Attentional networks in normal aging and Alzheimer's disease

Inhibition changes across the lifespan: experimental evidence from the Stroop task

Individuals constantly exert inhibitory control over their thoughts and behaviors to plan actions that compete with habits and impulses. Cognitive inhibition enhances the selection of task-relevant stimuli and is closely related to neural changes that occur across the lifespan. Since few studies have focused on the entire lifespan, this study aimed to assess cognitive inhibition abilities in a sample of 425 healthy participants (age range: 7-88 years) using the Stroop task. The participants were grouped according to age into children, adolescents, young adults, adults, middle-aged adults, and older adults. A series of ANOVAs considered Group as the independent variable and Performance indices as the dependent variables. The children did not show an interference effect (Stroop effect), likely due to the lack of an automated reading process as a consequence of ongoing brain maturation. Adolescents and young adults performed significantly faster than older adults did. The results indicate that response speed reaches its peak during adolescence and young adulthood and then slightly decreases until older age. Nevertheless, when compared with the other groups, only older adults showed significant differences in the Stroop effect, suggesting that inhibitory abilities remain relatively consistent throughout adulthood but rapidly worsen in recent years due to the physiological decline in cognitive and brain functioning associated with aging.

Age differences in inhibitory and working memory functioning: limited evidence of system interactions

Debate persists regarding the nature of age-related deficits in inhibition, and whether inhibitory functioning depends on working memory systems. The current research aimed to measure age-related differences in inhibition and working memory, characterize the relationship between inhibitory functions and working memory performance, and determine how these relationships are affected by age. Toward these ends, we measured performance on a range of established paradigms in 60 young adults (18-30 years) and 60 older adults (60-88 years). Our findings support age-related increases in reflexive inhibition (based on the fixation offset effect and inhibition of return) and age-related decrements in volitional inhibition (based on several paradigms: antisaccade, Stroop, flanker, and Simon). This evidence of stronger reflexive inhibition combined with weaker volitional inhibition suggests that age-related deterioration of cortical structures may allow subcortical structures to operate less controlled. Regarding working memory, older adults had lower backward digit scores and lower forward and backward spatial scores. However, of the 32 analyses (16 in each age group) that tested for dependence of inhibitory functioning on working memory functioning, only one (in young adults) indicated that inhibition performance significantly depended on working memory performance. These results indicate that inhibition and working memory function largely independently in both age groups, and age-related working memory difficulties cannot account for age-related declines in inhibitory control.

Neural Underpinnings of Learning in Dementia Populations: A Review of Motor Learning Studies Combined with Neuroimaging

The intent of this review article is to serve as an overview of current research regarding the neural characteristics of motor learning in Alzheimer disease (AD) as well as prodromal phases of AD: at-risk populations, and mild cognitive impairment. This review seeks to provide a cognitive framework to compare various motor tasks. We will highlight the neural characteristics related to cognitive domains that, through imaging, display functional or structural changes because of AD progression. In turn, this motivates the use of motor learning paradigms as possible screening techniques for AD and will build upon our current understanding of learning abilities in AD populations.

Bilateral anterior corona radiata microstructure organisation relates to impaired social cognition in schizophrenia

OBJECTIVE

The Corona Radiata (CR) is a large white matter tract in the brain comprising of the anterior CR (aCR), superior CR (sCR), and posterior CR (pCR), which have associations with cognition, self-regulation, and, in schizophrenia, positive symptom severity. This study tested the hypothesis that the microstructural organisation of the aCR, as measured by Fractional Anisotropy (FA) using Diffusion Tensor Imaging (DTI), would relate to poorer social cognitive outcomes and higher positive symptom severity for people with schizophrenia, when compared to healthy participants. We further hypothesised that increased positive symptoms would relate to poorer social cognitive outcomes.

METHODS

Data were derived from n = 178 healthy participants (41 % females; 36.11 ± 12.36 years) and 58 people with schizophrenia (30 % females; 42.4 ± 11.1 years). The Positive and Negative Symptom Severity Scale measured clinical symptom severity. Social Cognition was measured using the Reading the Mind in the Eyes Test (RMET) Total Score, as well as the Positive, Neutral, and Negative stimuli valence. The ENIGMA-DTI protocol tract-based spatial statistics (TBSS) was used.

RESULTS

There was a significant difference in FA for the CR, in individuals with schizophrenia compared to healthy participants. On stratification, both the aCR and pCR were significantly different between groups, with patients showing reduced white matter tract microstructural organisation. Significant negative correlations were observed between positive symptomatology and reduced microstructural organisation of the aCR. Performance for RMET negative valence items was significantly correlated bilaterally with the aCR, but not the sCR or pCR, and no relationship to positive symptoms was observed.

CONCLUSIONS

These data highlight specific and significant microstructural white-matter differences for people with schizophrenia, which relates to positive clinical symptomology and poorer performance on social cognition stimuli. While reduced FA is associated with higher positive symptomatology in schizophrenia, this study shows the specific associated with anterior frontal white matter tracts and reduced social cognitive performance. The aCR may have a specific role to play in frontal-disconnection syndromes, psychosis, and social cognitive profile within schizophrenia, though further research requires more sensitive, specific, and detailed consideration of social cognition outcomes.

Analysis of Physical-Cognitive Tasks Including Feedback-Based Technology for Alzheimer's Disorder in a Randomized Experimental Pilot Study

INTRODUCTION

Alzheimer's disease causes great changes, with the prefrontal cortex being the most frequently damaged zone; these changes affect physical and cognitive behavior and compromise autonomy.

OBJECTIVE

The objective of this study was to evaluate the effects of physical-cognitive tasks on memory, attention, balance, gait, and risk of falling in Alzheimer's by using feedback-based technology.

METHODS

Forty patients with Alzheimer's were recruited from an Alzheimer's Association; of these, 15 met the inclusion criteria and were included in the pilot RCT (eight in the control group; seven in the experimental group).

ASSESSMENT TOOLS

The Cognitive Mini-Examination Scale, Oddball Test and Attention Network, Berg Scale, Tinetti, Timed Up and Go, and Geriatric Deterioration Scale. The experimental group was treated with physical-cognitive tasks by using combined feedback-based technology (visual, acoustic, simultaneous, immediate, and terminal feedback, as well as knowledge of the results and performance) under the supervision of physiotherapists twice per week for 16 thirty-minute sessions. The control group underwent their usual care (pharmacological treatment, mobility exercises, and cognitive stimulation sessions).

