scholarly journals Neural Reorganization and Compensation in Aging

2015 ◽  
Vol 27 (7) ◽  
pp. 1275-1285 ◽  
Author(s):  
Alexa M. Morcom ◽  
Wendy Johnson
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Cognitive Function ◽  
Old Age ◽  
Functional Imaging ◽  
Current Evidence ◽  
Imaging Studies ◽  
Functional Reorganization ◽  
Theories Of Aging ◽  
The Brain

According to prominent theories of aging, the brain may reorganize to compensate for neural deterioration and prevent or offset cognitive decline. A frequent and striking finding in functional imaging studies is that older adults recruit additional regions relative to young adults performing the same task. This is often interpreted as evidence for functional reorganization, suggesting that, as people age, different regions or networks may support the same cognitive functions. Associations between additional recruitment and better performance in older adults have led to the suggestion that the additional recruitment may contribute to preserved cognitive function in old age and may explain some of the variation among individuals in preservation of function. However, many alternative explanations are possible, and recent findings and methodological developments have highlighted the need for more systematic approaches to determine whether reorganization occurs with age and whether it benefits performance. We reevaluate current evidence for compensatory functional reorganization in the light of recent moves to address these challenges.

scholarly journals The functional brain favours segregated modular connectivity at old age unless affected by neurodegeneration

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xue Chen ◽  
Joe Necus ◽  
Luis R. Peraza ◽  
Ramtin Mehraram ◽  
Yanjiang Wang ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Old Age ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Brain Regions ◽  
Functional Brain ◽  
The Brain ◽  
Universal Pattern ◽  
Shape And Size

AbstractBrain’s modular connectivity gives this organ resilience and adaptability. The ageing process alters the organised modularity of the brain and these changes are further accentuated by neurodegeneration, leading to disorganisation. To understand this further, we analysed modular variability—heterogeneity of modules—and modular dissociation—detachment from segregated connectivity—in two ageing cohorts and a mixed cohort of neurodegenerative diseases. Our results revealed that the brain follows a universal pattern of high modular variability in metacognitive brain regions: the association cortices. The brain in ageing moves towards a segregated modular structure despite presenting with increased modular heterogeneity—modules in older adults are not only segregated, but their shape and size are more variable than in young adults. In the presence of neurodegeneration, the brain maintains its segregated connectivity globally but not locally, and this is particularly visible in dementia with Lewy bodies and Parkinson’s disease dementia; overall, the modular brain shows patterns of differentiated pathology.

Exercise Impacts Age-Related Changes in Cognitive Function and Neural Complexity

2016 ◽  
Vol 5 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Jennifer J. Heisz ◽  
Ana Kovacevic
Keyword(s):  
Older Adults ◽  
Cognitive Function ◽  
Executive Functions ◽  
Cognitive Outcomes ◽  
Physically Active ◽  
Age Related ◽  
The Neural Network ◽  
Future Work ◽  
The Brain ◽  
Age Related Changes

Age-related changes in the brain can compromise cognitive function. However, in some cases, the brain is able to functionally reorganize to compensate for some of this loss. The present paper reviews the benefits of exercise on executive functions in older adults and discusses a potential mechanism through which exercise may change the way the brain processes information for better cognitive outcomes. Specifically, older adults who are more physically active demonstrate a shift toward local neural processing that is associated with better executive functions. We discuss the use of neural complexity as a sensitive measure of the neural network plasticity that is enhanced through exercise. We conclude by highlighting the future work needed to improve exercise prescriptions that help older adults maintain their cognitive and physical functions for longer into their lifespan.

scholarly journals Disentangle the neural correlates of attachment style in healthy individuals

2019 ◽  
Vol 28 (04) ◽  
pp. 371-375 ◽  
Author(s):  
Cinzia Perlini ◽  
Marcella Bellani ◽  
Maria Gloria Rossetti ◽  
Niccolò Zovetti ◽  
Giulia Rossin ◽  
...  
Keyword(s):  
Personality Traits ◽  
Attachment Style ◽  
Functional Imaging ◽  
Psychosocial Functioning ◽  
Attachment Styles ◽  
Neural Correlates ◽  
Current Evidence ◽  
Healthy Individuals ◽  
Imaging Studies ◽  
Wide Range

