Neural Substrates of Response Selection in Older Adults

2021 ◽  
Author(s):  
◽  
Si Jing Tan
2019 ◽  
Vol 75 (6) ◽  
pp. 1219-1229 ◽  
Author(s):  
Kelly Cotton ◽  
Joe Verghese ◽  
Helena M Blumen

Abstract Objective We examined the neural substrates of social support in older adults. Social support is associated with better outcomes in many facets of aging—including cognitive and functional health—but the underlying neural substrates remain largely unexplored. Methods Voxel-based morphometry and multivariate statistics were used to identify gray matter volume covariance networks associated with social support in 112 older adults without dementia (M age = 74.6 years, 50% female), using the Medical Outcomes Study Social Support Survey. Results A gray matter network associated with overall social support was identified and included prefrontal, hippocampal, amygdala, cingulate, and thalamic regions. A gray matter network specifically associated with tangible social support (e.g., someone to help you if you were confined to bed) was also identified, included prefrontal, hippocampal, cingulate, insular, and thalamic regions, and correlated with memory and executive function. Discussion Gray matter networks associated with overall and tangible social support in this study were composed of regions previously associated with memory, executive function, aging, and dementia. Longitudinal research of the interrelationships between social support, brain structure, and cognition is needed, but strengthening social support may represent a new path toward improving cognition in aging that should be explored.


2020 ◽  
Vol 16 (4) ◽  
pp. 621-629
Author(s):  
Patrick J. Sparto ◽  
Andrea L. Rosso ◽  
Ayushi A. Divecha ◽  
Andrea L. Metti ◽  
Caterina Rosano

2003 ◽  
Vol 15 (8) ◽  
pp. 1080-1094 ◽  
Author(s):  
Yuhong Jiang ◽  
Nancy Kanwisher

In many situations, people can only compute one stimulus-to-response mapping at a time, suggesting that response selection constitutes a “central processing bottleneck” in human information processing. Using fMRI, we tested whether common or distinct brain regions were involved in response selection across visual and auditory inputs, and across spatial and nonspatial mapping rules. We isolated brain regions involved in response selection by comparing two conditions that were identical in perceptual input and motor output, but differed in the complexity of the mapping rule. In the visual—manual task of Experiment 1, four vertical lines were positioned from left to right, and subjects pressed one of four keys to report which line was unique in length. In the auditory—manual task of Experiment 2, four tones were presented in succession, and subjects pressed one of four keys to report which tone was unique in duration. For both visual and auditory tasks, the mapping between target position and key position was either spatially compatible or incompatible. In the verbal task of Experiment 3, subjects used nonspatial mappings that were either compatible (“same” if colors matched; “different” if they mismatched) or incompatible (the opposite). Extensive activation overlap was observed across all three experiments for incompatible versus compatible mapping in bilateral parietal and frontal regions. Our results indicate that common neural substrates are involved in response selection across input modalities and across spatial and nonspatial domains of stimulus-to-response mapping, consistent with behavioral evidence that response selection is a central process.


2017 ◽  
Author(s):  
Abigail B. Waters ◽  
Kayle S. Sawyer ◽  
David A. Gansler

AbstractIntroductionIn middle age, declines in executive functioning (EF) are associated with decrements in the quality and/or quantity of white and grey matter. Recruitment of homologous regions has been identified as a compensatory mechanism for cognitive decline in later middle age, however research into neural substrates of EF has yet to be guided by dedifferentiation models. We hypothesized that frontal-parietal grey matter volume, interhemispheric white matter and intrahemispheric white matter fractional anisotropy (FA) will be predictive of EF. Further, we hypothesized that the comparative association between interhemispheric white matter and EF will increase with age, because of compensatory recruitment.MethodsNeurocognitive test data, DTI, and T1 MPRAGE scans (n = 444) were obtained from the NKI-Rockland Sample. Structural equation modeling was used to examine the relationship between age, EF, interhemispheric white matter (forceps minor; FM), intrahemispheric white matter (superior longitudinal fasciculus; SLF), and a frontal-parietal grey matter network. EF and grey matter were modelled as latent variables, with EF examined as the criterion. Additionally, a subsample of participants aged 55-85 (n = 168) was analyzed to examine the influence of age related compensatory mechanisms.ResultsThere was a significant relationship between FM, grey matter, and EF, which was fully mediated by age. There was a significant relationship between SLF and EF, which was not mediated by age. For older adults, only the age-mediated pathway from FM to EF was significant.DiscussionUsing structural imaging data, support was found for age-related interhemispheric mechanisms of compensation, but not intrahemispheric mechanisms.Key points(1) Neural substrates of executive functioning are not static across the lifespan. (2) In older adults, white matter becomes more salient as a structural correlate of executive functioning, as recruitment needs increase. (3) While the importance of interhemispheric white matter is mediated by age, intrahemispheric recruitment remains consistent across the lifespan, and is not the primary mechanism of age-based compensation in community dwelling older adults.


2012 ◽  
Vol 50 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Stefanie E. Kuchinsky ◽  
Jayne B. Ahlstrom ◽  
Kenneth I. Vaden ◽  
Stephanie L. Cute ◽  
Larry E. Humes ◽  
...  

