scholarly journals Older adults benefit from more widespread brain network integration during working memory

2019 ◽  
Author(s):  
C.A. Crowell ◽  
S.W. Davis ◽  
L. Beynel ◽  
L. Deng ◽  
D. Lakhlani ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Network Connectivity ◽  
Task Demands ◽  
Global Network ◽  
Aging Brain ◽  
Network Integration ◽  
Younger Adults ◽  
Age Related ◽  
Cortical Regions

AbstractNeuroimaging evidence suggests that the aging brain relies on a more distributed set of cortical regions than younger adults in order to maintain successful levels of performance during demanding cognitive tasks. However, it remains unclear how task demands give rise to this age-related expansion in cortical networks. To investigate this issue, we used functional magnetic resonance imaging to measure univariate activity, network connectivity, and cognitive performance in younger and older adults during a working memory (WM) task. In the WM task investigated, participants hold letters online (maintenance) while reordering them alphabetically (manipulation). WM load was titrated to obtain four individualized difficulty levels. Network integration—defined as the ratio of within-versus between-network connectivity—was linked to individual differences in WM capacity. The study yielded three main findings. First, as task difficulty increased, network integration decreased in younger adults, whereas it increased in older adults. Second, age-related increases in network integration were driven by increases in right hemispheric connectivity to both left and right cortical regions, a finding that helps to reconcile extant theories of compensatory recruitment in aging to address the multivariate dynamics of global network functioning. Lastly, older adults with higher WM capacity demonstrated higher levels of network integration in the most difficult condition. These results shed light on the mechanisms of age-related network reorganization by suggesting that changes in network connectivity may act as an adaptive form of compensation, with older adults recruiting a more distributed cortical network as task demands increase.Significance statementOlder adults often activate brain regions not engaged by younger adults, but the circumstances under which this widespread network emerges are unclear. Here, we examined the effects of aging on network connectivity between task regions recruited during a working memory (WM) manipulation task, and the rest of the brain. We found an age-related increase in the more global network integration in older adults, and an association between this integration and working memory capacity in older adults. The findings are generally consistent with the compensatory interpretation of these effects.

scholarly journals Age-related and Genetic Modulation of Frontal Cortex Efficiency

2014 ◽  
Vol 26 (4) ◽  
pp. 746-754 ◽  
Author(s):  
Lars Nyberg ◽  
Micael Andersson ◽  
Karolina Kauppi ◽  
Anders Lundquist ◽  
Jonas Persson ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Representative Sample ◽  
Task Demands ◽  
Bold Signal ◽  
Bold Response ◽  
Younger Adults ◽  
Age Related ◽  
Low Efficiency ◽  
Large Representative

The dorsolateral pFC (DLPFC) is a key region for working memory. It has been proposed that the DLPFC is dynamically recruited depending on task demands. By this view, high DLPFC recruitment for low-demanding tasks along with weak DLPFC upregulation at higher task demands reflects low efficiency. Here, the fMRI BOLD signal during working memory maintenance and manipulation was examined in relation to aging and catechol-O-methyltransferase (COMT) Val158Met status in a large representative sample (n = 287). The efficiency hypothesis predicts a weaker DLPFC response during manipulation, along with a stronger response during maintenance for older adults and COMT Val carriers compared with younger adults and COMT Met carriers. Consistent with the hypothesis, younger adults and met carriers showed maximal DLPFC BOLD response during manipulation, whereas older adults and val carriers displayed elevated DLPFC responses during the less demanding maintenance condition. The observed inverted relations support a link between dopamine and DLPFC efficiency.

scholarly journals Advanced Aging Enhances the Positivity Effect in Memory: Due to Cognitive Control or Age-Related Decline in Emotional Processing?

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Michiko Sakaki ◽  
Jasmine A. L. Raw ◽  
Jamie Findlay ◽  
Mariel Thottam
Keyword(s):  
Older Adults ◽  
Cognitive Control ◽  
Emotional Processing ◽  
Aging Brain ◽  
Control Mechanisms ◽  
Younger Adults ◽  
Positivity Effect ◽  
Old Adults ◽  
Age Related ◽  
Conditioned Responses

