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• We delineated brain network correlates of two executive functions in older adults. • Frontoparietal functional connectivity was linked to working memory updating. • Cortico-basal ganglia functional connectivity was linked to decision-making. • Frontoparietal tract integrity was associated with updating, but not decision-making. • Function-specific targeted modulation of brain networks may delay cognitive decline. Executive functions, essential for daily life, are known to be impaired in older age. Some executive functions, including working memory updating and value-based decision-making, are specifically sensitive to age-related deterioration. While their neural correlates in young adults are well-described, a comprehensive delineation of the underlying brain substrates in older populations, relevant to identify targets for modulation against cognitive decline, is missing. Here, we assessed letter updating and Markov decision-making task performance to operationalize these trainable functions in 48 older adults. Resting-state functional magnetic resonance imaging was acquired to quantify functional connectivity (FC) in task-relevant frontoparietal and default mode networks. Microstructure in white matter pathways mediating executive functions was assessed with diffusion tensor imaging and quantified by tract-based fractional anisotropy (FA). Superior letter updating performance correlated with higher FC between dorsolateral prefrontal cortex and left frontoparietal and hippocampal areas, while superior Markov decision-making performance correlated with decreased FC between basal ganglia and right angular gyrus. Furthermore, better working memory updating performance was related to higher FA in the cingulum bundle and the superior longitudinal fasciculus. Stepwise linear regression showed that cingulum bundle FA added significant incremental contribution to the variance explained by fronto-angular FC alone. Our findings provide a characterization of distinct functional and structural connectivity correlates associated with performance of specific executive functions. Thereby, this study contributes to the understanding of the neural correlates of updating and decision-making functions in older adults, paving the way for targeted modulation of specific networks by modulatory techniques such as behavioral interventions and non-invasive brain stimulation. [ABSTRACT FROM AUTHOR]

We recently showed that incentive motivation improves the precision of the Approximate Number System (ANS) in young adults. To shed light on the development of incentive motivation, the present study investigated whether this effect and its underlying mechanisms may also be observed in younger samples. Specifically, seven-year-old children (n = 23; 12 girls) and 14-year-old adolescents (n = 30; 15 girls) performed a dot comparison task with monetary reward incentives. Both age groups showed higher accuracy in a reward compared to a neutral condition and, similarly, higher processing efficiency as revealed by the drift rate parameter of the EZ-diffusion model. Furthermore, in line with the Incentive Salience Hypothesis, phasic pupil dilations—indicating the activation of the brain's salience network—were greater in incentivized trials in both age groups. Together these finding suggest that incentive modulation improves numerosity discrimination in children and adolescents by enhancing the perceptual saliency of numerosity information. However, the observed reward anticipation effects were less pronounced in children relative to adolescents. Furthermore, unlike previous findings regarding young adults, the decision thresholds of children and adolescents were not raised by the monetary reward, which may indicate a more protracted development of incentive regulation of response caution than perceptual evidence accumulation. [ABSTRACT FROM AUTHOR]

Sequence memory is subject to age-related decline, but the underlying processes are not yet fully understood. We analyzed electroencephalography (EEG) in 21 healthy older (60–80 years) and 26 young participants (20–30 years) and compared time-frequency spectra and theta-gamma phase-amplitude-coupling (PAC) during encoding of the order of visually presented items. In older adults, desynchronization in theta (4–8 Hz) and synchronization in gamma (30–45 Hz) power did not distinguish between subsequently correctly and incorrectly remembered trials, while there was a subsequent memory effect for young adults. Theta-gamma PAC was modulated by item position within a sequence for older but not young adults. Specifically, position within a sequence was coded by higher gamma amplitude for successive theta phases for later correctly remembered trials. Thus, deficient differentiation in theta desynchronization and gamma oscillations during sequence encoding in older adults may reflect neurophysiological correlates of age-related memory decline. Furthermore, our results indicate that sequences are coded by theta-gamma PAC in older adults, but that this mechanism might lose precision in aging. • Sequence memory, an important aspect of episodic memory, declines in healthy aging. • Lower theta and higher gamma activity in encoding of correct trials in young adults. • No subsequent memory effect in oscillatory brain activity in healthy older adults. • Theta phase modulates gamma amplitude to code for item position in older adults. [ABSTRACT FROM AUTHOR]

• Culture is characterized in fundamental biobehavioral dimensions and behavior. • Cultural neuroscience within the RDoC framework advances evidence-based research. • Cultural aspects contribute to translational efforts in global mental health. A comprehensive understanding of the basic molecular and cellular mechanisms of the brain is important for the scientific discovery of root causes, risk and protective factors for mental disorders in global mental health. Systematic research in cultural neuroscience within the research domain criteria (RDoC) framework investigates the fundamental biobehavioral dimensions and observable behavior across cultures. Cultural dimensions are characterized in elements of circuit-based mechanisms and behavior across a range of analysis. Research approaches in cultural neuroscience within the RDoC framework advance the evidence-based resources for the development and implementation of cures, preventions and interventions to mental disorders in global mental health. This review presents a novel synthesis of foundations in cultural neuroscience within the research domain criteria framework to advance integrative, translational efforts in discovery and delivery science of mental disorders across cultural contexts in global mental health. [ABSTRACT FROM AUTHOR]

• The large-strain approach with logarithmic plastic strain and elastic strain in plastic region is derived. • The failure of surrounding rock for circular opening as an unstable state driven by energy. • The energy support design of surrounding rock is obtained considering the effect of three-dimensional mechanical properties. This study analyzes the stability of surrounding rock for a circular opening based on the energy and cavity expansion theory, and regards the surrounding rock failure of circular opening as an unstable state driven by energy. Firstly, based on the large-strain cylindrical cavity contraction and energy dissipation method, the deformation caused by the excavation of surrounding rock is regarded as the cylindrical cavity contraction process. By introducing the energy dissipation mechanism, the energy dissipation solution of cylindrical cavity contraction is obtained. The energy dissipation process of surrounding rock is characterized by the strain energy changes in the elastic and elasto-plastic regions of this cavity contraction analysis. Secondly, the deformation control effect of support and surrounding rock parameters on the energy dissipation of surrounding rock is studied based on the energy dissipation solution of surrounding rock under support conditions. Finally, the effectiveness and reliability of the analytical approach was demonstrated by comparing the support design results with those in the literature. The research results indicate that the three-dimensional mechanical properties and dilatancy angle of rock and soil mass have a significant impact on the energy support design of surrounding rock. This study provides a general analysis method for the stability analysis of surrounding rock of deep buried tunnels and roadway. [ABSTRACT FROM AUTHOR]

