Converging evidence that visuospatial cognition is more age-sensitive than verbal cognition

Training attentive individuation leads to visuo-spatial working memory improvement in low-performing older adults: An online study

Cognitive decrements are typical of physiological aging. Among these age-related cognitive changes, visuo-spatial working memory (vWM) decline has a prominent role due to its effects on other cognitive functions and daily routines. To reinforce vWM in the aging population, several cognitive training interventions have been developed in the past years. Given that vWM functioning depends (at least partially) on the efficiency of attention selection of the relevant objects, in the present study we implemented a short (five sessions), online intervention that primarily trained attentive individuation of target items and tested training effects on a vWM task. Attention training effects were compared with practice (i.e., a group that repeatedly performed the same vWM task) and test-retest effects (i.e., a passive group). After the training, the results showed attention training effects of the same magnitude as practice effects, confirming that the enhancement of attentive individuation has a positive cascade influence on maintaining items in vWM. Moreover, training and practice effects were only evident in low-performing older adults. Thus, interindividual differences at baseline crucially contribute to training outcomes and are a fundamental factor to be accounted for in the implementation of cognitive training protocols.

Inter- and Intra-Hemispheric Age-Related Remodeling in Visuo-Spatial Working Memory

Electroencephalography (EEG) studies investigating visuo-spatial working memory (vWM) in aging typically adopt an event-related potential (ERP) analysis approach that has shed light on the age-related changes during item retention and retrieval. However, this approach does not fully enable a detailed description of the time course of the neural dynamics related to aging. The most frequent age-related changes in brain activity have been described by two influential models of neurocognitive aging, the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) and the Posterior-Anterior Shift in Aging (PASA). These models posit that older adults tend to recruit additional brain areas (bilateral as predicted by HAROLD and anterior as predicted by PASA) when performing several cognitive tasks. We tested younger (N = 36) and older adults (N = 35) in a typical vWM task (delayed match-to-sample) where participants have to retain items and then compare them to a sample. Through a data-driven whole scalp EEG analysis we aimed at characterizing the temporal dynamics of the age-related activations predicted by the two models, both across and within different stages of stimulus processing. Behaviorally, younger outperformed older adults. The EEG analysis showed that older adults engaged supplementary bilateral posterior and frontal sites when processing different levels of memory load, in line with both HAROLD and PASA-like activations. Interestingly, these age-related supplementary activations dynamically developed over time. Indeed, they varied across different stages of stimulus processing, with HAROLD-like modulations being mainly present during item retention, and PASA-like activity during both retention and retrieval. Overall, the present results suggest that age-related neural changes are not a phenomenon indiscriminately present throughout all levels of cognitive processing.

A Longitudinal Study Examining Self-Regulation Practices in Older Drivers with and without Suspected Mild Cognitive Impairment

Purpose

Mild cognitive impairment can impact driving performance and self-regulation practices. However, there is little evidence on how cognitive impairment may impact these self-regulation practices over a period of time. Therefore, the aim of this study was to examine changes in the number and type of situations in which older drivers with and without suspected mild cognitive impairment (MCI) self-regulate their driving over a one-year period, after accounting for relevant confounders.

Participants and Methods

A longitudinal cohort study involving older drivers (65+ years) from metropolitan Western Australia was interviewed by a telephone interview at baseline and one-year follow-up. The Telephone Cognitive Screen (T-CogS) was also administered to determine changes in their cognitive status. The outcome of interest was the number and type of situations older drivers self-regulated their driving.

Results

A total of 670 drivers were interviewed at baseline (suspected MCI: n = 227; no cognitive impairment: n = 443) and one-year follow-up (suspected MCI: n = 251; no cognitive impairment: n = 419), which provided 1340 observations. Drivers with suspected MCI increased the number of driving situations in which they self-regulated by 13% over a period of one-year compared with drivers without cognitive impairment (IRR = 1.13, 95% CI = 1.02–1.27, p = 0.025). Specifically, drivers with suspected MCI had 60% increased odds of self-regulating when “making turns across oncoming traffic” compared with drivers without cognitive impairment (unadjusted OR = 1.60, 95% CI = 1.02–2.53, p = 0.041). Other significant factors included being female (IRR = 1.87, 95% = 1.52–2.32, p = 0.001), aged 75+ years (IRR = 1.33, 95% CI = 1.10–1.60, p = 0.003), higher number of comorbidities (1–3 comorbidities: IRR = 1.26, 95% CI = 1.01–1.58, p = 0.040; 4+ comorbidities: IRR = 1.39, 95% CI = 1.08–1.78, p = 0.011), “decreased driving confidence” (IRR = 1.32, 95% CI = 1.10–1.58, p-value = 0.003) and “preference of having someone else drive” (IRR = 1.38, 95% CI = 1.12–1.70, p = 0.003). Having one or more traffic infringements was also associated with a decrease in the number of self-regulated driving situations (IRR = 0.80, 95% CI = 0.67–0.95, p = 0.011).

Conclusion

Over a one-year period, drivers with suspected MCI increased the number of situations in which they self-regulated their driving compared with drivers without cognitive impairment, particularly when “making turns across oncoming traffic”. Future studies should examine whether this increase in the types and number of self-regulated driving situations is enough to compensate for declines in cognition.

Age-Related Changes in Hemispherical Specialization for Attentional Networks

Many cognitive functions face a decline in the healthy elderly. Within the cognitive domains, both attentional processes and executive functions are impaired with aging. Attention includes three attentional networks, i.e., alerting, orienting, and executive control, showing a hemispheric lateralized pattern in adults. This lateralized pattern could play a role in modulating the efficiency of attentional networks. For these reasons, it could be relevant to analyze the age-related change of the hemispheric specialization of attentional networks. This study aims to clarify this aspect with a lateralized version of the Attentional Network Test for Interaction (ANTI)-Fruit. One hundred seventy-one participants took part in this study. They were divided in three age groups: youth (N = 57; range: 20-30); adults (N = 57; range 31-64), and elderly/older people (N = 57; range: 65-87). The results confirmed the previous outcomes on the efficiency and interactions among attentional networks. Moreover, an age-related generalized slowness was evidenced. These findings also support the hypothesis of a hemispheric asymmetry reduction in elderly/older adults.

