Age-related Differences In Functional Connectivity Research Articles

Age-related differences in functional connectivity associated with pain modulation

Growing evidence suggests that aging is associated with impaired endogenous pain modulation, and that this likely underlies the increased transition from acute to chronic pain in older individuals. Resting-state functional connectivity (rsFC) offers a valuable tool to examine the neural mechanisms behind these age-related changes in pain modulation. RsFC studies generally observe decreased within-network connectivity due to aging, but its relevance for pain modulation remains unknown. We compared rsFC within a set of brain regions involved in pain modulation between young and older adults and explored the relationship with the efficacy of distraction from pain. This revealed several age-related increases and decreases in connectivity strength. Importantly, we found a significant association between lower pain relief and decreased strength of three connections in older adults, namely between the periaqueductal gray and right insula, between the anterior cingulate cortex (ACC) and right insula, and between the ACC and left amygdala. These findings suggest that the functional integrity of the pain control system is critical for effective pain modulation, and that its function is compromised by aging.

Difficulty sensitivity replaces reward sensitivity during adolescence: Task-related fMRI and functional connectivity during self-regulative learning choices

AimWe examined age-related differences in valuation and cognitive control circuits during value-based decision-making. Methods13-year-olds (N = 25) and 17-year-olds (N = 22) made a metacognitive choice to be tested or not on an upcoming learning task, based on reward and difficulty associated with word-pairs. To investigate whether these determinants of subjective value are differently processed at different ages, we performed region-of-interest(ROI)-based analyses of task-related and functional connectivity data.Results: We observed age-related differences in responsiveness of valuation structures (amygdala, ventral striatum, ventromedial prefrontal cortex) and caudate nucleus, with activity modulated by reward in 13-year-olds, while in 17-year-olds activity being responsive to difficulty. These accompanied age-related differences in functional connectivity between medial prefrontal and striatal/amygdala seeds. DiscussionThese results are in line with current views that sensitivity changes for reward and difficulty during adolescence are the result of a maturational switch in effort-related signalling in the cognitive control circuit, which increasingly regulates value-signalling structures.

Effect of Alzheimer's Pathology on Task-Related Brain Network Reconfiguration in Aging.

Large-scale brain networks undergo widespread changes with older age and in neurodegenerative diseases such as Alzheimer's disease (AD). Research in young adults (YA) suggest that the underlying functional architecture of brain networks remains relatively consistent between rest and task states. However, it remains unclear whether the same is true in aging and to what extent any changes may be related to accumulation of AD pathology such as β-amyloid (Aβ) and tau. Here, we examined age-related differences in functional connectivity (FC) between rest and an object-scene mnemonic discrimination task using fMRI in young and older adults (OA; both females and males). We used an a priori episodic memory network (EMN) parcellation scheme associated with object and scene processing, that included anterior-temporal regions and posterior-medial regions. We also used positron emission topography to measure Aβ and tau in older adults. The correlation between rest and task FC (i.e., FC similarity) was reduced in older compared with younger adults. Older adults with lower FC similarity in EMN had higher levels of tau in the same EMN regions and performed worse during object, but not scene, trials during the fMRI task. These findings link AD pathology, particularly tau, to a less stable functional architecture in memory networks. They also suggest that smaller changes in FC organization between rest and task states may facilitate better performance in older age. Interpretations are limited by methodological factors related to different acquisition directions and durations between rest and task scans.SIGNIFICANCE STATEMENT The brain's large-scale network organization is relatively consistent between rest and task states in young adults (YA). We found that memory networks in older adults (OA) were less correlated between rest and (memory) task states compared with young adults. Older adults with less correlated brain networks also had higher levels of Alzheimer's disease (AD) pathology in the same regions, suggesting that a less stable network architecture may reflect the early evolution of AD. Older adults with less correlated brain networks also performed worse during the memory task suggesting that more similar network organization between rest and task states may facilitate better performance in older age.

Discrete Ricci curvatures capture age-related changes in human brain functional connectivity networks.