Recent studies show that training the approximate number system (ANS) holds promise for improving symbolic math abilities. Extending this line of research, the present study aims to shed light on incentive motivation of numerosity discrimination and the underlying mechanisms. Thirty-two young adults performed a novel incentivized dot comparison task, that we developed, to discern the larger of two numerosities. An EZ-diffusion model was applied to decompose motivational effects on component processes of perceptual decision-making. Furthermore, phasic pupil dilation served as an indicator of the involvement of the salience network. The results of improved accuracy and a higher information accumulation rate under the reward condition suggest that incentive motivation boosts the precision of the ANS. These novel findings extend earlier evidence on reward-related enhancements of perceptual discrimination to the domain of numerosity perception. In light of the Adaptive Gain Theory, we interpret the results in terms of two processes of gain modulation driven by the locus coeruleus-norepinephrine system. Specifically, the reward-induced increase in pupil dilation may reflect incentive modulation of (i) salience attention during reward anticipation towards incentivized stimuli to upregulate stimulus processing that results in a larger drift rate; and (ii) response caution that leads to an increased decision threshold. [ABSTRACT FROM AUTHOR]

The relationship between tics and preceding urges in Tourette syndrome suggests that abnormal internal monitoring is reflected in abnormal perceptual, attentional, and response selection. This article uses the theory of event coding to conceptualize Tourette syndrome as a disorder of the integration of perception and action. Given that Tourette syndrome is a prototypical neurodevelopmental disorder with a characteristic clinical course in childhood and early adolescence, we focus on reviewing developmental trajectories of perception-action binding and their neural correlates in Tourette and healthy controls with a view toward the dopaminergic system. Future cross-sectional and longitudinal research systematically comparing typical development and Tourette-related alterations of neurophysiological correlates underlying perception-action binding may shed light on individual differences in the clinical course in adolescence and adulthood. [ABSTRACT FROM AUTHOR]

As the coastal region is the most developed region in China, an increasing number of engineering projects are under construction in it in recent years. However, the quality of these projects is significantly affected by groundwater, which is influenced by tidal variations. Therefore, the regional groundwater dynamic characteristics under tidal impact and the spatiotemporal evolution of the seepage field must be considered in the construction of the projects. Then, Boussinesq function was introduced into the research to deduce the seepage equation under tidal influence for the coastal area. To determine the spatiotemporal evolution of the deep foundation pit seepage field and the coastal seepage field evolution model, numerical calculations based on changes in the tidal water level and seepage equation were performed using MATLAB. According to the developed model, the influence of the seepage field on the foundation pit supporting structure in the excavation process was analyzed through numerical simulations. The results of this research could be considered in design and engineering practice. [ABSTRACT FROM AUTHOR]

Spatial and temporal variations in the species composition of assemblages are common in many marine organisms, including fishes. Variations in the fish species composition of subtidal coral reefs have been well documented, however much less is known about such differences for intertidal fish assemblages. This is surprising, given that intertidal fishes are more vulnerable to terrestrial human disturbances. It is critical to evaluate the ecology and biology of intertidal fishes before they are severely impacted by coastal development, especially in developing countries such as those in the tropical western Pacific region where coastal development is rapidly increasing. In this study, we investigated the species composition, abundance, biomass and species number (richness) for intertidal fish assemblages in subtropical (northern) and tropical (southern) Taiwan across four seasons by collecting fishes from tidepools using clove oil. We also examined the gut contents of collected fishes to identify their trophic functional groups in order to investigate regional and seasonal variations for different trophic groups. We found significant differences in the species composition of tidepool fish assemblages between subtropical and tropical Taiwan. Bathygobius fuscus, Abudefduf vaigiensis and Istiblennius dussumieri were dominant species in subtropical Taiwan, whereas Bathygobius coalitus, Abudefduf septemfasciatus and Istiblennius lineatus were dominant in tropical Taiwan. Other species such as Bathygobius cocosensis, Abudefduf sordidus and Istiblennius edentulus were common in both regions. For trophic groups, omnivores and detritivores had or showed trends towards higher species numbers and abundances in the subtropical region, whereas herbivores, planktivores and general carnivores had or showed trends towards higher species numbers and biomass in the tropical region. Overall, many intertidal fish species and trophic groups showed differences in abundance, biomass and species number between subtropical and tropical Taiwan. Further studies on large scale geographical gradients in trophic groups and species compositions in the Indo-west Pacific region are encouraged to assist with ecosystem monitoring and assessment. [ABSTRACT FROM AUTHOR]

In everyday life, individuals often need to make choices about the difficulty level of tasks they wish to perform. Here, we investigate age- and gender-related differences in the monitoring of discrepancies between the difficulty of a given task and one's own performance level, and in the likelihood to select task difficulties that match one's performance level. Male and female children, teenagers, younger adults, and older adults (total N = 160) were asked to play a modified version of the BINGO game. Task difficulty was operationalized as the number of cards played simultaneously. We expected that (a) discrepancies between individuals' self-selected difficulty levels and their objectively assessed maximum manageable task difficulty (MMTD) would be lowest in early adulthood; (b) children and teenagers, on average, would select relatively difficult task difficulties; and (c) males would overestimate their performance levels, on average, to a greater extent than females. As predicted, younger adults selected task difficulties closest to their MMTD. All other age groups, including older adults, chose task difficulties above their MMTD. The expected gender differences were restricted to children, with boys showing more pronounced performance overestimations than girls. Children and teenagers fluctuated more in their difficulty choices than adults, and many of them, especially boys, occasionally chose difficulty levels far beyond their performance capabilities. We conclude that task-difficulty choices are an interesting topic for lifespan studies. Future research should systematically vary the physical risk involved in a task, and also include the presence of peers. [ABSTRACT FROM AUTHOR]

