index (PFPI). Participants also performed the Digit Span and alpha span tests, which were used to compute an independent index of WMC. Results revealed the classic parietal over frontal P300 predominance. They also indicated that the PFPI decreased as task load increased, owing mainly to an increase in frontal P300 amplitude. Interestingly, WMC was positively correlated with the PFPI, suggesting that individuals with greater WMC exhibited greater parietal over frontal predominance. These correlations did not vary across set sizes. Parietal over frontal predominance was reduced in individuals with lower WMC, who relied more on frontal neural resources. This frontal upregulation may have reflected the recruitment of supplementary attentional executive operations to compensate for less efficient working memory maintenance operations.

Cognitive mechanisms underlying free recall in episodic memory performance across the lifespan: testing the control/representation model.

Episodic memory (EM) develops up to early adulthood, and declines in aging, following an inverted U-shaped profile. This study assessed the contribution of both Control (processes enabling adaptive and flexible behaviour in line with current goals) and Representation (crystallized schemas involved in memory and general knowledge) as factors likely to underlie this pattern of change. We hypothesized that these two cognitive resources are differentially involved in EM performance across development and aging. Participants from 8 to 80 years were administered a free-recall task and tests measuring control and representation. Results show that EM and control scores follow an inverted U-shaped profile (i.e., quadratic relationship), whereas representation increases across the lifespan. EM was associated with representation at all ages, while it was associated with control only in the youngest children and in the adults groups. Representation mainly contributed to age-related difference in EM performance across development. Across aging, control, and to a lesser extent, representation, accounted for EM performance decline. These results showed that EM development and decline do not depend on the same cognitive resources, increased representation being crucial for EM development, and a decline in control with advancing age being responsible for the age-related change in EM performance.

Involvement of executive control in neural capacity related to working memory in aging: an ERP P300 study.

Executive control could be involved in neural capacity, which corresponds to the modulation of neural activity with increased task difficulty. Thus, by exploring the P300-an electrophysiological correlate of working memory-we examined the role played by executive control in both the age-related decline in working memory and neural capacity in aging. Event-related potentials (ERPs) were recorded while younger and older participants performed a Sternberg task with two set sizes (2 vs. 6 items), allowing us to calculate a neural capacity index. Participants also completed two control tasks (Stroop and 3-back tests), which were used to calculate a composite executive control index. Results indicated that working memory performance decreased with aging and difficulty. At the neural level, results indicated that the P300 amplitude varied with aging and also with task difficulty. In the low difficulty condition, frontal P300 amplitude was higher for older than for younger adults, whereas in the high difficulty condition, the amplitude of frontal and parietal P300 did not differ between both age groups. Results also suggest that task difficulty led to a decrease in parietal amplitude in both age groups and to an increase in frontal amplitude in younger but not older adults. Both executive control and frontal neural capacity mediated the age-related variance in working memory for older adults. Moreover, executive control mediated the age-related variance in the frontal neural capacity of older adults. Thus, the present study suggests a model for older adults in which executive control deficits with advancing age lead to less efficient frontal recruitment to cope with task difficulty (neural capacity), which in turn has a negative impact on working memory functioning.

Inhibitory control of threat remembering in PTSD.

Intrusive traumatic recollections suggest an inability in Posttraumatic Stress Disorder (PTSD) to control and notably to inhibit memories for trauma-related information. Supported by inhibitory deficits found on experimental settings in PTSD, memory functioning and memory biases in the disorder were usually explained through inhibitory and control deficits in the processing of trauma-related information. The present study aimed to directly assess this hypothesis by investigating memory control abilities for emotional information in PTSD. For this purpose, 34 patients diagnosed with PTSD were compared to 37 non-PTSD controls on an item-cued directed forgetting paradigm for emotional words combined with a Remember/Know recognition procedure. Results revealed enhanced amounts of Remember recognitions for trauma-related words in PTSD. Moreover, we replicated findings of memory control impairments in the disorder. However, such impairments only occurred for non-trauma-related words. Accordingly, it appeared that PTSD patients presented preserved memory control abilities for trauma-related words, at the expenses of other emotional valences. Surprisingly, PTSD patients presented a preserved ability to control and notably to inhibit their memory functioning for trauma-related material. In addition to potential theoretical and clinical relevance, these results are discussed in the light of resource reallocation hypotheses and vigilant-avoidant theories of information processing in PTSD.

