Digit Symbol Substitution Task Research Articles

Assessment of the Effect of Smoking on Cognition in Young Adults

Smoking is an action in which the resultant smoke post-burning is breathed in to be gustated and released into the bloodstream. It causes many undesired effects in people. The main aim of the present investigation is to investigate the effect of smoking on cognition in young adults. For this, a questionnaire and some simple tests have been performed for the selected students. A total of 40 students were taken into study, out of which 20 were smokers and 20 were non-smokers. In the digit symbol substitution test, students were asked to draw a circle around even numbers and a triangle over odd numbers. In the digit vigilance test, the students were asked to cut off all 6 and 9 numbers. In the category fluency test, they were asked to list out the animal names in one minute. In attention switching task, a total of 30 slides were displayed and for each condition different sounding patterns should be made on the table. Smokers took more time to perform digit symbol substitution, digit vigilance and attention-switching tasks than non-smokers. Smokers could not write more animal names when compared to non-smokers. In all the tests, the number of errors performed by smokers is greater than that of non-smokers. This indicates reduced psychomotor and brain functioning in smokers when compared to non-smokers. All the results were statistically analyzed. Thus, from the current research, it was concluded that smoking in young adult students has declined cognitive functioning.

Revisiting delusion subtypes in schizophrenia based on their underlying structures

A clear understanding of the pathophysiology of schizophrenia and related spectrum disorders has been limited by clinical heterogeneity. We investigated whether relative severity and predominance of one or more delusion subtypes might yield clinically differentiable patient profiles. Patients (N = 286) with schizophrenia spectrum disorders (SSD) completed the 21-item Peters et al. Delusions Inventory (PDI-21). We performed factor analysis followed by k-means clustering to identify delusion factors and patient subtypes. Patients were further assessed via the Brief Psychiatric Rating Scale, Brief Negative Symptom Scale, Digit Symbol and Digit Substitution tasks, use of cannabis and tobacco, and stressful life events. The overall patient sample clustered into subtypes corresponding to Low-Delusion, Grandiose-Predominant, Paranoid-Predominant, and Pan-Delusion patients. Paranoid-Predominant and Pan-Delusion patients showed significantly higher burden of positive symptoms, while Low-Delusion patients showed the highest burden of negative symptoms. The Paranoia delusion factor score showed a positive association with Digit Symbol and Digit Substitution tasks in the overall sample, and the Paranoid-Predominant subtype exhibited the best performance on both tasks. Grandiose-Predominant patients showed significantly higher tobacco smoking severity than other subtypes, while Paranoid-Predominant patients were significantly more likely to have a lifetime diagnosis of Cannabis Use Disorder. We suggest that delusion self-report inventories such as the PDI-21 may be of utility in identifying sub-syndromes in SSD. From the current study, a Paranoid-Predominant form may be most distinctive, with features including less cognitive impairment and a stronger association with cannabis use.

NONINVASIVE INTERVENTIONS IN HEALTHY AND AT-RISK OLDER ADULTS: THE CASE FOR SOCIAL DANCING

Abstract Physical and cognitive activities can induce neuroplasticity and lead to modest improvements on cognition in healthy and at-risk older adults. Yet, many unanswered questions remain – including what type of physical, cognitive, or combination of physical and cognitive activities, are most beneficial, and to whom (e.g., healthy, or at-risk older adults). This single-blind randomized clinical trial (RCT; NCT03475316) contrasted 6 months of social ballroom dancing with 6 months of treadmill-walking. Twenty-five dementia-at-risk older adults (mean age = 76.45 years; 66% women; 48% White/Caucasian; 24% Black/African American; 20% Hispanic/Latino) were randomized between June 2019 and March 2020. Sixteen participants completed this RCT prior to early study termination due to COVID-19 (8 in each study arm). Dementia-at-risk was defined as a memory impairment screen score of ≥3 to ≤6, and/or and AD-dementia screening interview of ≥1. A composite measure of executive function – generated from digit-symbol-substitution, flanker interference, and walking-while-talking tasks – improved following both social dancing and treadmill-walking. Yet, social dancing generated greater improvements than treadmill-walking on the digit symbol substitution task. No intervention-related differences were observed in brain activation. Less hippocampal atrophy, however, was observed in the social dancing arm than in the treadmill-walking arm. These preliminary findings partly support the hypothesis that social dancing may promote neuroplasticity and benefit cognition to a greater extent than traditional physical activities. This is presumably because social dancing is not only a physical demanding activity, but also a socially and cognitively challenging activity. Yet, these findings need to be confirmed in larger-scale RCTs