Older adults typically remember more positive than negative information compared to their younger counterparts; a phenomenon referred to as the ‘positivity effect.’ According to the socioemotional selectivity theory (SST), the positivity effect derives from the age-related motivational shift towards attaining emotionally meaningful goals which become more important as the perception of future time becomes more limited. Cognitive control mechanisms are critical in achieving such goals and therefore SST predicts that the positivity effect is associated with preserved cognitive control mechanisms in older adults. In contrast, the aging-brain model suggests that the positivity effect is driven by an age-related decline in the amygdala which is responsible for emotional processing and emotional learning. The aim of the current research was to address whether the age-related positivity effect is associated with cognitive control or impaired emotional processing associated with aging. We included older old adults, younger old adults and younger adults and tested their memory for emotional stimuli, cognitive control and amygdala-dependent fear conditioned responses. Consistent with prior research, older adults, relative to younger adults, demonstrate better memory for positive over negative images. We further found that within a group of older adults, the positivity effect increases as a function of age, such that older old adults demonstrated a greater positivity effect compared to younger older adults. Furthermore, the positivity effect in older old adults was associated with preserved cognitive control, supporting the prediction of SST. Contrary to the prediction of the aging-brain model, participants across all groups demonstrated similar enhanced skin conductance responses to fear conditioned stimuli – responses known to rely on the amygdala. Our results support SST and suggest that the positivity effect in older adults is achieved by the preserved cognitive control mechanisms and is not a reflection of the impaired emotional function associated with age.

scholarly journals Resolving Age-Related Differences in Working Memory: Equating Perception and Attention Makes Older Adults Remember as Well as Younger Adults

2019 ◽  
Vol 45 (2) ◽  
pp. 120-134 ◽  
Author(s):  
Paul Verhaeghen ◽  
Shriradha Geigerman ◽  
Haoxiang Yang ◽  
Alejandra C. Montoya ◽  
Dobromir Rahnev
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Younger Adults ◽  
Age Related

scholarly journals Evidence of degraded representation of speech in noise, in the aging midbrain and cortex

2016 ◽  
Vol 116 (5) ◽  
pp. 2346-2355 ◽  
Author(s):  
Alessandro Presacco ◽  
Jonathan Z. Simon ◽  
Samira Anderson
Keyword(s):  
Older Adults ◽  
Speech Processing ◽  
Background Noise ◽  
Low Frequency ◽  
Network Connectivity ◽  
Younger Adults ◽  
Auditory Temporal Processing ◽  
Age Related ◽  
Speech Envelope ◽  
Impaired Speech

Humans have a remarkable ability to track and understand speech in unfavorable conditions, such as in background noise, but speech understanding in noise does deteriorate with age. Results from several studies have shown that in younger adults, low-frequency auditory cortical activity reliably synchronizes to the speech envelope, even when the background noise is considerably louder than the speech signal. However, cortical speech processing may be limited by age-related decreases in the precision of neural synchronization in the midbrain. To understand better the neural mechanisms contributing to impaired speech perception in older adults, we investigated how aging affects midbrain and cortical encoding of speech when presented in quiet and in the presence of a single-competing talker. Our results suggest that central auditory temporal processing deficits in older adults manifest in both the midbrain and in the cortex. Specifically, midbrain frequency following responses to a speech syllable are more degraded in noise in older adults than in younger adults. This suggests a failure of the midbrain auditory mechanisms needed to compensate for the presence of a competing talker. Similarly, in cortical responses, older adults show larger reductions than younger adults in their ability to encode the speech envelope when a competing talker is added. Interestingly, older adults showed an exaggerated cortical representation of speech in both quiet and noise conditions, suggesting a possible imbalance between inhibitory and excitatory processes, or diminished network connectivity that may impair their ability to encode speech efficiently.

scholarly journals Span, CRUNCH, and Beyond: Working Memory Capacity and the Aging Brain

2010 ◽  
Vol 22 (4) ◽  
pp. 655-669 ◽  
Author(s):  
Nils J. Schneider-Garces ◽  
Brian A. Gordon ◽  
Carrie R. Brumback-Peltz ◽  
Eunsam Shin ◽  
Yukyung Lee ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Neural Circuits ◽  
Memory Span ◽  
Brain Activity ◽  
Memory Search ◽  
Brain Activation ◽  
Aging Brain ◽  
Younger Adults ◽  
The Brain

Neuroimaging data emphasize that older adults often show greater extent of brain activation than younger adults for similar objective levels of difficulty. A possible interpretation of this finding is that older adults need to recruit neuronal resources at lower loads than younger adults, leaving no resources for higher loads, and thus leading to performance decrements [Compensation-Related Utilization of Neural Circuits Hypothesis; e.g., Reuter-Lorenz, P. A., & Cappell, K. A. Neurocognitive aging and the compensation hypothesis. Current Directions in Psychological Science, 17, 177–182, 2008]. The Compensation-Related Utilization of Neural Circuits Hypothesis leads to the prediction that activation differences between younger and older adults should disappear when task difficulty is made subjectively comparable. In a Sternberg memory search task, this can be achieved by assessing brain activity as a function of load relative to the individual's memory span, which declines with age. Specifically, we hypothesized a nonlinear relationship between load and both performance and brain activity and predicted that asymptotes in the brain activation function should correlate with performance asymptotes (corresponding to working memory span). The results suggest that age differences in brain activation can be largely attributed to individual variations in working memory span. Interestingly, the brain activation data show a sigmoid relationship with load. Results are discussed in terms of Cowan's [Cowan, N. The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87–114, 2001] model of working memory and theories of impaired inhibitory processes in aging.