The efficacy of various transmitter systems declines with advancing age. Of particular interest, various pre-synaptic and post-synaptic components of the dopaminergic system change across the human lifespan; impairments in these components play important roles in cognitive deficits commonly observed in the elderly. Here, we review evidence from recent multimodal neuroimaging, pharmacological and genetic studies that have provided new insights for the associations among dopamine functions, aging, functional brain activations and behavioral performance across key cognitive functions, ranging from working memory and episodic memory to goal-directed learning and decision making. Specifically, we discuss these empirical findings in the context of an established neurocomputational theory of aging neuronal gain control. We also highlight gaps in the current understanding of dopamine neuromodulation and aging brain functions and suggest avenues for future research. [ABSTRACT FROM AUTHOR]

Stability control of surrounding rock of underground caverns in deep resources development must face the post-peak deformation and failure problems of cataclastic rock mass, but the research of the post-peak deformation and strength characteristics is insufficient at the moment, so often leading to the large volume collapse, large deformation and other major projects accident. The conventional triaxial compression test of pre-existing transfixion jointed rock cylindrical standard specimen was made by using RLW-1000 type triaxial servo rigid machine in order to study the post-peak strength and deformation characteristics of fractured rock masses in different confining pressures. The results show that the peak strength, residual strength and peak strain of the fractured specimens essentially increases with the confining pressure; The smaller the confining pressure, the more obvious post-peak expansion of fractured rock, rocks expansion with confining pressure decreases, and the combined of rock plasticity and confining pressure effect rock expansion. Combined with the test results analysis found that the post-peak discontinuous deformation control in the initial stage of the residual strength, and relatively low support resistance can effectively control the excessive rupture expansion deformation, to ensure the stability of tunnel surrounding rock. [ABSTRACT FROM AUTHOR]

Aim Hepatic steatosis is an important histopathological feature of chronic hepatitis C virus ( HCV) infection. Silent information regulator 1 ( SIRT1) plays key role in regulation of hepatic lipid metabolism. We investigated the possible effect of HCV replication on lipid metabolism of hepatocytes and expression of SIRT1 using Huh-7.5 cells harboring HCV replicon. Methods The level of reactive oxygen species ( ROS) and malondialdehyde ( MDA), the activity of superoxide dismutase ( SOD), and the value of nicotinamide adenine dinucleotide ( NAD+)/ NADH was detected. The level of triacylglycerol ( TG), total cholesterol ( TC) and fatty acid β-oxidation rate was detected. The activity and expression levels of SIRT1 and expression of its downstream lipid-metabolism genes were measured. Results In replicon cells, the level of ROS and MDA increased, SOD activity and the value of NAD+/ NADH decreased, then the activity and expression level of m RNA and protein of SIRT1 reduced. Inhibition of SIRT1 decreased phosphorylation of forkhead box O1 ( FoxO1), which not only upregulated SREBP-1c, FAS, ACC, SREBP-2, HMGR and HMGS genes and increased fatty acid synthesis; but also downregulated PPAR-α and CPT1A genes and decreased fatty acid β-oxidation. Interferon treatment restored aforementioned changes. SIRT1 activator improved lipid metabolism disorders by an increase in fatty acid β-oxidation and a decrease in TG and TC synthesis and inhibited HCV replication. Conclusion HCV replication decreasing NAD+/ NADH ratio may downregulate the activity and the expression of SIRT1, then change the expression profile of lipid metabolism-related genes, thereby cause lipid metabolism disorders of hepatocytes and promote HCV replication. Treatment with SIRT1 activator ameliorates lipid metabolic disorders and inhibits HCV replication. [ABSTRACT FROM AUTHOR]

Behavioral, cognitive, and motivational development entails co-constructive interactions between the environmental and social influences from the developmental context, on the one hand, and the individual's neurobiological inheritance, on the other hand. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines and acetylcholine). Thus, the maturation and senescence of neurotransmitter systems have direct implications for lifespan development. In addition to reviewing evidence on life age differences in dopaminergic modulation and cognitive development, this brief review selectively highlights recent findings on how important influences from the developmental context, such as reward-mediated motivational processes, transgenerational stress transmission, psychosocial stress, and cognitive interventions, may, in part, exert their effects on brain and behavioral development through their effects on neuromodulatory mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: Using a specific variant of the dichotic listening paradigm, we studied the influence of dopamine on attentional modulation of auditory perception by assessing effects of allelic variation of a single-nucleotide polymorphism (SNP) rs907094 in the DARPP-32 gene (dopamine and adenosine 3′, 5′-monophosphate-regulated phosphoprotein 32 kilodations; also known as PPP1R1B) on behavior and cortical evoked potentials. A frequent DARPP-32 haplotype that includes the A allele of this SNP is associated with higher mRNA expression of DARPP-32 protein isoforms, striatal dopamine receptor function, and frontal–striatal connectivity. As we hypothesized, behaviorally the A homozygotes were more flexible in selectively attending to auditory inputs than any G carriers. Moreover, this genotype also affected auditory evoked cortical potentials that reflect early sensory and late attentional processes. Specifically, analyses of event-related potentials (ERPs) revealed that amplitudes of an early component of sensory selection (N1) and a late component (N450) reflecting attentional deployment for conflict resolution were larger in A homozygotes than in any G carriers. Taken together, our data lend support for dopamine's role in modulating auditory attention both during the early sensory selection and late conflict resolution stages. [Copyright &y& Elsevier]

Abstract: The capacity of visual–spatial working memory (WM) declines from early to late adulthood. Recent attempts at identifying neural correlates of WM capacity decline have focused on the maintenance phase of WM. Here, we investigate neural mechanisms during the encoding phase as another potential mechanism contributing to adult age differences in WM capacity. We used electroencephalography to track neural activity during encoding and maintenance on a millisecond timescale in 35 younger and 35 older adults performing a visual–spatial WM task. As predicted, we observed pronounced age differences in ERP indicators of WM encoding: Younger adults showed attentional selection during item encoding (N2pc component), but this selection mechanism was greatly attenuated in older adults. Conversely, older adults showed more pronounced signs of early perceptual stimulus processing (N1 component) than younger adults. The amplitude modulation of the N1 component predicted WM capacity in older adults, whereas the attentional amplitude modulation of the N2pc component predicted WM capacity in younger adults. Our findings suggest that adult age differences in mechanisms of WM encoding contribute to adult age differences in limits of visual–spatial WM capacity. [Copyright &y& Elsevier]