Measuring Situational Cognitive Performance in the Wild: A Psychometric Evaluation of Three Brief Smartphone-Based Test Procedures

Mobile devices provide new opportunities to draw conclusions about cognitive performance in everyday situations. To gain insights into cognitive performance patterns in healthy adult populations, we adapted three established cognitive tests for smartphone use: the Digit Symbol Substitution Task (DSST), Sustained Attention to Response Task (SART), and Psychomotor Vigilance Task (PVT). To increase their feasibility for ambulatory assessment, we identified the minimum measurement durations that provide reliable and valid state measures of cognitive performance. Over 2 weeks, 46 participants performed each test once per day at random times, along with self-reports (e.g., on concentration, mood, and mental demands). The validity and reliability of change are promising for the 30-second PVT and 90-second DSST and SART. The DSST and SART provide fruitful outcomes for ambulatory field studies linked to mood, stress, and mental demands. We provide digital versions of the adapted DSST and SART online for free.

Enhancing the Standardized Field Sobriety Test to detect cannabis impairment: An observational study

Objective The purpose of this study was to explore various tests of impairment that could potentially be added to the Standardized Field Sobriety Test (SFST) to enhance its sensitivity to identify drivers whose abilities are adversely affected by cannabis. Methods An observational study was conducted in which participants were invited to use their own cannabis at the research facility. Once prior to cannabis use and at four times during the 150 min after cannabis use, participants performed the three tests of the Standardized Field Sobriety Test (SFST) (i.e., Horizontal Gaze Nystagmus, Walk and Turn, and One Leg Stand) as well as the Modified Romberg Balance and Finger to Nose tests. In addition, assessments were made of physiological indicators (i.e., eyelid, leg and body tremors, rebound dilation, lack of convergence) and vital signs (pulse, blood pressure and body temperature). Participants also completed a digit-symbol substitution task at each testing interval. With the exception of vital signs and the digit symbol task, all tests and assessments were administered and scored by certified Drug Recognition Experts using the standard procedures of the Drug Evaluation and Classification Program. Results Twenty minutes after vaping cannabis (mean THC concentration = 6.34 ng/mL), participants displayed performance deficits on a variety of tasks; 67% met the criterion for suspected impairment on the SFST. Addition of the Finger-to-Nose (FTN) test along with observations of head movements and jerks (HMJ) increased the percentage of participants who met the criterion for suspected impairment by 33% and improved the sensitivity of the test from 0.67 to 0.88. Conclusions The results of this study support supplementing the SFST with the Finger-to-Nose test and observations of HMJ to assist in the detection of drivers who are adversely affected by the use of cannabis. The observational study design and the use of assessors who were not blinded as to the use of cannabis by participants limits the strength of the evidence. Further research, including randomized trials and field studies of drivers, is required to confirm and validate this enhanced version of the SFST.

Low thalamic activity during a digit-symbol substitution task is associated with symptoms of subjective cognitive decline.

Subjective cognitive decline (SCD) may represent the earliest preclinical stage of Alzheimer's Disease (AD) for some older adults. However, the underlying neurobiology of SCD is not completely understood. Since executive function may be affected earlier than memory function in the progression of AD, we aimed to characterize SCD symptoms in terms of fMRI brain activity during the computerized digit-symbol substitution task (DSST), an executive function task. We also explored associations of DSST task performance with brain activation, SCD severity, and amyloid-ß (Aß) load. We analyzed data from 63 cognitively normal older individuals (mean age 73.6 ± 7.2) with varying degree of SCD symptoms. Participants completed a computerized version of DSST in the MR scanner and a Pittsburgh Compound-B (PiB)-PET scan to measure global cerebral Aß load. A voxel-wise analysis revealed that greater SCD severity was associated with lower dorsomedial thalamus activation. While task performance was not associated with brain activation nor Aß load, slower reaction time was associated with greater SCD severity. The observed lower dorsomedial thalamus activation may reflect declining familiarity-based working memory and the trans-thalamic executive function pathway in SCD. SCD symptoms may reflect altered neural function and subtle decline of executive function, while Aß load may have an indirect impact on neural function and performance. Self-perceived cognitive decline may serve as a psychological/subjective marker reflecting subtle brain changes.