Brain tissue pulsatility mediates cognitive and electrophysiological changes in normal aging: Evidence from ultrasound tissue pulsatility imaging (TPI).

Aging is characterized by a cognitive decline of fluid abilities and is also associated with electrophysiological changes. The vascular hypothesis proposes that brain is sensitive to vascular dysfunction which may accelerate age-related brain modifications and thus explain age-related neurocognitive decline. To test this hypothesis, cognitive performance was measured in 39 healthy participants from 20 to 80 years, using tests assessing inhibition, fluid intelligence, attention and crystallized abilities. Brain functioning associated with attentional abilities was assessed by measuring the P3b ERP component elicited through an auditory oddball paradigm. To assess vascular health, we used an innovative measure of the pulsatility of deep brain tissue, due to variations in cerebral blood flow over the cardiac cycle. Results showed (1) a classical effect of age on fluid neurocognitive measures (inhibition, fluid intelligence, magnitude and latency of the P3b) but not on crystallized measures, (2) that brain pulsatility decreases with advancing age, (3) that brain pulsatility is positively correlated with fluid neurocognitive measures and (4) that brain pulsatility strongly mediated the age-related variance in cognitive performance and the magnitude of the P3b component. The mediating role of the brain pulsatility in age-related effect on neurocognitive measures supports the vascular hypothesis of cognitive aging.

Episodic feeling-of-knowing relies on noncriterial recollection and familiarity: Evidence using an online remember-know procedure.

We examined the hypothesis that feeling-of-knowing judgments rely on recollection as well as on familiarity prompted by the cue presentation. A remember-know-no memory procedure was combined with the episodic FOK procedure employing a cue-target pair memory task. The magnitude of FOK judgments and FOK accuracy were examined as a function of recollection, familiarity, or the "no memory" option. Results showed that the proportion of R and K responses was similar. FOK accuracy and magnitude of FOK judgments were higher for R and K responses than for N responses. FOK accuracy related to R and K responses were above chance level, but FOK was not accurate in the "no memory" condition. Finally, both FOK magnitude and FOK accuracy were related more to recollection than to familiarity. These results support the hypothesis that both recollection and familiarity are determinants of the FOK process, although they suggest that recollection has a stronger influence.

Age-related differences in time-based prospective memory: The role of time estimation in the clock monitoring strategy.

Time-based prospective memory (TBPM) is required when it is necessary to remember to perform an action at a specific future point in time. This type of memory has been found to be particularly sensitive to ageing, probably because it requires a self-initiated response at a specific time. In this study, we sought to examine the involvement of temporal processes in the time monitoring strategy, which has been demonstrated to be a decisive factor in TBPM efficiency. We compared the performance of young and older adults in a TBPM task in which they had to press a response button every minute while categorising words. The design allowed participants to monitor time by checking a clock whenever they decided. Participants also completed a classic time-production task and several executive tasks assessing inhibition, updating and shifting processes. Our results confirm an age-related lack of accuracy in prospective memory performance, which seems to be related to a deficient strategic use of time monitoring. This could in turn be partially explained by age-related temporal deficits, as evidenced in the duration production task. These findings suggest that studies designed to investigate the age effect in TBPM tasks should consider the contribution of temporal mechanisms.

Ageing-related stereotypes in memory: When the beliefs come true.

Age-related stereotype concerns culturally shared beliefs about the inevitable decline of memory with age. In this study, stereotype priming and stereotype threat manipulations were used to explore the impact of age-related stereotype on metamemory beliefs and episodic memory performance. Ninety-two older participants who reported the same perceived memory functioning were divided into two groups: a threatened group and a non-threatened group (control). First, the threatened group was primed with an ageing stereotype questionnaire. Then, both groups were administered memory complaints and memory self-efficacy questionnaires to measure metamemory beliefs. Finally, both groups were administered the Logical Memory task to measure episodic memory, for the threatened group the instructions were manipulated to enhance the stereotype threat. Results indicated that the threatened individuals reported more memory complaints and less memory efficacy, and had lower scores than the control group on the logical memory task. A multiple mediation analysis revealed that the stereotype threat effect on the episodic memory performance was mediated by both memory complaints and memory self-efficacy. This study revealed that stereotype threat impacts belief in one's own memory functioning, which in turn impairs episodic memory performance.

