Visual Information Processing in Young and Older Adults

Consumer Engagement in the Design of Educational Nutrition Information for Older Adults and Their Caregivers: A Scoping Review

Consumer engagement is important to design high-quality educational nutrition information that holistically addresses consumers' needs. This can occur through consultation and feedback mechanisms like surveys or focus groups, consumer expert panels or advisory boards to provide the consumers' perspective, or through participatory research methods. The extent of consumer engagement also varies with differing levels of influence over the decision-making process. This systematic scoping review aimed to explore and synthesize the extent to which consumers are engaged in designing various types of educational nutrition interventions, the methods and levels of consumer engagement, and its impact on the resulting educational nutrition information presented. We comprehensively searched Medline via OVID, Scopus, Web of Science, CINAHL, and PsycINFO. Each article was independently screened by 2 authors by title and abstract. Two reviewers independently assessed the full text of the remaining articles for eligibility. Two authors independently extracted data from the 36 final articles (15 original and 21 substudies), including consumer engagement assessment per the International Association of Public Participation (IAP2) spectrum. Fourteen of the 15 studies obtained input from consumers to inform the design of the educational nutrition information in terms of content, design, wording, and platform. However, consumer engagement across the studies mostly sat within the "Consult" and "Involve" level of the IAP2 spectrum, with only 1 study achieving a "Collaborate" engagement level. This suggests a low level of genuine consumer partnership in the studies to date. Consumer engagement across the studies differed on how and the extent to which consumers were engaged in designing educational nutrition information. Greater emphasis on shared decision-making and collaborating with consumers right from the start is key to ensuring that educational nutrition information designed for them best addresses their needs and preferences, which potentially translates to better health outcomes.

A Systems Neuroscience Approach to Diagnosis and Rehabilitation of Post COVID Neurological Syndrome Based on the Systems Neuroscience Test Battery (SNTB) Study Protocol

The proposed study reports the design and development of a rapid screening tool, the Systems Neuroscience Test Battery (SNTB), for diagnosing and evaluating the neurological manifestations of Post-COVID-19 Neurological Syndrome (PCNS) within the broader context of Post-Acute Sequelae to COVID-19 (PASC). The SNTB is designed to incorporate a behaviorally relevant Telehealth component that enhances consumer confidence in symptom discrimination, management of PCNS, and guides rehabilitation programs while allowing for continuous evaluation of intervention effectiveness.The study employs a longitudinal design, with telehealth and routine blood assessments conducted at three-month intervals, including at least two follow-ups post-recruitment. These assessments will involve Consumer-Reported Symptoms, Clinical History, Neuropsychological Data, and Timed Psychophysics, aimed at rapid screening of PCNS-related symptoms including 'brain fog" and its affect on visually driven attention, cognition and visually driven motor behaviors. These assessments are intended to validate the characteristics of 'brain fog' and identify predictive behavioral biomarkers for the development of PCNS.The target population includes adults aged 18-65 who have experienced persistent neurological symptoms for at least three months following a confirmed COVID-19 infection. Exclusion criteria include individuals unable to undergo radiological examinations, such as pregnant women or those with contraindications to MRI, ensuring the robustness of the sample and reducing potential selection bias.The SNTB tool will facilitate the online identification of predictive biomarkers for PCNS and aid in the discovery of effective molecular biomarker combinations for medical intervention and rehabilitation. Complementary to the Telehealth Assessment, hospital facilities will be utilized for radiological and blood-based molecular assessments, ensuring concurrent profiling of structural and functional changes during 'brain fog' and recovery from PCNS symptoms.

Exploring the General Acceptability and User Experience of a Digital Therapeutic for Cognitive Training in a Singaporean Older Adult Population: Qualitative Study

BACKGROUND

Singapore's large aging population poses significant challenges for the health care system in managing cognitive decline, underscoring the importance of identifying and implementing effective interventions. Cognitive training delivered remotely as a digital therapeutic (DTx) may serve as a scalable and accessible approach to overcoming these challenges. While previous studies indicate the potential of cognitive training as a promising solution for managing cognitive decline, understanding the attitudes and experiences of older adults toward using such DTx platforms remains relatively unexplored.

OBJECTIVE

This study aimed to characterize the general acceptability and user experience of CURATE.DTx, a multitasking-based DTx platform that challenges the cognitive domains of attention, problem-solving, and executive function in the Singaporean older adult population.