The reliability, stability, and signal-to-noise ratio ( SNR) of event-related potentials ( ERPs) were investigated in children, adolescents, younger adults, and older adults in performance monitoring tasks. P2, N2, P3, and P2- N2 peak-to-peak amplitude showed high odd-even split reliabilities in all age groups, ranging from.70 to.90. Multigroup analyses showed that test-retest stabilities (across 2 weeks) of ERP amplitudes did not differ among the four age groups. In contrast, relative to adolescents and younger adults, SNRs were lower in children and older adults, with higher noise levels in children and lower signal power in older adults. We conclude that age differences in the SNR of stimulus-locked ERPs can be successfully compensated by the averaging procedure with about 40 trials in the average. However, age differences in baseline noise and split-half reliability should be considered when comparing age groups in single trial measures or time-varying processes with ERPs. [ABSTRACT FROM AUTHOR]

Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines and acetylcholine). Thus, the maturation and senescence of neurotransmitter systems have direct implications for life span development. Recent progress in molecular genetics has opened new avenues for investigating neuromodulation of behavioral and cognitive development. This special section features 6 selected reviews of recent cognitive genetic evidence on the roles of dopamine and other transmitters in different domains of behavioral and cognitive development, ranging from temperament, executive control, and working memory to motivation and goal-directed behavior in different life periods. [ABSTRACT FROM AUTHOR]

Based on the construction of Changchengling double-arch tunnel with heavily jointed soft rock mass, a model test was carried out to analyze the stress characteristics during the excavation. With the help of monitoring instruments, the datas of stress, strain and pressure were collected and analyzed. Then a numberical simulation was carried out with FLAC3D, and its results verify the conclusions of model test. Combining with numerical analysis, the results of the model test reveals the variation laws of the tunnel surrounding rock stress and the change trends of pressure above and below the middle wall. [ABSTRACT FROM AUTHOR]

Abstract: We recorded Electroencephalograms (EEGs) during a cued Continuous Performance Task (CPT) to investigate lifespan differences in the efficiency of response conflict processing under conditions that put high demands on the ability to suppress a prepotent response. Previous evidence indicates that children and adolescents commit more errors under such conditions than younger adults, whereas older adults are disproportionately slow in responding. We measured event-related potentials (ERPs) in a sample of 45 children, 44 adolescents, 46 younger adults, and 47 older adults to investigate response conflict monitoring (Nogo-N2), cue utilization (Cue-P3), response anticipation (contingent negative variation, CNV), and response suppression (Nogo-P3). In comparison to adolescents and adults, children showed larger ERPs associated with cue utilization. At the same time, children committed more errors and their ERPs reflecting response anticipation and response suppression were smaller and uncorrelated. In contrast, older adults showed ERP indices of attentional distraction (P3a elicited by the infrequent Non-Cue stimuli), reduced conflict monitoring signals (Nogo-N2), and took more time to respond than the other age groups. The present findings reveal marked lifespan differences in processes related to response conflict monitoring. In middle childhood, the readiness to utilize cues for guiding actions is not yet fully matched by the ability to suppress prepotent responses, leading to a relatively large number of commission errors. In older adults, higher indices of attentional distraction as well as lower conflict monitoring signals were observed. This might reflect a dampened build-up of response tendencies, thereby leading to slower responding and relatively low error rates. [ABSTRACT FROM AUTHOR]

Abstract: Economic decision making is a complex process of integrating and comparing various aspects of economically relevant choice options. Neuroeconomics has made important progress in grounding these aspects of decision making in neural systems and the neurotransmitters therein. The dopaminergic and serotoninergic brain systems have been identified as key neurotransmitter systems involved in economic behavior. Both are known to be prone to significant changes during the adult lifespan. Similarly, economic behavior undergoes significant age-related changes over the course of the adult lifespan. Here we propose a triadic relationship between (a) economic decision making, (b) dopaminergic and serotonergic neuromodulation, and (c) aging. In this review, we describe the different relationships around this triad in detail and summarize current evidence that supports them. Based on the reviewed evidence, we propose new research agendas that take the entire triad into account. [Copyright &y& Elsevier]

Abstract: Neurocomputational modeling and empirical evidence suggest that losses in neuronal signaling fidelity cause senescent changes in behavior. We applied structural equation modeling to five-occasion 13-year longitudinal data from the Berlin Aging Study (n =447; age range at t1=70–102 years) to test whether trial-to-trial reaction time variability in perceptual speed (identical pictures) antecedes and signals longitudinal decline in levels of performance on perceptual speed (digit letter and identical pictures) and ideational fluency (category fluency). Higher trial-to-trial variability preceded and predicted greater cognitive decline in perceptual speed and ideational fluency. We conclude that trial-to-trial variability signals impending decline in cognitive performance, and that theories of neurocognitive aging need to postulate developmental cascades between senescent changes in variability and central tendency. [Copyright &y& Elsevier]

Founded in 1981 by the late Paul B. Baltes, the Center for Lifespan Psychology at the Max Planck Institute for Human Development has helped to establish lifespan psychology as a distinct conceptual approach within developmental psychology. Recently, the Center has extended its research programme into developmental behavioural neuroscience. Here, we provide an overview of the Center's conceptual agenda, and present two of its seven research projects in greater detail. Work at the Center is guided by three propositions: (1) to study lifespan changes in behaviour as interactions among maturation, learning, and senescence; (2) to develop theories and methods that integrate empirical evidence across domains of functioning, timescales, as well as behavioural and neuronal levels of analysis; (3) to identify mechanisms of development by exploring age-graded differences in plasticity. The Intra-Person Dynamics Project studies the organization of cognitive abilities within individuals of different ages, and investigates lifespan age differences in the plasticity and components of episodic memory performance. The Sensorimotor-Cognitive Couplings Project examines lifespan differences in dynamic dependencies between sensorimotor and cognitive performance. Both projects combine behavioural assessments with methods from developmental neuroscience to delineate age-graded changes in brain-behaviour mappings. Current research in other projects includes: (1) behavioural development in very old age, as assessed in the Berlin Aging Study; (2) the interplay of motivation, affect, and cognition in developmental regulation; (3) behavioural and electrophysiological mechanisms of social interaction from infancy to adulthood; and (4) formal and statistical issues in structural equation modelling, with an emphasis on latent growth curve modelling. Graduate education and research at the Center profit greatly from cooperation with other institutions in Berlin and Potsdam as well as from national and international collaboration. [ABSTRACT FROM AUTHOR]