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

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

Guilty, Innocent, or Just Not Proven? Bayesian Verdicts in the Case of Inhibitory Deficits

Background: This study addresses two issues: Whether age-related differences in working memory (WM) can be studied in online samples, and whether such differences reflect an inhibitory deficit. Currently, the evidence is mixed, but the playing field was not level because traditional statistics cannot provide evidence for the null hypothesis.Experiment 1: MTurk workers (ages 19-74) performed simple and complex visuospatial WM tasks to determine whether a secondary task affected the rate of age-related decline. Performance on both tasks replicated previous laboratory studies, establishing that age-related differences in WM can be studied online. Bayesian analyses revealed it is ten times as likely that there is no inhibitory deficit on visuospatial WM tasks as that there is.Experiment 2: The effects of irrelevant location information on visuospatial WM were examined in older (M_age = 64.0) and younger (M_age = 25.0) MTurk workers. Irrelevant locations produced interference, but both groups were equally affected. Bayesian analyses provided support for the null hypothesis of no age difference.Conclusions: The results of both experiments on working memory not only revealed equivalent visuospatial inhibitory function in older and younger adults, they also demonstrated that age-related differences in visuospatial WM can be effectively studied online as well as in the laboratory.

Learning by task repetition enhances object individuation and memorization in the elderly

A decline in visuospatial Working Memory (vWM) is a hallmark of cognitive aging across various tasks, and facing this decline has become the target of several studies. In the current study we tested whether older adults can benefit from task repetition in order to improve their performance in a vWM task. While learning by task repetition has been shown to improve vWM performance in young adulthood, little is known on whether a similar enhancement can be achieved also by the aging population. By combining different behavioral and electrophysiological measures, we investigated whether practicing a specific task (delayed match-to-sample judgement) over four consecutive sessions could improve vWM in healthy aging, and which are the neurophysiological and cognitive mechanisms modulated by learning. Behavioral data revealed that task repetition boosted performance in older participants, both in terms of sensitivity to change (as revealed by d’ measures) as well as capacity estimate (as measured by k values). At the electrophysiological level, results indicated that only after task repetition both target individuation (as evidenced by the N2pc) and vWM maintenance (as reflected by the CDA) were modulated by target numerosity. Our results suggest that repetition learning is effective in enhancing vWM in aging and acts through modifications at different stages of stimulus processing.

Cognitive aging and verbal labeling in continuous visual memory

The decline of working memory (WM) is a common feature of general cognitive decline, and visual and verbal WM capacity appear to decline at different rates with age. Visual material may be remembered via verbal codes or visual traces, or both. Souza and Skóra, Cognition, 166, 277-297 (2017) found that labeling boosted memory in younger adults by activating categorical visual long-term memory (LTM) knowledge. Here, we replicated this and tested whether it held in healthy older adults. We compared performance in silence, under instructed overt labeling (participants were asked to say color names out loud), and articulatory suppression (repeating irrelevant syllables to prevent labeling) in the delayed estimation paradigm. Overt labeling improved memory performance in both age groups. However, comparing the effect of overt labeling and suppression on the number of coarse, categorical representations in the two age groups suggested that older adults used verbal labels subvocally more than younger adults, when performing the task in silence. Older adults also appeared to benefit from labels differently than younger adults. In younger adults labeling appeared to improve visual, continuous memory, suggesting that labels activated visual LTM representations. However, for older adults, labels did not appear to enhance visual, continuous representations, but instead boosted memory via additional verbal (categorical) memory traces. These results challenged the assumption that visual memory paradigms measure the same cognitive ability in younger and older adults, and highlighted the importance of controlling differences in age-related strategic preferences in visual memory tasks.

Age-related visual dynamics in HIV-infected adults with cognitive impairment

OBJECTIVE

To investigate whether aging differentially affects neural activity serving visuospatial processing in a large functional neuroimaging study of HIV-infected participants and to determine whether such aging effects are attributable to differences in the duration of HIV infection.

METHODS

A total of 170 participants, including 93 uninfected controls and 77 HIV-infected participants, underwent neuropsychological assessment followed by neuroimaging with magnetoencephalography (MEG). Time-frequency analysis of the MEG data followed by advanced image reconstruction of neural oscillatory activity and whole-brain statistical analyses were used to examine interactions between age, HIV infection, and cognitive status. Post hoc testing for a mediation effect of HIV infection duration on the relationship between age and neural activity was performed using a quasi-Bayesian approximation for significance testing.

RESULTS

Cognitively impaired HIV-infected participants were distinguished from unimpaired HIV-infected and control participants by their unique association between age and gamma oscillations in the parieto-occipital cortex. This relationship between age and gamma was fully mediated by the duration of HIV infection in cognitively impaired participants. Impaired HIV-infected participants were also distinguished by their atypical relationship between alpha oscillations and age in the superior parietal cortex.

CONCLUSIONS

Impaired HIV-infected participants exhibited markedly different relationships between age and neural responses in the parieto-occipital cortices relative to their peers. This suggests a differential effect of chronological aging on the neural bases of visuospatial processing in a cognitively impaired subset of HIV-infected adults. Some of these relationships were fully accounted for by differences in HIV infection duration, whereas others were more readily associated with aging.