Effect of a multicomponent programme based on reality orientation therapy on the physical performance and cognitive function of elderly community-dwellers: a quasi-experimental study.

Effects of a multicomponent exercise programme have an impact on the physical, cognitive, and psychological domains in elderly community-dwellers. However, some individuals aged 65 years or more have not shown positive effects after the intervention as reported in similar research. The objective of this quasi-experimental study was to clarify the effectiveness of a multicomponent programme based on reality orientation therapy (ROT) on the physical performance, cognitive ability, and psychological state in the elderly. Participants were recruited from the general public in 20 areas of Akita Prefecture, Japan, and they took part in each exercise programme for 90 min a day, once every 2 weeks, for 3 months, according to the group classification using cluster randomization into 20 cohorts in Akita. Physical, cognitive, and geriatric depression assessments were performed at baseline and after the 3-month intervention in both the ROT-based intervention group and the control group. The final samples for analysis consisted of 31 participants in the control group and 30 participants in the intervention group. The results of the statistical analysis comparing the two groups showed that the 5-repetition sit-to-stand test was performed significantly faster (P < 0.05) and that the results of the word list memory (WM) test and the Symbol Digit Substitution Task also had significantly improved (P < 0.05) after the intervention in both groups. The WM score did not show an interactive effect between the group and time factors, but it had a significant main effect on time in both groups (P < 0.05). The results of our quasi-experimental study indicated that the multicomponent programme based on the ROT would be as effective as the original multicomponent programme combined with aerobic exercise and cognitive tasks, as highlighted in the WM.

Holding your liquor: Comparison of alcohol-induced psychomotor impairment in drinkers with and without alcohol use disorder.

Behavioral tolerance to alcohol underscores the widely accepted notion that individuals who regularly drink alcohol become less sensitive to its impairing effects. However, previous research assessing alcohol-induced impairment in humans has primarily focused on social drinkers. This has limited our understanding of the nature and extent of behavioral tolerance among heavier drinkers, such as those with alcohol use disorder (AUD). Data from three cohorts of the Chicago Social Drinking Project were evaluated to examine the acute effects of alcohol on psychomotor performance across the breath alcohol curve in light drinkers (LDs; n = 86), heavy drinkers (HDs; n = 208), and individuals with AUD (AUDs; n = 103). Before and at several intervals after ingesting either alcohol (0.8 g/kg, peak BrAC = 0.09 g/dL) or placebo in two random-order laboratory sessions, participants completed a test of fine motor coordination (Grooved Pegboard), a test of perceptual-motor processing(Digit Symbol Substitution Task), and a self-reported survey of perceived impairment. Sixty individuals with AUD completed a third session with a very high dose of alcohol (1.2 g/kg, peak BrAC = 0.13 g/dL). The AUD and HD groups, relative to the LD group, perceived less impairment and demonstrated greater behavioral tolerance to an intoxicating dose of alcohol, exhibited by reduced peak impairment and a quicker return to baseline performance on psychomotor measures. Among individuals with AUD who consumed the very high dose, impairment was more than double that following the usual high dose, and it exceeded the impairment among LDs following the usual high dose. In this sample of young adult drinkers, relative to the LD group, those with heavier drinking patterns (AUD and HD groups) showed greater behavioral tolerance to 0.8 g/kg alcohol, a dose typically associated with a binge drinking episode. However, when challenged with a very high alcohol dose commensurate with high-intensity drinking, individuals with AUD showed substantial psychomotor impairment.

