Benefits and Costs of Context Reinstatement in Episodic Memory: An ERP Study

2017 ◽  
Vol 29 (1) ◽  
pp. 52-64 ◽  
Author(s):  
Inês Bramão ◽  
Mikael Johansson

This study investigated context-dependent episodic memory retrieval. An influential idea in the memory literature is that performance benefits when the retrieval context overlaps with the original encoding context. However, such memory facilitation may not be driven by the encoding–retrieval overlap per se but by the presence of diagnostic features in the reinstated context that discriminate the target episode from competing episodes. To test this prediction, the encoding–retrieval overlap and the diagnostic value of the context were manipulated in a novel associative recognition memory task. Participants were asked to memorize word pairs presented together with diagnostic (unique) and nondiagnostic (shared) background scenes. At test, participants recognized the word pairs in the presence and absence of the previously encoded contexts. Behavioral data show facilitated memory performance in the presence of the original context but, importantly, only when the context was diagnostic of the target episode. The electrophysiological data reveal an early anterior ERP encoding–retrieval overlap effect that tracks the cost associated with having nondiagnostic contexts present at retrieval, that is, shared by multiple previous episodes, and a later posterior encoding–retrieval overlap effect that reflects facilitated access to the target episode during retrieval in diagnostic contexts. Taken together, our results underscore the importance of the diagnostic value of the context and suggest that context-dependent episodic memory effects are multiple determined.

2000 ◽  
Vol 12 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Tetsuya Iidaka ◽  
Nicole D. Anderson ◽  
Shitij Kapur ◽  
Roberto Cabez ◽  
Fergus I. M. Craik

The effects of divided attention (DA) on episodic memory encoding and retrieval were investigated in 12 normal young subjects by positron emission tomography (PET). Cerebral blood flow was measured while subjects were concurrently performing a memory task (encoding and retrieval of visually presented word pairs) and an auditory tone-discrimination task. The PET data were analyzed using multivariate Partial Least Squares (PLS), and the results revealed three sets of neural correlates related to specific task contrasts. Brain activity, relatively greater under conditions of full attention (FA) than DA, was identified in the occipital-temporal, medial, and ventral-frontal areas, whereas areas showing relatively more activity under DA than FA were found in the cerebellum, temporo-parietal, left anterior-cingulate gyrus, and bilateral dorsolateral-prefrontal areas. Regions more active during encoding than during retrieval were located in the hippocampus, temporal and the prefrontal cortex of the left hemisphere, and regions more active during retrieval than during encoding included areas in the medial and right-prefrontal cortex, basal ganglia, thalamus, and cuneus. DA at encoding was associated with specific decreases in rCBF in the left-prefrontal areas, whereas DA at retrieval was associated with decreased rCBF in a relatively small region in the right-prefrontal cortex. These different patterns of activity are related to the behavioral results, which showed a substantial decrease in memory performance when the DA task was performed at encoding, but no change in memory levels when the DA task was performed at retrieval.


2018 ◽  
Author(s):  
Christiane Oedekoven ◽  
James L. Keidel ◽  
Stuart Anderson ◽  
Angus Nisbet ◽  
Chris Bird

Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of lifelike events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis revealed that in controls the functional connectivity between these regions when watching the videos was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of multimodal representations of the contents of an event.


2021 ◽  
Vol 15 ◽  
Author(s):  
Alicja Anna Binkowska ◽  
Natalia Jakubowska ◽  
Maciej Gaca ◽  
Natalia Galant ◽  
Agnieszka Piotrowska-Cyplik ◽  
...  