Age-Related Decline of Low-Spatial-Frequency Bias in Context-Dependent Visual Size Perception

Global precedence has been found to decline or even shift to local precedence with increasing age. Little is known about the consequence of this age-related decline of global precedence on other aspects of older adults’ vision. The global and local processing has been preferentially associated with the low-spatial-frequency (LSF) and high-spatial-frequency (HSF) channels, respectively. Here, we used low- and high-pass filtered faces together with the Ebbinghaus illusion whose magnitude is an index of context sensitivity. The results demonstrated that, relative to HSF faces, prior exposure to LSF faces increased the illusion magnitude for younger participants, but it reduced the illusion magnitude for older participants. Significant age group difference was observed only with prior exposure to LSF faces but not to HSF faces. Moreover, similar patterns of results were observed when the filtered faces were rendered invisible with backward masking, and the magnitude of age-related decline was comparable to the visible condition. Our study reveals that LSF-related enhancement of context sensitivity declines with advancing age, and this age-related decline was independent of the awareness of the spatial frequency information. Our findings support the right hemi-aging model and suggest that the magnocellular projections from subcortical to cortical regions might also be vulnerable to age-related changes.

Effect of age on spatial memory performance in real museum vs. computer simulation

BACKGROUND

Healthy older adults frequently complain on difficulty in recalling the locations of objects of everyday use. Cognitive abilities decline with normal aging; inefficiencies of information processing, as well as deterioration of neuronal structures, may impede the performance of complex cognitive skills such as spatial memory. Extraneous, task-irrelevant cognitive load in real environments is usually high and might interfere with spatial memory abilities of older adults. The purpose of this study was to determine (1) the extent to which older adults maintain their cognitive capacity during a spatial memory task as compared to young adults and (2) whether this capacity is affected by performance of the task in a real environment setting where the cognitive demands are similar to a simulation, but the physical demands (navigating via walking versus via a mouse) vary.

METHODS

In the museum, participants physically moved between display stations to locate hidden tokens performing a task in which an ongoing representation of previous searches had to be remembered. A comparable task was implemented via mouse actions on a computer simulation. Seventeen healthy older (60-80 years) and twenty younger (20-45 years) adults performed both tasks in a counterbalanced order.

RESULTS

The younger group was superior to the older group in terms of success rate and completion time for both conditions. All participants performed better during the simulated task. The delta between the total performance score in the two settings of the older group was significantly larger as compared to the younger group, suggesting a differential impact of setting on the groups.

CONCLUSIONS

Our results highlight the importance and feasibility of experimentation in ecologically relevant settings: differences were found in the way the cognitive performance of older and younger adults was affected by setting. Older adults appear to preserve basic cognitive abilities required for successful performance of object-location memory tasks. However, real museum setting appeared to impose higher demands on the older adults.

The impact of age and sex on the oscillatory dynamics of visuospatial processing

The ability to dynamically allocate neural resources within the visual space is supported by a number of spectrally-specific oscillatory responses, and such visuospatial processing has been found to decline moderately with age and differ by sex. However, the direct effects of age and sex on these oscillatory dynamics remains poorly understood. Using magnetoencephalography (MEG), structural magnetic resonance imaging, and advanced source reconstruction and statistical methods, we investigated the impact of aging and sex on behavioral performance and the underlying neural dynamics during visuospatial processing. In a large sample spanning a broad age range, we find that a number of prototypical attention and perception network components, both spectrally- and spatially-defined, exhibit complex and uniquely informative relationships with age and sex. Specifically, neural responses in the theta range (4-10 Hz) were found to covary with chronological age in prefrontal and motor cortices, signifying a possible relationship between age and cognitive control. Further, we found that beta (18-24 Hz) activity covaried with age across a large swath of the somato-motor strip, supporting previous findings of motor planning and execution deficits with increasing age. Finally, gamma-frequency (48-70 Hz) oscillations were found to exhibit robust covariance with age in superior parietal and temporo-parietal areas, indicating that the mapping of saliency in visual space is modulated by the normal aging process. Interestingly, behavioral performance and some of these oscillatory neural responses also exhibited interactions between age and sex, indicating sex differences in the evolution of the neural coding of visual perception as age increases. In particular, men were found to have stronger correlations between age and neural oscillatory responses during task performance than women in lateral occipital and superior temporal regions in the alpha band and in dorsolateral prefrontal cortex in the gamma band, while women exhibited more robust covariance between age and neural responses than men in inferior temporal and medial prefrontal cortex in the theta range.

Negative Facial Expressions - But Not Visual Scenes - Enhance Human Working Memory in Younger and Older Participants

Many studies have investigated the influence of emotion on memory processes across the human lifespan. Some results have shown older adults (OA) performing better with positive stimuli, some with negative items, whereas some found no impact of emotional valence. Here we tested, in two independent studies, how younger adults (YA) and OA would perform in a visuospatial working memory (VSWM) task with positive, negative, and neutral images. The task consisted of identifying the new location of a stimulus in a crescent set of identical stimuli presented in different locations in a touch-screen monitor. In other words, participants should memorize the locations previously occupied to identify the new location. For each trial, the number of occupied locations increased until 8 or until a mistake was made. In study 1, 56 YA and 38 OA completed the task using images from the International Affective Picture System (IAPS). Results showed that, although YA outperformed OA, no effects of emotion were found. In study 2, 26 YA and 25 OA were tested using facial expressions as stimuli. Data from this study showed that negative faces facilitated performance and this effect did not differ between age groups. No differences were found between men and women. Taken together, our findings suggest that YA and OA’s VSWM can be influenced by the emotional valence of the information, though this effect was present only for facial stimuli. Presumably, this may have happened due to the social and biological importance of such stimuli, which are more effective in transmitting emotions than IAPS images. Critically, our results also indicate that the mixed findings in the literature about the influence of aging on the interactions between memory and emotion may be caused by the use of different stimuli and methods. This possibility should be kept in mind in future studies about memory and emotion across the lifespan.

