Longitudinal stability of the brain functional connectome is associated with episodic memory performance in aging

AbstractThe brain functional connectome forms a relatively stable and idiosyncratic backbone that can be used for identification or “fingerprinting” of individuals with a high level of accuracy. While previous cross-sectional evidence has demonstrated increased stability and distinctiveness of the brain connectome during the course of childhood and adolescence, less is known regarding the longitudinal stability in middle and old age. Here we collected structural and resting state functional MRI data at two time-points separated by 2-3 years in 75 middle-aged and older adults (age 49-80, SD = ± 6.91 years) which allowed us to assess the long-term stability of the functional connectome. We show that the connectome backbone generally remains stable over a 2-3 year time frame in middle- and old age. Independent of age, cortical volume was associated with the connectome stability of several canonical resting-state networks, suggesting that the connectome backbone relates to the structural integrity of the cortex. Moreover, individual longitudinal stability of subcortical and default mode networks were associated with differences in cross-sectional and longitudinal measures of episodic memory performance, supporting the functional relevance. The findings encourage the use of connectome stability analyses for understanding individual differences in cognitive aging. Furthermore, the observation that age-related changes in episodic memory performance relates to the stability of subcortical and default mode networks, provides new longitudinal evidence for the importance of these networks in maintaining mnemonic processing in old age.

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Predicting multilingual effects on executive function and individual connectomes in children: An ABCD study

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2110811118 ◽

2021 ◽

Vol 118 (49) ◽

pp. e2110811118

Author(s):

Young Hye Kwon ◽

Kwangsun Yoo ◽

Hillary Nguyen ◽

Yong Jeong ◽

Marvin M. Chun

Keyword(s):

Working Memory ◽

Executive Function ◽

Functional Connectivity ◽

Memory Performance ◽

Occipital Lobe ◽

Stop Signal Task ◽

Functional Connectome ◽

Prediction Approach ◽

The Brain ◽

Back Task

While there is a substantial amount of work studying multilingualism’s effect on cognitive functions, little is known about how the multilingual experience modulates the brain as a whole. In this study, we analyzed data of over 1,000 children from the Adolescent Brain Cognitive Development (ABCD) Study to examine whether monolinguals and multilinguals differ in executive function, functional brain connectivity, and brain–behavior associations. We observed significantly better performance from multilingual children than monolinguals in working-memory tasks. In one finding, we were able to classify multilinguals from monolinguals using only their whole-brain functional connectome at rest and during an emotional n-back task. Compared to monolinguals, the multilingual group had different functional connectivity mainly in the occipital lobe and subcortical areas during the emotional n-back task and in the occipital lobe and prefrontal cortex at rest. In contrast, we did not find any differences in behavioral performance and functional connectivity when performing a stop-signal task. As a second finding, we investigated the degree to which behavior is reflected in the brain by implementing a connectome-based behavior prediction approach. The multilingual group showed a significant correlation between observed and connectome-predicted individual working-memory performance scores, while the monolingual group did not show any correlations. Overall, our observations suggest that multilingualism enhances executive function and reliably modulates the corresponding brain functional connectome, distinguishing multilinguals from monolinguals even at the developmental stage.

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Age-Related Compensatory Reconfiguration of PFC Connections during Episodic Memory Retrieval

Cerebral Cortex ◽

10.1093/cercor/bhaa192 ◽

2020 ◽

Author(s):

Lifu Deng ◽

Mathew L Stanley ◽

Zachary A Monge ◽

Erik A Wing ◽

Benjamin R Geib ◽

...

Keyword(s):

Episodic Memory ◽

Memory Retrieval ◽

Medial Temporal Lobe ◽

Memory Performance ◽

Functional Integration ◽

Brain Network ◽

Age Related ◽

Connectivity Patterns ◽

The Brain ◽

Related Increase

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.

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Impact of Comorbid Depression on Serial Position Effects in Alzheimer’s Disease

GeroPsych ◽

10.1024/1662-9647/a000115 ◽

2014 ◽

Vol 27 (4) ◽

pp. 161-169 ◽

Cited By ~ 1

Author(s):

Nienke A. Hofrichter ◽

Sandra Dick ◽

Thomas G. Riemer ◽

Carsten Schleussner ◽

Monique Goerke ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Serial Position ◽

Episodic Memory ◽

Memory Performance ◽

Memory Function ◽

Word List ◽

Position Effects ◽

Serial Position Effects ◽

List Memory

Hippocampal dysfunction and deficits in episodic memory have been reported for both Alzheimer’s disease (AD) and major depressive disorder (MDD). Primacy performance has been associated with hippocampus-dependent episodic memory, while recency may reflect working memory performance. In this study, serial position profiles were examined in a total of 73 patients with MDD, AD, both AD and MDD, and healthy controls (HC) by means of CERAD-NP word list memory. Primacy performance was most impaired in AD with comorbid MDD, followed by AD, MDD, and HC. Recency performance, on the other hand, was comparable across groups. These findings indicate that primacy in AD is impaired in the presence of comorbid MDD, suggesting additive performance decrements in this specific episodic memory function.

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Study of the relationship between episodic memory performance and hippocampal subfield volumes in major depressive disorder

PsycEXTRA Dataset ◽

10.1037/e534982014-059 ◽

2013 ◽

Author(s):

N. V. Malykhin ◽

S. Travis ◽

Y. Huang ◽

N. J. Coupland ◽

P. Silverstone ◽

...

Keyword(s):

Major Depressive Disorder ◽

Depressive Disorder ◽

Episodic Memory ◽

Memory Performance ◽

Major Depressive ◽

The Relationship

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Knowledge is power: prior knowledge aids memory formation for both congruent and incongruent events, but in different ways.