METHODS

A total of 15 older adult participants (mean age 66.1, SD 3.5 years) were recruited for a 90-minute in-person session. This session included a 30-minute playtest of CURATE.DTx, followed by a 60-minute semistructured interview to understand their overall attitudes, experience, motivation, and views of the intervention. Interviews were audio-recorded and transcribed verbatim, then analyzed using an inductive approach. Thematic analysis was used to identify emerging patterns and insights.

RESULTS

A total of 3 main themes, and their respective subthemes, emerged from the interviews: comprehension, with subthemes of instruction and task comprehension; acceptability, with subthemes of tablet usability, engagement and enjoyment, and attitude and perceived benefits; and facilitators to adoption, with subthemes of framing and aesthetics, motivation recommendations and the role of medical professionals. Our findings revealed that participants encountered some challenges with understanding certain elements of CURATE.DTx. Nevertheless, they were still highly engaged with it, finding the challenge to be enjoyable. Participants also showed a strong awareness of the importance of cognitive training and expressed a keen interest in using CURATE.DTx for this purpose, especially if recommended by medical professionals.

CONCLUSIONS

Given the positive engagement and feedback obtained from Singaporean older adults on CURATE.DTx, this study can serve as a basis for future platform iterations and strategies that should be considered during implementation. Future studies should continue implementing an iterative codesign approach to ensure the broader applicability and effectiveness of interventions tailored to this demographic.

Dendritic Spines of Layer 5 Pyramidal Neurons of the Aging Somatosensory Cortex Exhibit Reduced Volumetric Remodeling

Impairments in synaptic dynamics and stability are observed both in neurodegenerative disorders and in the healthy aging cortex, which exhibits elevated dendritic spine turnover and decreased long-term stability of excitatory connections at baseline, as well as an altered response to plasticity induction. In addition to the discrete gain and loss of synapses, spines also change in size and strength both during learning and in the absence of neural activity, and synaptic volume has been associated with stability and incorporation into memory traces. Furthermore, intrinsic dynamics, an apparently stochastic component of spine volume changes, may serve as a homeostatic mechanism to prevent stabilization of superfluous connections. However, the effects of age on modulation of synaptic weights remain unknown. Using two-photon excitation (2PE) microscopy of spines during chemical plasticity induction in vitro and analyzing longitudinal in vivo 2PE images after a plasticity-inducing manipulation, we characterize the effects of age on volumetric changes of spines of the apical tuft of layer 5 pyramidal neurons of mouse primary somatosensory cortex. Aged mice exhibit decreased volumetric volatility and delayed rearrangement of synaptic weights of persistent connections, as well as greater susceptibility to spine shrinkage in response to chemical long-term depression. These results suggest a deficit in the aging brain's ability to fine-tune synaptic weights to properly incorporate and retain novel memories. This research provides the first evidence of alterations in spine volumetric dynamics in healthy aging and may support a model of impaired processing and learning in the aged somatosensory system.

Prevalence and intervention strategies of health misinformation among older adults: A meta-analysis

The rapid expansion of the Internet and social media has intensified the spread of health misinformation, posing significant risks, especially for older adults. This meta-analysis synthesizes evidence on the prevalence and interventions of health misinformation among older adults. Our findings reveal a high prevalence rate of 47% (95% CI [33%, 60%]), surpassing recent estimates. Offline research settings have a higher prevalence of health misinformation. Despite methodological variances, the prevalence remains consistent across different measures and development levels. Interventions show significant effectiveness (Hedges' g = 0.76, 95% CI [0.25, 1.26]), with graphic-based approaches outperforming video-based ones. These results underscore the urgent need for tailored, large-scale interventions to mitigate the adverse impacts of health misinformation on older adults. Further research should focus on refining intervention strategies and extending studies to underrepresented regions and populations.