Shifts in Audiovisual Processing in Healthy Aging

Purpose of Review

The integration of information across sensory modalities into unified percepts is a fundamental sensory process upon which a multitude of cognitive processes are based. We review the body of literature exploring aging-related changes in audiovisual integration published over the last five years. Specifically, we review the impact of changes in temporal processing, the influence of the effectiveness of sensory inputs, the role of working memory, and the newer studies of intra-individual variability during these processes.

Recent Findings

Work in the last five years on bottom-up influences of sensory perception has garnered significant attention. Temporal processing, a driving factors of multisensory integration, has now been shown to decouple with multisensory integration in aging, despite their co-decline with aging. The impact of stimulus effectiveness also changes with age, where older adults show maximal benefit from multisensory gain at high signal-to-noise ratios. Following sensory decline, high working memory capacities have now been shown to be somewhat of a protective factor against age-related declines in audiovisual speech perception, particularly in noise. Finally, newer research is emerging focusing on the general intra-individual variability observed with aging.

Summary

Overall, the studies of the past five years have replicated and expanded on previous work that highlights the role of bottom-up sensory changes with aging and their influence on audiovisual integration, as well as the top-down influence of working memory.

Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

BACKGROUND/STUDY CONTEXT

Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the "common cause" hypothesis of Lindenberger & Baltes, 1994, Psychology and Aging, 9, 339-355). McGowan, Patterson, and Jordan (2013, Experimental Aging Research, 39, 70-79) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (La Fleur and Salthouse, 2014, Psychonomic Bulletin & Review, 21, 1202-1208) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic.

METHODS

Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better).

RESULTS

As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria.

CONCLUSION

The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance-thereby replicating La Fleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g., contrast sensitivity, luminance) affect age differences in cognitive functioning.

Spatial-Sequential Working Memory in Younger and Older Adults: Age Predicts Backward Recall Performance within Both Age Groups

Working memory is vulnerable to age-related decline, but there is debate regarding the age-sensitivity of different forms of spatial-sequential working memory task, depending on their passive or active nature. The functional architecture of spatial working memory was therefore explored in younger (18-40 years) and older (64-85 years) adults, using passive and active recall tasks. Spatial working memory was assessed using a modified version of the Spatial Span subtest of the Wechsler Memory Scale - Third Edition (WMS-III; Wechsler, 1998). Across both age groups, the effects of interference (control, visual, or spatial), and recall type (forward and backward), were investigated. There was a clear effect of age group, with younger adults demonstrating a larger spatial working memory capacity than the older adults overall. There was also a specific effect of interference, with the spatial interference task (spatial tapping) reliably reducing performance relative to both the control and visual interference (dynamic visual noise) conditions in both age groups and both recall types. This suggests that younger and older adults have similar dependence upon active spatial rehearsal, and that both forward and backward recall require this processing capacity. Linear regression analyses were then carried out within each age group, to assess the predictors of performance in each recall format (forward and backward). Specifically the backward recall task was significantly predicted by age, within both the younger and older adult groups. This finding supports previous literature showing lifespan linear declines in spatial-sequential working memory, and in working memory tasks from other domains, but contrasts with previous evidence that backward spatial span is no more sensitive to aging than forward span. The study suggests that backward spatial span is indeed more processing-intensive than forward span, even when both tasks include a retention period, and that age predicts backward spatial span performance across the adult lifespan, within both younger and older adulthood.

Visual word recognition across the adult lifespan

The current study examines visual word recognition in a large sample (N = 148) across the adult life span and across a large set of stimuli (N = 1,187) in three different lexical processing tasks (pronunciation, lexical decision, and animacy judgment). Although the focus of the present study is on the influence of word frequency, a diverse set of other variables are examined as the word recognition system ages and acquires more experience with language. Computational models and conceptual theories of visual word recognition and aging make differing predictions for age-related changes in the system. However, these have been difficult to assess because prior studies have produced inconsistent results, possibly because of sample differences, analytic procedures, and/or task-specific processes. The current study confronts these potential differences by using 3 different tasks, treating age and word variables as continuous, and exploring the influence of individual differences such as vocabulary, vision, and working memory. The primary finding is remarkable stability in the influence of a diverse set of variables on visual word recognition across the adult age spectrum. This pattern is discussed in reference to previous inconsistent findings in the literature and implications for current models of visual word recognition. (PsycINFO Database Record

Shutting Down Sensorimotor Interferences after Stroke: A Proof-of-Principle SMR Neurofeedback Study

Introduction: Neurofeedback training aims at learning self-regulation of brain activity underlying cognitive, emotional or physiological functions. Despite of promising investigations on neurofeedback as a tool for cognitive rehabilitation in neurological diseases, such as after stroke, there is still a lack of research on feasibility and efficiency of neurofeedback in this field.

Methods: The present study aimed at investigating behavioral and electrophysiological effects of 10 sessions of sensorimotor rhythm (SMR) neurofeedback in a 74-years-old stroke patient (UG20). Based on previous results in healthy young participants, we hypothesized that SMR neurofeedback leads to a decrease in sensorimotor interferences and improved stimulus processing, reflected by changes in event-related potentials (ERPs) and electrophysiological coherence. To assess whether UG20 benefited from the training as much as healthy persons of a similar age, a healthy control group of N = 10 elderly persons was trained as well. Before and after neurofeedback training, participants took part in a multichannel electroencephalography measurement conducted during a non-verbal and a verbal learning task.

Results: Both UG20 and the healthy controls were able to regulate their SMR activity during neurofeedback training. Moreover, in a non-verbal learning task, changes in ERPs and coherence were observed after training: UG20 showed a better performance in the non-verbal learning task and a higher P3 amplitude after training than before, and coherence between central and parietal electrodes decreased after training. The control group also showed a behavioral improvement in the non-verbal learning task and tendencies for higher P3 amplitudes and decreased central-parietal coherence after training. Single-case analyses indicated that the changes observed in UG20 were not smaller than the changes in healthy controls.