2014 ◽  
Vol 28 (3) ◽  
pp. 187-201 ◽  
Author(s):  
Sergei A. Schapkin ◽  
Patrick D. Gajewski ◽  
Gabriele Freude

The study investigated the neuronal mechanisms of age-related changes in mixing costs during memory-based task switching with two levels of working memory (WM) load. Forty-eight healthy younger and 45 healthy older participants performed a memory based (high WM load) and a memory plus cue based (low WM load) switching task while event-related brain potentials (ERPs) were registered. Older adults revealed larger mixing costs in both reaction time (RT) and accuracy at higher WM loads than younger adults. The presence of explicit cues substantially reduced age differences in mixing costs for accuracy but not for RT. Similarly, no age differences regarding local switch costs were found at lower WM load. Surprisingly, larger RT local costs in younger adults than in older adults were found in the memory-based block. The CNV was reduced under high WM load and positively correlated with accuracy mixing costs in older adults. The target-locked occipital N1 and fronto-central P2 were larger in older adults relative to younger adults irrespective of WM load. The P2 latency reflected the pattern of switch costs observed in behavioral data. Moreover, P2 latency positively correlated with RT mixing costs in older adults. Elderly also showed a delayed N2 and a delayed and reduced P3b. The results suggest that age-related differences in mixing costs may be partially due to a less efficient task preparation and task set maintenance (CNV) in elderly. However, elderly attempted to compensate for these deficits by permanent activation of mechanisms relating to stimulus encoding (N1) and task-set retrieval (P2). Finally, the delayed fronto-central N2 as well as the delayed and reduced parietal P3b strongly suggest delays of response selection and working memory updating in elderly due to an increase in selection threshold or in response selection variability constituting the performance decline.


2020 ◽  
Author(s):  
Si Jing Tan ◽  
Hannah L. Filmer ◽  
Paul E. Dux

AbstractThe ability to process multiple sources of information concurrently is particularly impaired as individuals age and such age-related increases in multitasking costs have been linked to impairments in response selection. Previous neuroimaging studies with young adults have implicated the left hemisphere prefrontal cortex (PFC) as a key neural substrate of response selection. In addition, several transcranial direct current stimulation studies (tDCS) have provided causal evidence implicating this region in response selection and multitasking operations. For example, Filmer at al. (2013b) demonstrated that typically observed response selection learning/training gains in young adults were disrupted via offline transcranial direct current stimulation (tDCS) of left, but not right, PFC. Here, considering evidence of functional dedifferentiation in the brains of older adults, we assessed if this pattern of response selection learning disruption via tDCS to the left PFC is observed in older adults, testing if this region remains a key response selection node as individuals age. In a pre-registered study with 58 older adults, we applied anodal, cathodal, and sham stimulation to left and right PFC, and measured performance as participants trained on low- and high-response selection load tasks. Active stimulation did not disrupt training in older adults as compared to younger adults. However, there was evidence of enhanced training gains via tDCS, which scaled with response selection task difficulty. The results highlight age-related differences in the casual neural substrates that subserve response selection and learning.


2007 ◽  
Vol 19 (11) ◽  
pp. 1854-1871 ◽  
Author(s):  
Emily S. Cross ◽  
Paul J. Schmitt ◽  
Scott T. Grafton

When individuals acquire new skills, initial performance is typically better and tasks are judged to be easier when the tasks are segregated and practiced by block, compared to when different tasks are randomly intermixed in practice. However, subsequent skill retention is better for a randomly practiced group, an effect known as contextual interference (CI). The present study examined the neural substrates of CI using functional magnetic resonance imaging (fMRI). Individuals learned a set of three 4-element sequences with the left hand according to a block or random practice schedule. Behavioral retest for skill retention confirmed the presence of a typical CI effect with the random group outperforming the block group. Using a go/no-go fMRI paradigm, sequence preparation during the premovement study period was separated from movement execution. Imaging data for the two groups were compared for the first 1/3 and final 1/3 of training trials. Toward the end of training, behavioral performance between the two groups was similar, although the random group would later display a performance advantage on retention testing. During study time, the random group showed greater activity in sensorimotor and premotor regions compared to the block group. These areas are associated with motor preparation, sequencing, and response selection. This pattern of recruitment is consistent with the hypothesis that CI benefits in a sequencing task are due to improved capacity to actively prepare motor responses.


2019 ◽  
Vol 30 (3) ◽  
pp. 1974-1983
Author(s):  
Federico d’Oleire Uquillas ◽  
Heidi I L Jacobs ◽  
Aaron P Schultz ◽  
Bernard J Hanseeuw ◽  
Rachel F Buckley ◽  
...  

Abstract Judgments of learning (JOL) pertain to introspective metamemory processes evaluating how well information is learned. Using a functional magnetic resonance imaging (fMRI) task, we investigated the neural substrates of JOL predictions in a group of 105 cognitively unimpaired older adults from the Harvard Aging Brain Study. Associations of JOL performance and its neural correlates with amyloid-β (Aβ) and tau pathology, two proteinopathies associated with Alzheimer’s disease (AD) and aging, were also examined. We found that trials judged as learned well relative to trials judged as learned less well (high JOL > low JOL) engaged the ventromedial prefrontal cortex and precuneus, among other midline regions, in addition to bilateral hippocampi. In this cohort of older adults, greater levels of entorhinal tau deposition were associated with overestimation of memory performance and with lower fMRI signal in midline regions during predicted memory success. No associations with Aβ were found. The findings suggest that tau pathology in unimpaired older adults may play a role in altered metamemory processes. We discuss our findings in light of the hypothesis that JOLs are partially dependent on a process involving attempts to retrieve a correct answer from memory, as well as implications for clinical research investigating unawareness of memory performance (i.e., anosognosia) in patients with AD dementia.


2019 ◽  
Vol 42 ◽  
Author(s):  
Colleen M. Kelley ◽  
Larry L. Jacoby

Abstract Cognitive control constrains retrieval processing and so restricts what comes to mind as input to the attribution system. We review evidence that older adults, patients with Alzheimer's disease, and people with traumatic brain injury exert less cognitive control during retrieval, and so are susceptible to memory misattributions in the form of dramatic levels of false remembering.


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