Background While research has consistently identified an association between long-term cannabis use and memory impairments, few studies have examined this relationship in a polydrug context (i.e., when combining cannabis with other substances).Aims: In this preliminary study, we used event-related potentials to examine the recognition process in a visual episodic memory task in cannabis users (CU) and cannabis polydrug users (PU). We hypothesized that CU and PU will have both–behavioral and psychophysiological–indicators of memory processes affected, compared to matched non-using controls with the PU expressing more severe changes.Methods 29 non-using controls (CG), 24 CU and 27 PU were enrolled into the study. All participants completed a visual learning recognition task while brain electrical activity was recorded. Event-related potentials were calculated for familiar (old) and new images from a signal recorded during a subsequent recognition test. We used receiver operating characteristic curves for behavioral data analysis.Results The groups did not differ in memory performance based on receiver operating characteristic method in accuracy and discriminability indicators nor mean reaction times for old/new images. The frontal old/new effect expected from prior research was observed for all participants, while a parietal old/new effect was not observed. While, the significant differences in the late parietal component (LPC) amplitude was observed between CG and PU but not between CG and CU nor CU and PU. Linear regression analysis was used to examine the mean amplitude of the LPC component as a predictor of memory performance accuracy indicator. LPC amplitude predicts recognition accuracy only in the CG.Conclusion The results showed alterations in recognition memory processing in CU and PU groups compared to CG, which were not manifested on the behavioral level, and were the most prominent in cannabis polydrug users. We interpret it as a manifestation of the cumulative effect of multiple drug usage in the PU group.


2020 ◽  
Vol 14 ◽  
Author(s):  
Giorgia Committeri ◽  
Agustina Fragueiro ◽  
Maria Maddalena Campanile ◽  
Marco Lagatta ◽  
Ford Burles ◽  
...  

The medial temporal lobe supports both navigation and declarative memory. On this basis, a theory of phylogenetic continuity has been proposed according to which episodic and semantic memories have evolved from egocentric (e.g., path integration) and allocentric (e.g., map-based) navigation in the physical world, respectively. Here, we explored the behavioral significance of this neurophysiological model by investigating the relationship between the performance of healthy individuals on a path integration and an episodic memory task. We investigated the path integration performance through a proprioceptive Triangle Completion Task and assessed episodic memory through a picture recognition task. We evaluated the specificity of the association between performance in these two tasks by including in the study design a verbal semantic memory task. We also controlled for the effect of attention and working memory and tested the robustness of the results by including alternative versions of the path integration and semantic memory tasks. We found a significant positive correlation between the performance on the path integration the episodic, but not semantic, memory tasks. This pattern of correlation was not explained by general cognitive abilities and persisted also when considering a visual path integration task and a non-verbal semantic memory task. Importantly, a cross-validation analysis showed that participants' egocentric navigation abilities reliably predicted episodic memory performance. Altogether, our findings support the hypothesis of a phylogenetic continuity between egocentric navigation and episodic memory and pave the way for future research on the potential causal role of egocentric navigation on multiple forms of episodic memory.


2020 ◽  
pp. 174702182098030
Author(s):  
Otto Waris ◽  
Daniel Fellman ◽  
Jussi Jylkkä ◽  
Matti Laine

Cognitive task performance is a dynamic process that evolves over time, starting from the first encounters with a task. An important aspect of these task dynamics is the employment of strategies to support successful performance and task acquisition. Focusing on episodic memory performance, we: (1) tested two hypotheses on the effects of novelty and task difficulty on strategy use; (2) replicated our previous results regarding strategy use in a novel memory task; and (3) evaluated whether repeated open-ended strategy queries affect task performance and/or strategy use. The present pre-registered online study comprised 161 adult participants who were recruited through the Prolific crowdsourcing platform. We employed two separate 5-block list learning tasks, one with 10 pseudowords and the other with 18 common nouns, and collected recall performance and strategy reports for each block. Using Bayesian linear mixed effects models, the present findings (1) provide some support for the hypothesis that task-initial strategy development is not triggered only by task novelty, but can appear also in a familiar, moderately demanding task; (2) replicate earlier findings from an adaptive working memory task indicating strategy use from the beginning of a task, associations between strategy use and objective task performance, and only modest agreement between open-ended vs. list-based strategy reports; and (3) indicate that repeated open-ended strategy reports do not affect objective recall. We conclude that strategy use is an important aspect of memory performance right from the start of a task, and it undergoes development at the initial stages depending on task characteristics. In a larger perspective, the present results concur with the views of skill learning and adaptivity in cognitive task performance.