Abstract: Developmental plasticity is the key mechanism that allows humans and other organisms to modify and adapt to contextual and experiential influences. Thus, reciprocal co-constructive interactions between behavioral and neuronal plasticity play important roles in regulating neurobehavioral development across the life span. This review focuses on behavioral and neuronal evidence of lifespan differences in associative memory plasticity and plasticity of the functional organization of cognitive and cortical processes, as well as the role of the dopaminergic system in modulating such plasticity. Special attention is given to neurocomputational models that help exploring lifespan differences in neuromodulation of neuronal and behavioral plasticity. Simulation results from these models suggest that lifespan changes in the efficacy of neuromodulatory mechanisms may shape associative memory plasticity and the functional organization of neurocognitive processes by affecting the fidelity of neuronal signal transmission, which has consequences for the distinctiveness of neurocognitive representations and the efficacy of distributed neural coding. [Copyright &y& Elsevier]

Abstract: Stochastic resonance (SR) is fundamental to physical and biological processes. Here, we use a stochastic gain-tuning model to investigate interactions between aging-related increase of endogenous neuronal noise and external input noise in affecting SR. Compared to networks that have optimal system gain parameter of the activation function, networks with attenuated endogenous gain tuning at the system level, simulating aging neurocognitive systems with more intrinsic neuronal noise but less plasticity, continue to exhibit the general SR effect; however, this effect is smaller and requires more external noise. This set of finding suggests that determining the optimal proportion of resonance-inducing external noise as a function of internal-system stochastic gain tuning properties promotes unified theorizing about sensory and cognitive aging at behavioral and neural levels of analysis. [Copyright &y& Elsevier]

Abstract: Postural control in everyday life is generally accompanied by posture-unrelated cognitive activity. Thus, mild forms of dual-tasking postural control are the norm rather than the exception. Based on this consideration and available evidence, we propose and empirically examined, in young and old adults, a non-monotonic, U-shaped relation between the efficacy of postural control and concurrent cognitive demands that reflect opposing trends of the effects of attention focus and attentional resource competition. When instructed to perform an easy cognitive task that presumably shifted the focus of attention away from posture control, the center of body pressure (COP) excursions decreased both in young and older adults relative to a single-task baseline where the focus of attention was explicitly directed towards the postural control task itself. However, when performing more demanding cognitive tasks, older adults showed increased COP displacements, in line with the predicted U-shape function, whereas young adults did not. We outline mechanisms linking postural control to cognitive demand and suggest routes for future investigation. [Copyright &y& Elsevier]

Hepatic steatosis is a histological feature in patients with chronic hepatitis C (CHC) and adversely affects the virologic response rates to anti-hepatitis C virus (HCV) therapy. The aim of this study is to investigate whether the fatty liver and related factors have impact on the efficacy in CHC treated with peginterferon and ribavirin, and the associations between HCV genotyping and fatty liver. Methods: Ninety-eight patients received subcutaneously 180 μg peginterferon α-2a once a week plus ribavirin. HCV genotypes and the levels of plasma insulin of patients were measured. Fatty liver was detected by B ultrasound. The body mass index (BMI), waist-to-hip ratio (WHR) and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. Results: Among 98 CHC patients, 38 (38.8%) were infected with genotype 1; 44 (44.9%) with genotype 2; 13 (13.3%) with genotype 3; 3 (3.0%) with indeterminate genotype. The prevalence of fatty liver was 10.5%, 11.4%, 38.5% in patients infected with HCV genotype 1, 2, 3, respectively, which suggested that the distribution of fatty liver in different HCV genotypes was imbalanced (χ2=6.758, P=0.034). In univariate analysis, the efficacy of combination therapy was significantly associated with BMI ( P=0.011), WHR ( P=0.024), the levels of plasma insulin ( P=0.001), genotype ( P=0.036), presence of fatty liver ( P=0.028), treatment dosage and duration ( P=0.012) and HOMA-IR ( P=0.002). With binary logistic regression analysis, the plasma insulin levels and HOMA-IR showed independent predictors to the efficacy of antiviral therapy. Conclusion: The prevalence of fatty liver in HCV genotype 3 was markedly higher than that of other genotypes. The BMI, WHR, the levels of plasma insulin, genotype, presence of fatty liver, treatment dosage and duration and HOMA-IR were associated with the sustained virologic response. The level of plasma insulin and HOMA-IR were independent factors for predicting effect of antiviral therapy. [ABSTRACT FROM AUTHOR]

Relative to young adults, older adults are particularly impaired in episodic memory tasks requiring associative binding of separate components into compound episodes, such as tasks requiring item-context and item-item binding. This associative-binding deficit has been attributed to senescent changes in frontal-hippocampal circuitry but has not been formally linked to impaired neuromodulation involving this circuitry. Previous neurocomputational work showed that impaired neuromodulation could result in less distinct neurocognitive representations. Here we extend this computational principle to simulate aging-related deficits in associative binding. As expected, networks with simulated deficiency in neuromodulation resulted in less distinct internal representations than did networks simulating the processing and performance of young adults, and were also more impaired under task conditions that required associative binding. The findings suggest that senescent changes in neuromodulatory mechanisms may play a basic role in aging-related impairment in associative binding by reducing the efficacy of distributed conjunctive coding. [ABSTRACT FROM AUTHOR]

Two-component theories of intellectual development over the life span postulate that fluid abilities develop earlier during child development and decline earlier during aging than crystallized abilities do, and that fluid abilities support or constrain the acquisition and expression of crystallized abilities. Thus, maturation and senescence compress the structure of intelligence by imposing age-specific constraints upon its constituent processes. Hence, the couplings among different intellectual abilities and cognitive processes are expected to be strong in childhood and old age. Findings from a population-based study of 291 individuals aged 6 to 89 years support these predictions. Furthermore, processing robustness, a frequently overlooked aspect of processing, predicted fluid intelligence beyond processing speed in old age but not in childhood, suggesting that the causes of more compressed functional organization of intelligence differ between maturation and senescence. Research on developmental changes in functional brain circuitry may profit from explicitly recognizing transformations in the organization of intellectual abilities and their underlying cognitive processes across the life span. [ABSTRACT FROM AUTHOR]

