Age-related Differences In Performance Research Articles

Memory Image Completion: Establishing a task to behaviorally assess pattern completion in humans.

For memory retrieval, pattern completion is a crucial process that restores memories from partial or degraded cues. Neurocognitive aging models suggest that the aged memory system is biased toward pattern completion, resulting in a behavioral preference for retrieval over encoding of memories. Here, we built on our previously developed behavioral recognition memory paradigm—the Memory Image Completion (MIC) task—a task to specifically target pattern completion. First, we used the original design with concurrent eye‐tracking in order to rule out perceptual confounds that could interact with recognition performance. Second, we developed parallel versions of the task to accommodate test settings in clinical environments or longitudinal studies. The results show that older adults have a deficit in pattern completion ability with a concurrent bias toward pattern completion. Importantly, eye‐tracking data during encoding could not account for age‐related performance differences. At retrieval, spatial viewing patterns for both age groups were more driven by stimulus identity than by response choice, but compared to young adults, older adults' fixation patterns overlapped more between stimuli that they (wrongly) thought had the same identity. This supports the observation that older adults choose responses perceived as similar to a learned stimulus, indicating a bias toward pattern completion. Additionally, two shorter versions of the task yielded comparable results, and no general learning effects were observed for repeated testing. Together, we present evidence that the MIC is a reliable behavioral task that targets pattern completion, that is easily and repeatedly applicable, and that is made freely available online.

Sensorimotor network segregation declines with age and is linked to GABA and to sensorimotor performance

Aging is typically associated with declines in sensorimotor performance. Previous studies have linked some age-related behavioral declines to reductions in network segregation. For example, compared to young adults, older adults typically exhibit weaker functional connectivity within the same functional network but stronger functional connectivity between different networks. Based on previous animal studies, we hypothesized that such reductions of network segregation are linked to age-related reductions in the brain's major inhibitory transmitter, gamma aminobutyric acid (GABA). To investigate this hypothesis, we conducted graph theoretical analyses of resting state functional MRI data to measure sensorimotor network segregation in both young and old adults. We also used magnetic resonance spectroscopy to measure GABA levels in the sensorimotor cortex and collected a battery of sensorimotor behavioral measures. We report four main findings. First, relative to young adults, old adults exhibit both less segregated sensorimotor brain networks and reduced sensorimotor GABA levels. Second, less segregated networks are associated with lower GABA levels. Third, less segregated networks and lower GABA levels are associated with worse sensorimotor performance. Fourth, network segregation mediates the relationship between GABA and performance. These findings link age-related differences in network segregation to age-related differences in GABA levels and sensorimotor performance. More broadly, they suggest a neurochemical substrate of age-related dedifferentiation at the level of large-scale brain networks.

Navigating the Online World: Gaze, Fixations, and Performance Differences between Younger and Older Users

ABSTRACTThe world’s populations and workforces are aging and older adults are now the fastest growing group of internet users. Unfortunately, age-related declines may prevent older adults from performing web-based tasks with the same ease as their younger counterparts. Recent studies have suggested that peripheral navigation may exacerbate age-related online performance gaps as older adults fail to adequately search peripheral elements. Such studies have however relied on the use of preexisting websites with no control for layout, complexity, or prior familiarity. This study tested whether age-related differences in online performance and search behavior exist across various navigational layouts. Participants (N = 47) completed four online tasks with purpose-built websites of equivalent difficulty, length, and content type, yet with varying navigational layouts (center; left-periphery; top-periphery; inconsistent). Participants’ performance (i.e., accuracy/efficiency), search behavior (i.e., eye gaze/fixation), and satisfaction were examined. Identifiable differences between age-groups and navigational layouts were found, with top-peripheral navigation proving most detrimental to the online performance and satisfaction of both younger and older adults. The results inform design principles that aim to increase older adults’ online functionality, and provide an extensive platform for further research.