Individual factors and vection in younger and older adults: How sex, field dependence, personality, and visual attention do (or do not) affect illusory self-motion

An important aspect to an immersive experience in Virtual Reality is vection, defined as the illusion of self-motion. Much of the literature to date has explored strategies to maximize vection through manipulations of the visual stimulus (e.g., increasing speed) or the experimental context (e.g., framing of the study instructions). However, the role of individual differences (e.g., age, biological sex) in vection susceptibility has received little attention. The objective of the current study was to investigate the influence of individual-difference factors on vection perception in younger and older adults. Forty-six younger adults (M age = 25.1) and 39 older adults (M age = 72.4) completed assessments of personality traits, field dependence, and visual attention prior to observing a moving visual stimulus aimed at inducing circular vection. Vection was measured using self-reports of onset latency, duration, and intensity. Results indicated that, in both age groups, females experienced longer-lasting vection compared to males. Additionally, the level of field dependence was related to vection intensity and duration in males but not in females. Variability in vection intensity was best explained by a mixture of biological, perceptual, cognitive, and personality variables. Taken together, these findings suggest that individual factors are important for understanding differences in vection susceptibility.

Dominance of attentional focus: a comparative study on its impact on standing postural control in healthy younger and older adults

Introduction

Attentional focus is a phenomenon in which shifting the focus of attention alters performance of standing postural control. It can be categorized as internal focus (IF), which directs attention to the body parts, or external focus (EF), which directs attention to the external environment. Although attentional focus that improves standing postural control in younger people exhibits individual dominance, the dominance of attentional focus in standing postural control in older adults remains ambiguous. Therefore, this study aimed to compare the dominance of attentional focus in standing postural control between healthy younger and older adults, a crucial step for understanding the aging process.

Methods

The participants performed a standing postural control task under the IF and EF conditions. Based on the condition during which they exhibited superior performance, the participants were divided into two groups: IF-dominant and EF-dominant. The standing postural control performance in each group under the IF and EF conditions was subsequently compared.

Results

The results showed that the participants, encompassing both younger and older adults, were divided into the IF-dominant and EF-dominant groups, confirming the dominance of attentional focus. The performance under the EF condition in older adults was also influenced by the dominance of attentional focus.

Conclusion

These results highlight the potential importance of intervention methods based on the dominance of attentional focus, providing valuable insights into future research and clinical practice.

Abnormalities in Electroencephalographic Microstates in Patients with Late-Life Depression

Background

Late-life depression (LLD) is characterized by disrupted brain networks. Resting-state networks in the brain are composed of both stable and transient topological structures known as microstates, which reflect the dynamics of the neural activities. However, the specific pattern of EEG microstate in LLD remains unclear.

Methods

Resting-state EEG were recorded for 31 patients with episodic LLD (eLLD), 20 patients with remitted LLD (rLLD) and 32 healthy controls (HCs) using a 64-channel cap. The clinical data of the patients were collected and the 17-Item Hamilton Rating Scale for Depression (HAMD) was used for symptom assessment. Duration, occurrence, time coverage and syntax of the four microstate classes (A-D) were calculated. Group differences in EEG microstates and the relationship between microstates parameters and clinical features were analyzed.

Results

Compared with NC and patients with rLLD, patients with eLLD showed increased duration and time coverage of microstate class D. Besides, a decrease in occurrence of microstate C and transition probability between microstate B and C was observed. In addition, the time coverage of microstate D was positively correlated with the total score of HAMD, core symptoms, and miscellaneous items.

Conclusion

These findings suggest that disrupted EEG microstates may be associated with the pathophysiology of LLD and may serve as potential state markers for the monitoring of the disease.

Visual Information Processing in Older Adults: Force Control and Motor Unit Pool Modulation

Increased visual information about a task impairs force control in older adults. To date, however, it remains unclear how increased visual information changes the activation of the motor unit pool differently for young and older adults. Therefore, this study aimed to determine how increased visual information alters the activation of the motor neuron pool and influences force control in older adults. Fifteen older adults (66-86 years, seven women) and fifteen young adults (18-30 years, eight women) conducted a submaximal constant force task (15% of maximum) with ankle dorsiflexion for 20 s. The visual information processing was manipulated by changing the amount of force visual feedback into a low-gain (0.05°) or high-gain (1.2°) condition. Older adults exhibited greater force variability, especially at high-gain visual feedback. This exacerbated force variability from low- to high-gain visual feedback was associated with modulations of multiple motor units, not single motor units. Specifically, increased modulation of multiple motor units from 10 to 35 Hz may contribute to the amplification in force variability. Therefore, our findings suggest evidence that high-gain visual feedback amplifies force variability of older adults which is related to increases in the activation of motor neuron pool from 10 to 35 Hz.