Background: Within-person, across-time variations in processes and performance are intrinsic to all aspects of human functioning. Objective: This article starts with a brief taxonomy of intraindividual dynamics. There are adaptive as well as non-adaptive types of intraindividual variations that unfold with different degrees of reversibility on different time scales and involve either single, or systems of, functions. Methods: Empirical findings regarding aging and a specific type of intraindividual variation, namely attenuated processing robustness, are then presented with respect to cognitive and sensorimotor functioning. Results: In both domains of functioning, old adults exhibit less robust functioning with a greater amount of week-to-week, day-to-day, or trial-by-trial fluctuations in their cognitive, walking, and postural control performances. Conclusion: Currently, the causes for the attenuation of processing robustness in cognitive and sensorimotor functioning are not well understood. Neurocomputational models are useful tools for exploring the tripartite relationships between the aging of neural information-processing fidelity, and cognitive, and sensorimotor processes.Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Besides neuroanatomical changes, neuromodulatory mechanisms are also compromised during aging. Neural network models are suitable tools for exploring the relatively broad and homogenous neuromodulatory influences on cortical function. Computational approaches for understanding neuromodulation of the dynamic properties of cortical function and recent neurocomputational theories relating different aspects of cognitive aging with declines in neuromodulation are reviewed. Considered within an integrative cross-level neurocomputational framework, aging-related decline in dopaminergic neuromodulation reduces the fidelity of neural information and gives rise to less distinctive neural pattern representations that may underlie various facets of aging cognitive and, possibly also, sensorimotor phenomena. [Copyright &y& Elsevier]

Basic cognitive mechanisms, such as the abilities to briefly maintain focus, and process information, decline with age. Related fields of cognitive aging research have been advancing rapidly, but mostly independently, at the biological, information processing, and behavioral levels. To facilitate integration, this article reviews research on cognitive aging at the different levels, and describes a recent integrative theory postulating that aging-related deficiencies in neurotransmission cause increased noise in information processing and less distinctive cortical representation, which in turn lead to cognitive deficits. Aging-related attenuation of catecholaminergic modulation can be modeled by lowering a neural network parameter to reduce the signal-to-noise ratio of information processing. The performance of such models is consistent with benchmark phenomena observed in humans, ranging from age differences in learning rate, asymptotic performance, and interference susceptibility to intra-and interindividual variability and ability dedifferentiation. Although the details of the conjectured sequence of effects linking neuromodulation to cognitive aging deficits await further empirical validation, cross-level theorizing of the kind illustrated here could foster the coevolution of related fields through cross-level data synthesis and hypothesis testing. [ABSTRACT FROM AUTHOR]

Hofer and Sliwinski raise a critical concern regarding a popular practice in aging research of inferring associations among aging changes of different processes from correlations based on cross-sectional age differences. It is shown analytically that cross-sectional information drawn from age-heterogeneous samples is not suitable for answering questions about the interdependence between aging changes. While in general we agree with the problem pointed out by Hofer and Sliwinski, the two aims of this commentary are: (1) to highlight links between the specific concern and two long-standing issues confronting life-span researchers and (2) to introduce alternative approaches that are currently underutilized in gerontological research. We elaborate general issues with respect to challenges in inferring aging changes from age differences and using age as a proxy for aging. We show that several other sources of variance independent of rates of change, such as cohort- and mortality-related selection effects, are confounded in age-heterogeneous designs. We suggest general considerations for developing more explicit theories of cognitive aging in the future. Alternative research methods and paradigms for studying the causes and mechanisms of the aging mind at different time scales and levels are also highlighted. The role of chronological age in aging research is rather "superficial". To understand the underlying processes and mechanisms of cognitive aging, classical process-oriented, rather than solely age-oriented, theoretical conceptions need to be reconsidered and reified with new methodological and empirical advances. Concerted gerontological research endeavors utilizing recent progresses made in statistical analyses of dynamic processes and in cognitive and computational neurosciences that may lead to fruitful breakthroughs. [ABSTRACT FROM AUTHOR]

Background: While age-related increases of between-person variability in a variety of cognitive measures are commonly reported in cross-sectional studies, the nature of short-term intraindividual fluctuation in elderly people’s performance is relatively unexplored. Objective: The goal of the present study is to examine short-term fluctuations in elderly people’s sensorimotor functioning and their relations to individual differences in verbal and spatial memory. Methods: Fluctuations in old adults’ (mean = 75.71 years, SD = 6.93 years) sensorimotor performance were investigated by biweekly measurements spanning approximately 7 months. Sensorimotor performance was measured by three walking tasks, including the duration and the number of steps taken to walk a 360-degree circle and to walk 10 feet both at normal and fast pace. Performances of verbal and spatial memory were assessed by weekly measurements of digit memory span, memory for short text and spatial recognition. Results: The magnitude of intraindividual fluctuation in most sensorimotor and memory tasks examined was at least half as great as the level of individual differences across persons. In addition, intraindividual fluctuation in sensorimotor performance is a relatively stable individual attribute, which correlates positively with age and negatively with the levels of sensorimotor, text and spatial memory performance. Although a substantial amount of individual differences in intraindividual fluctuation was shared with mean performance level, variance component and hierarchical regression analyses showed that intraindividual fluctuation in walking steps added significant independent contribution over and above that given by level of performance in predicting text and spatial memory. Conclusion: Taking these results together, we suggest that intraindividual fluctuations in elderly people’s performance should not be ignored or simply treated as measurement error; rather, they are potentially important empirical variables for understanding sensory and cognitive aging and the nature of intraindividual response variations in general.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Digital technologies, such as virtual or augmented reality, can potentially support neurocognitive functions of the aging populations worldwide and complement existing intervention methods. However, aging-related declines in the frontal-parietal network and dopaminergic modulation which progress gradually across the later periods of the adult lifespan may affect the processing of multisensory congruence and expectancy based contextual plausibility. We assessed hemodynamic brain responses while middle-aged and old adults experienced car-riding virtual-reality scenarios where the plausibility of vibrotactile stimulations was manipulated by delivering stimulus intensities that were either congruent or incongruent with the digitalized audio-visual contexts of the respective scenarios. Relative to previous findings observed in young adults, although highly plausible vibrotactile stimulations confirming with contextual expectations also elicited higher brain hemodynamic responses in middle-aged and old adults, this effect was limited to virtual scenarios with extreme expectancy violations. Moreover, individual differences in plausibility-related frontal activity did not correlate with plausibility violation costs in the sensorimotor cortex, indicating less systematic frontal context-based sensory filtering in older ages. These findings have practical implications for advancing digital technologies to support aging societies. [ABSTRACT FROM AUTHOR]