Connectome-based models predict attentional control in aging adults

There are well-characterized age-related differences in behavioral and neural responses to tasks of attentional control. However, there is also increasing recognition of individual variability in the process of neurocognitive aging. Using connectome-based predictive modeling, a method for predicting individual-level behaviors from whole-brain functional connectivity, a sustained attention connectome-based prediction model (saCPM) has been derived in young adults. The saCPM consists of two large-scale functional networks: a high-attention network whose strength predicts better attention and a low-attention network whose strength predicts worse attention. Here we examined the generalizability of the saCPM for predicting inhibitory control in an aging sample. Forty-two healthy young adults (n = 21, ages 18–30) and older adults (n = 21, ages 60–80) performed a modified Stroop task, on which older adults exhibited poorer performance, indexed by higher reaction time cost between incongruent and congruent trials. The saCPM generalized to predict reaction time cost across age groups, but did not account for age-related differences in performance. Exploratory analyses were conducted to characterize the effects of age on functional connectivity and behavior. We identified subnetworks of the saCPM that exhibited age-related differences in strength. The strength of two low-attention subnetworks, consisting of frontoparietal, medial frontal, default mode, and motor nodes that were more strongly connected in older adults, mediated the effect of age group on performance. These results support the saCPM's ability to capture attention-related patterns reflected in each individual's functional connectivity signature across both task context and age. However, older and younger adults exhibit functional connectivity differences within components of the saCPM networks, and it is these connections that better account for age-related deficits in attentional control.

Effects of presentation formats on consumers’ performance and perceptions in the use of personal health records among older and young adults

ObjectiveTo examine the effects of presentation formats on consumers’ performance and perceptions in the use of personal health records (PHRs) and to compare the effects between older and young adults. MethodsA two-factor, mixed design experiment was conducted, where 36 older and 36 young participants were presented with hypothetical PHRs. The PHRs were randomly presented by six presentation formats: three tables and three line graphs, varying by visual cues. Participants’ performance and perceptions in the use of PHRs were measured. ResultsPresentation formats affected participants’ performance and perceptions. Visual cue-enhanced line graphs and tables yielded less time and fewer errors, were considered easier and more useful in information comprehension, and resulted in higher confidence in correct comprehension of PHRs (all p's < 0.01), compared with their basic counterparts. There were age-related differences in task performance (all p's < 0.05), while young and older adults had similar perceptions for the six formats. Line graph with colored background was most preferred by both groups. ConclusionVisual cue-enhanced presentation formats appear effective in facilitating comprehension and eliciting favorable perceptions of PHRs for both young and older adults. Practice implicationsConsumer-facing displays of PHRs could use visual cue-enhanced presentation formats to facilitate comprehension.

Age-dependent effects of brain stimulation on network centrality

Functional magnetic resonance imaging (fMRI) studies have suggested that advanced age may mediate the effects of transcranial direct current stimulation (tDCS) on brain function. However, studies directly comparing neural tDCS effects between young and older adults are scarce and limited to task-related imaging paradigms. Resting-state (rs-) fMRI, that is independent of age-related differences in performance, is well suited to investigate age-associated differential neural tDCS effects. Three “online” tDCS conditions (anodal, cathodal, sham) were compared in a cross-over, within-subject design, in 30 young and 30 older adults. Active stimulation targeted the left sensorimotor network (active electrode over left sensorimotor cortex with right supraorbital reference electrode). A graph-based rs-fMRI data analysis approach (eigenvector centrality mapping) and complementary seed-based analyses characterized neural tDCS effects. An interaction between anodal tDCS and age group was observed. Specifically, centrality in bilateral paracentral and posterior regions (precuneus, superior parietal cortex) was increased in young, but decreased in older adults. Seed-based analyses revealed that these opposing patterns of tDCS-induced centrality modulation originated from differential effects of tDCS on functional coupling of the stimulated left paracentral lobule. Cathodal tDCS did not show significant effects. Our study provides first evidence for differential tDCS effects on neural network organization in young and older adults. Anodal stimulation mainly affected coupling of sensorimotor with ventromedial prefrontal areas in young and decoupling with posteromedial areas in older adults.