Why do children with autism spectrum disorder have abnormal visual perception?

Autism spectrum disorder (ASD) is associated with severe impairment in social functioning. Visual information processing provides nonverbal cues that support social interactions. ASD children exhibit abnormalities in visual orientation, continuous visual exploration, and visual-spatial perception, causing social dysfunction, and mechanisms underlying these abnormalities remain unclear. Transmission of visual information depends on the retina-lateral geniculate nucleus-visual cortex pathway. In ASD, developmental abnormalities occur in rapid expansion of the visual cortex surface area with constant thickness during early life, causing abnormal transmission of the peak of the visual evoked potential (P100). We hypothesized that abnormal visual perception in ASD are related to the abnormal visual information transmission and abnormal development of visual cortex in early life, what's more, explored the mechanisms of abnormal visual symptoms to provide suggestions for future research.

Cognitive and visual task effects on gaze behaviour and gait of younger and older adults

Cognitive dual tasks alter gait of younger and older adults and recent research has demonstrated that they also influence gaze behaviour and standing postural control. These findings suggest that age-related changes in cognitive and gaze function might increase fall risk in older adults. The purpose of this study was to determine the effect cognitive and visual dual tasks on the gait and gaze behaviour of younger and older adults. Ten older and ten younger adults walked for 3 min on a treadmill at preferred walking speed under three conditions, single task, cognitive and visual dual task conditions. Gait dynamics were measured using accelerometry and gaze behaviour was measured using wearable eye-trackers. Stride time variability and centre of mass (COM) motion complexity increased in dual-task conditions in older adults but had no difference for younger adults. Dual tasks had limited effect on gaze behaviour; however, visual input duration was greater, and visual input frequency and saccade frequency were lower in older than younger adults. The gaze adaptations in older adults may be the result of slower visual processing or represent a compensatory strategy to suppress postural movement. The increase in gait COM motion complexity in older adults suggests the dual tasks led to more automatic gait control resulting from both cognitive and visual tasks.

Scoping review of the preferences of older adults for patient education materials

OBJECTIVE

To provide an overview of studies that describe the preferred mode and format of delivery of patient education materials to older adults.

METHODS

A scoping review was used to identify relevant literature published between January 2010 and June 2021, with specific attention given to studies conducted in high income countries with similar health systems.

RESULTS

A total of 3245 titles were identified, and 20 met the inclusion criteria and were included in this scoping review. Older adults preferred written information that could be accessed via health professionals or downloaded online. Other key features were identified including logical layout, signposted information, larger text size, labelled visual aids, and use of images appropriate and relevant to the target group were preferred. Audio visual resources were also considered valuable when well designed. Formats for patient education such as apps, group classes and online courses were less popular with older adults.

CONCLUSIONS

Patient education materials for older adults should be carefully designed, with attention to layout and content. Older adults indicated a preference for hard copy handouts or in a format that can be downloaded.

PRACTICE IMPLICATIONS

Regular engagement with older consumers about their preferences is important as technology for delivery of patient education materials evolve. Key features for specific attention during the design process include a logical layout (tested with consumers), signposted information, text size, labelled visual aids and appropriate images. The perspectives of other key groups of older adults such as those from minority populations or other disadvantaged groups are largely unexplored.

Set Size of Information in Long-Term Memory Similarly Modulates Retrieval Dynamics in Young and Older Adults

Our ability to rapidly distinguish new from already stored (old) information is important for behavior and decision making, but the underlying processes remain unclear. Here, we tested the hypothesis that contextual cues lead to a preselection of information and, therefore, faster recognition. Specifically, on the basis of previous modeling work, we hypothesized that recognition time depends on the amount of relevant content stored in long-term memory, i.e., set size, and we explored possible age-related changes of this relationship in older humans. In our paradigm, subjects learned by heart four different word lists (24, 48, 72, and 96 words) written in different colors (green, red, orange, and blue). On the day of testing, a color cue (e.g., green) indicated with a probability of 50% that a subsequent word might be from the corresponding list or from a list of new words. The old/new status of the word had to be distinguished via button press. As a main finding, we can show in a sample of n = 49 subjects, including 26 younger and 23 older humans, that response times increased linearly and logarithmically as a function of set size in both age groups. Conversely, corrected hit rates decreased as a function of set size with no statistically significant differences between both age groups. As such, our findings provide empirical evidence that contextual information can lead to a preselection of relevant information stored in long-term memory to promote efficient recognition, possibly by cyclical top-down and bottom-up processing.