Empirical evidence has shown that visually enhancing the saliency of reward probabilities can ease the cognitive demands of value comparisons and improve value-based decisions in old age. In the present study, we used a time-varying drift diffusion model that includes starting time parameters to better understand (1) how increasing the saliency of reward probabilities may affect the dynamics of value-based decision-making and (2) how these effects may interact with age. We examined choices made by younger and older adults in a mixed lottery choice task. On a subset of trials, we used a color-coding scheme to highlight the saliency of reward probabilities, which served as a decision-aid. The results showed that, in control trials, older adults started to consider probability relative to magnitude information sooner than younger adults, but that their evidence accumulation processes were less sensitive to reward probabilities than that of younger adults. This may indicate a noisier and more stochastic information accumulation process during value-based decisions in old age. The decision-aid increased the influence of probability information on evidence accumulation rates in both age groups, but did not alter the relative timing of accumulation for probability versus magnitude in either group. [ABSTRACT FROM AUTHOR]

Presents information on a study, which examined the associations between three measures of tactile information processing and intelligence among middle-aged adults. Methodology used in the study; Examination of the three different tactile measures; Results of the study.

Presents experiments on the forward and backward recall processes. Effect on forward recall of tasks that interfere with the formation of inter-item associations; Effect on backward recall of tasks that alter the visual-spatial characteristics of the study material; Application of Temporal Distinctiveness Theory to the study; Models of the retrieval processes.

Reports on four experiments in which the effects of an intralist distractor task were compared for forward and backward recall. Serial-order version of theory of distributed associative memory (TODAM); Disruption of forward but not backward recall by distractor task; Retrieval-based account within the framework of temporal distinctiveness theory.

Identifies six problems brought up in Mewhort et al.'s critique of Lewandowsky and Murdock's model for serial recall based on the theory of distributed associative memory (TODAM). Exaggeration of fears arising from flaws in TODAM memory component; Implementation of deblurring mechanism to answer problems arising from response selection.

Presents an alternative technique for scope evaluation to model analysis in cognitive psychology which examines the ratio between the overall interdependence among model parameters and their sensitivity. Parameter independence and sensitivity as reliable predictor of scope; Additive model's low sensitivity parameters precision; Model scope estimation.

The author comments on a study on ontogeny to highlight that developmental processes constitute mechanisms that channel bi-directional interactive processes between gene-based and culture-based niche construction. To add specificity to one type of ontogenetic mechanism, the author focuses on the maturation and senescence of neurotransmitter systems which play crucial roles in the development of executive control, motivation and the regulation of reactions to social and environmental stressors.

The error-related negativity (ERN/Ne) as well as the early and late error positivity (Pe) are electrophysiological correlates known to reflect error detection and error awareness. Despite much evidence on age differences in mastering response conflicts, the development and the functional distinctiveness of these components across the lifespan is still unclear. Here we investigated maturation- and aging-related differences in the ERN/Ne, the early and late Pe during a response conflict task in a lifespan sample that included 45 children, 42 adolescents, 39 younger and 34 older adults. Lifespan age differences were characterized by marked declines of all three components in older age, whereas clear maturation effects from childhood to adolescence were only observed for error detection reflected in the ERN/Ne component. Furthermore, using regression analyses, we examined functional relationships of the error monitoring components to behavioral indicators of task performance. Across all age groups, both the ERN/Ne and the early Pe were related to response accuracy, but only the early Pe was further associated with performance in a covariate task indicative of perceptual processing and attention capacities. Our results suggest that the ERN/Ne, the early and late Pe reflect distinct but complementary processes of error monitoring across the lifespan. • ERP correlates of error monitoring were investigated from childhood to old age. • Aging affected ERP components of error detection and awareness. • Maturation from childhood to adolescence only affected error detection (ERN/Ne). • Only the early Pe was related to perceptual processing and attention allocation. • ERN/Ne and Pe components distinct but complementary processes of error monitoring. [ABSTRACT FROM AUTHOR]

Human aging is characterized by impaired spatial cognition and reductions in the distinctiveness of category-specific fMRI activation patterns. Yet, little is known about age-related decline in neural distinctiveness of information that humans use when navigating spatial environments. Here, we asked whether neural tuning functions of walking direction are broadened in older versus younger adults. To test this idea, we developed a novel method that allowed us to investigate changes in fMRI-measured pattern similarity while participants navigated in different directions in a virtual spatial navigation task. We expected that directional tuning functions would be broader in older adults, and thus activation patterns that reflect neighboring directions would be less distinct as compared to non-adjacent directions. Because loss of distinctiveness leads to more confusions when information is read out by downstream areas, we analyzed predictions of a decoder trained on directional fMRI patterns and asked (1) whether decoder confusions between two directions increase proportionally to their angular similarity, (2) and how this effect may differ between age groups. Evidence for tuning-function-like signals was found in the retrosplenial complex and early visual cortex, reflecting the primarily visual nature of directional information in our task. Significant age differences in tuning width, however, were only found in early visual cortex, suggesting that less precise visual information could lead to worse directional signals in older adults. At the same time, only directional information encoded in RSC, but not visual cortex, correlated with memory on task. These results shed new light on neural mechanisms underlying age-related spatial navigation impairments and introduce a novel approach to measure tuning specificity using fMRI. Image 1 • We developed a novel approach to study neural tuning functions in humans using fMRI. • fMRI decoder confusion functions used as proxy measure for population-based tuning. • Walking direction could be decoded from retrosplenial complex and early visual cortex. • Age-related broadening of directional tuning found only in visual cortex. • Approach offers a novel window into age-related dedifferentiation. [ABSTRACT FROM AUTHOR]