Conclusion: Neurofeedback can be successfully applied in a stroke patient and in healthy elderly persons. We suggest that SMR neurofeedback leads to a shutting-down of sensorimotor interferences which benefits semantic encoding and retrieval.

Effects of age and environmental support for rehearsal on visuospatial working memory

The present study investigated whether older adults' visuospatial working memory shows effects of environmental support for rehearsal similar to those observed in young adults (Lilienthal, Hale, & Myerson, 2014). When the duration of interitem intervals was 4 s and participants had sufficient time to rehearse, location memory spans were larger in both age groups when environmental support was present than when support was absent. Critically, however, the age-related difference in memory was actually larger when support was provided, suggesting that young and older adults may differ in their rehearsal of to-be-remembered locations. (PsycINFO Database Record

An Autistic Endophenotype and Testosterone Are Involved in an Atypical Decline in Selective Attention and Visuospatial Processing in Middle-Aged Women

Mothers of offspring with autism spectrum disorders (ASD) could present mild forms of their children's cognitive characteristics, resulting from prenatal brain exposure and sensitivity to testosterone (T). Indeed, their cognition is frequently characterized by hyper-systemizing, outperforming in tests that assess cognitive domains such as selective attention, and fine motor and visuospatial skills. In the general population, all these start to decline around the mid-forties. This study aimed to characterize whether middle-aged women who are biological mothers of individuals with ASD had better performance in the aforementioned cognitive skills than mothers of normative children (in both groups n = 22; mean age = 45), using the standardized Stroop and mirror-drawing tests. We also examined the role of T in their performance in the aforementioned tests. ASD mothers outperformed controls in both tests, giving more correct answers and making fewer mistakes. In addition, they presented higher T levels, which have been associated with better cognitive performance. Cognitive decline in specific skills with aging could be delayed in these middle-aged women, corresponding to a cognitive endophenotype, T playing an important role in this process.

Brain activation during visual working memory correlates with behavioral mobility performance in older adults

Functional mobility and cognitive function often decline with age. We previously found that functional mobility as measured by the Timed Up and Go Test (TUG) was associated with cognitive performance for visually-encoded (i.e., for location and face) working memory (WM) in older adults. This suggests a common neural basis between TUG and visual WM. To elucidate this relationship further, the present study aimed to examine the neural basis for the WM-mobility association. In accordance with the well-known neural compensation model in aging, we hypothesized that "attentional" brain activation for easy WM would increase in participants with lower mobility. The data from 32 healthy older adults were analyzed, including brain activation during easy WM tasks via functional Magnetic Resonance Imaging (fMRI) and mobility performance via both TUG and a simple walking test. WM performance was significantly correlated with TUG but not with simple walking. Some prefrontal brain activations during WM were negatively correlated with TUG performance, while positive correlations were found in subcortical structures including the thalamus, putamen and cerebellum. Moreover, activation of the subcortical regions was significantly correlated with WM performance, with less activation for lower WM performers. These results indicate that older adults with lower mobility used more cortical (frontal) and fewer subcortical resources for easy WM tasks. To date, the frontal compensation has been proposed separately in the motor and cognitive domains, which have been assumed to compensate for dysfunction of the other brain areas; however, such dysfunction was less clear in previous studies. The present study observed such dysfunction as degraded activation associated with lower performance, which was found in the subcortical regions. We conclude that a common dysfunction-compensation activation pattern is likely the neural basis for the association between visual WM and functional mobility.

An examination of age-related changes in the control of lexical and sublexical pathways in mapping spelling to sound

The current study investigated the extent to which young and older adults are able to direct attention to distinct processes in mapping spelling onto sound. Young and older adults completed either a speeded pronunciation task (reading aloud words) or regularization task (pronouncing words based on spelling-to-sound correspondences, e.g., pronouncing PINT such that it rhymes with HINT) in order to bias processing of lexical, whole-word information, or sublexical, spelling-to-sound mapping, respectively. Both younger and older adults produced reduced word-frequency effects and lexicality effects in the regularization task compared to the normal pronunciation task. Importantly, compared to younger adults, older adults produced exaggerated effects of task (i.e., pronunciation vs. regularization) on the observed frequency and lexicality effects. These results highlight both the flexibility of the lexical processing system and changes in the influence of the underlying lexical route due to additional 50 years of reading experience and/or changes in attentional control.

Online cognitive training in healthy older adults: a preliminary study on the effects of single versus multi-domain training

It has been argued that cognitive training may be effective in improving cognitive performance in healthy older adults. However, inappropriate active control groups often hinder the validity of these claims. Additionally there are relatively few independent empirical studies on popular commercially available cognitive training programs. The current research extends on previous work to explore cognitive training employing a more robust control group. Twenty-eight healthy older adults (age: M = 64.18, SD = 6.9) completed either a multi-faceted online computerised cognitive training program or trained on a simple reaction time task for 20 minutes a day over a 28 day period. Both groups significantly improved performance in multiple measures of processing speed. Only the treatment group displayed improved performance for measures of memory accuracy. These results suggest improvements in processing speed and visual working memory may be obtained over a short period of computerized cognitive training. However, gains over this time appear only to show near transfer. The use of similar active control groups in future research are needed in order to better understand changes in cognition after cognitive training.

Greater BOLD variability in older compared with younger adults during audiovisual speech perception

Older adults exhibit decreased performance and increased trial-to-trial variability on a range of cognitive tasks, including speech perception. We used blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) to search for neural correlates of these behavioral phenomena. We compared brain responses to simple speech stimuli (audiovisual syllables) in 24 healthy older adults (53 to 70 years old) and 14 younger adults (23 to 39 years old) using two independent analysis strategies: region-of-interest (ROI) and voxel-wise whole-brain analysis. While mean response amplitudes were moderately greater in younger adults, older adults had much greater within-subject variability. The greatly increased variability in older adults was observed for both individual voxels in the whole-brain analysis and for ROIs in the left superior temporal sulcus, the left auditory cortex, and the left visual cortex. Increased variability in older adults could not be attributed to differences in head movements between the groups. Increased neural variability may be related to the performance declines and increased behavioral variability that occur with aging.