0459 Cardiovascular Endpoints for Obstructive Sleep Apnea with Twelfth Nerve Stimulation: Measures of Sleep-Related Function

Abstract Introduction Obstructive sleep apnea (OSA) is an increasingly prevalent sleep-related breathing disorder linked to cognitive dysfunction and daytime sleepiness. Positive airway pressure (PAP) therapy, the first-line treatment for OSA, may improve cognitive function and sleepiness, but responses vary. Hypoglossal nerve stimulation (HGNS) is a novel and effective PAP alternative, but its effect on mitigating cognitive decline secondary to OSA is unknown. In the first sham-controlled HGNS trial, we evaluated the effect of HGNS therapy on cognitive measures and patient-reported outcomes (PROs) in patients with moderate-severe OSA. Methods In a double-blind, sham-controlled, randomized crossover therapy trial, patients already stabilized on HGNS therapy underwent four weeks of active and four weeks of sham HGNS, each with a 1-week washout period. Sham therapy was defined as the lowest voltage at which HGNS was sensed by the patient or visualized by the clinician. Cognitive measures (Psychomotor Vigilance Test [PVT], Digit Symbol Substitution Task [DSST]) and sleep-related PROs (Epworth Sleepiness Scale [ESS], Snoring Visual Analog Scale [VAS], Insomnia Severity Index [ISI], Functional Outcomes of Sleep Questionnaire [FOSQ]) were assessed after each 4-week period and compared between active and sham therapy. Results Sixty randomized patients were included. On average, participants were elderly (67.3±9.9 years), overweight (BMI 28.7±4.6 kg/m2) and had severe OSA prior to HGNS therapy (AHI 33.1±14.9 events/hour). Patients’ AHI decreased to 23.0±15.6 events/hour with sham therapy (p=0.0001) and 18.1±14.8 events/hour with active therapy (p&amp;lt; 0.0001), with a 4.9 event/hour decrease between active and sham therapy (p=0.014). There were no significant differences in performance measures on PVT or DSST between active and sham HGNS. All sleep-related PROs were statistically significant with moderately large (effect sizes ~0.41-0.56) improvements following active HGNS. Conclusion The HGNS system permits a unique investigation of the therapy “on/off” effect on measures of cognitive function. In the first sham-controlled, randomized crossover trial of patients using HGNS, all sleep-related PROs, but not objective measures of cognition, were significantly different between sham and active (therapeutic) levels. These findings warrant additional investigation examining the relationship between subjective and objective measures of function in OSA. Support (if any) American Heart Association (17SDG33670349) American Sleep Medicine Foundation (176-JF-17) National Institutes of Health (P01-HL094307)

Transcranial Alternating Current Stimulation (tACS) and Its Role in Schizophrenia: A Scoping Review.

Transcranial alternating current stimulation (tACS) may modulate neuronal oscillations by applying sinusoidal alternating current, thereby alleviating associated symptoms in schizophrenia. Considering its possible utility in schizophrenia, we reviewed the literature for tACS protocols administered in schizophrenia and their findings. A scoping review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline in databases and clinical trial registers. The search resulted in 59 publications. After excluding review articles unrelated to tACS, trials without published results or not involving patients with schizophrenia, 14 studies were included. Among the included studies/case reports only 5 were randomized controlled therapeutic trials. The studies investigated the utility of tACS for clinical and neurobiological outcomes. All studies reported good tolerability with only transient mild side effects. It was administered mostly during the working memory task (such as computerized n-back task, dual back task, and computerized digit symbol substitution task) for schizophrenia patients with cognitive deficits and during resting state while targeting positive symptoms. A possible reduction in hallucinations and delusions using alpha tACS, and improvement in negative and cognitive deficits with theta and gamma tACS were reported. Nevertheless, one of the randomized controlled trials targeting hallucinations was negative and rigorous large-sample studies are lacking for other domains. The current evidence for tACS in schizophrenia is preliminary though promising. In future, more sham controlled randomized trials assessing the effect of tACS on various domains are needed to substantiate these early findings.