24.3 EIGHTEEN-YEAR COURSE OF COGNITIVE FUNCTIONING IN PSYCHOTIC DISORDERS: FINDINGS FROM THE SUFFOLK COUNTY MENTAL HEALTH LONGITUDINAL STUDY

BackgroundKnowledge about the long-term cognitive course in psychotic disorders is limited. In this 18-year follow-up of participants of the Suffolk County project we report on the longitudinal course of cognitive performance in individuals with schizophrenia spectrum disorders, affective psychoses and other psychoses. We investigate (i) change in functioning in 6 cognitive domains from 2-years to 20-years follow-up after first admission; (ii) 20-year performance and age-related differences in cognitive performance in patients relative to a never psychotic comparison group; and (iii) key predictors of clinically meaningful cognitive decline in patients.MethodsData came from the Suffolk County Mental Health Project, a prospective study of first-admission patients. Cognitive tests were administered 2 years (n = 399; schizophrenia spectrum: 285, affective psychoses: 226, other psychoses: 117) and 20 years (n = 240; 115, 92, and 34, respectively) after first admission, with 195 individuals completing cognitive tests at both time points. A never psychotic comparison group (N=260) was assessed at year 20.ResultsIndividuals with schizophrenia spectrum disorders showed lower cognitive functioning than those with affective and other psychoses. Over time, patients declined in cognitive performance on almost all tests (d = 0.24 (range 0.12- 0.44)) with comparable magnitude across diagnoses. Longer duration of untreated psychosis and low childhood IQ were significantly associated with clinically relevant decline (>0.5SD) in general verbal ability and processing speed, but there were no robust predictors of cognitive decline across tests. Cross-sectional comparisons of patients to controls showed increasing impairments with age for general verbal ability, verbal fluency, and executive functioning.DiscussionOur findings indicate that cognitive functioning in psychotic disorders continues to decline after the illness onset, that this decline is not specific to schizophrenia but present across psychotic disorders, and that, relative to never-psychotic individuals, impairments on some key-cognitive domains worsen with age. These results imply that cognitive treatment should not only include cognitive remediation but also prevention of age-related cognitive stagnation and/or decline.

Aging and n-Back Performance: A Meta-Analysis.

To provide a systematic review of age-related differences in n-back performance. Meta-analytic data aggregation. Access for items stored within the focus of attention (0-back and 1-back) was very fast and quasi-perfect; when items are held outside the focus (n > 1), an additional cost was accrued in both accuracy and response time. Age-related differences in accuracy conformed to this bifurcation. Longer lists led to larger costs when going from 1-back to 2-back in older adults. For 1-back accuracy, studies that used visual (as opposed to verbal) stimuli, were experimenter-paced, and used shorter list lengths led to larger age-related differences; for 2-back accuracy, a larger difference in chronological age, visual stimuli, and a higher target proportion led to larger age-related differences. For 1-back response times, age-related differences were larger for studies that had a larger chronological age difference, used experimenter pacing, did not contain lures, and used shorter list lengths; for 2-back response times, age-related differences were larger for studies with larger chronological age differences, visual presentation, experimenter pacing, and a higher target proportion. The results suggest a specific age-related deficit associated with focus switching within working memory. Evidence for specific executive-control-related explanations, in contrast, is mixed.

Sex- and age-related differences in half-marathon performance and competitiveness in the world’s largest half-marathon – the GöteborgsVarvet

ABSTRACTIn road runners, the age-related performance decline has been well investigated for marathoners, but little is known for half-marathoners. We analysed data from 138,616 runners (48,148 women and 90,469 men) competing between 2014 and 2016 in GöteborgsVarvet, the world’s largest half-marathon. The men-to-women ratio in participants increased with age, the fastest race times were observed in age groups ˂35 and 35–39 years in women and in age group 35–39 years in men, the main effect of sex and the sex × age group interaction on race time were trivial, and the competitiveness was denser in men and in the younger age groups. In summary, in half-marathon running in the largest half-marathon in the world, the GöteborgsVarvet, women achieved the fastest race time at an earlier age compared to men where the fastest race times were observed in women in age groups ˂35 and 35–39 years and in men in age group 35–39 years.