Proportional Changes in Cognitive Subdomains During Normal Brain Aging

Background: Neuroscience lacks a reliable method of screening the early stages of dementia. Objective: To improve the diagnostics of age-related cognitive functions by developing insight into the proportionality of age-related changes in cognitive subdomains. Materials and Methods: We composed a battery of psychophysiological tests and collected an open-access psychophysiological outcomes of brain atrophy (POBA) dataset by testing individuals without dementia. To extend the utility of machine learning (ML) classification in cognitive studies, we proposed estimates of the disproportional changes in cognitive functions: an index of simple reaction time to decision-making time (ISD), ISD with the accuracy performance (ISDA), and an index of performance in simple and complex visual-motor reaction with account for accuracy (ISCA). Studying the distribution of the values of the indices over age allowed us to verify whether diverse cognitive functions decline equally throughout life or there is a divergence in age-related cognitive changes. Results: Unsupervised ML clustering shows that the optimal number of homogeneous age groups is four. The sample is segregated into the following age-groups: Adolescents ∈ [0, 20), Young adults ∈ [20, 40), Midlife adults ∈ [40, 60) and Older adults ≥60 year of age. For ISD, ISDA, and ISCA values, only the median of the Adolescents group is different from that of the other three age-groups sharing a similar distribution pattern (p > 0.01). After neurodevelopment and maturation, the indices preserve almost constant values with a slight trend toward functional decline. The reaction to a moving object (RMO) test results (RMO_mean) follow another tendency. The Midlife adults group's median significantly differs from the remaining three age subsamples (p < 0.01). No general trend in age-related changes of this dependent variable is observed. For all the data (ISD, ISDA, ISCA, and RMO_mean), Levene's test reveals no significant changes of the variances in age-groups (p > 0.05). Homoscedasticity also supports our assumption about a linear dependency between the observed features and age. Conclusion: In healthy brain aging, there are proportional age-related changes in the time estimates of information processing speed and inhibitory control in task switching. Future studies should test patients with dementia to determine whether the changes of the aforementioned indicators follow different patterns.

The Age-Related Changes in Speed of Visual Perception, Visual Verbal and Visuomotor Performance, and Nonverbal Intelligence During Early School Years

Speed of sensory information processing has long been recognized as an important characteristic of global intelligence, though few studies have concurrently investigated the contribution of different types of information processing to nonverbal IQ in children, nor looked at whether chronological age vs. months of early schooling plays a larger role. Thus, this study investigated the speed of visual information processing in three tasks including a simple visual inspection time (IT) task, a visual-verbal processing task using Rapid Automatic Naming (RAN) of objects as an accepted preschool predictor of reading, and a visuomotor processing task using a game-like iPad application, (the "SLURP" task) that requires writing like skills, in association with nonverbal IQ (Raven's Coloured Progressive Matrices) in children (n = 100) aged 5-7 years old. Our results indicate that the rate and accuracy of information processing for all three tasks develop with age, but that only RAN and SLURP rates show significant improvement with years of schooling. RAN and SLURP also correlated significantly with nonverbal IQ scores, but not with IT. Regression analyses demonstrate that months of formal schooling provide additional contributions to the speed of dual-task visual-verbal (RAN) and visuomotor performance and Raven's scores supporting the domain-specific hypothesis of processing speed development for specific skills as they contribute to global measures such as nonverbal IQ. Finally, RAN and SLURP are likely to be useful measures for the early identification of young children with lower intelligence and potentially poor reading.