2020 ◽  
Author(s):  
Lifu Deng ◽  
Mathew L Stanley ◽  
Zachary A Monge ◽  
Erik A Wing ◽  
Benjamin R Geib ◽  
...  

Abstract During demanding cognitive tasks, older adults (OAs) frequently show greater prefrontal cortex (PFC) activity than younger adults (YAs). This age-related increase in PFC activity is often associated with enhanced cognitive performance, suggesting functional compensation. However, the brain is a complex network of interconnected regions, and it is unclear how network connectivity of PFC regions differs for OAs versus YAs. To investigate this, we examined the age-related difference on the functional brain networks mediating episodic memory retrieval. YAs and OAs participants encoded and recalled visual scenes, and age-related differences in network topology during memory retrieval were investigated as a function of memory performance. We measured both changes in functional integration and reconfiguration in connectivity patterns. The study yielded three main findings. First, PFC regions were more functionally integrated with the rest of the brain network in OAs. Critically, this age-related increase in PFC integration was associated with better retrieval performance. Second, PFC regions showed stronger performance-related reconfiguration of connectivity patterns in OAs. Finally, the PFC reconfiguration increases in OAs tracked reconfiguration reductions in the medial temporal lobe (MTL)—a core episodic memory region, suggesting that PFC connectivity in OAs may be compensating for MTL deficits.


2015 ◽  
Vol 21 (10) ◽  
pp. 780-790 ◽  
Author(s):  
Scott M. Hayes ◽  
Michael L. Alosco ◽  
Jasmeet P. Hayes ◽  
Margaret Cadden ◽  
Kristina M. Peterson ◽  
...  

AbstractAging is associated with performance reductions in executive function and episodic memory, although there is substantial individual variability in cognition among older adults. One factor that may be positively associated with cognition in aging is physical activity. To date, few studies have objectively assessed physical activity in young and older adults, and examined whether physical activity is differentially associated with cognition in aging. Young (n=29, age 18–31 years) and older adults (n=31, ages 55–82 years) completed standardized neuropsychological testing to assess executive function and episodic memory capacities. An experimental face-name relational memory task was administered to augment assessment of episodic memory. Physical activity (total step count and step rate) was objectively assessed using an accelerometer, and hierarchical regressions were used to evaluate relationships between cognition and physical activity. Older adults performed more poorly on tasks of executive function and episodic memory. Physical activity was positively associated with a composite measure of visual episodic memory and face-name memory accuracy in older adults. Physical activity associations with cognition were independent of sedentary behavior, which was negatively correlated with memory performance. Physical activity was not associated with cognitive performance in younger adults. Physical activity is positively associated with episodic memory performance in aging. The relationship appears to be strongest for face-name relational memory and visual episodic memory, likely attributable to the fact that these tasks make strong demands on the hippocampus. The results suggest that physical activity relates to cognition in older, but not younger adults. (JINS, 2015, 21, 780–790)


2021 ◽  
Vol 37 (3) ◽  
pp. 468-477
Author(s):  
Alba Fernández ◽  
Susana Cid-Fernández ◽  
Fernando Díaz