Spatial learning can be based on intramaze cues and environmental boundaries. These processes are predominantly subserved by striatal- and hippocampal-dependent circuitries, respectively. Maturation and aging processes in these brain regions may affect lifespan differences in their contributions to spatial learning. We independently manipulated an intramaze cue or the environment's boundary in a navigation task in 27 younger children (6–8 years), 30 older children (10–13 years), 29 adolescents (15–17 years), 29 younger adults (20–35 years) and 26 older adults (65–80 years) to investigate lifespan age differences in the relative prioritization of either information. Whereas learning based on an intramaze cue showed earlier maturation during the progression from younger to later childhood and remained relatively stable across adulthood, maturation of boundary-based learning was more protracted towards peri-adolescence and showed strong aging-related decline. Furthermore, individual differences in prioritizing intramaze cue- over computationally more demanding boundary-based learning was positively associated with cognitive processing fluctuations and this association was partially mediated by spatial working memory capacity during adult, but not during child development. This evidence reveals different age gradients of two modes of spatial learning across the lifespan, which seem further influenced by individual differences in cognitive processing fluctuations and working memory, particularly during aging. [ABSTRACT FROM AUTHOR]

Background: Repeated sessions of training and non-invasive brain stimulation have the potential to enhance cognition in patients with cognitive impairment. We hypothesized that combining cognitive training with anodal transcranial direct current stimulation (tDCS) will lead to performance improvement in the trained task and yield transfer to non-trained tasks. Methods: In our randomized, sham-controlled, double-blind study, 46 patients with cognitive impairment (60–80 years) were randomly assigned to one of two interventional groups. We administered a 9-session cognitive training (consisting of a letter updating and a Markov decision-making task) over 3 weeks with concurrent 1-mA anodal tDCS over the left dorsolateral prefrontal cortex (20 min in tDCS, 30 s in sham group). Primary outcome was trained task performance (letter updating task) immediately after training. Secondary outcomes included performance in tasks testing working memory (N-back task), decision-making (Wiener Matrices test) and verbal memory (verbal learning and memory test), and resting-state functional connectivity (FC). Tasks were administered at baseline, at post-assessment, and at 1- and 7-month follow-ups (FU). MRI was conducted at baseline and 7-month FU. Thirty-nine participants (85%) successfully completed the intervention. Data analyses are reported on the intention-to-treat (ITT) and the per-protocol (PP) sample. Results: For the primary outcome, no difference was observed in the ITT (β = 0.1, 95%-CI [− 1.2, 1.3, p = 0.93] or PP sample (β = − 0.2, 95%-CI [− 1.6, 1.2], p = 0.77). However, secondary analyses in the N-back working memory task showed that, only in the PP sample, the tDCS outperformed the sham group (PP: % correct, β = 5.0, 95%-CI [− 0.1, 10.2], p = 0.06, d-prime β = 0.2, 95%-CI [0.0, 0.4], p = 0.02; ITT: % correct, β = 3.0, 95%-CI [− 3.9, 9.9], p = 0.39, d-prime β = 0.1, 95%-CI [− 0.1, 0.3], p = 0.5). Frontoparietal network FC was increased from baseline to 7-month FU in the tDCS compared to the sham group (pFDR < 0.05). Exploratory analyses showed a correlation between individual memory improvements and higher electric field magnitudes induced by tDCS (ρtDCS = 0.59, p = 0.02). Adverse events did not differ between groups, questionnaires indicated successful blinding (incidence rate ratio, 1.1, 95%-CI [0.5, 2.2]). Conclusions: In sum, cognitive training with concurrent brain stimulation, compared to cognitive training with sham stimulation, did not lead to superior performance enhancements in patients with cognitive impairment. However, we observed transferred working memory benefits in patients who underwent the full 3-week intervention. MRI data pointed toward a potential intervention-induced modulation of neural network dynamics. A link between individual performance gains and electric fields suggested dosage-dependent effects of brain stimulation. Together, our findings do not support the immediate benefit of the combined intervention on the trained function, but provide exploratory evidence for transfer effects on working memory in patients with cognitive impairment. Future research needs to explore whether individualized protocols for both training and stimulation parameters might further enhance treatment gains. Trial registration: The study is registered on ClinicalTrials.gov (NCT04265378). Registered on 7 February 2020. Retrospectively registered. [ABSTRACT FROM AUTHOR]

Older adults experience difficulties in daily situations that require flexible information selection in the presence of multiple competing sensory inputs, like for instance multi-talker situations. Modulations of rhythmic neural activity in the alpha–beta (8–30 Hz) frequency range in posterior brain areas have been established as a cross-modal neural correlate of selective attention. However, research linking compromised auditory selective attention to changes in rhythmic neural activity in aging is sparse. We tested younger (n = 25; 22–35 years) and older adults (n = 26; 63–76 years) in an attention modulated dichotic listening task. In this, two streams of highly similar auditory input were simultaneously presented to participants' both ears (i.e., dichotically) while attention had to be focused on the input to only one ear (i.e. target) and the other, distracting information had to be ignored. We here demonstrate a link between severely compromised auditory selective attention in aging and a partial reorganization of attention-related rhythmic neural responses. In particular, in old age we observed a shift from a self-initiated, preparatory modulation of lateralized alpha rhythmic activity to an externally driven response in the alpha–beta range. Critically, moment-to-moment fluctuations in the age-specific patterns of self-initiated and externally driven lateralized rhythmic activity were associated with behavioral performance. We conclude that adult age differences in spatial selective attention likely derive from a functional reorganization of rhythmic neural activity within the aging brain. • The ability to filter relevant from irrelevant information is diminished in aging. • Modulations of alpha–beta (8–30 Hz) oscillatory power underpin selective attention. • Younger adults prepare for upcoming relevant stimuli by modulating alpha activity. • Older adults modulate alpha–beta activity only after stimulus presentation. • Single trial performance can be predicted from alpha–beta oscillatory activity. • Age differences in attention may stem from a reorganization of oscillatory activity. [ABSTRACT FROM AUTHOR]