Geometry-inspired notions of discrete Ricci curvature have been successfully used as markers of disrupted brain connectivity in neuropsychiatric disorders, but their ability to characterize age-related changes in functional connectivity is unexplored. We apply Forman-Ricci curvature and Ollivier-Ricci curvature to compare functional connectivity networks of healthy young and older subjects from the Max Planck Institute Leipzig Study for Mind-Body-Emotion Interactions (MPI-LEMON) dataset (N = 225). We found that both Forman-Ricci curvature and Ollivier-Ricci curvature can capture whole-brain and region-level age-related differences in functional connectivity. Meta-analysis decoding demonstrated that those brain regions with age-related curvature differences were associated with cognitive domains known to manifest age-related changes-movement, affective processing, and somatosensory processing. Moreover, the curvature values of some brain regions showing age-related differences exhibited correlations with behavioral scores of affective processing. Finally, we found an overlap between brain regions showing age-related curvature differences and those brain regions whose non-invasive stimulation resulted in improved movement performance in older adults. Our results suggest that both Forman-Ricci curvature and Ollivier-Ricci curvature correctly identify brain regions that are known to be functionally or clinically relevant. Our results add to a growing body of evidence demonstrating the sensitivity of discrete Ricci curvature measures to changes in the organization of functional connectivity networks, both in health and disease.

Task difficulty modulates age-related differences in functional connectivity during word production

Older adults typically report increased difficulty with language production, while its neural bases are less clear. The current study investigated the neural bases of age-related differences in language production at the word level and the modulating effect of task difficulty, focusing on task-based functional connectivity. Using an English phonological Go/No-Go picture naming task, task difficulty was manipulated by varying the proportion of naming trials (Go trials) and inhibition trials (No-Go trials) across runs. Behaviorally, compared to younger adults, older adults performed worse, and showed larger effects of task difficulty. Neurally, older adults had lower within language network connectivity compared to younger adults. Moreover, older adults’ language network became less segregated as task difficulty increased. These results are consistent with the Compensation-Related Utilization of Neural Circuits Hypothesis, suggesting that the brain becomes less specified and efficient with increased task difficulty, and that these effects are stronger among older adults (i.e., more dedifferentiated).

Task-Induced Functional Connectivity of Picture Naming in Healthy Aging: The Impacts of Age and Task Complexity

The topological organization of the brain, governed by the capacity of brain regions to synchronize their activity, allows for cost-effective performance during everyday cognitive activity. Functional connectivity is an fMRI method deemed task-specific and demand-dependent. Although the brain undergoes significant changes during healthy aging, conceptual knowledge and word-production accuracy are generally preserved. The exploration of task-induced functional connectivity patterns during active picture naming may thus provide additional information about healthy functional cerebral mechanisms that are specifically adapted to the cognitive activity at hand. The goal of this study is to assess and describe age-related differences in functional connectivity during an overt picture-naming task, as well as to compare age-related differences under complex task demand, defined by lexical frequency. Results suggest both age-specific and task-specific mechanisms. In the context of preserved behavioral performance in a picture-naming task, older adults show a complex array of differences in functional connectivity architecture, including both increases and decreases. In brief, there is increased segregation and specialization of regions that are classically assigned to naming processes. Results also expand on previous word-production studies and suggest that motor regions are particularly subject to age-related differences. This study also provides the first indication that intrinsic task demand, as manipulated by lexical frequency, interacts little with the relationship between age and functional connectivity. Together, these findings confirm the value of task-induced functional connectivity analysis in revealing the brain organization that subserves task performance during healthy aging.

Age-variant and age-invariant features of functional brain organization in middle-aged and older autistic adults

BackgroundThe majority of research effort into autism has been dedicated to understanding mechanisms during early development. As a consequence, research on the broader life course of an autism spectrum condition (ASC) has largely been neglected and almost nothing is known about ASC beyond middle age. Differences in brain connectivity that arise during early development may be maintained across the lifespan and may play protective or detrimental roles in older age.MethodThis study explored age-related differences in functional connectivity across middle and older age in clinically diagnosed autistic adults (n = 44, 30–73 years) and in an age-matched typical comparison group (n = 45).ResultsThe results indicated parallel age-related associations in ASC and typical aging for the local efficiency and connection strength of the default mode network and for the segregation of the frontoparietal control network. In contrast, group differences in visual network connectivity are compatible with a safeguarding interpretation of less age-related decline in brain function in ASC. This divergence was mirrored in different associations between visual network connectivity and reaction time variability in the ASC and comparison group.LimitationsThe study is cross-sectional and may be affected by cohort effects. As all participants received their autism diagnosis in adulthood, this might hinder generalizability.ConclusionThese results highlight the complexity of aging in ASC with both parallel and divergent trajectories across different aspects of functional network organization.

Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome.

Event Abstract Back to Event Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome. Perrine Ferre1* 1 Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Canada According to the World Health Organization, the proportion of individuals over age 60 is expected to double by 2050. Cognitive impairments can be extremely frequent in particular in older age, and has been recurrently shown to be the most feared health conditions associated with aging. In this context, a better understanding of the mechanisms that can support cognitive health during aging is crucial. Most of the current knowledge about the aged-related changes in brain neurofunctional organization stems from studies using cognitive tasks for which performance has a tendency to decrease with aging (e.g.: working memory). Few of those studies have looked at language processing related to vocabulary and semantic knowledge, abilities that have been shown to be relatively preserved in aging. The way by which the aging brain can continue to be efficient such as it is the case for vocabulary and semantic knowledge is still poorly looked at. Over the last decade, an increasing interest has been devoted to describing age-related changes in the functional connectivity of the brain. However, in most cases, these studies have been conducted while participants were in a “resting state”, namely without engaging in any particular cognitive task. Important changes in the pattern of functional connectivity has been described in such resting state conditions. It remains to be determined if age-related differences in functional connectivity are also present within the neurofunctional organization in specific cognitive contexts, and in particular when participants are engaged in tasks requiring verbal and semantic processing of words. In the present study, a brain connectome analysis was performed on 300 adults ranging from 18 to 80 years old. They were tested systematically for whole brain connectivity to search for consistent differences as a function of age, performance, education or cognitive reserve factors during an fMRI session of resting-state and while performing three lexical-semantic tasks (antonyms, synonyms, picture naming). Then, similarities in age effect on brain connectivity across all tasks was examined for language-related seed regions. Results confirm that performances for the lexical-semantic tasks are preserved. Brain imaging also shows the existence of qualitative discrepancies between task-evoked and resting state connectivity patterns. Mean functional connectivity shows a general tendency to decrease with age, whatever the cognitive context. However, during lexical-semantic tasks, enhanced connectivity in semantic and visual-attentional regions is revealed. No interactions were to be found between connectivity patterns and performance, education or cognitive reserve as a function of age, thus not bringing imaging support to some of the determinants of presumed compensation of cognitive aging. The results of the present study suggest that investigation of functional connectivity in aging cannot solely rely on resting-state imaging data, especially when interpretation of cognitive processes is at stake. Our results also challenge the current models of aging in their ability to account for age differences in the semantic-language domain. Keywords: lexical-semantics, Aging, functional connectivity (FC), Resting-state fMRI, Task-based functional connectivity Conference: Academy of Aphasia 56th Annual Meeting, Montreal, Canada, 21 Oct - 23 Oct, 2018. Presentation Type: poster presentation Topic: not eligible for a student prize Citation: Ferre P (2019). Resting state versus Task Based Exploration of Age-Related Changes of the Neurofunctional Connectome. . Conference Abstract: Academy of Aphasia 56th Annual Meeting. doi: 10.3389/conf.fnhum.2018.228.00011 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 25 Apr 2018; Published Online: 22 Jan 2019. * Correspondence: Miss. Perrine Ferre, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, Canada, perrine_ferre@hotmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Perrine Ferre Google Perrine Ferre Google Scholar Perrine Ferre PubMed Perrine Ferre Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. 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The relation of structural integrity and task-related functional connectivity in the aging brain

The relations among structural integrity, functional connectivity (FC), and cognitive performance in the aging brain are still understudied. Here, we used multimodal and multivariate approaches to specifically examine age-related changes in task-related FC, gray-matter volumetrics, white-matter integrity, and performance. Our results are two-fold, showing (i) age-related differences in FC of the working memory network and (ii) age-related recruitment of a compensatory network associated with better accuracy on the task. Increased connectivity in the compensatory network correlates positively with preserved white-matter integrity in bilateral frontoparietal tracks and with larger gray-matter volume of right inferior parietal lobule. These findings demonstrate the importance of structural integrity and FC in working memory performance associated with healthy aging.