El objetivo principal del presente estudio fue determinar los efectos de la tDCS anódica vs placebo, administrada sobre el dlPFC durante la fase de codificación de una tarea de memoria episódica, sobre la tasa de aciertos (TA) y el tiempo de reacción (TR) medidos en las fases de recuerdo inmediato y demorado de la tarea, en un grupo de 23 participantes jóvenes sanos. Se realizó un estudio doble ciego aleatorizado. Los resultados evidenciaron efectos principales significativos para los factores Bloque, Sesión y Demora en la TA y en el TR, pero no para el factor del Grupo. Se encontraron efectos robustos de aprendizaje intrasesión e intersesiones, pero ningún efecto Grupo (tDCS anódica vs placebo) en el rendimiento de la memoria episódica o en los tests neuropsicológicos pre-post intervención. Sin embargo, los participantes que recibieron tDCS anódica mostraron un TR acortado en el intervalo de demora de 24 horas que mantuvieron una semana más tarde, mientras que los que recibieron tDCS placebo no mostraron acortamiento del TR a las 24 horas, pero si un aumento del TR una semana después. Estos resultados podrían indicar un sutil efecto modulador de la tDCS anódica en el decaimiento de la memoria en los intervalos de demora. El protocolo experimental mostró su utilidad potencial para ser utilizado en muestras de participantes mayores sanos o con deterioro cognitivo leve The main aim of the present study was to determine the effects of anodal vs sham tDCS administered over the dlPFC during the encoding phase of an episodic memory task, on the accuracy rate (AR) and reaction time (RT) measured in the immediate and delayed recall phases of the task, in a group of 23 healthy young participants. A randomized double-blind sham-controlled study of tDCS was carried out. The results evidenced significant main effects for factors Block, Session, and Delay on the AR and on RT, but not for the Group factor. Robust intra-session and inter-session learning effects but no Group (anodal vs sham tDCS) effect in episodic memory performance or in pre-post intervention neuropsychological tests were found. However, participants who received anodal tDCS showed shorter RT in the 24 hours delay interval and maintained it one week later, while those who received sham tDCS did not show the 24 hours RT shortening and even showed a RT increase one week later. These results could indicate a subtle modulatory effect of anodal tDCS on memory decay along delay intervals. The experimental protocol showed its potential utility to be used in samples of healthy elderly or mild cognitive impairment participants


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 704-705
Author(s):  
Atsuko Hayashi

Abstract In older adults, it is important to maintain awareness of memory as well as memory performance. However, it is not clear whether the awareness of episodic and lexical memory changes with age and is related to self-evaluation of memory and executive function. Here age-related changes and the relationship between metamemory, executive function, and metamemory scale were investigated. Healthy old (n=40) and young (n=34) groups participated in this study. In the episodic memory task, participants were asked to memorize ten Kanji words and to estimate the number of words they could recall after ten minutes. In the lexical memory task, they rated the likelihood that they could write a target Kanji word written in hiragana and then wrote them down. They were also asked to complete the metamemory in adulthood(MIA) and the position stroop task. In the episodic and lexical memory and the position stroop task and MIA subscales, the performances of the younger group were significantly better than those of the older group. In the episodic memory task, there were correlations between the metamemory and MIA subscales in both groups, but in the lexical memory task, only in the old group. No correlation was found between the results of both memory tasks and the stroop test. These results suggest that older people overestimate memory performances in the episodic and lexical memory tasks and metamemory performances may be associated with self-evaluation of memory. In addition, metamemory might not be related to frontal lobe function as shown in executive function tasks.


2017 ◽  
Vol 76 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Marine Beaudoin ◽  
Olivier Desrichard

Abstract. The present research examined the role persistence plays in mediating the positive impact of memory self-efficacy (MSE, i.e., one’s confidence in one’s own memory abilities) on older adults’ memory performance. In three studies, 81 to 264 older adults completed an MSE scale and carried out an explicit episodic memory task, during which we recorded their study time as an indicator of task persistence. We found that higher MSE was indirectly related to better memory performance through greater persistence during encoding, as measured by longer study time. Indirect effects were of medium size, with point estimates ranging from 0.64 to 0.85. This mediation effect was independent of factors that could be confounded with study time: chronological age, memory span, prior level of memory performance, episodic memory ability, and use of learning strategies (encoding strategies and self-testing). When confronted with difficult memory tasks, older adults who lack confidence in their memory abilities cease their efforts prematurely, which contributes to a decrease in their performance. Encouraging older adults to persist in the face of difficulties during encoding and retrieval may help alleviate the negative impact of low MSE on memory performance and allow researchers and clinicians to more accurately estimate older adults’ true memory abilities.


Sign in / Sign up

Export Citation Format

Share Document