scholarly journals What affects the magnitude of age-related dual-task costs in working memory? The role of stimulus domain and access to semantic representations

2020 ◽  
pp. 174702182097074
Author(s):  
Agnieszka J Jaroslawska ◽  
Stephen Rhodes ◽  
Clément Belletier ◽  
Jason M Doherty ◽  
Nelson Cowan ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Dual Task ◽  
Memory Task ◽  
Semantic Representations ◽  
Younger Adults ◽  
Task Effects ◽  
Concurrent Processing ◽  
Age Related

Although there is evidence that the effect of including a concurrent processing demand on the storage of information in working memory is disproportionately larger for older than younger adults, not all studies show this age-related impairment, and the critical factors responsible for any such impairment remain elusive. Here we assess whether domain overlap between storage and processing activities, and access to semantic representations, are important determinants of performance in a sample of younger and older adults ( N = 119). We developed four versions of a processing task by manipulating the type of stimuli involved (either verbal or non-verbal) and the decision that participants had to make about the stimuli presented on the screen. Participants either had to perform a spatial judgement, in deciding whether the verbal or non-verbal item was presented above or below the centre of the screen, or a semantic judgement, in deciding whether the stimulus refers to something living or not living. The memory task was serial-ordered recall of visually presented letters. The study revealed a large increase in age-related memory differences when concurrent processing was required. These differences were smaller when storage and processing activities both used verbal materials. Dual-task effects on processing were also disproportionate for older adults. Age differences in processing performance appeared larger for tasks requiring spatial decisions rather than semantic decisions. We discuss these findings in relation to three competing frameworks of working memory and the extant literature on cognitive ageing.

A-3 Cingulo-Opercular and Frontoparietal Control Network Connectivity and Executive Functioning in Older Adults

2021 ◽  
Vol 36 (6) ◽  
pp. 1024-1024
Author(s):  
Hanna K Hausman ◽  
Cheshire Hardcastle ◽  
Alejandro Albizu ◽  
Jessica N Kraft ◽  
Nicole D Evangelista ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Executive Functioning ◽  
Resting State ◽  
Digit Span ◽  
Network Connectivity ◽  
Cognitive Domain ◽  
Set Shifting ◽  
Age Related ◽  
Memory Inhibition

Abstract Objective Executive functioning is a cognitive domain that typically declines with normal aging. Age-related disrupted connectivity in cingulo-opercular (CON) and frontoparietal control (FPCN) resting-state networks is associated with worse performance across various executive functioning tasks. This study examines the relationships between CON and FPCN connectivity and executive functioning performance in older adults across three subdomains: working memory, inhibition, and set-shifting. Methods 274 healthy older adults (age M = 71.7, SD = 5.1; 87% Caucasian) from a clinical trial at the University of Florida and University of Arizona completed tasks of working memory (Digit Span Backwards [DSB]; Letter Number Sequencing [LNS]), inhibition (Stroop), and set-shifting (Trail Making Test Part B [TMT-B]). Participants underwent resting-state functional magnetic resonance imaging. CONN Toolbox (18b) was used for extracting average within-network connectivity of CON and FPCN. Multiple linear regressions were conducted with average network connectivity predicting performance, controlling for age, sex, education, and scanner. Results Greater average CON connectivity was associated with better performance on DSB (β = 0.26, p < 0.001), LNS (β = 0.23, p < 0.001), Stroop (β = 0.24, p < 0.001), and TMT-B (β = −0.26, p < 0.001). Greater average FPCN connectivity was associated with better performance on DSB (β = 0.22, p < 0.001) and LNS (β = 0.18, p = 0.002). Conclusions CON connectivity was significantly associated with working memory, inhibition, and set-shifting. FPCN connectivity was significantly associated with working memory. Future research should conduct regional connectivity analyses within these networks to identify intervention targets to improve executive functioning in older adults.