RESULT

In the experimental group, the contrast tests showed differences for the re-test (except in attention), with the significative Timed Up and Go test being significant (p = 0.020). The interaction between groups showed significant differences for the experimental group according to the MEC (p = 0.029; d = 0.14) and Tinetti (p = 0.029; d = 0.68).

DISCUSSION/CONCLUSION

Memory, balance, gait, and risk of falling improved in the Alzheimer's patients through the use of physical-cognitive tasks involving combined feedback-based technology. The effects on attention were inconclusive. The outcomes should be treated with caution due to the sample. This can promote intergenerational bonds, use at home, and adherence to treatment.

Specific but not general declines in attention and executive function with aging: Converging cross-sectional and longitudinal evidence across the adult lifespan

Objective

Attention and executive function (EF) are vulnerable to aging. However, whether all these functions generally decline with aging is not known. Furthermore, most evidence is based on cross-sectional data and fewer follow-up data are available in the literature. Longitudinal follow-up studies are necessary to characterize individualized and precise changes in cognitive function. Additionally, relatively few aging studies have included middle-aged adults to examine age-related differences in attention and EF. Therefore, this study aims to examine whether general or specific attention and EF decline with aging from adulthood to old age by combining cross-sectional and longitudinal follow-up approaches.

Methods

This study recruited 253 participants aged 20 to 78  years. passing a prescreening procedure (see main text for detail) for the baseline session, and 123 of them were invited to return 1 ~ 2  years after their first visit to participate in the follow-up session. The participants completed a series of attention and EF tasks at both the baseline and follow-up sessions, which measured alerting, orienting, conflict control, stopping, memory updating, and switching abilities. We applied linear and nonlinear regression models to evaluate the cross-sectional age effect on attention and EF and employed a modified Brinley plot to inspect follow-up performance against baseline in attention and EF.

Results

The results of cross-sectional data showed that older adults exhibited decreased efficiency in alerting, stopping, and memory updating but paradoxically increased efficiency in conflict control and switching abilities and no changes in orienting efficiency with age. However, the results of longitudinal data showed that only alerting and memory updating continued to show decreased efficiency. Furthermore, conflict control and switching showed increased efficiency with aging, whereas the orienting network, and stopping no longer showed decreased efficiency.

Conclusion

Thus, converging the cross-sectional and longitudinal data showed that the alerting and memory updating function exhibited the most robust deficit with age (cross-sectional) and aging (longitudinal). Alerting and memory updating abilities are crucial survival skills for human beings. Therefore, developing methods to prevent and improve an individual’s alertness and working memory ability is an important practical issue in aging research.

Adult Age Differences in the Temporal Dynamics of Motivated Attention

Reward-based motivation modulates attention and cognitive control across the life span, but little is known about age differences in the temporal dynamics of motivated attention. The current study examined the effects of financial incentives on visual attention using ERPs. Participants (26 younger, aged 18-33 years; 24 older, aged 65-95 years) completed an incentivized flanker task in which trial-level incentive cues signaled the availability of performance-contingent reward, and subsequent alerting cues signaled the onset of the flanker target. ERP components of interest included cue-related components (incentive-cue P2 and contingent negative variation, and alerting-cue N1) as well as target-related components (target N1 and P3). Transient effects of incentives were assessed by comparing ERP amplitudes across incentive and non-incentive trials from mixed-incentive blocks. Sustained effects of incentives were assessed by comparing ERP amplitudes across non-incentive trials from mixed-incentive blocks and non-incentive trials from pure non-incentive blocks. Younger adults showed transient effects of incentives on all components, whereas older adults showed these effects for incentive-cue P2 and alerting-cue N1 only. Both age groups showed sustained effects of incentives on cue-locked ERPs, but only younger adults showed sustained effects on target-locked ERPs. RT patterns mirrored the ERP findings, in that younger adults showed greater incentive-based modulation than older adults, but at a greater cost to accuracy. Overall, these findings reveal widespread age differences in the dynamics of incentive-motivated attention and cognitive control, particularly at longer timescales.

Impaired attention mechanisms in confabulating patients: A VLSM and DWI study

Attention is one of the most studied cognitive functions in brain-damaged populations or neurological syndromes, as its malfunction can be related to deficits in other higher cognitive functions. In the present study, we aimed at delimiting the attention deficits of a sample of brain-injured patients presenting confabulations by assessing their performance on alertness, spatial orienting, and executive control tasks. Confabulating patients, who present false memories or beliefs without intention to deceive, usually show memory deficits and/or executive dysfunction. However, it is also likely that attention processes may be impaired in patients showing confabulations. Here, we compared confabulating patients' attention performance to a lesion control group and a healthy control group. Confabulating patients' mean overall accuracy was lower than the one of healthy and lesion controls along the three experimental tasks. Importantly, confabulators presented a greater Simon congruency effect than both lesion controls and healthy controls in the presence of predictive spatial cues, besides a lower percentage of hits and longer RTs in the Go-NoGo task, demonstrating deficits in executive control. They also showed a higher reliance on alerting and spatially predictive orienting cues in the context of a deficient performance. Grey and white matter analyses showed that patients' percentage of hits in the Go-NoGo task was related to damage to the right inferior frontal gyrus (pars triangularis and pars opercularis), whereas the integrity of the right inferior fronto-occipital fasciculus was negatively correlated with their alertness effect. These results are consistent with previous literature highlighting an executive dysfunction in confabulating patients, and suggest that some additional forms of attention, such as alertness and spatial orienting, could be selectively impaired in this clinical syndrome.

Happy and sad music acutely modulate different types of attention in older adults

Of the three subtypes of attention outlined by the attentional subsystems model, alerting (vigilance or arousal needed for task completion) and executive control (the ability to inhibit distracting information while completing a goal) are susceptible to age-related decline, while orienting remains relatively stable. Yet, few studies have investigated strategies that may acutely maintain or promote attention in typically aging older adults. Music listening may be one potential strategy for attentional maintenance as past research shows that listening to happy music characterized by a fast tempo and major mode increases cognitive task performance, likely by increasing cognitive arousal. The present study sought to investigate whether listening to happy music (fast tempo, major mode) impacts alerting, orienting, and executive control attention in 57 middle and older-aged adults (M = 61.09 years, SD = 7.16). Participants completed the Attention Network Test (ANT) before and after listening to music rated as happy or sad (slow tempo, minor mode), or no music (i.e., silence) for 10 min. Our results demonstrate that happy music increased alerting attention, particularly when relevant and irrelevant information conflicted within a trial. Contrary to what was predicted, sad music modulated executive control performance. Overall, our findings indicate that music written in the major mode with a fast tempo (happy) and minor mode with a slow tempo (sad) modulate different aspects of attention in the short-term.