Does the Number of Available Strategies Change How Children Perform Cognitive Tasks? Insights from Arithmetic

Fifth and seventh-graders accomplished computational estimation tasks in conditions where only one versus two strategies were available. Children were told which strategy to execute on each problem. Results showed that both groups of children were faster under one-strategy condition than under two-strategy condition and that age-related differences in performance were larger under two-strategy condition. Also, differences in strategy performance tended to vary as a function of the number of strategies, and this strategy difference was largest in younger children. These findings have implications to further our understanding of strategy execution in arithmetic and in other cognitive domains, as well as of age-related differences in children’s performance during cognitive development.

Influence of Cognitive Functioning on Age-Related Performance Declines in Visuospatial Sequence Learning.

Objectives: The aim of this study was to investigate how age-related performance differences in a visuospatial sequence learning task relate to age-related declines in cognitive functioning.Method: Cognitive functioning of 18 younger and 18 older participants was assessed using a standardized test battery. Participants then undertook a perceptual visuospatial sequence learning task. Various relationships between sequence learning and participants’ cognitive functioning were examined through correlation and factor analysis.Results: Older participants exhibited significantly lower performance than their younger counterparts in the sequence learning task as well as in multiple cognitive functions. Factor analysis revealed two independent subsets of cognitive functions associated with performance in the sequence learning task, related to either the processing and storage of sequence information (first subset) or problem solving (second subset). Age-related declines were only found for the first subset of cognitive functions, which also explained a significant degree of the performance differences in the sequence learning task between age-groups.Discussion: The results suggest that age-related performance differences in perceptual visuospatial sequence learning can be explained by declines in the ability to process and store sequence information in older adults, while a set of cognitive functions related to problem solving mediates performance differences independent of age.

Relationships Among and Differences between Muscle Quality and Functional Performance in Younger and Older Women

The quality of skeletal muscle has been identified as an important factor that is used to describe intramuscular changes associated with muscle function in aging. Traditionally, muscle quality (MQ) has been calculated as maximal muscle strength expressed per unit of muscle mass. More recently, however, the echo intensity (EI) of skeletal muscle ultrasound images has been used as a surrogate measure of muscle quality. PURPOSE: The purpose of this study was to examine the relationships among and differences between commonly-used measures of MQ and functional performance in younger (YW) and older women (OW). METHODS: 15 YW (mean ± SD: 22 ± 2 yrs) and 15 OW (74 ± 5 yrs) completed this study. Muscle cross section area (mCSA) and EI of the rectus femoris were measured from ultrasound scans at the midpoint of the thigh. Each participant completed two maximal voluntary isometric knee extension contractions (MVICs) to determine MVIC strength. Each participant also completed three maximal velocity sit-to-stand movements, during which power and movement velocity were measured. MQ was calculated as MVIC strength ÷ mCSA. Independent samples t-tests were used to analyze differences between YW and OW and Pearson’s correlation coefficients were also used to analyze the relationships among the dependent variables in the YW and OW. RESULTS: MVIC strength (166 ± 37 vs 105 ± 28 Nm), mean velocity (0.6 ± 0.1 vs 0.4 ± 0.1 m/s), peak velocity (0.9 ± 0.2 vs 0.7 ± 0.1), mean power (435 ± 81 vs 299 ± 57 W), peak power (1070 ± 265 vs 597 ± 127 W) were greater and EI (39 ± 8 vs 52 ± 10 au) was lower in the YW than OW, respectively. There was no difference in muscle quality (p = 0.96). EI and MQ were not significantly related (r = 0.12) in the YW, but were significantly related in the OW (r = 0.54). EI was inversely related to mCSA in the YW (r = -0.53) and OW (r = -0.54). In addition, MVIC was significantly related to mCSA (r = 0.75) in the OW, and was not significantly related to EI or MQ in either the YW or OW. CONCLUSION: There were age-related differences in muscle strength, muscle size, echo intensity, and functional performance, but no age-related difference in traditionally measured MQ. EI was related to MQ in the OW, but not the YW. Although EI has been used as a surrogate for MQ, these data suggest that MQ and EI may reflect different qualities of skeletal muscle in aging.