Visuomotor control dynamics of quiet standing under single and dual task conditions in younger and older adults

Visual input facilitates stable postural control; however, ageing alters visual gaze strategies and visual input processing times. Understanding the complex interaction between visual gaze behaviour and the effects of age may inform future interventions to improve postural control in older adults. The purpose of this study was to determine effects of age and dual task on gaze and postural sway dynamics, and the sway-gaze complexity coupling to explore the coupling between sensory input and motor output. Ten older and 10 younger adults performed single and dual task quiet standing while gaze behaviour and centre of mass motion were recorded. The complexity and stability of postural sway, saccade characteristics, visual input duration and complexity of gaze were calculated in addition to sway-gaze coupling quantified by cross-sample entropy. Dual tasking increased complexity and decreased stability of sway with increased gaze complexity and visual input duration, suggesting greater automaticity of sway with greater exploration of the visual field but with longer visual inputs to maintain postural stability in dual task conditions. In addition, older adults had lower complexity and stability of sway than younger adults indicating less automated and stable postural control. Older adults also demonstrated lower gaze complexity, longer visual input durations and greater sway-gaze coupling. These findings suggest older adults adopted a strategy to increase the capacity for visual information input, whilst exploring less of the visual field than younger adults.

The neural-vascular basis of age-related processing speed decline

Most studies examining neurocognitive aging are based on the blood-oxygen level-dependent signal obtained during functional magnetic resonance imaging (fMRI). The physiological basis of this signal is neural-vascular coupling, the process by which neurons signal cerebrovasculature to dilate in response to an increase in active neural metabolism due to stimulation. These fMRI studies of aging rely on the hemodynamic equivalence assumption that this process is not disrupted by physiologic deterioration associated with aging. Studies of neural-vascular coupling challenge this assumption and show that neural-vascular coupling is closely related to cognition. In this review, we put forward a theory of processing speed decline in aging and how it is related to age-related neural-vascular coupling changes based on the results of studies elucidating the relationships between cognition, cerebrovascular dynamics, and aging.

Frontoparietal microstructural damage mediates age-dependent working memory decline in face and body information processing: Evidence for dichotomic hemispheric bias mechanisms

Age-associated damage in the microstructure of frontally-based connections (e.g. genu of the corpus callosum and superior longitudinal fasciculus) is believed to lead to impairments in processing speed and executive function. Using mediation analysis, we tested the potential contribution of callosal and frontoparietal association tracts to age-dependent effects on cognition/executive function as measured with 1-back working memory tasks for visual stimulus categories (i.e. faces and non-emotional bodies) in a group of 55 healthy adults (age range 23-79 years). Constrained spherical deconvolution-based tractography was employed to reconstruct the genu/prefrontal section of the corpus callosum (GCC) and the central/second branch of the superior longitudinal fasciculus (CB-SLF). Age was associated with (i) reductions in fractional anisotropy (FA) in the GCC and in the right and left CB-SLF and (iii) decline in visual object category processing. Mediation analysis revealed that microstructural damage in right hemispheric CB-SLF is associated with age-dependent decline in face processing likely reflecting the stimulus-specific/holistic nature of face processing within dedicated/specialized frontoparietal routes. By contrast, microstructural damage in left hemispheric CB-SLF associated with age-dependent decline in non-emotional body processing, consistent with the more abstract nature of non-emotional body categories. In sum, our findings suggest that frontoparietal microstructural damage mediates age-dependent decline in face and body information processing in a manner that reflects the hemispheric bias of holistic vs. abstract nature of face and non-emotional body category processing.

Exaggerated cortical representation of speech in older listeners: mutual information analysis

Aging is associated with an exaggerated representation of the speech envelope in auditory cortex. The relationship between this age-related exaggerated response and a listener's ability to understand speech in noise remains an open question. Here, information-theory-based analysis methods are applied to magnetoencephalography recordings of human listeners, investigating their cortical responses to continuous speech, using the novel nonlinear measure of phase-locked mutual information between the speech stimuli and cortical responses. The cortex of older listeners shows an exaggerated level of mutual information, compared with younger listeners, for both attended and unattended speakers. The mutual information peaks for several distinct latencies: early (∼50 ms), middle (∼100 ms), and late (∼200 ms). For the late component, the neural enhancement of attended over unattended speech is affected by stimulus signal-to-noise ratio, but the direction of this dependency is reversed by aging. Critically, in older listeners and for the same late component, greater cortical exaggeration is correlated with decreased behavioral inhibitory control. This negative correlation also carries over to speech intelligibility in noise, where greater cortical exaggeration in older listeners is correlated with worse speech intelligibility scores. Finally, an age-related lateralization difference is also seen for the ∼100 ms latency peaks, where older listeners show a bilateral response compared with younger listeners' right lateralization. Thus, this information-theory-based analysis provides new, and less coarse-grained, results regarding age-related change in auditory cortical speech processing, and its correlation with cognitive measures, compared with related linear measures.NEW & NOTEWORTHY Cortical representations of natural speech are investigated using a novel nonlinear approach based on mutual information. Cortical responses, phase-locked to the speech envelope, show an exaggerated level of mutual information associated with aging, appearing at several distinct latencies (∼50, ∼100, and ∼200 ms). Critically, for older listeners only, the ∼200 ms latency response components are correlated with specific behavioral measures, including behavioral inhibition and speech comprehension.