Attentional Control in Subjective Cognitive Decline

BACKGROUND

Attention is an essential cognitive ability that is necessary in other cognitive processes. Only few studies have focused on decline in specific functions of attention in older adults with cognitive decline. No research explores the difference in the proactive and reactive mode of control between the healthy control (HC) and older adults with subjective cognitive decline (SCD).

OBJECTIVE

The current work investigated whether there was any decline in alerting, orienting, and executive control in SCD. Particularly, the present study further explored the impairment of the proactive and reactive control in SCD.

METHODS

We recruited 25 HC and 26 SCD. All participants first finished a set of neuropsychological assessments. They then completed an Attention Network Test for measuring the alerting, orienting, and executive control, the List-wide and the Item-specific Proportion Congruency Effect task for measuring the proactive and reactive mode of control, respectively.

RESULTS

No difference was found in alerting, orienting, and executive control measured by the ANT between SCD and HC. The results also indicated no difference in the reactive control between SCD and HC. However, older adults with SCD performed worse in the proactive control as compared to HC.

CONCLUSION

Older adults with SCD showed an impairment in the proactive control. The current findings help us better understand objective decline in cognitive domains other than memory and shed light on early assessment and prevention of AD.

The Effects of Normal Aging, Subjective Cognitive Decline, Mild Cognitive Impairment, or Alzheimer’s Disease on Visual Search

Background: Alzheimer’s disease (AD) has been confirmed as an influencing factor of visual impairment, but potential concomitant effects on visual and cognitive performance are not well understood. Objective: To provide a new method for early screening of Alzheimer’s disease and further explore the theoretical mechanism of the decline of whole visual and cognitive performance in AD. Methods: We studied 60 individuals without dementia as normal control (NC), 74 individuals with subjective cognitive decline (SCD), 60 individuals with amnesia mild cognitive impairment (aMCI), and 75 patients with AD on a battery of tests designed to measure multiple aspects of basic and higher-order visual perception and cognition. All subjects performed on same visual and cognitive test batteries. Results: The results showed both of four groups, with the stimulus-presentation time being longer, the visual-search performance improved, and both the eye interest-area first fixation duration and the interest-area-fixation count increased. Particularly under the noise-masking condition, the AD group performed the worst at stimulus-presentation times between 300 and 900 ms. The aMCI group, but not the SCD group, performed worse than the NC group at the stimulus-presentation time of either 300 or 500 ms. The interest-area-fixation count was higher in all the patient groups than that in the NC group, and distinguishable between participants with AD and those with SCD or aMCI. Conclusion: The visual-search performance combined with eye-movement tracking under the noise-masking condition can be used for distinguishing AD from normal aging, SCD, and aMCI.

Right fronto-parietal networks mediate the neurocognitive benefits of enriched environments

Exposure to enriched environments throughout a lifetime, providing so-called reserve, protects against cognitive decline in later years. It has been hypothesized that high levels of alertness necessitated by enriched environments might strengthen the right fronto-parietal networks to facilitate this neurocognitive resilience. We have previously shown that enriched environments offset age-related deficits in selective attention by preserving grey matter within right fronto-parietal regions. Here, using neurite orientation dispersion and density imaging, we examined the relationship between enriched environments, microstructural properties of fronto-parietal white matter association pathways (three branches of the superior longitudinal fasciculus), structural brain health (atrophy), and attention (alertness, orienting and executive control) in a group of older adults. We show that exposure to enriched environments is associated with a lower orientation dispersion index within the right superior longitudinal fasciculus 1 which in turn mediates the relationship between enriched environments and alertness, as well as grey and white matter atrophy. This suggests that enriched environments may induce white matter plasticity (and prevent age-related dispersion of axons) within the right fronto-parietal networks to facilitate the preservation of neurocognitive health in later years.

Functional Brain Connectivity and Inhibitory Control in Older Adults: A Preliminary Study

According to the inhibition deficit hypothesis, the ability to inhibit unwanted or irrelevant thoughts and behaviors decreases with age, which can have a significant impact on cognitive and emotional processing. However, studies examining inhibition and age have shown mixed results, with some studies finding a decrease in inhibitory control as individuals age, while others have found no relationship. The goal of this proof-of-concept study was to examine the underlying neural mechanisms that may explain why some older adults are better than others at inhibitory control by investigating the relationship between resting-state functional connectivity (rsFC) of the salience network, a network critical for detecting and focusing attention toward relevant stimuli while ignoring irrelevant information in the environment, and a behavioral measure of inhibitory control (Stroop Task interference score) in a sample of 65 healthy older individuals (ages 65+). Results revealed no direct effect of age on Stroop performance; however, there was an indirect effect of age on Stroop performance through rsFC. These results suggest that rsFC of the salience network may be an important factor to consider when it comes to understanding individual differences in inhibitory control behavior among older adults.

Overview of (f)MRI Studies of Cognitive Aging for Non-Experts: Looking through the Lens of Neuroimaging

This special issue concerning Brain Functional and Structural Connectivity and Cognition aims to expand our understanding of brain connectivity. Herein, I review related topics including the principle and concepts of functional MRI, brain activation, and functional/structural connectivity in aging for uninitiated readers. Visuospatial attention, one of the well-studied functions in aging, is discussed from the perspective of neuroimaging.

The Effects of Aging and Time of Day on Inhibitory Control: An Event-Related Potential Study

Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one’s chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.

Are you more impulsive with age? Examining age, marital status, and gender on cognitive ageing

Understanding non-pathological cognitive aging processes remains a public health goal and research priority. Age-associated cognitive aging is a normal human process, however, individual differences may aid in the mitigation of cognitive aging. Assessing the role of certain protective factors (i.e., age, marital status, and gender) that influence age-related cognitive aging is imperative to slow down the progression of unwarranted cognitive aging. Participants aged over 18 (N = 123; 97 females and 26 males) recruited from Sydney, New South Wales, and Gold Coast, Queensland, completed an online neuropsychological test battery with computer-administered tasks, assessing impulsivity and working memory, which were entered as dependent variables. A 3(Age Group: 18-27 years; 28-61 years; 62+ years) x2(Marital Status: married; single) x2(Gender: male; female) Multivariate Analysis of Covariance (MANCOVA) design was used to examine the relationship between age, marital status, and gender (entered as independent variables) on cognitive aging. Participants' total scores from psychometrically sound measures assessing depressive symptomology, personal wellbeing, resilience, and social network engagement, were entered as covariates. No significant effects were found from the independent variables included in the MANCOVA. A significant covariate effect for resilience and depressive symptomology on impulsivity was found. A multiple regression analysis was performed on the significant covariates, and revealed increased resilience and depressive symptomology to significantly predict greater impulsivity.