AbstractSince its development and theorisation in the 60s, attachment theory has greatly influenced both clinical and developmental psychology suggesting the existence of complex dynamics based on the relationship between an infant and its caregiver, that affects personality traits and interpersonal relationships in adulthood. Many studies have been conducted to explore the association between attachment styles and psychosocial functioning and mental health. By contrast, only a few studies have investigated the neurobiological underpinnings of attachment style, showing mixed results. Therefore, in this review, we described current evidence from structural and functional imaging studies with the final aim to disentangle the neural correlates of attachment style in healthy individuals. Overall, different attachment styles have been correlated with volumetric alterations mainly in the cingulate cortex, amygdala, hippocampus and anterior temporal pole. Consistently, functional imaging studies suggested patterns of activations in fronto-striatal-limbic circuits during the processing of social and attachment-related stimuli. Further studies are needed to clarify the neurobiological signature of attachment style, possibly taking into consideration a wide range of demographic, psychosocial and clinical factors that may mediate the associations between the style of attachment and brain systems (e.g., gender, personality traits, psychosocial functioning, early-life experience).

scholarly journals Blood-Based Oxidative Stress Markers and Cognitive Performance in Early Old Age: The HAPIEE Study

2016 ◽  
Vol 42 (5-6) ◽  
pp. 297-309 ◽  
Author(s):  
Pia Horvat ◽  
Ruzena Kubinova ◽  
Andrzej Pajak ◽  
Abdonas Tamosiunas ◽  
Ben Schöttker ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Older Adults ◽  
Cognitive Function ◽  
Old Age ◽  
Verbal Fluency ◽  
Community Dwelling ◽  
Cognitive Test ◽  
Oxidative Stress Markers ◽  
Stress Markers ◽  
Early Old Age

Background/Aims: Oxidative stress is involved in Alzheimer disease pathology, but its impact on cognitive function in community-dwelling older adults remains unknown. We estimated associations between serum oxidative stress markers and cognitive function in early old age. Methods: Subjects aged 45-69 years recruited in urban centers in Central and Eastern Europe had memory, verbal fluency, and processing speed assessed at baseline (2002-2005) and 3 years later. Derivatives of reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and total thiol levels (TTLs) were measured at baseline in a subsample. Linear regression was used to estimate associations of biomarkers with cognitive test scores cross-sectionally (n = 4,304) and prospectively (n = 2,882). Results: Increased d-ROM levels were inversely associated with global cognition and verbal fluency cross-sectionally and in prospective analysis; observed effects corresponded to 3-4 years' higher age. TTL was inconsistently associated with memory. BAP was not related to cognitive function. Conclusion: This study found modest evidence for a relationship between serum d-ROMs and cognitive function in a population sample of older adults.

scholarly journals Treated hypothyroidism, cognitive function, and depressed mood in old age: the Rancho Bernardo Study

2009 ◽  
Vol 161 (6) ◽  
pp. 917-921 ◽  
Author(s):  
Caroline K Kramer ◽  
Denise von Mühlen ◽  
Donna Kritz-Silverstein ◽  
Elizabeth Barrett-Connor
Keyword(s):  
Older Adults ◽  
Cognitive Function ◽  
Thyroid Hormone ◽  
Old Age ◽  
Depressed Mood ◽  
Medication Use ◽  
Antidepressant Medication ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism

ObjectiveOvert hypothyroidism is associated with cognitive impairment, which can be reversed if treated early and appropriately. We compared cognitive function (CF) of euthyroid older adults with those who had long-term treated hypothyroidism.MethodsBetween 1999 and 2003, the CF of 885 euthyroid and 149 hypothyroid-treated older adults (primary hypothyroidism after surgery or autoimmune thyroid disease) was assessed using three standardized CF tests: the modified mini-mental state examination, Trails B, and verbal fluency. Depressed mood was assessed using the Beck Depression Inventory (BDI). Only participants with thyroid stimulating hormone (TSH) in the normal range were included.ResultsThe treated hypothyroid group had been treated with l-thyroxine for an average of 20 years. Those with treated hypothyroidism were older than the euthyroid group (76.1±9.6 vs 73.6±10.2 years, P=0.005) and were much more often women (81.6 vs 54.8%, P<0.001). TSH levels were similar between groups (median interquartile range=1.57 (1.19) vs 1.54 (1.59) mIU/l, P=0.81). Compared to euthyroid, the treated hypothyroidism group had more frequent antidepressant medication use (19.5 vs 8.5%, P<0.001) but similar BDI scores. Performance on the three CF tests did not differ by thyroid hormone treatment. Results were not changed after adjustment for age, sex, antidepressant medication use, exercise, and total cholesterol.ConclusionLong-term treated hypothyroidism is not associated with impaired CF or depressed mood in old age. The lack of association with CF is reassuring with regard to long-term use of thyroid hormone therapy.