OLDER AND YOUNGER ADULTS’ STRATEGIC CONTROL OF METACOGNITIVE MONITORING: THE ROLE OF CONSEQUENCES, TASK EXPERIENCE, AND PRIOR KNOWLEDGE

Background/Study Context: Although explicit memory abilities decline during older adulthood, there is evidence that suggests that metacognitive capabilities are relatively well preserved. However, it is unclear what effect aging, consequences of forgetting, prior knowledge, and task experience have on the strategic control and use of one’s metacognitive capabilities.Methods: In the current study, older and younger adults were presented with six unique lists of words (Experiment 1), related and unrelated word pairs (Experiment 2), or items within specific scenarios (e.g., items to bring on a picnic; Experiment 3). For each item, participants assigned it a point value (from 0 to 10) that was akin to “betting” on the likelihood the item would be remembered. If the item was recalled (free recall in Experiments 1 and 3, cued recall in Experiment 2), participants received the points they had assigned to it, but if the item was forgotten they lost those points. Participants were told to maximize their point score and were told their score at the end of each list.Results: Although younger adults remembered more words in Experiment 1, older and younger adults were equally able to remember items assigned higher values, and accuracy of predictions and point scores increased with task experience. In Experiments 2 and 3, when participants were able to rely on semantic knowledge, age-related differences in memory performance were eliminated.Conclusion: The results suggest that both younger and older adults achieve accurate metacognitive insight and are able to use this knowledge strategically in order to maximize goal-related memory outcomes and performance.

Sex Matters: Hippocampal Volume Predicts Individual Differences in Associative Memory in Cognitively Normal Older Women but Not Men.

The hippocampus plays a prominent role in associative memory by supporting relational binding and recollection processes. Structural atrophy in the hippocampus is likely to induce associative memory deficits in older adults. Previous studies have primarily focused on average age-related differences in hippocampal structure and memory performance. To date, however, it remains unclear whether individual differences in hippocampal morphometry underlie differential associative memory performance, and whether there are sex differences in the structural correlates of associative memory in healthy older adults. Here, we used voxel-based morphometry (VBM) to examine the extent to which gray matter volume (GMV) of the hippocampus predicts associative memory performance in cognitively normal older adults. Seventy-one participants completed a cued recall paired-associative learning test (PALT), which consists of novel associations and semantically related associations, and underwent magnetic resonance imaging (MRI). We observed worse associative memory performance and larger variability for novel associations than for semantically related associations. The VBM results revealed that higher scores on associative memory for novel associations were related to greater hippocampal GMV across all older adults. When considering men and women separately, the correlation between hippocampal GMV and associative memory performance for novel associations reached significance only in older women. These findings suggest that hippocampal structural volumes may predict individual differences in novel associative memory in older women but not men.