Evidence that ageing yields improvements as well as declines across attention and executive functions

Many but not all cognitive abilities decline during ageing. Some even improve due to lifelong experience. The critical capacities of attention and executive functions have been widely posited to decline. However, these capacities are composed of multiple components, so multifaceted ageing outcomes might be expected. Indeed, prior findings suggest that whereas certain attention/executive functions clearly decline, others do not, with hints that some might even improve. We tested ageing effects on the alerting, orienting and executive (inhibitory) networks posited by Posner and Petersen's influential theory of attention, in a cross-sectional study of a large sample (N = 702) of participants aged 58-98. Linear and nonlinear analyses revealed that whereas the efficiency of the alerting network decreased with age, orienting and executive inhibitory efficiency increased, at least until the mid-to-late 70s. Sensitivity analyses indicated that the patterns were robust. The results suggest variability in age-related changes across attention/executive functions, with some declining while others improve.

Propofol Versus Sevoflurane General Anaesthesia for Selective Impairment of Attention Networks After Gynaecological Surgery in Middle-Aged Women: A Randomised Controlled Trial

PURPOSE

Attention is an essential component of cognitive function that may be impaired after surgery with anaesthesia. Propofol intravenous anaesthesia and sevoflurane inhalational anaesthesia are frequently used in gynaecological surgery. However, which type of anaesthetic has fewer cognitive effects postoperatively remains unclear. We compared the differences in attention network impairment after surgery in women receiving propofol versus sevoflurane general anaesthesia.

PATIENTS AND METHODS

Eighty-three patients with gynaecological diseases who were 40-60 years of age were involved in the study. All patients underwent elective gynaecological surgery under either total intravenous anaesthesia or sevoflurane inhalational anaesthesia, depending on randomisation. The efficiencies of the three attention networks were captured using the attention network test preoperatively and on the 1st and 5th postoperative days.

RESULTS

Both groups of patients showed differences in impairments on the 1st and 5th postoperative days. Pairwise comparisons indicated that the alerting and orienting networks of patients in the propofol group were impaired to a greater extent than those of patients in the sevoflurane group on the 1st postoperative day, while the executive control network was impaired to a lesser extent. On the 5th postoperative day, the alerting networks of both groups recovered to the baseline level. Patients in the propofol group still showed impairment of the orienting network, while patients in the sevoflurane group recovered to baseline. For the executive control network, patients in the sevoflurane group still exhibited more severe impairment than those in the propofol group.

CONCLUSION

In middle-aged women, propofol impaired orienting and alerting networks more than sevoflurane, while sevoflurane showed more residual impairment of the executive control network.

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.

Age-related effects on a novel dual-task Stroop paradigm

The Stroop task is a traditional measure of cognitive control processes, yet results remain mixed when it comes to assessing age-related differences perhaps in part due to strategies participants use to reduce inhibitory control demands required for success on the task. Thirty-three older adults and 34 younger adults completed a Baseline (traditional, single-task) version of Stroop, followed by two, novel dual-task Stroop variants: Color-Dual (maintain secondary count of prespecified font color regardless the lexical content) and Lexical-Dual (maintain secondary count of prespecified word regardless the font color). With regard to Baseline performance, we predicted an Age x Trial Type interaction in which older adults would be selectively impaired on Incongruent trials compared to younger adults, and this prediction was supported. When we added secondary task demands, we predicted a Trial Type x Dual-Task Type interaction in which performance in the Lexical-Dual condition would be worse than performance in the Color-Dual condition. This prediction was also supported, suggesting that having a secondary task that activated the irrelevant stream of information required more inhibitory control. Finally, we also predicted that Age would interact with Trial Type and Dual-Task Type, which was partially supported in response latencies and more definitively supported in error rates. Overall, our results indicate that Stroop performance is differentially influenced by additional dual-task demands that potentially minimize strategy usage, which has implications for both young and older adult Stroop performance.

Age differences in risk taking: now you see them, now you don't

Older age has often, but not always, been associated with less risk taking. Inconsistencies may be due to diversity in the risk-taking measures used and/or individual differences in cognitive abilities. We investigated the robustness of age differences in risk taking across three measures, and tested whether age differences in risk taking remained after accounting for cognitive abilities. Younger (aged 25-36) and older (aged 60+) adults completed behavioral (i.e., Balloon Analogue Risk Task, BART) and self-report (i.e., framing tasks and Choice Dilemmas Questionnaire) measures of risk, as well as several measures of cognitive ability (i.e., analytic thinking, numeracy, processing speed, memory, and attention). Older adults showed significantly less risk taking than younger adults on the behavioral measure of risk, but not on the two self-report measures. Older adults also had significantly lower analytic thinking, slower processing speed, and worse executive control compared to younger adults. Less risk taking on the BART was associated with lower analytic thinking and numeracy, slower processing speed, and worse shifting of attention. Age differences in risk taking on the BART remained after accounting for older adults' lower scores on tests of cognitive abilities. Implications for measuring age differences in risk taking are discussed.

Phasic alerting increases visual processing speed in amnestic mild cognitive impairment

External warning cues temporarily increase the brain's sensitivity for upcoming events, helping individuals to flexibly adapt their reactions to the requirements of complex visual environments. Previous studies reported that younger and cognitively normal older adults profit from phasic alerting cues. Such an intact phasic alerting mechanism could be even more relevant in individuals with Alzheimer's disease who are characterized by reduced processing capacities. The present study employed a theory of visual attention based verbal whole report paradigm with auditory cues in order to investigate phasic alerting effects in amnestic mild cognitive impairment (aMCI). Patients with aMCI were also compared to a previously reported sample of cognitively normal older adults. In patients with aMCI, visual processing speed was higher in the cue compared to the no-cue condition. Further, visual processing speed was reduced in patients with aMCI compared to cognitively normal older adults. Taken together, the results suggest that the processing system of patients with aMCI exhibits general declines but can still integrate auditory warning signals on a perceptual level.