Kinematic observation reduces effect of aging on episodic memory performance.

This study investigated the influence of kinematics observation (i.e., observing action from only the motion of the main joints of an actor) on episodic memory performance differences between young and older adults. To this end, 42 young (20-35 years) and 45 older (60-75 years) participants performed a free recall task in two different conditions: either after an encoding phase consisting of the visual presentation and reading of action verbs or after an encoding phase consisting of the visual presentation and naming of point-light displays of humans performing the same actions. Results showed a beneficial effect of point-light display encoding for both young and older participants but with a more pronounced benefit for the older participants compared to young adults. These findings are discussed in relation to the embodied view of memory which considers that memory is directly linked to the sensorimotor experiences and the environmental support hypothesis which postulates that elaborate processing can improve memory performance. In conclusion, kinematic observation could constitute an interesting potential intervention for supporting memory in older adults.

The respective contribution of cognitive control and working memory to semantic and subjective organization in aging.

Organizing information is beneficial to episodic memory performance. Among several possible organizational strategies, two consist of organizing the information in semantic clusters (semantic organization) or self-organizing the information based on new associations that do not exist in semantic memory (subjective organization). Here, we investigated in a single study how these two organizational behaviors were underlined by different controlled processes and whether these relations were subjected to age-related differences. We tested 123 younger adults (n = 63) and older adults (n = 60) on two episodic memory tasks, one where the words were organizable and another where the words were not organizable, allowing for semantic and subjective organization, respectively. Additionally, participants were tested on three cognitive control tasks (Wisconsin Card Sorting Test, Stroop Test and Trail Making Test) and three working memory tasks (Backward Digit Span, Alpha Span and N-back test). Results revealed well-established age-related differences in terms of recall performance and organizational strategy implementation. More importantly, we found evidence that the different cognitive tests statistically yielded two different latent factors, a cognitive control factor and a working memory factor. Based on this dissociation, we found that only cognitive control contributed to semantic organization in all age groups whereas only working memory contributed to subjective organization, also in all age groups. These results shed new lights on our understanding of how controlled processes differently contribute to organizational behaviors in episodic memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Episodic memory and ageing: the role of cognitive reserve factors and cognitive resources according to task difficulty.

BACKGROUND: Episodic memory is the memory system which is most affected by ageing. However, similar memory decline is not seen in all older adults. Various cognitive reserve factors, such as the Openness Personality Trait and level of educational attainment, and cognitive resources linked to these factors, such as executive control and crystallised knowledge, can predict older adults' memory performance. OBJECTIVE: This study examined the link between and the role of these variables in older adults' memory performances according to the difficulty of the task. METHODS: Forty participants (aged between 60 and 82) learned 24 paired words with two encoding conditions (reading and generation), and then performed a cued recall. They were asked for their level of educational attainment, and their openness, executive control and crystallised knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). RESULTS: Only crystallised knowledge predicts older adults' recall of generated words while openness and executive control predict and mediate the effect of level of education on older adults' recall of read words. CONCLUSION: Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

The age-related effect on electrophysiological correlates of successful episodic memory encoding supports the hypothesis of a deficit in self-initiated encoding processes in aging.

Episodic memory decline with aging may be due to an age-related deficit in encoding processing, older adults having increasing difficulty to self-initiate encoding strategies that support later retrieval. Using event-related potentials (ERPs), the present study explored for the first time the neural correlates of successful encoding in a resource-dependent episodic memory task, in which participants had to self-initiate processes at both encoding and retrieval. At the behavioral level, results confirm the better memory performance of young than older adults. Comparing the neural activity elicited by studied items that were and were not subsequently recalled (Subsequent Memory Effect, SME), electrophysiological data revealed that younger adults showed a significant and sustained SME, shifting from parietal to frontal areas, suggesting that they self-initiated deep encoding strategies. In older adults, the duration of brain activity was shorter and located more in the parietal than frontal areas, suggesting that they used shallow rather than deep processes. Consistent with the hypothesis of a deficit in self-initiated strategies in aging, our findings suggest that when older adults are faced with a difficult memory task (no encoding support and no cue at retrieval), they engage fewer elaborative strategies than young adults, resulting in impaired episodic memory performance.