Age-related effects on spatial memory across viewpoint changes relative to different reference frames

Remembering object positions across different views is a fundamental competence for acting and moving appropriately in a large-scale space. Behavioural and neurological changes in elderly subjects suggest that the spatial representations of the environment might decline compared to young participants. However, no data are available on the use of different reference frames within topographical space in aging. Here we investigated the use of allocentric and egocentric frames in aging, by asking young and older participants to encode the location of a target in a virtual room relative either to stable features of the room (allocentric environment-based frame), or to an unstable objects set (allocentric objects-based frame), or to the viewer's viewpoint (egocentric frame). After a viewpoint change of 0° (absent), 45° (small) or 135° (large), participants judged whether the target was in the same spatial position as before relative to one of the three frames. Results revealed a different susceptibility to viewpoint changes in older than young participants. Importantly, we detected a worst performance, in terms of reaction times, for older than young participants in the allocentric frames. The deficit was more marked for the environment-based frame, for which a lower sensitivity was revealed as well as a worst performance even when no viewpoint change occurred. Our data provide new evidence of a greater vulnerability of the allocentric, in particular environment-based, spatial coding with aging, in line with the retrogenesis theory according to which cognitive changes in aging reverse the sequence of acquisition in mental development.

A rightward shift in the visuospatial attention vector with healthy aging

The study of lateralized visuospatial attention bias in non-clinical samples has revealed a systematic group-level leftward bias (pseudoneglect), possibly as a consequence of right hemisphere (RH) dominance for visuospatial attention. Pseudoneglect appears to be modulated by age, with a reduced or even reversed bias typically present in elderly participants. It has been suggested that this shift in bias may arise due to disproportionate aging of the RH and/or an increase in complementary functional recruitment of the left hemisphere (LH) for visuospatial processing. In this study, we report rightward shifts in subjective midpoint judgment relative to healthy young participants whilst elderly participants performed a computerized version of the landmark task (in which they had to judge whether a transection mark appeared closer to the right or left end of a line) on three different line lengths. This manipulation of stimulus properties led to a similar behavioral pattern in both the young and the elderly: a rightward shift in subjective midpoint with decreasing line length, which even resulted in a systematic rightward bias in elderly participants for the shortest line length (1.98° of visual angle, VA). Overall performance precision for the task was lower in the elderly participants regardless of line length, suggesting reduced landmark task discrimination sensitivity with healthy aging. This rightward shift in the attentional vector with healthy aging is likely to result from a reduction in RH resources/dominance for attentional processing in elderly participants. The significant rightward bias in the elderly for short lines may even suggest a reversal of hemisphere dominance in favor of the LH/right visual field under specific conditions.

Characterization of a normal control group: are they healthy?

We examined the health of a control group (18-81years) in our aging study, which is similar to control groups used in other neuroimaging studies. The current study was motivated by our previous results showing that one third of the elder control group had moderate to severe white matter hyperintensities and/or cortical volume loss which correlated with poor performance on memory tasks. Therefore, we predicted that cardiovascular risk factors (e.g., hypertension, high cholesterol) within the control group would account for significant variance on working memory task performance. Fifty-five participants completed 4 verbal and spatial working memory tasks, neuropsychological exams, diffusion tensor imaging (DTI), and blood tests to assess vascular risk. In addition to using a repeated measures ANOVA design, a cluster analysis was applied to the vascular risk measures as a data reduction step to characterize relationships between conjoint risk factors. The cluster groupings were used to predict working memory performance. The results show that higher levels of systolic blood pressure were associated with: 1) poor spatial working memory accuracy; and 2) lower fractional anisotropy (FA) values in multiple brain regions. In contrast, higher levels of total cholesterol corresponded with increased accuracy in verbal working memory. An association between lower FA values and higher cholesterol levels were identified in different brain regions from those associated with systolic blood pressure. The conjoint risk analysis revealed that Risk Cluster Group 3 (the group with the greatest number of risk factors) displayed: 1) the poorest performance on the spatial working memory tasks; 2) the longest reaction times across both spatial and verbal memory tasks; and 3) the lowest FA values across widespread brain regions. Our results confirm that a considerable range of vascular risk factors are present in a typical control group, even in younger individuals, which have robust effects on brain anatomy and function. These results present a new challenge to neuroimaging studies both for defining a cohort from which to characterize 'normative' brain circuitry and for establishing a control group to compare with other clinical populations.

Reconstructing wholes from parts: effects of modality, age, and hearing loss on word recognition

OBJECTIVE

In this study, the effects of age, hearing loss, and modality on the ability to integrate partial information in degraded stimuli, either speech or text, were examined using isolated words. It was hypothesized that the ability to make use of partial information in speech diminishes with age. It was also hypothesized that additional contributions of cochlear pathology underlying hearing loss would be manifest as a further decrement in performance for older adults with hearing loss, relative to older adults with normal hearing. Furthermore, it was hypothesized that, if the ability to integrate partial information in speech is amodal, then recognition performance for degraded speech would be associated with recognition performance for parallel measures of degraded text. Last, it was hypothesized that, if the nature of the amodal ability to integrate partial information is cognitive, then the performance on auditory and visual measures of word recognition would be correlated with performance on measures of working memory.

DESIGN

Twenty-five young adults with normal hearing, 20 older adults with normal hearing, and 21 older adults with hearing loss participated in this study. All participants completed three auditory and two parallel visual tasks consisting of listening to or reading degraded words or text. Older participants also completed a working-memory test battery. Group effects were examined for each of the auditory and visual measures. Performance of older participants on cognitive measures was compared with available data from a younger group participating in a different study in our laboratory (with similar protocol). Correlations between auditory and visual measures of speech recognition were examined for all participants. In addition, correlations between perceptual and cognitive measures were computed for the older participants. Finally, the relationship between dependent auditory measures and other independent measures in older adults were further examined using stepwise linear regression analyses.