Consciousness is slower than you think

2002 ◽  
Vol 55 (4) ◽  
pp. 1081-1092 ◽  
Author(s):  
Patrick Rabbitt
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Reaction Time ◽  
Error Correction ◽  
Old Age ◽  
Choice Reaction Time ◽  
Incorrect Response ◽  
Response Signal ◽  
Subsequent Recall

In easy serial choice reaction time tasks (CRT tasks) young adults can very rapidly “correct” nearly all their errors by making the responses that they should have made (error-correcting responses). They are much less accurate at signalling their errors by making the same, deliberate, response to each (error-signalling responses), and they poorly remember errors that they have not signalled or corrected. When instructed to ignore errors they nevertheless involuntarily register them because the response immediately following them (responses following unacknowledged errors) are unusually slow, and they sometimes make involuntary error correction responses. Errors that are neither signalled nor remembered are registered at some level because responses following unacknowledged errors are slowed. Old age does not impair the accuracy of error correction or reduce the proportion of errors that are acknowledged because they are followed by unusually slow responses, but it does reduce the accuracy of error signalling and of recall of errors. Groups of 40 young adults (mean age 20.1 years, SD 1.1) and 40 older adults (mean 71.2 years, SD 5.1) signalled and recalled their errors increasingly accurately as intervals between each response and the next signal were increased from 150 ms to 1000 ms. Error signalling and recall improved as response-signal interval (RSI) durations increased, reaching asymptote at RSIs of 800 ms for the young and 1000 ms for the older adults. Thus processes necessary for conscious and deliberate choice or error-signalling responses and for subsequent recall of errors require more than 150 ms to complete, are slowed by old age, and may be interrupted by onset of new signals occurring earlier than 800 to 1000 ms after completion of an incorrect response.

scholarly journals Neural pattern similarity differentially affects memory performance of younger and older adults: Age differences in neural similarity and memory

2019 ◽  
Author(s):  
Verena R. Sommer ◽  
Yana Fandakova ◽  
Thomas H. Grandy ◽  
Yee Lee Shing ◽  
Markus Werkle-Bergner ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Memory Performance ◽  
Activity Patterns ◽  
Quality Of Information ◽  
Neural Representations ◽  
Age Related ◽  
Pattern Similarity ◽  
The Brain

AbstractAge-related memory decline is associated with changes in neural functioning but little is known about how aging affects the quality of information representation in the brain. Whereas a long-standing hypothesis of the aging literature links cognitive impairments to less distinct neural representations in old age, memory studies have shown that high similarity between activity patterns benefits memory performance for the respective stimuli. Here, we addressed this apparent conflict by investigating between-item representational similarity in 50 younger (19–27 years old) and 63 older (63–75 years old) human adults (male and female) who studied scene-word associations using a mnemonic imagery strategy while electroencephalography was recorded. We compared the similarity of spatiotemporal frequency patterns elicited during encoding of items with different subsequent memory fate. Compared to younger adults, older adults’ memory representations were more similar to each other but items that elicited the most similar activity patterns early in the encoding trial were those that were best remembered by older adults. In contrast, young adults’ memory performance benefited from decreased similarity between earlier and later periods in the encoding trials, which might reflect their better success in forming unique memorable mental images of the joint picture–word pair. Our results advance the understanding of the representational properties that give rise to memory quality as well as how these properties change in the course of aging.Significance statementDeclining memory abilities are one of the most evident limitations for humans when growing older. Despite recent advances of our understanding of how the brain represents and stores information in distributed activation patterns, little is known about how the quality of information representation changes during aging and thus affects memory performance. We investigated how the similarity between neural representations relates to subsequent memory quality in younger and older adults. We present novel evidence that the interaction of pattern similarity and memory performance differs between age groups: Older adults benefited from increased similarity during early encoding whereas young adults benefited from decreased similarity between early and later encoding. These results provide insights into the nature of memory and age-related memory deficits.