Aging, memory performance and metacognitive beliefs: a narrative review / Vieillissement, performances mnésiques et croyances métacognitives : une revue narrative

Aging is characterized by an increase in older adults' negative beliefs about their memory. These negative metamemory beliefs are thought to decrease their motivation to engage in memory tasks and to implement effective memory strategies leading to decreased memory performance. Memory assessment conditions tend to accentuate this phenomenon by increasing the salience of negative metamemory beliefs, resulting in an artificial reduction in memory performance (i.e., stereotype threat). However, experimental interventions like allowing participants to successfully complete a cognitive task before memory assessment (i.e., prior task success condition) would improve older adults' metamemory beliefs, allowing them to increase their memory performance. The effect of these psycho-emotional and contextual factors must be taken into account, as they are likely to induce bias in research and clinical examinations.

Le vieillissement est caractérisé par une augmentation des croyances négatives des adultes âgés à propos de leur mémoire. Ces croyances métamnésiques négatives diminueraient leur motivation à s'engager dans les tâches de mémoire et à mettre en place les stratégies efficaces conduisant à une diminution des performances mnésiques. Les conditions d'évaluation de la mémoire tendent à accentuer ce phénomène en augmentant la saillance des croyances métamnésiques négatives, ce qui entraîne une réduction artificielle des performances de mémoire (i.e., menace du stéréotype). Toutefois, certaines interventions expérimentales (e.g., réussite préalable) permettraient d'améliorer les croyances métamnésiques des adultes âgés, augmentant ainsi leur performance de mémoire. La prise en compte de l'effet de ces facteurs psychoaffectifs et contextuels est importante puisqu'ils sont susceptibles d'induire des biais lors des recherches et des examens cliniques.

The protective effect of educational level varies as a function of the difficulty of the memory task in ageing.

This study aimed to explore the effects of age and educational level on recall performance and organisational strategies used during recall as a function of the level of memory task difficulty. Younger (n = 55, age range = 20-39 years) and older (n = 45, age range = 65-75 years) adults learned a word list where the words were either already semantically grouped (easier) or presented in pseudo-random order (harder), and then recalled the words. The number of words recalled was calculated, and an index of clustering was computed to assess organisational strategies. Older adults recalled less words than the younger ones. Older adults with a higher educational level recalled more words than their counterparts with a lower educational level when the memory task was easier, but they all performed similarly on the harder memory task. Moreover, we noted a strong positive association between educational level and semantic organisation in older adults when the memory task was easier. Regardless of educational level, older adults used semantic organisation as much as younger adults when the memory task was easier. However, when the memory task was harder, older adults showed significantly less organisational strategies than younger adults, the latter using semantic organisation to boost their recall performance. In sum, the protective effect of educational level seems to be restricted on recall performance, but not organisational strategies, in easy memory tasks providing sufficient external information about the most efficient mnemonic strategy to use. Supplementary Information: The online version contains supplementary material available at 10.1007/s10433-022-00724-z.

Metamemory mediates the protective effect of cognitive reserve on episodic memory during aging.

The present study investigated the impact of cognitive reserve on episodic memory and metamemory control during aging using a multidimensional index of cognitive reserve and a measure of metamemory control abilities. We tested the hypotheses that cognitive reserve may play a protective role against age-related differences in episodic memory and metamemory control and that metamemory control may mediate the effect of cognitive reserve on episodic memory during aging. Young and older adults carried out a readiness-recall task in which task difficulty was manipulated through a variation of the nature of the cue-target pair link (weak vs. strong semantic associates). Episodic memory was assessed through recall performance, and metamemory by a task difficulty index reflecting the ability to adjust study time to task difficulty. Results confirmed that older adults recall fewer words, indicating an age-related deficit in episodic memory, and that older adults adjust less to task difficulty, suggesting impaired metamemory control. Findings also showed that metamemory control moderates the age-related decline in episodic memory and that cognitive reserve plays a protective role against age-related deficits in episodic memory and metamemory control. In addition, metamemory abilities mediated the beneficial effect of cognitive reserve on episodic memory performance during aging. Hence, this study sheds new light on the mechanisms underlying the impact of cognitive reserve on cognitive aging, highlighting the role of metacognitive processes.

Two hemispheres for better memory in old age: role of executive functioning.