Age-related differences in SSVEP-based BCI performance

Brain–Computer Interface (BCI) systems analyze brain signals to generate control commands for computer applications or external devices. Utilized as alternative communication channel, BCIs have the potential to assist people with severe motor disabilities to interact with their environment and to participate in daily life activities. Handicapped people from all age groups could benefit from such BCI technologies. Although some papers have previously reported slightly worse BCI performance by older subjects, in many studies BCI systems were tested with young subjects only.In the presented paper age-associated differences in BCI performance were investigated. We compared accuracy and speed of a steady-state visual evoked potential (SSVEP)-based BCI spelling application controlled by participants of two different equally sized age groups. Twenty subjects (eleven female and nine male) participated in this study; each age group consisted of ten subjects, ranging from 19 to 27 years and from 64 to 76 years. Our results confirm that elderly people may have a deteriorated information transfer rate (ITR). The mean (SD) ITR of the young age group was 27.36 (6.50) bit/min while the elderly people achieved a significantly lower ITR of 16.10 (5.90) bit/min. The average time window length associated with the signal classification was usually larger for the participants of advanced age. These findings show that the subject age must be taken into account during the development of SSVEP-based applications.

Changes in the correlation between spatial and temporal source memory performance and BOLD activity across the adult lifespan

Studies investigating age-related functional differences associated with source memory have recently focused on the importance of clarifying the relationship between effects of age and performance on memory-related brain activations. One methodological challenge has been in discriminating between effects of age on memory-related brain activations that are independent from age-related differences in performance. In the current study, event-related functional magnetic resonance imaging (fMRI) was used to identify brain activity during spatial and temporal source encoding and retrieval across the adult lifespan. We used multivariate behavior partial least squares (B-PLS) to identify patterns of brain activity during source encoding and source retrieval that were associated with age and/or retrieval accuracy. The PLS analysis identified three significant effects. The first effect indicated that encoding and retrieval activity in fusiform, middle occipital–temporal and inferior parietal cortices increased with age and decreased with performance. The second effect showed that dorsolateral prefrontal cortex and limbic activity increased with age at encoding, and increased with performance at retrieval. The third effect indicated that activity in right ventrolateral prefrontal and bilateral hippocampus increased with age during retrieval and was differentially related to performance during encoding versus retrieval. We conclude that although some age-related differences in brain activity observed during source encoding and retrieval are associated with individual differences in performance, age-related differences in prefrontal and hippocampal areas exhibit more complex patterns of interactions between age, performance, and phase-related activity.

Developmental differences in dynamic muscle-tendon behaviour: implications for movement efficiency.

Children perform cyclic motor tasks less efficiently than adults; however, the mechanisms underlying such differences are not fully understood. One mechanism that may contribute to these age-related differences is a differential contribution of muscles and tendons to a given muscle-tendon unit (MTU) excursion. The aims of this study were to (i) compare muscle and tendon excursion between children and adults performing vertical hopping, and (ii) determine whether children and adults choose a hopping frequency that maximizes movement efficiency, based on the utilization of energy-saving mechanisms. Twelve children (8.8±0.3 years) and 12 adults (26.0±2.1 years) performed 20 s of two-legged hopping at a self-selected frequency and at 1.33, 2.00, 2.67 and 3.33 Hz. Gastrocnemius medialis MTU excursion was estimated from kinematic data and muscle and tendon excursions were derived using a combination of 3D-motion capture and ultrasonography. Optimum hopping frequency was determined as the frequency that maximized surrogate measures of elastic energy storage potential of the tendon and minimized muscle excursion. Adults presented a significantly greater potential for elastic energy storage in combination with lower muscle excursion than children at their self-selected frequency, suggesting that children do not utilize these energy-saving mechanisms as effectively as adults. However, tendon elastic energy storage was maximized and muscle excursion minimized at the preferred frequency in both children and adults, indicating that children may select their preferred hopping frequency based on the same criteria as adults. These findings increase our understanding of the mechanisms contributing to the higher energy cost of movement performance in children, and have implications for the interpretation of age-related differences in complex task performance.

Task Inhibition and Response Inhibition in Older vs. Younger Adults: A Diffusion Model Analysis.