scholarly journals Behavioral and fMRI evidence that arousal enhances bottom-up attention and memory selectivity in young but not older adults

2021 ◽  
Author(s):  
Sara N Gallant ◽  
Briana L Kennedy ◽  
Shelby L Bachman ◽  
Ringo Huang ◽  
Tae-Ho Lee ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Age Differences ◽  
Emotional Experience ◽  
Noradrenergic System ◽  
Attention And Memory ◽  
Bottom Up ◽  
Age Related ◽  
Selective Processing ◽  
The Brain

During a challenge or emotional experience, increases in arousal help us focus on the most salient or relevant details and ignore distracting stimuli. The noradrenergic system integrates signals about arousal states throughout the brain and helps coordinate this adaptive attentional selectivity. However, age-related changes in the noradrenergic system and attention networks in the brain may reduce the efficiency of arousal to modulate selective processing in older adults. In the current neuroimaging study, we examined age differences in how arousal affects bottom-up attention to category-selective stimuli differing in perceptual salience. We found a dissociation in how arousal modulates selective processing in the young and older brain. In young adults, emotionally arousing sounds enhanced selective incidental memory and brain activity in the extrastriate body area for salient versus non-salient images of bodies. Older adults showed no such advantage in selective processing under arousal. These age differences could not be attributed to changes in the arousal response or less neural distinctiveness in old age. Rather, our results suggest that, relative to young adults, older adults become less effective at focusing on salient over non-salient details during increases in emotional arousal.

scholarly journals A lifespan program of mouse synaptome architecture

2019 ◽  
Author(s):  
Mélissa Cizeron ◽  
Zhen Qiu ◽  
Babis Koniaris ◽  
Ragini Gokhale ◽  
Noboru H. Komiyama ◽  
...  
Keyword(s):  
Young Adults ◽  
Old Age ◽  
Mouse Brain ◽  
Protein Composition ◽  
Brain Regions ◽  
Intellectual Ability ◽  
Brain Circuits ◽  
Brain Circuitry ◽  
Wide Scale ◽  
The Brain

AbstractHow synapses change molecularly during the lifespan and across all brain circuits is unknown. We analyzed the protein composition of billions of individual synapses from birth to old age on a brain-wide scale in the mouse, revealing a program of changes in the lifespan synaptome architecture spanning individual dendrites to the systems level. Three major phases were uncovered, corresponding to human childhood, adulthood and old age. An arching trajectory of synaptome architecture drives the differentiation and specialization of brain regions to a peak in young adults before dedifferentiation returns the brain to a juvenile state. This trajectory underscores changing network organization and hippocampal physiology that may account for lifespan transitions in intellectual ability and memory, and the onset of behavioral disorders.One sentence summaryThe synaptome architecture of the mouse brain undergoes continuous changes that organize brain circuitry across the lifespan.

Effects of Age on Searching for and Enumerating Targets that Cannot be Detected Efficiently

2005 ◽  
Vol 58 (6) ◽  
pp. 1119-1142 ◽  
Author(s):  
Derrick G. Watson ◽  
Elizabeth A. Maylor ◽  
Lucy A. M. Bruce
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Old Age ◽  
Counting Function ◽  
Specific Task ◽  
Single Target ◽  
Task Differences

We investigated the effects of old age on search, subitizing, and counting of difficult-to-find targets. In Experiment 1, young and older adults enumerated targets (Os) with and without distractors (Qs). Without distractors, the usual subitization-counting function occurred in both groups, with the same subitization span of 3.3 items. Subitization disappeared with distractors; older adults were slowed more overall by their presence but enumeration rates were not slowed by ageing either with or without distractors. In contrast, search rates for a single target (O among Qs) were twice as slow for older as for young adults. Experiment 2 tested and ruled out one account of age-equivalent serial enumeration based on the need to subvocalize numbers as items are enumerated. Alternative explanations based on the specific task differences between detecting and enumerating stimuli are discussed.

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