Dimensional Change Card Sort performance associated with age-related differences in functional connectivity of lateral prefrontal cortex

The Dimensional Change Card Sort (DCCS) is a standard procedure for assessing executive functioning early in development. In the task, participants switch from sorting cards one way (e.g., by color) to sorting them a different way (e.g., by shape). Traditional accounts associate age-related changes in DCCS performance with circumscribed changes in lateral prefrontal cortex (lPFC) functioning, but evidence of age-related differences in the modulation of lPFC activity by switching is mixed. The current study therefore tested for possible age-related differences in functional connectivity of lPFC with regions that comprise a larger cognitive control network. Functional magnetic resonance imaging (fMRI) data collected from children and adults performing the DCCS were analyzed by means of independent components analysis (ICA). The analysis revealed several important age-related differences in functional connectivity of lPFC. In particular, lPFC was more strongly connected with the anterior cingulate, inferior parietal cortex, and the ventral tegmental area in adults than in children. Theoretical implications are discussed.

Maturation of task-induced brain activation and long range functional connectivity in adolescence revealed by multivariate pattern classification

The present study uses multivariate pattern classification analysis to examine maturation in task-induced brain activation and in functional connectivity during adolescence. The multivariate approach allowed accurate discrimination of adolescent boys of respectively 13, 17 and 21years old based on brain activation during a gonogo task, whereas the univariate statistical analyses showed no or only very few, small age-related clusters. Developmental differences in task activation were spatially distributed throughout the brain, indicating differences in the responsiveness of a wide range of task-related and default mode regions. Moreover, these distributed age-distinctive patterns generalized from a simple gonogo task to a cognitively and motivationally very different gambling task, and vice versa. This suggests that functional brain maturation in adolescence is driven by common processes across cognitive tasks as opposed to task-specific processes. Although we confirmed previous reports of age-related differences in functional connectivity, particularly for long range connections (>60mm), these differences were not specific to brain regions that showed maturation of task-induced responsiveness. Together with the task-independency of brain activation maturation, this result suggests that brain connectivity changes in the course of adolescence affect brain functionality at a basic level. This basic change is manifest in a range of tasks, from the simplest gonogo task to a complex gambling task.

Caudate Dopamine D1 Receptor Density Is Associated with Individual Differences in Frontoparietal Connectivity during Working Memory

We assess the relationship of age-related losses in striatal D1 receptor densities to age-related reductions in functional connectivity between spatially distinct cortical regions in healthy human participants. Previous neuroimaging studies have reported age-related differences in functional connectivity of the frontoparietal working memory network and the default mode network during task performance. We used functional magnetic resonance imaging and seed-based connectivity (right dorsolateral and medial prefrontal cortex) to extend these findings: Anterior-posterior connectivity of both these functional networks was reduced in older (65-75 years, n = 18) compared with younger (20-30 years, n = 19) adults, whereas bilateral connectivity in prefrontal cortex was increased in older adults. Positron emission tomography with the D1 receptor ligand [(11)C]SCH23390 was used to assess caudate D1 receptor density in the same sample. Older adults showed significantly reduced caudate D1 receptor density compared to the younger adults. Of key interest, partial correlations showed that individual differences in caudate D1 receptor density were positively associated with individual differences in dorsolateral prefrontal connectivity to right parietal cortex (BA40) and negatively with medial prefrontal connectivity to right parietal cortex (BA40 and postcentral gyrus), after controlling for age. We found no correlation of caudate D1 receptor density with anterior-posterior coupling within the default mode network or with bilateral frontal connectivity. These results are consistent with animal work that has identified a role for caudate D1 receptors in mediating information transfer between prefrontal areas and parietal cortex.