Influence of Background Musical Emotions on Attention in Congenital Amusia

Congenital amusia in its most common form is a disorder characterized by a musical pitch processing deficit. Although pitch is involved in conveying emotion in music, the implications for pitch deficits on musical emotion judgements is still under debate. Relatedly, both limited and spared musical emotion recognition was reported in amusia in conditions where emotion cues were not determined by musical mode or dissonance. Additionally, assumed links between musical abilities and visuo-spatial attention processes need further investigation in congenital amusics. Hence, we here test to what extent musical emotions can influence attentional performance. Fifteen congenital amusic adults and fifteen healthy controls matched for age and education were assessed in three attentional conditions: executive control (distractor inhibition), alerting, and orienting (spatial shift) while music expressing either joy, tenderness, sadness, or tension was presented. Visual target detection was in the normal range for both accuracy and response times in the amusic relative to the control participants. Moreover, in both groups, music exposure produced facilitating effects on selective attention that appeared to be driven by the arousal dimension of musical emotional content, with faster correct target detection during joyful compared to sad music. These findings corroborate the idea that pitch processing deficits related to congenital amusia do not impede other cognitive domains, particularly visual attention. Furthermore, our study uncovers an intact influence of music and its emotional content on the attentional abilities of amusic individuals. The results highlight the domain-selectivity of the pitch disorder in congenital amusia, which largely spares the development of visual attention and affective systems.

Behavioral and electrophysiological correlates of Simon and flanker conflict interference in younger and older adults

Conflict processing and interference control have been popular topics of research in the study of pathological brain aging. However, there remains much to be learned about how these cognitive processes are altered in the course of healthy brain aging. Moreover, few studies have combined multiple measures of interference control using factorial designs. The aim of this study was to determine the nature of age-related changes in behavioral and electroencephalographic correlates of interference control using a factorial combination of the Simon and flanker interference conditions. Data were collected from a group of younger and high-functioning older adults. Behavioral results indicated the presence of conflict interference effects in both groups, that both Simon and flanker conflict effects are increased in high-functioning older adults, that the two types of conflict interference interact superadditively, and that older adults are more susceptible to the superadditive costs of multiple conflict types. ERP analyses revealed that early perceptual and response-selection processes are differentially modulated by flanker and Simon conflict respectively, however, there was no evidence that these early processes were impaired in older adults. Later components of the ERP in the P3 time range mirrored behavioral results, reflecting the increased susceptibility to flanker and Simon conflict in older adults.

Altered phase and nonphase EEG activity expose impaired maintenance of a spatial-object attentional focus in multiple sclerosis patients

Some of the anatomical and functional basis of cognitive impairment in multiple sclerosis (MS) currently remains unknown. In particular, there is scarce knowledge about modulations in induced EEG (nonphase activity) for diverse frequency bands related to attentional deficits in this pathology. The present study analyzes phase and nonphase alpha and gamma modulations in 26 remitting-relapsing multiple sclerosis patients during their participation in the attention network test compared with twenty-six healthy controls (HCs) matched in sociodemographic variables. Behavioral results showed that the MS group exhibited general slowing, suggesting impairment in alerting and orienting networks, as has been previously described in other studies. Time–frequency analysis of EEG revealed that the gamma band was related to the spatial translation of the attentional focus, and the alpha band seemed to be related to the expectancy mechanisms and cognitive processing of the target. Moreover, phase and nonphase modulations differed in their psychophysiological roles and were affected differently in the MS and HC groups. In summary, nonphase modulations can unveil hidden cognitive mechanisms for phase analysis and complete our knowledge of the neural basis of cognitive impairment in multiple sclerosis pathology.

Perceptual Priming Can Increase or Decrease With Aging

A decline in declarative or explicit memory has been extensively characterized in cognitive aging and is a hallmark of cognitive impairments. However, whether and how implicit perceptual memory varies with aging or cognitive impairment is unclear. Here, we compared implicit perceptual memory and explicit memory measures in three groups of participants: (1) 59 healthy young volunteers (20–30 years); (2) 269 healthy old volunteers (50–90 years) and (3) 21 patients with mild cognitive impairment, i.e., MCI (50–90 years). To measure explicit memory, participants were tested on standard recognition and recall tasks. To measure implicit perceptual memory, we used a classic perceptual priming paradigm. Participants had to report the shape of a visual search pop-out target whose color or position was varied randomly across trials. Perceptual priming was measured as the speedup in response time for targets that repeated in color or position. Our main findings are as follows: (1) Explicit memory was weaker in old compared to young participants, and in MCI patients compared to age- and education-matched controls; (2) Surprisingly, perceptual priming did not always decline with age: color priming was smaller in older participants but position priming was larger; (3) Position priming was less frequent in the MCI group compared to matched controls; (4) Perceptual priming and explicit memory were uncorrelated across participants. Thus, perceptual priming can increase or decrease with age or cognitive impairment, but these changes do not covary with explicit memory.

Normative data of neuropsychological tests of attention and executive functions in Ecuadorian adult population

OBJECTIVE

The purpose of this study was to generate normative data for five tests of attention and executive functions (M-WCST, Stroop test, TMT, BTA, and SDMT), in a group of 322 Ecuadorian adults from Quito between the ages of 18 and 85.

METHOD

Multiple regression analyzes taking into account age, education, and gender were used to generate the normative data.

RESULTS

Age and education were significantly related to test performance such that scores decreased with age and improved as a function of education. An online calculator is provided to generate normative test scores.

CONCLUSIONS

This is the first study that presents normative data for tests of executive functions and attention in an Ecuadorian adult population. This data will improve the clinical practice of neuropsychology and help to develop the field in the country.

Dissociated deficits in attentional networks in social anxiety and depression

A critical cognitive symptom that is commonly involved in social anxiety and depression is attentional deficit. However, the functional relationship between attentional deficit and these two disorders remains poorly understood. Here, we behaviorally disentangled the three key attentional components (alerting, orienting, and executive control) using the established attentional network task (ANT) to investigate how social anxiety and depression are related to deficits in these attention components. We identified a double dissociation between the symptoms of social anxiety and depression and the attentional component deficits when processing non-emotional stimuli. While individuals vulnerable to social anxiety exhibited deficits in the orienting component, individuals vulnerable to depression were impaired in the executive control component. Our findings showed that social anxiety and depression were associated with deficits in different attentional components, which are not specific to emotional information.