10.31234/osf.io/um4ga ◽

2017 ◽

Author(s):

Andrea Greve ◽

Elisa Cooper ◽

Roni Tibon ◽

Richard Henson

Keyword(s):

Episodic Memory ◽

Prior Knowledge ◽

Memory Performance ◽

Memory Formation ◽

Memory Test ◽

World Knowledge ◽

Apparent Paradox ◽

Power Prior

Events that conform to our expectations, i.e, are congruent with our world knowledge or schemas, are better remembered than unrelated events. Yet events that conflict with schemas can also be remembered better. We examined this apparent paradox in four experiments, in which schemas were established by training ordinal relationships between randomly-paired objects, while episodic memory was tested for the number of objects on each trial. Better memory was found for both congruent and incongruent trials, relative to unrelated trials, producing memory performance that was a “U-shaped” function of congruency. Furthermore, the incongruency advantage, but not congruency advantage, emerged even if the information probed by the memory test was irrelevant to the schema, while the congruency advantage, but not incongruency advantage, also emerged after initial encoding. Schemas therefore augment episodic memory in multiple ways, depending on the match between novel and existing information.

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Development of the brain functional connectome follows puberty-dependent nonlinear trajectories

NeuroImage ◽

10.1016/j.neuroimage.2021.117769 ◽

2021 ◽

Vol 229 ◽

pp. 117769

Author(s):

Zeus Gracia-Tabuenca ◽

Martha Beatriz Moreno ◽

Fernando A. Barrios ◽

Sarael Alcauter

Keyword(s):

Functional Connectome ◽

The Brain

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Individual Uniqueness in the Neonatal Functional Connectome

Cerebral Cortex ◽

10.1093/cercor/bhab041 ◽

2021 ◽

Author(s):

Qiushi Wang ◽

Yuehua Xu ◽

Tengda Zhao ◽

Zhilei Xu ◽

Yong He ◽

...

Keyword(s):

Individual Differences ◽

Individual Identification ◽

Imaging Data ◽

Functional Connectome ◽

Middle Range ◽

Human Connectome Project ◽

The Individual ◽

And Behavior ◽

Identification Analysis ◽

The Brain

Abstract The functional connectome is highly distinctive in adults and adolescents, underlying individual differences in cognition and behavior. However, it remains unknown whether the individual uniqueness of the functional connectome is present in neonates, who are far from mature. Here, we utilized the multiband resting-state functional magnetic resonance imaging data of 40 healthy neonates from the Developing Human Connectome Project and a split-half analysis approach to characterize the uniqueness of the functional connectome in the neonatal brain. Through functional connectome-based individual identification analysis, we found that all the neonates were correctly identified, with the most discriminative regions predominantly confined to the higher-order cortices (e.g., prefrontal and parietal regions). The connectivities with the highest contributions to individual uniqueness were primarily located between different functional systems, and the short- (0–30 mm) and middle-range (30–60 mm) connectivities were more distinctive than the long-range (>60 mm) connectivities. Interestingly, we found that functional data with a scanning length longer than 3.5 min were able to capture the individual uniqueness in the functional connectome. Our results highlight that individual uniqueness is present in the functional connectome of neonates and provide insights into the brain mechanisms underlying individual differences in cognition and behavior later in life.

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Bi-Temporal Anodal Transcranial Direct Current Stimulation during Slow-Wave Sleep Boosts Slow-Wave Density but Not Memory Consolidation

Brain Sciences ◽

10.3390/brainsci11040410 ◽

2021 ◽

Vol 11 (4) ◽

pp. 410

Author(s):

Simon Ruch ◽

Kristoffer Fehér ◽

Stephanie Homan ◽

Yosuke Morishima ◽

Sarah Maria Mueller ◽

...

Keyword(s):

Episodic Memory ◽

Slow Wave ◽

Direct Current ◽

Memory Consolidation ◽

Transcranial Direct Current Stimulation ◽

Slow Wave Sleep ◽

Memory Performance ◽

Direct Current Stimulation ◽

Sleep Parameters ◽

Episodic Memories

Slow-wave sleep (SWS) has been shown to promote long-term consolidation of episodic memories in hippocampo–neocortical networks. Previous research has aimed to modulate cortical sleep slow-waves and spindles to facilitate episodic memory consolidation. Here, we instead aimed to modulate hippocampal activity during slow-wave sleep using transcranial direct current stimulation in 18 healthy humans. A pair-associate episodic memory task was used to evaluate sleep-dependent memory consolidation with face–occupation stimuli. Pre- and post-nap retrieval was assessed as a measure of memory performance. Anodal stimulation with 2 mA was applied bilaterally over the lateral temporal cortex, motivated by its particularly extensive connections to the hippocampus. The participants slept in a magnetic resonance (MR)-simulator during the recordings to test the feasibility for a future MR-study. We used a sham-controlled, double-blind, counterbalanced randomized, within-subject crossover design. We show that stimulation vs. sham significantly increased slow-wave density and the temporal coupling of fast spindles and slow-waves. While retention of episodic memories across sleep was not affected across the entire sample of participants, it was impaired in participants with below-average pre-sleep memory performance. Hence, bi-temporal anodal direct current stimulation applied during sleep enhanced sleep parameters that are typically involved in memory consolidation, but it failed to improve memory consolidation and even tended to impair consolidation in poor learners. These findings suggest that artificially enhancing memory-related sleep parameters to improve memory consolidation can actually backfire in those participants who are in most need of memory improvement.

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