Working Memory Training From an Individual Differences Perspective

2019 ◽  
pp. 14-39
Author(s):  
Erika Borella ◽  
Barbara Carretti ◽  
Cesare Cornoldi ◽  
Rossana De Beni
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Task Demands ◽  
Memory Training ◽  
Training Procedure ◽  
Adaptive Procedure ◽  
Age Related ◽  
Short And Long Term ◽  
Underlying Processes

This chapter presents and discusses a verbal WM training developed for older adults. The model of working memory (WM) proposed by Cornoldi and Vecchi, which is based on an analysis of individual and age-related differences, is used as a framework for discussing the efficacy of the WM training procedure proposed and developed for older adults. The model (a) assumes that different WM tasks (and underlying processes) may be located along two continua that describe the type of content to be processed and the degree of active control required by the task and (b) considers metacognitive/motivational aspects, which also have a role in determining WM performance. The WM training procedure presented here takes into account not only the capacity to use WM resources and attentional control by adopting an adaptive procedure, but also the importance of including variations in the training task demands to produce a challenging and engaging task that sustains motivation and favor the training’s short- and long-term efficacy, at least in older adults. These aspects seem crucial in explaining the results obtained with this verbal WM training program in aging.

scholarly journals Catechol-O-methyltransferase (COMT) Genotype Affects Age-Related Changes in Plasticity in Working Memory: A Pilot Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Stephan Heinzel ◽  
Thomas G. Riemer ◽  
Stefanie Schulte ◽  
Johanna Onken ◽  
Andreas Heinz ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Genetic Variation ◽  
Behavioral Plasticity ◽  
Memory Performance ◽  
Dopamine Metabolism ◽  
Comt Genotype ◽  
Younger Adults ◽  
Age Related ◽  
Age Related Changes

Objectives. Recent work suggests that a genetic variation associated with increased dopamine metabolism in the prefrontal cortex (catechol-O-methyltransferase Val158Met; COMT) amplifies age-related changes in working memory performance. Research on younger adults indicates that the influence of dopamine-related genetic polymorphisms on working memory performance increases when testing the cognitive limits through training. To date, this has not been studied in older adults.Method. Here we investigate the effect of COMT genotype on plasticity in working memory in a sample of 14 younger (aged 24–30 years) and 25 older (aged 60–75 years) healthy adults. Participants underwent adaptive training in then-back working memory task over 12 sessions under increasing difficulty conditions.Results. Both younger and older adults exhibited sizeable behavioral plasticity through training (P<.001), which was larger in younger as compared to older adults (P<.001). Age-related differences were qualified by an interaction with COMT genotype (P<.001), and this interaction was due to decreased behavioral plasticity in older adults carrying the Val/Val genotype, while there was no effect of genotype in younger adults.Discussion. Our findings indicate that age-related changes in plasticity in working memory are critically affected by genetic variation in prefrontal dopamine metabolism.

Measuring the subjective cost of listening effort using a discounting task

2020 ◽  
Author(s):  
Drew Jordan McLaughlin ◽  
Todd Samuel Braver ◽  
Jonathan E. Peelle
Keyword(s):  
Older Adults ◽  
Decision Making ◽  
Working Memory ◽  
Economic Status ◽  
Monetary Reward ◽  
Future Research ◽  
Listening Effort ◽  
Younger Adults ◽  
Age Related ◽  
Economic Decision Making

Purpose: Objective measures of listening effort have been gaining prominence, as they provide metrics to quantify the difficulty of understanding speech under a variety of circumstances. A key challenge has been to develop paradigms that enable the complementary measurement of subjective listening effort in a quantitatively precise manner. In the present study, we introduce a novel decision-making paradigm to examine age-related and individual differences in subjective effort during listening.Method: Older and younger adults were presented with spoken sentences mixed with speech-shaped noise at multiple signal-to-noise ratios (SNRs). On each trial subjects were offered the choice between completing an easier listening trial (presented at +20 dB SNR) for a smaller monetary reward, or a harder listening trial (presented at either +4, 0, -4, -8, or -12 dB SNR) for a greater monetary reward. By varying the amount of the reward offered for the easier option, the subjective value of performing effortful listening trials at each SNR could be assessed. Results: Older adults discounted the value of effortful listening to a greater degree than young adults, opting to accept less money in order to avoid more difficult SNRs. Additionally, older adults with poorer hearing and smaller working memory capacities were more likely to choose easier trials; however, in younger adults, no relationship with hearing or working memory was found. Self-reported measures of economic status did not affect these relationships. Conclusion: These findings suggest that subjective listening effort depends on factors including, but not necessarily limited to, hearing and working memory. Additionally, this study demonstrates that economic decision-making paradigms can be a useful approach for assessing subjective listening effort, and may prove beneficial in future research.

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