RESULTS

Of the 10 possible comparisons between the young and the two older groups for the five primary dependent measures, the young performed significantly better than the elderly did, 8 of the 10 times. The two older groups performed similarly for most tasks. In young adults, performance among the auditory tasks and between the two visual tasks was significantly and moderately to strongly correlated. In addition, performance on one of the visual tasks was weakly to moderately significantly correlated with performance on each of the three auditory tasks. Similar moderate to strong correlations were found within the auditory and visual modalities in older adults. However, none of the between-modality correlations were significant in the elderly.

CONCLUSIONS

In summary, the results of this study suggest that the ability to integrate partial information in degraded words diminishes with age. Once audibility is accounted for, this ability does not seem to diminish with cochlear pathology. In young adults, both modality-specific factors and amodal cognitive factors seem to contribute to this ability. In older adults, although modality-specific factors continue to be important, it seems that the perceptual mechanisms that underlie the processing of degraded speech and text are separate, at least for isolated words. Our results suggest that, when peripheral factors are accounted for, some higher-level, yet-to-be identified, age-related factors contribute to speech-communication difficulties in the elderly.

Cognitive processing speed in older adults: relationship with white matter integrity

Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI), at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.

Input, retention, and output factors affecting adult age differences in visuospatial short-term memory

OBJECTIVES

The sources of age differences in short-term memory for spatial locations were explored in 2 experiments that examined factors related to input, to maintenance, and to output.

METHOD

In each experiment, 4 dots were presented briefly, followed after a retention interval by a probe dot, which was judged to either match or not match one of the 4 memory-set dots.

RESULTS AND DISCUSSION

Results showed that poorer performance by older adults could be attributed independently to reduced visual acuity, to less effective use of rehearsal strategies, and to differences in response biases.

The structure of working memory abilities across the adult life span

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20-89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation.

Working memory and aging: separating the effects of content and context

In 3 experiments, we investigated the hypothesis that age-related differences in working memory might be due to the inability to bind content with context. Participants were required to find a repeating stimulus within a single series (no context memory required) or within multiple series (necessitating memory for context). Response time and accuracy were examined in 2 task domains: verbal and visuospatial. Binding content with context led to longer processing time and poorer accuracy in both age groups, even when working memory load was held constant. Although older adults were overall slower and less accurate than young adults, the need for context memory did not differentially affect their performance. It is therefore unlikely that age differences in working memory are due to specific age-related problems with content-with-context binding.

Performance level modulates adult age differences in brain activation during spatial working memory

Working memory (WM) shows pronounced age-related decline. Functional magnetic resonance imaging (fMRI) studies have revealed age differences in task-related brain activation. Evidence based primarily on episodic memory studies suggests that brain activation patterns can be modulated by task difficulty in both younger and older adults. In most fMRI aging studies on WM, however, performance level has not been considered, so that age differences in activation patterns are confounded with age differences in performance level. Here, we address this issue by comparing younger and older low and high performers in an event-related fMRI study. Thirty younger (20-30 years) and 30 older (60-70 years) healthy adults were tested with a spatial WM task with three load levels. A region-of-interest analysis revealed marked differences in the activation patterns between high and low performers in both age groups. Critically, among the older adults, a more "youth-like" load-dependent modulation of the blood oxygen level-dependent signal was associated with higher levels of spatial WM performance. These findings underscore the need of taking performance level into account when studying changes in functional brain activation patterns from early to late adulthood.

The Indiana faces in places test: preliminary findings on a new visuospatial memory test in patients with mild cognitive impairment

Memory assessment is an important component of a neuropsychological evaluation, but far fewer visual than verbal memory instruments are available. We examined the preliminary psychometric properties and clinical utility of a novel, motor-free paper and pencil visuospatial memory test, the Indiana faces in places test (IFIPT). The IFIPT and general neuropsychological performance were assessed in 36 adults with amnestic mild cognitive impairment (aMCI) and 113 older adults with no cognitive impairment at baseline, 1 week, and 1 year. The IFIPT is a visual memory test with 10 faces paired with spatial locations (three learning trials and non-cued delayed recall). Results showed that MCI participants scored lower than controls on several variables, most notably total learning (p < .001 at all three time points), delayed recall (baseline p = .03, 1 week p < .001, 1 year p < .001), and false-positive errors (range p = .03 to <0.001). The IFIPT showed similar test-retest reliability at 1-week and 1-year follow-up to other neuropsychological tests (r = 0.71-0.84 for MCI and 0.53-0.72 for controls). Diagnostic accuracy was modest for this sample (areas under the receiver operating characteristic curve between 0.64 and 0.66). Preliminary psychometric analyses support further study of the IFIPT. The measure showed evidence of clinical utility by demonstrating group differences between this sample of healthy adults and those with MCI.

Aging affects the mental rotation of left and right hands

BACKGROUND

Normal aging significantly influences motor and cognitive performance. Little is known about age-related changes in action simulation. Here, we investigated the influence of aging on implicit motor imagery.

METHODOLOGY/PRINCIPAL FINDINGS

Twenty young (mean age: 23.9+/-2.8 years) and nineteen elderly (mean age: 78.3+/-4.5 years) subjects, all right-handed, were required to determine the laterality of hands presented in various positions. To do so, they mentally rotated their hands to match them with the hand-stimuli. We showed that: (1) elderly subjects were affected in their ability to implicitly simulate movements of the upper limbs, especially those requiring the largest amplitude of displacement and/or with strong biomechanical constraints; (2) this decline was greater for movements of the non-dominant arm than of the dominant arm.

CONCLUSIONS/SIGNIFICANCE

These results extend recent findings showing age-related alterations of the explicit side of motor imagery. They suggest that a general decline in action simulation occurs with normal aging, in particular for the non-dominant side of the body.