Cognitive processes in aging effects on attentional alerting

Alerting, the process of achieving and maintaining a state of optimal vigilance, is crucial for detecting relevant stimuli and task performance. Age-related decline in the ability to use alerting cues is widely reported and attributed to changes in noradrenergic signaling. However, it remains to be determined whether aging affects all forms of alerting cues equally and whether older adults differently modulate their alerting sensitivity based on differences in cue predictivity relevant to the target task. We examined the performance of 135 younger adults and 103 older adults on three versions of the Attention Networks Test, using locational but spatially nonpredictive visual cues, locational spatially predictive visual cues, and spatially predictive auditory cues. Analysis of alerting effects indicated that while older adults derived less benefit from visual alerting cues than younger adults, they used auditory alerting cues equally well. Furthermore, cue spatial predictivity did not impact on aging effects on alerting. This heterogeneity in aging effects on alerting may indicate that they result primarily from cognitive rather than neuromodulatory changes.

Impaired perception of simultaneous stimuli in a patient with posterior cortical atrophy: an attentional account

We assessed visuospatial abilities in PCA. Sequential display of two simple geometric figures enhanced detection and discrimination relative to simultaneous display (Exps 1 & 2). Comparing edges of a single object enhanced discrimination relative to comparing edges of two separate objects, consistent with object-based attention (Exp. 3). Recognition of complex line drawings was spared for a single object but disrupted by an attention-grabbing small circle (Exp. 4). A covert orienting task showed difficulty disengaging from previous locations and attentional bias toward the right visual field (Exp. 5). These findings shed light on the role of visual attention in perceptual awareness.

Age-related changes in the functional integrity of the phasic alerting system: a pupillometric investigation

Enhanced processing following a warning cue is thought to be mediated by a phasic alerting response involving the locus coeruleus-noradrenergic (LC-NA) system. We examined the effect of aging on phasic alerting using pupil dilation as a marker of LC-NA activity in conjunction with a novel assessment of task-evoked pupil dilation. While both young and older adults displayed behavioral and pupillary alerting effects, reflected in decreased RT and increased pupillary response under high (tone) versus low (no tone) alerting conditions, older adults displayed a weaker pupillary response that benefited more from the alerting tone. The strong association between dilation and speed displayed by older adults in both alerting conditions was reduced in young adults in the high alerting condition, suggesting that in young (but not older) adults the tone conferred relatively little behavioral benefit beyond that provided by the alerting effect elicited by the target. These findings suggest a functioning but deficient LC-NA alerting system in older adults, and help reconcile previous results concerning the effects of aging on phasic alerting.

Aging in cognitive control of social processing: evidence from the attention network test

Aging seems to be associated with impairment of attentional network functioning. It is not known whether social information can modulate this age-related decline. We used three variants of Attention Network test to examine the age-related decline of attentional effects in response to stimuli with and without social-cognitive content. Three groups of younger, middle-aged, and older participants performed the ANT, using fish, drawings, or photographs of faces looking to the left or right as target and flanker stimuli. The results showed that both executive attention and alerting were more resistant to the age-related decline with social stimuli and that orienting attention scores showed a progressive increase with age in the presence of this kind of stimuli. These findings underline the importance of social information in modulating and contrasting the age-related decline and support the status of human faces as a special class of visual stimuli for the human attentional systems.

Exercise mode and attentional networks in older adults: a cross-sectional study

Background

Previous studies have indicated that physical exercise enhances attentional function; however, the relationship between exercise mode and attentional networks has not been clarified for older adults (>60 years old). This study aimed to investigate the relationship between attentional networks and different exercise modes in older adults.

Methods

Two hundred and fifty-nine participants aged between 60 to 81 years were enrolled and classified into three groups (closed-skill group, open-skill group, or sedentary control group) using an exercise-related questionnaire. All participants completed an attention network test (ANT), which measured executive control, orienting, and alerting networks.

Results

The open-skill group had significantly higher executive network efficiency compared to the closed-skill (p < 0.01) and sedentary (p < 0.01) groups. The closed-skill group had significantly higher values compared to the sedentary control group (p < 0.05). Differences were not detected among groups for alerting and orienting networks (p > 0.05). The open-skill group had significantly higher values compared to the sedentary control group regarding proportion score of executive network (p < 0.01). In comparison, no significant differences were detected among groups for proportion scores of alerting and orienting networks.

Conclusion

This study extends current knowledge by demonstrating that open-skill exercises selectively enhance the executive control of attentional networks in older adults. Open-skill exercises combines physical exercise and cognitive training, potentially representing a more effective exercise mode to maintain or enhance attentional function in older adults.

Inflammation Mediates Body Weight and Ageing Effects on Psychomotor Slowing

Inflammation (immune system activation) affects neuronal function and may have consequences for the efficiency and speed of functional brain processes. Indeed, unusually slow psychomotor speed, a measure predictive of behavioural performance and health outcomes, is found with obesity and ageing, two conditions also associated with chronic inflammation. Yet whether inflammation is the mediating factor remains unclear. Here, we assessed inflammation by indexing interleukin-6 level in blood and measured psychomotor speed as well as indices of selective visual attention in young (mean = 26 years) or old (mean = 71 years) adults (N = 83) who were either lean or currently significantly overweight (mean body mass index = 22.4 and 33.8, respectively). Inflammation was positively and significantly correlated with psychomotor speed, age, and body mass index but not with attention measures. Using mediation analyses we show for the first time that inflammation fully accounts for the significant psychomotor slowing found in those with high BMI. Moreover, we further show that age-related psychomotor slowing is partially mediated by inflammation. These findings support the proposal that reducing inflammation may mitigate weight- and age-related cognitive decline and thereby improve performance on daily tasks and health outcomes more generally.

Multifactorial effects of aging on the orienting of visual attention

Differential sensitivity of brain areas to the effects of healthy aging may lead to multifactorial influences on the orienting of spatial attention. We examined how aging affects two key aspects of orienting: the benefits of orienting to valid spatial cues vs. the costs of re-orienting following invalid cues, and the impact on orienting of prior cue validity, in the context of different degrees of cue predictivity and types of cue manifestation. We analyzed accuracy and response time data from the performance of 103 older adults and 135 younger adults in three versions of the Attention Networks Test. Participants engaged in target discrimination following either locational cues that were generally non-predictive, locational cues that were generally predictive, or symbolic cues that were generally predictive. We found that healthy older adults did not exhibit greater re-orienting response time costs than younger adults across all cueing types, nor did they differ in the orienting benefits provided by predictive locational cues. However, older adults derived greater benefit from valid cues in a generally non-predictive cueing context, and lesser benefit from valid cues in a symbolic predictive cueing context. Additionally, aging had no impact on the effects of prior trial validity on subsequent trial validity benefits. A comprehensive appreciation of the effects of aging on attention may be informed by these distinctions.