Aerobic exercise is associated with region-specific changes in volumetric, tensor-based, and fixel-based measures of white matter integrity in healthy older adults

White matter integrity and cognition have been found to decline with advancing adult age. Aerobic exercise may be effective in counteracting these declines. Generally, white matter integrity has been quantified using a volumetric measure (WMV) and with tensor-based parameters, such as fractional anisotropy (FA) and mean diffusivity (MD), the validity of which appears to be compromised in the presence of crossing fibers. Fixel-based analysis techniques claim to overcome this problem by yielding estimates of fiber density (FD), cross-section (FC), and their product (FDC) in multiple directions per voxel. In a sample of 61 healthy older adults (63–76 years old), we quantified changes in white matter integrity following an aerobic exercise intervention with the commonly used volumetric and tensor-based metrics (WMV, FA, MD) and with fixel-based metrics (FD, FC, FDC). We investigated the associations of changes in these white matter parameters with changes in cardiovascular fitness and Digit Symbol Substitution task (DSST) performance, a marker of perceptual speed. In line with previous findings, we observed maintained WMV in the corpus callosum of exercisers, and positive change-change correlations between WMV and fitness, and between WMV and perceptual speed. For FA and MD, group differences in change opposite to those hypothesized were found in the corpus callosum, posterior corona radiata, and superior longitudinal fasciculus at an uncorrected significance threshold. Likewise, regions in superficial WM in the prefrontal cortex showed group differences in FD and FDC change, uncorrected, with more positive change in controls and more negative change in exercisers. Finally, changes in FD and FDC were found to be inversely correlated to changes in fitness and DSST performance. The present results corroborate previous findings of WMV changes, but cast doubt on current physiological interpretations of both tensor-based and fixel-based indicators of white matter properties in the context of exercise intervention studies.

The Impact of Nature Imagery and Mystery on Attention Restoration

The factors contributing to urbanization, such as population growth and the development of mega-cities, have increased environmental stressors on top of everyday stressors, resulting in information overload. This has led to the increasing incidence of direct attentional fatigue, which causes stress and mental fatigue. The attention restoration theory centres on the environment’s capacity to restore attentional deficits and suggests that there are certain qualities in the environment that restore attention, which leads to improvements in our physical, mental, and social well-being. An environment can be restorative through the activation of involuntary attention, which limits the need for directed attention. This study explored for effects of natural, built, and mixed environment types and levels of mystery on attention restoration in university undergraduates. Perceived and actual levels of attention restoration were measured using a perceived restoration scale (PRS) and the digit symbol substitution task (DSST), respectively. A total of 101 participants viewed a restorative image followed by the completion of the DSST and the PRS for each of the 18 images depicting different environments. Actual attention restoration was measured by latency values in the DSST instead of through both speed and error rates due to some operational issues with the DSST which interfered with the full achievement of the study’s aims. There was an effect of different environments and mystery on perceived attention restoration. However, there appeared to be no effect on actual attention restoration, indicating a disconnect between perceived and actual restoration. Further research is required to confirm the specific effects of natural and built environments and mystery on attention restoration.

Does Leisure-time Physical Activity Variety Lead To Better Cognitive Function Despite Not Meeting Pa Guidelines?

PURPOSE: Examine whether engaging in a variety of leisure-time physical activities (LTPA), despite not meeting physical activity (PA) guidelines, leads to better cognitive function in older adults. METHODS: Data was retrieved from the 1999-2002 National Health and Nutrition Examination Survey (NHANES). Older adults (N = 2,773, M age = 71.4 yrs, 50.6% ♀, 60.9% non-Hispanic White) reported their moderate- and vigorous-intensity LTPA during the past 30 days, including the specific type (e.g., hiking, tennis, or running), frequency (e.g., d·wk-1), and average duration. Moderate-to-vigorous physical activity (MVPA) was calculated by multiplying the metabolic equivalent values of the activities MET) by the frequency and duration (MVPA-min·wk-1 = MET level x frequency x duration). A dichotomous variable was created categorizing those who met PA guidelines (n = 831) based on federal guidelines (≥600 MVPA-min·wk-1). LTPA-variety was calculated as the total number of activities participated in at least once a month. Cognitive function was assessed via the Digit Symbol Substitution Task (DSST). Age, sex, education, race, and whether the reported PA was similar over the previous 10-years were used as covariates in all analyses. Total minutes spent in MVPA was controlled for in all analyses as it was possible to engage in some PA and not meet PA guidelines. RESULTS: A multivariable linear regression model revealed a significant effect of LTPA-Variety on DSST (β = 7.14, 95% CI: 4.78-9.50, P < 0.01); MVPA--min·wk-1 was not a significant predictor (P = 0.41). Univariate analysis of covariance (ANCOVA) of those not meeting PA guidelines (n = 1942) revealed a significant effect (F1,29 = 7.99, r2 = 0.41, P < 0.01) for LTPA-Variety on DSST. In those not meeting PA guidelines, engaging in 2 or more different types of LTPA, compared to less, resulted in significantly greater cognitive functioning (M = 45.60 vs M = 40.09, P < 0.01) when accounting for MVPA--min·wk-1. CONCLUSIONS: These results suggest that, for older adults, engaging in a greater variety of leisure-time physical activities can promote greater cognitive function regardless of the amount of time spent in moderate-to-vigorous activities. This has future implications for examining the primary metric of focus for physical activity engagement in this population.