This experiment explored the functional significance of age-related hemispheric asymmetry reduction associated with episodic memory and the cognitive mechanisms that mediate this brain pattern. ERPs were recorded while young and older adults performed a word-stem cued-recall task. Results confirmed that the parietal old/new effect was of larger latency and reduced magnitude and less lateralized in the older group than the young group. Correlational and regression analyses indicated that the degree of laterality of brain activity determines the accuracy of memory performance and mediates age-related differences in memory performance among older participants. They also confirmed a cascade model in which the individual level of executive functioning of older adults mediates age-related differences in the degree of lateralization of brain activity, which in turn mediates age-related differences in memory performance.

Neural correlates of episodic memory change in increasing age: a longitudinal event-related potential study.

Using a longitudinal design, we examined whether event-related brain potentials (ERPs) correlates of successful episodic memory retrieval varied over a 4-year period according to the level of memory change. ERPs were recorded while participants performed a word-stem cued-recall task, and this procedure was repeated 4 years later. We compared the ERP old/new effect patterns of participants whose memory performance remained stable over time (stable group) with those of participants experiencing episodic memory decline (decline group). The pattern of change of the old/new effect differed between groups. At T1, the two groups exhibited the same pattern, with a positive frontal and parietal old/new effect. For the decline group, the old/new effect pattern did not change between T1 and T2. By contrast, for the stable group, the positive parietal old/new effect at T1 no longer appeared at T2, but a negative old/new effect was exhibited at frontal sites. This brain reorganization pattern could be a compensatory mechanism supporting strategic processes and allowing memory abilities to be maintained over time.

[Episodic memory and aging: The role of cognitive reserve and cognitive resources according to task difficulty]. / Mémoire épisodique et vieillissement : rôle des facteurs de réserve et des ressources cognitives selon la difficulté de la tâche.

BACKGROUND: Episodic memory is the most affected memory system in aging. However, memory decline is not similar in every older adult. Various cognitive reserve factors, as Openness personality trait or educational level, and cognitive resources linked to these factors, as executive control and crystallized knowledge, can predict older adults' memory performance. OBJECTIVE: This study examined the link between and the role of these variables in older adults' memory performances according to the task difficulty. METHODS: Forty participants (60-82 years old) learned 24 paired words with two encoding conditions (reading and generation) and then performed a cued recall. Their educational level was asked, and their Openness, executive control and crystallized knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). RESULTS: Only crystallized knowledge predicts older adults' generated words recall while Openness and executive control predict and mediate educational level effect on older adults' read words recall. CONCLUSION: Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

Effect of self-reported internal memory strategy use on age-related episodic and working memory decline: Contribution of control processes.

We explored whether control processes could account for age-related differences in internal strategy use, which in turn would contribute to episodic and working memory decline in aging. Young and older adults completed the internal strategy subscale of the Metamemory in Adulthood (MIA) questionnaire, a free-recall task (FRT), a reading span task (RST), and 3 executive control tasks (the Wisconsin Card Sorting Test, the Initial Letter Fluency Test, and the Digit Symbol Substitution Test) allowing us to calculate a composite index of control processes. Results indicated that both self-reported internal strategy use and control processes index accounted for a significant proportion of the age-related variance in the FRT and the RST. However, once the control processes index was controlled for, variance in both the FRT and RST explained by internal strategy use were significantly reduced. Additionally, age-related variance in internal strategy use was mediated by the control processes index. These results suggest a cascade model in which individual control level would mediate age-related differences in internal strategy use, which in turn would mediate age-related differences in episodic and working memory performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Protective role of educational level on episodic memory aging: an event-related potential study.

The aim of the present experiment was to investigate whether educational level could modulate the effect of aging on episodic memory and on the electrophysiological correlates of retrieval success. Participants were divided into four groups based on age (young vs. older) and educational level (high vs. low), with 14 participants in each group. Event-related potentials (ERP) were recorded while participants performed a word-stem cued-recall task. Age-related memory deficits were greater for the less educated individuals. Age differences in the ERP old/new effects were also modulated by the level of education. This study demonstrated that the effects of age on episodic memory and ERP correlates of retrieval success are smaller in participants with high educational levels than those with lower levels. These findings provide support for the reserve hypothesis and highlight the need to consider individual differences when studying cognitive and cerebral changes in aging.