4,4'-Diaminodiphenyl Sulfone (DDS) as an Inflammasome Competitor

The aim of this study is to examine the use of an inflammasome competitor as a preventative agent. Coronaviruses have zoonotic potential due to the adaptability of their S protein to bind receptors of other species, most notably demonstrated by SARS-CoV. The binding of SARS-CoV-2 to TLR (Toll-like receptor) causes the release of pro-IL-1β, which is cleaved by caspase-1, followed by the formation and activation of the inflammasome, which is a mediator of lung inflammation, fever, and fibrosis. The NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome is implicated in a variety of human diseases including Alzheimer's disease (AD), prion diseases, type 2 diabetes, and numerous infectious diseases. By examining the use of 4,4'-diaminodiphenyl sulfone (DDS) in the treatment of patients with Hansen's disease, also diagnosed as Alzheimer's disease, this study demonstrates the diverse mechanisms involved in the activation of inflammasomes. TLRs, due to genetic polymorphisms, can alter the immune response to a wide variety of microbial ligands, including viruses. In particular, TLR2Arg677Trp was reported to be exclusively present in Korean patients with lepromatous leprosy (LL). Previously, mutation of the intracellular domain of TLR2 has demonstrated its role in determining the susceptibility to LL, though LL was successfully treated using a combination of DDS with rifampicin and clofazimine. Of the three tested antibiotics, DDS was effective in the molecular regulation of NLRP3 inflammasome activators that are important in mild cognitive impairment (MCI), Parkinson's disease (PD), and AD. The specific targeting of NLRP3 itself or up-/downstream factors of the NLRP3 inflammasome by DDS may be responsible for its observed preventive effects, functioning as a competitor.

The Contribution of Oculomotor Functions to Rates of Visual Information Processing in Younger and Older Adults

Oculomotor functions are established surrogate measures of visual attention shifting and rate of information processing, however, the temporal characteristics of saccades and fixations have seldom been compared in healthy educated samples of younger and older adults. Thus, the current study aimed to compare duration of eye movement components in younger (18-25 years) and older (50-81 years) adults during text reading and during object/alphanumeric Rapid Automatic Naming (RAN) tasks. The current study also aimed to examine the contribution of oculomotor functions to threshold time needed for accurate performance on visually-driven cognitive tasks (Inspection Time [IT] and Change Detection [CD]). Results showed that younger adults fixated on individual stimuli for significantly longer than the older participants, while older adults demonstrated significantly longer saccade durations than the younger group. Results also demonstrated that older adults required longer threshold durations (i.e., performed slower) on the visually-driven cognitive tasks, however, the age-group time difference on the CD task was eradicated when the effects of saccade duration were covaried. Thus, these results suggest that age-related cognitive decline is also related to increased duration of saccades and hence, highlights the need to dissociate the age-related motor constraints on the temporal aspects of oculomotor function from visuo-cognitive speed of processing.

Time for a Systems Biological Approach to Cognitive Aging?-A Critical Review

The underlying premise of current theories of cognitive decline with age tend to be primarily cognitive or biological explanations, with relatively few theories adequately integrating both aspects. Though literature has also emphasized the importance of several factors that contribute to cognitive aging including: (a) decline in sensory abilities; (b) the effect of motor speed on paper-pencil measures of cognitive speed; (c) the impact of level of education and physical activity; and (d) molecular biological changes that occur with age, these factors have seldom been implicated into any single theoretical model of cognitive aging. Indeed, such an integrated bio-cognitive model of aging has the potential to provide a more comprehensive understanding of attention, perception, learning, and memory across the lifespan. Thus, the aim of this review was to critically evaluate common theories of age-related cognitive decline and highlight the need for a more comprehensive systems neuroscience approach to cognitive aging.