Differences in inhibitory ability between older (64–79 years, N = 24) and younger adults (18–26 years, N = 24) were investigated using a diffusion model analysis. Participants performed a task-switching paradigm that allows assessing n−2 task repetition costs, reflecting inhibitory control on the level of tasks, as well as n−1 response-repetition costs, reflecting inhibitory control on the level of responses. N−2 task repetition costs were of similar size in both age groups. Diffusion model analysis revealed that for both younger and older adults, drift rate parameters were smaller in the inhibition condition relative to the control condition, consistent with the idea that persisting task inhibition slows down response selection. Moreover, there was preliminary evidence for task inhibition effects in threshold separation and non-decision time in the older, but not the younger adults, suggesting that older adults might apply different strategies when dealing with persisting task inhibition. N−1 response-repetition costs in mean RT were larger in older than younger adults, but in mean error rates tended to be larger in younger than older adults. Diffusion-model analysis revealed longer non-decision times in response repetitions than response switches in both age groups, consistent with the idea that motor processes take longer in response repetitions than response switches due to persisting response inhibition of a previously executed response. The data also revealed age-related differences in overall performance: Older adults responded more slowly and more accurately than young adults, which was reflected by a higher threshold separation parameter in diffusion model analysis. Moreover, older adults showed larger non-decision times and higher variability in non-decision time than young adults, possibly reflecting slower and more variable motor processes. In contrast, overall drift rate did not differ between older and younger adults. Taken together, diffusion model analysis revealed differences in overall performance between the age groups, as well as preliminary evidence for age differences in dealing with task inhibition, but no evidence for an inhibitory deficit in older age.

Dissociation of local and global contributions to detection of shape with age.

Radial Frequency (RF) patterns are a useful stimulus for assessing sensitivity to changes in shape. With these patterns it is possible to separate sensitivity to local curvature information from the ability to globally integrate information around the contour. Previous work has demonstrated that young, school-age children are less sensitive to deformation in RF patterns than adults. However, since the efficiency of contour integration was not assessed, age-related differences in performance could arise from either changes in the strength of global pooling of information, the sensitivity to local curvature information, or both. In this study, psychophysical methods were used to reassess changes in sensitivity to RF patterns, separating changes in sensitivity to local curvature information from changes in contour integration strength. Typically developing observers (aged 6-24, N = 104) were tested using a 2-alternative forced-choice discrimination task with either 1, 2 or 3 cycles of sinusoidal modulation in a pattern of fixed RF. Thresholds were lower for older observers but the rate of change, as more modulation cycles were added, was approximately constant across age. The results indicate that changes in sensitivity to RF3 patterns across age are due to changes in local curvature sensitivity and not to the strength of contour integration. (PsycINFO Database Record

Cortical activity modulations underlying age-related performance differences during posture-cognition dual tasking.

To date, no systematic research investigating cortical correlates of performance changes in dual tasking has been reported in the elderly population. Thus, we monitored whole-scalp cortical activations (EEG) during both single task and posture-cognition dual tasking with the main goal of understanding cortical activity modulations underlying age-related differences on posture-cognition dual tasking conditions. Postural and cognitive data analyses showed that elderly people had decreased cognitive performance even during challenging single cognitive tasks. Working memory impairments in the elderly group can be observed when a challenging cognitive task is performed in any postural condition, while postural control performance differences only became significant during challenging dual task conditions. Behavioral performance results, in general, indicate that elderly subjects may adopt a non-automated conscious control strategy and prioritize postural performance over cognitive performance to maintain upright stance only when the cognitive load is low. EEG analyses showed increased delta, theta and gamma oscillations, primarily over frontal, central-frontal, central and central-parietal cortices during dual tasking conditions. We found that delta oscillations were more responsive to challenging postural conditions presumably related to cortical representations of changing sensory conditions in postural tasks. Theta rhythms, on the other hand, were more responsive to cognitive task difficulty in both groups, with more pronounced increases in younger subjects which may underlie neural correlates of high-level cognitive computations including encoding and retrieval. Gamma oscillations also increased in the elderly primarily over central and central-parietal cortices during challenging postural tasks, indicating increased allocation of attentional sources to postural tasks.