Dysfunctional interactions between the default mode network and the dorsal attention network in subtypes of amnestic mild cognitive impairment

An anticorrelated relationship in the spontaneous fluctuations between the default mode network (DMN) and dorsal attention network (DAN) is a robust feature of intrinsic brain organization in healthy individuals. Prior studies have reported a decreased anticorrelation between the DMN and the DAN in Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, it is unclear how this anticorrelation changes as MCI progresses to AD. We hypothesized that dysfunctional connectivity between the DMN and DAN may reflect the gradual decline from MCI to AD. To test this hypothesis, we investigated alterations in functional connectivity between the DMN and DAN in subtypes of amnestic MCI (aMCI) by comparing with the same functional pattern in healthy elderly individuals and patients with AD. We retrospectively collected brain imaging and neuropsychological data from 20 AD participants, 22 participants with multiple-domain aMCI (aMCI-m), 29 participants with single-domain aMCI (aMCI-s) and 23 sex-matched normal controls in this study. Resting-state functional connectivity analysis revealed that aMCI-s and aMCI-m groups demonstrated different magnitudes of increased anticorrelation between the DMN and DAN relative to the AD group. Furthermore, in aMCI-s, aMCI-m and AD participants, hypoconnectivity was found in specific regions within the DMN, including the precuneus and angular gyrus, and hyperconnectivity was found in areas outside the typical DMN networks, including the middle occipital gyrus, lingual gyrus and visual cortex, which indicated disease-related adaptations of brain networks. Our findings suggest that DMN-DAN anticorrelation may shed light on the understanding of the adaptations in brain function during the progression from MCI to AD and may serve as a potential biomarker to detect AD in the preclinical stage.

Impairments of attention in Alzheimer's disease

Alzheimer's Disease (AD) is characteristically perceived as primarily being a disorder of episodic memory, with prominent attentional impairments more typically being associated with other neurodegenerative conditions, such as Dementia with Lewy Bodies. However, attention is also affected early on in Alzheimer's, particularly in individuals with young onset and atypical syndromes. In addition, some initial symptoms that are apparently due to episodic memory loss may be secondary to failures of attentional processes. This review delineates the various attentional impairments that can be observed in patients with AD, and addresses them through the conceptual framework of attention proposed by Posner and Petersen. It also describes how current knowledge of the development of AD has influenced our understanding of how these deficits arise. Finally, there is a brief summary of the effects of current AD treatments on attentional processes, and how future pharmacological approaches might better target these deficits.

Attentional Reorientation and Inhibition Adjustment in a Verbal Stroop Task: A Lifespan Approach to Interference and Sequential Congruency Effect

Several parameters influence the interference effect elicited in a Stroop task, especially contextual information. Contextual effects in the Stroop paradigms are known as the Gratton or Sequential congruency effect (SCE). This research aims at isolating two processes contributing to the SCE in a Stroop paradigm, namely attentional reorientation from the color to the word and vice-versa, as well as inhibition (engagement/disengagement from one trial to the next one). To this end, in Study 1 subprocesses of the SCE were isolated. Specifically, attentional reorientation and inhibition were segregated by submitting young adults to a discrete verbal Stroop task including neutral trials. In Study 2, the same procedure was applied to 124 participants aged from 10 to 80 years old to analyze how interference, SCE, and the aforementioned decomposition of attention and inhibition change across the lifespan. In both studies, the Gratton effect was only partially replicated, while both attentional reorientation and inhibition effects were observed, supporting the idea that these two processes contribute to SCE on top of conflict monitoring and of other processes highlighted in different theories (contingency learning, feature integration, and repetition expectancy). Finally, the classical age-related evolution was replicated in Study 2 on raw interference scores, but no age effect was observed when processing speed was taken into account, nor on the isolated attentional reorientation and inhibition processes, which is in line with the hypothesis of stability of the inhibition processes over age.

Reduced Capacity of Cognitive Control in Older Adults with Mild Cognitive Impairment

Cognitive control for the coordination of mental operations is essential in normal cognitive functioning of daily life. Although the decline of cognitive control in older adults with mild cognitive impairment (MCI) has been demonstrated, whether this decline is a core deficit in MCI remains unclear. In this study, we employed a perceptual decision-making task to estimate the capacity of cognitive control (CCC) in older adults with MCI (n = 55) and the age-, sex-, and education-matched healthy controls (HC, n = 55) selected based on a commonly used battery of ten neuropsychological tests in five cognitive domains. We found that the CCC was significantly correlated to the neuropsychological measures of the battery. The mean CCC was significantly lower in the MCI group (3.06 bps) than in the HC group (3.59 bps) and significantly lower in the amnestic MCI subgroup (2.90 bps) than in the nonamnestic MCI subgroup (3.22 bps). In detecting and classifying MCI using machine learning, the classifier with the CCC as the input feature outperformed the overall classification with neuropsychological measures in a single cognitive domain. The classification performance was significantly increased when the CCC was included as a feature in addition to measures in a single domain, and the CCC served as a key feature in optimal classifiers with inputs from multiple domains. These results support the hypothesis that the decline in cognitive control is a core deficit in MCI and suggest that the CCC may serve as a key index in the diagnosis of MCI.

Age-related differences in the attentional white bear

The cognitive aging literature suggests that aging populations exhibit impairments in the proactive inhibition of attention. Although proactive inhibition is often preceded by the allocation of attention toward the predicted or known spatial location of to-be-ignored stimuli, proactive allocation of attention has not been assessed in aging populations. In this study, an older and younger cohort engaged in the attentional-white-bear paradigm which measures proactive allocation of attention. In this task, on 80% of trials, participants must identify a centrally located letter surrounded by congruent or incongruent flanker letters. The flanker locations are fixed and predictable within each block of the study. On 20% of trials, they must identify which of two dots appear first on the screen. One dot appears in the same location as the flanker, and one appears in an empty location during the flanker task. The typical white-bear effect is that, despite the dots appearing at the same time, participants more often report the dot in the location of the flanker (i.e., the potentially to-be-ignored location) to appear first. The magnitude of this effect is interpreted as the magnitude of attentional allocation prior to inhibition. In Experiment 1, there was no difference in the magnitude of the attentional white bear between younger and aging cohorts. However, when the attentional system was sufficiently taxed by reducing the flanker presentation (Experiments 2a and 2b), age-related differences emerged. In particular, older participants showed a reduced white-bear effect, reflecting a potential impairment in the proactive allocation of attention toward the location of expected distractors.