Are there age differences in the executive component of working memory? Evidence from domain-general interference effects

Young and older adults performed verbal and spatial storage-only and storage-plus-processing working memory tasks while performing a secondary finger tapping task, and the effects on both the maximum capacity (measured as the longest series correct) and the reliability (measured as the proportion of items correct) of working memory were assessed. Tapping tended to produce greater disruption of working memory tasks that place greater demands on executive processes (i.e., storage-plus-processing tasks compared to storage-only span tasks). Moreover, tapping produced domain-general interference, disrupting both verbal and spatial working memory, providing further support for the idea that tapping interferes with the executive component of the working memory system, rather than domain-specific maintenance processes. Nevertheless, tapping generally produced equivalent interference effects in young and older adults. Taken together, these findings are inconsistent with the hypothesis that age-related declines in working memory are primarily attributable to a deficit in the executive component.

Age effects on load-dependent brain activations in working memory for novel material

Three competing models of cognitive aging (neural compensation, capacity limitations, neural inefficiency) were examined in relation to working memory for novel non-verbal material. To accomplish this goal young (n=25) and old (n=25) participants performed a delayed item recognition (DIR) task while being scanned with bold fMRI. The stimuli in the DIR task consisted of computer-generated closed-curve shapes with each shape presented only once in the testing conditions of each participant. This ensured that both the novelty and appearance of the shapes maximized visual demands and limited the extent of phonologic processing. Behaviorally, as expected, the old participants were slower and less accurate compared to the young participants. Spatial patterns of brain activation that corresponded to load-dependent (stimulus set size ranged from 1 to 3) fMRI signal during the three phases of the DIR task (memory set presentation, retention delay, probe presentation) were evaluated in both age groups. Support for neural compensation and capacity limitation was evident in retention delay and the probe phase, respectively. Data were inconsistent with the neural inefficiency model. The process specific support for the theories we examined is consistent with a large corpus of research showing that the substrates underlying the encoding, retention and probe phases are different. That is, cognitive aging theories can be specific to the neural networks/regions underlying the different phases of working memory. Delineating how these theories work in concert can increase knowledge of age-related effects on working memory.

Human aging magnifies genetic effects on executive functioning and working memory

We demonstrate that common genetic polymorphisms contribute to the increasing heterogeneity of cognitive functioning in old age. We assess two common Val/Met polymorphisms, one affecting the Catechol-O-Methyltransferase (COMT) enzyme, which degrades dopamine (DA) in prefrontal cortex (PFC), and the other influencing the brain-derived neurotrophic factor (BDNF) protein. In two tasks (Wisconsin Card Sorting and spatial working memory), we find that effects of COMT genotype on cognitive performance are magnified in old age and modulated by BDNF genotype. Older COMT Val homozygotes showed particularly low levels of performance if they were also BDNF Met carriers. The age-associated magnification of COMT gene effects provides novel information on the inverted U-shaped relation linking dopaminergic neuromodulation in PFC to cognitive performance. The modulation of COMT effects by BDNF extends recent evidence of close interactions between frontal and medial-temporal circuitries in executive functioning and working memory.

Activation of the medial septum reverses age-related hippocampal encoding deficits: a place field analysis

When a rat runs through a familiar environment, the hippocampus retrieves a previously stored spatial representation of the environment. When the environment is modified a new representation is seen, presumably corresponding to the hippocampus encoding the new information. The medial septum is hypothesized to modulate whether the hippocampus engages in retrieval or encoding. The cholinergic agonist carbachol was infused into the medial septum, and hippocampal CA1 place cells were recorded in freely moving rats. In a familiar environment, septal activation impaired the retrieval of a previously stored hippocampal place cell representation regardless of age. When the environment was changed, medial septal activation impaired the encoding process in young, but facilitated the encoding of the new information in aged rats. Moreover, the improved encoding was evident during a subsequent exposure to the modified environment 24 h later. The findings support the role the septum plays in modulating hippocampal retrieval/encoding states. Furthermore, our data indicate a mechanism of age-related cognitive impairment.

The Model Human Processor and the older adult: parameter estimation and validation within a mobile phone task

The authors estimate weighted mean values for nine information processing parameters for older adults using the Card, Moran, and Newell (1983) Model Human Processor model. The authors validate a subset of these parameters by modeling two mobile phone tasks using two different phones and comparing model predictions to a sample of younger (N = 20; M-sub(age) = 20) and older (N = 20; M-sub(age) = 69) adults. Older adult models fit keystroke-level performance at the aggregate grain of analysis extremely well (R = 0.99) and produced equivalent fits to previously validated younger adult models. Critical path analyses highlighted points of poor design as a function of cognitive workload, hardware/software design, and user characteristics. The findings demonstrate that estimated older adult information processing parameters are valid for modeling purposes, can help designers understand age-related performance using existing interfaces, and may support the development of age-sensitive technologies.

Age-Associated Memory Changes in Adults With Williams Syndrome

Age-associated changes on measures of episodic and working memory were examined in 15 adults with Williams Syndrome (WS; M age = 48.3 years, SD = 14.7; M IQ = 62.9, SD = 8.5) and their performance was compared to that of 33 adults with mental retardation (MR) with unspecified etiologies (M age = 54.2 years, SD = 8.9; M IQ = 61.7, SD = 6.5). Among the group with WS, older adults were significantly poorer than younger adults on the free recall task, a measure of episodic memory. Although this finding is consistent with normal aging, it occurred at a chronologically early age in adults with WS and was not found in their peers with unspecified MR. Although both groups showed small declines with age on a backward digit span task, a measure of working memory, for the group with WS the rate of decline on backward digit span was slower as compared to their performance on the free recall task. The findings from this study indicate a chronologically early and precipitous age-associated decrease in long-term, episodic memory in adults with WS.