Instrument Playing as a Cognitive Intervention Task for Older Adults: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to review studies that applied musical instrument playing as an intervention to improve cognitive functioning of older adults with and without cognitive impairment. English-language articles published between 1990 and 2018 were searched using electronic databases. Music therapy journals were also hand searched for relevant research. Inclusion criteria for participants were older adults, ages 60 years and older, and any clinical diagnosis of cognitive impairment had to be due to aging. Searches used combinations of the following keywords: older adults, instrument playing, and cognitive outcomes measures. A total of 10 studies that met the inclusion criteria were included in the final analysis: five studies with healthy older adults, two with older adults with mild cognitive impairment (MCI), two studies with older adults with dementia, and one study with both healthy older adults and older adults with MCI. The results of this meta-analysis demonstrated that different types of cognitive involvement were demanded from instrument playing. Furthermore, depending on the type of involvement, a target cognitive domain was found to be differentially impacted by the instrument playing intervention. This study supports using different types of instrument playing for interventions targeting specific cognitive domains of older adults with varying levels of cognitive aging.

Impaired conflict monitoring in cognitive decline

Resolving conflicts is an important cognitive ability of executive function, and it may decrease with cognitive decline. The flanker task is a practical test used to assess the ability to suppress responses that are inappropriate in a particular context. The aims of the present study were to investigate conflict monitoring of cognitive control in subjects with different levels of cognitive impairment, and clarify the usefulness of the flanker task in screening cognitive decline. We recruited 50 subjects with mild cognitive impairment (MCI) and 34 patients with Alzheimer's disease (AD), and 44 mentally healthy elderly subjects as a control group. To evaluate cognitive performance, each participant underwent a neuropsychological assessment using the Cognitive Abilities Screening Instrument and a modified flanker task. Compared with the normal controls and those with MCI, the patients with AD had a significantly lower accuracy rate and longer reaction time in both congruent and incongruent trials. The diagnosis of AD predicted significantly poorer performances on the flanker tasks. Furthermore, behavioral data of the patients with AD were significantly correlated with the results of neuropsychological tests. Our results indicated that executive cognitive deficits in conflict monitoring as detected by the flanker task were significantly impaired in the patients with AD. The flanker task could be a quick and easier alternative tool for screening AD among elderly people with suspicious cognitive impairment.

Structural Brain Correlates of Attention Dysfunction in Lewy Body Dementias and Alzheimer's Disease

Lewy body dementia (LBD) and Alzheimer's disease (AD) are common forms of dementia that have different clinical profiles but are both commonly associated with attentional deficits. The aim of this study was to investigate efficiency of different attentional systems in LBD and AD and its association with brain structural abnormalities. We studied reaction time (RT) data from 45 LBD, 31 AD patients and 22 healthy controls (HCs) using the Attention Network Test (ANT) to assess the efficiency of three different attentional systems: alerting, orienting and executive conflict. Voxel-based morphometry (VBM) was used to investigate relations between different attention components and cortical volume. Both dementia groups showed slower overall RTs than controls, with additional slowing in LBD relative to AD. There was a significant alerting effect in controls which was absent in the dementia groups, the executive conflict effect was greater in both dementia groups compared to controls, but the orienting effect did not differ between groups. Mean RT in AD was negatively correlated with occipital gray matter (GM) volume and in LBD orienting efficiency was negatively related to occipital white matter (WM) volume. Given that previous studies in less impaired patients suggest a maintenance of the alerting effect, the absent alerting effect in our study suggests a loss of alerting efficiency with dementia progression. While orienting was largely preserved, it might be related to occipital structural abnormalities in LBD. Executive function was markedly impaired in both dementia groups, however, the absence of relations to brain volume suggests that it might be more related to functional rather than macrostructural pathophysiological changes.

Ten years younger: Practice of chronic aerobic exercise improves attention and spatial memory functions in ageing

Aerobic exercise is associated with changes in brain morphology and improvement of cognitive functions. Physical activity may be especially important after age 60 when cognitive decline is more pronounced. In this paper, the effect of chronic practice of aerobic sports was studied in old adults by assessing their executive and mnesic functions, supported by frontal and temporal brain structures. Two groups were formed according to their age (60-69 and 70-79 years-old) including sportsmen (n = 23) and sedentary men (n = 24). Spatial memory and efficiency of attentional networks were measured, as well as general intelligence. Results showed that sportsmen outperformed sedentary participants in many of the tests employed. Thus their alerting, orienting and executive networks worked more effectively in the ANT-I task for executive functions, and they were more accurate in the spatial memory task, displaying a better spatial orientation. Scores in other neuropsychological tasks followed the same tendency. These data support the protective effect of aerobic exercise on cognitive functions.

Attention-Related Brain Activation Is Altered in Older Adults With White Matter Hyperintensities Using Multi-Echo fMRI

Cognitive decline is often undetectable in the early stages of accelerated vascular aging. Attentional processes are particularly affected in older adults with white matter hyperintensities (WMH), although specific neurovascular mechanisms have not been elucidated. We aimed to identify differences in attention-related neurofunctional activation and behavior between adults with and without WMH. Older adults with moderate to severe WMH (n = 18, mean age = 70 years), age-matched adults (n = 28, mean age = 72), and healthy younger adults (n = 19, mean age = 25) performed a modified flanker task during multi-echo blood oxygenation level dependent functional magnetic resonance imaging. Task-related activation was assessed using a weighted-echo approach. Healthy older adults had more widespread response and higher amplitude of activation compared to WMH adults in fronto-temporal and parietal cortices. Activation associated with processing speed was absent in the WMH group, suggesting attention-related activation deficits that may be a consequence of cerebral small vessel disease. WMH adults had greater executive contrast activation in the precuneous and posterior cingulate gyrus compared to HYA, despite no performance benefits, reinforcing the network dysfunction theory in WMH.

Attentional ERPs distinguish aging and early Alzheimer's dementia

The early detection of Alzheimer's disease requires our distinguishing it from cognitive aging. Here, we test whether spatial attentional changes might support that distinction. We engaged young normal (YN), older normal (ON), and patients with early Alzheimer's dementia (EAD) in an attentionally cued, self-movement heading discrimination task while we recorded push-button response times and event related potentials. YNs and ONs show the behavioral effects of attentional shifts from the cue to the target, whereas EAD patients did not (p < 0.001). YNs and ONs also show the shifting lateralization of a newly described attentional event related potentials component, whereas EAD patients did not (p < 0.001). Our findings suggest that spatial inattention in EAD patients may contribute to heading direction processing impairments that distinguish them from ONs and undermine their navigational capacity and driving safety.