A-111 Validation of a Rapid Screening Measure for The Early Detection of Mild Cognitive Impairment in Older Adults

Abstract Objective: Examine the psychometric properties and classification accuracy of a digit symbol substitution task (DSST) to screen for mild cognitive impairment (MCI) in older adults. Methods: Twenty-seven older adults with MCI and 50 demographically-matched healthy controls (HC) over age 60 completed the MMSE, Quick MCI (Qmci), and DSST, the latter of which was administered twice to examine the added utility of practice effects. Results: Patients with MCI performed significantly worse than their HC counterparts on the MMSE (η2 = 0.191), Qmci (η2 = 0.153), and the first (η2 = 0.337) and second (η2 = 0.393) administration of the DSST. HC participants also demonstrated significantly greater practice effects than those with MCI who did not appear to benefit from task repetition (mean score increases of 7.4 and 0.5, respectively). The DSST exhibited excellent within-session test–retest reliability (R2 = 0.774) and was more strongly correlated with Qmci (R2 = 0.311) than MMSE (R2 = 0.112) scores. ROC analyses indicated that a cutoff score of 23.5 for the first administration (AUC = 0.860) and 27.5 for the second administration (AUC = 0.900) of the DSST were associated with superior classification accuracy to that of the MMSE (AUC = 0.759) and Qmci (AUC = 0.777). DSST difference scores (AUC = 0.764) reflecting within-session practice effects were slightly superior to the MMSE but not the Qmci. In logistic regression analyses, scores from the first administration of the DSST significantly predicted group membership and the addition of practice effects significantly improved model fit (p &amp;lt; 0.001) resulting in an overall classification accuracy of 85.1%. Conclusions: Findings suggest that the DSST is a valid and reliable rapid screening measure which may prove useful for clinicians and researchers alike.

Association between use of systemic and inhaled glucocorticoids and changes in brain volume and white matter microstructure: a cross-sectional study using data from the UK Biobank

ObjectiveTo test the hypothesis that systemic and inhaled glucocorticoid use is associated with changes in grey matter volume (GMV) and white matter microstructure.DesignCross-sectional study.SettingUK Biobank, a prospective population-based cohort study...

Association of social isolation and smartphone use on cognitive functions

BackgroundThe number of socially isolated older adults has increased owing to the coronavirus disease pandemic, thus leading to a decrease in cognitive functions among this group. Smartphone use is expected to be a reasonable preventive measure against cognitive decline in this social context. Thus, this study aimed to investigate the influence of social isolation and smartphone use on cognitive functions in community-dwelling older adults. MethodsWe divided 4,601 community-dwelling older adults into four groups based on their levels of social isolation and smartphone use. Then, we conducted cognitive functions tests including a word list memory task, trail-making test, and symbol digit substitution task. Social isolation was defined when participants met two or more of the following measures: domestic isolation, less social contact, and social disengagement. We used an analysis of covariance adjusted by background information to measure between-group differences in levels of cognitive functions and social isolation. A linear regression model was used to analyze the association of standardized scores of cognitive function tests with smartphone use. ResultsSmartphone users’ scores of the symbol digit substitution task were superior compared with both non-users with social isolation and without. All cognitive functions were associated with smartphone use among non-socially and socially isolated participants. Socially isolated older adults showed an association only between trail making test- part A and smartphone use. ConclusionsSmartphone use was associated with cognitive functions (memory, attentional function, executive function, and processing speed) even in socially isolated community-dwelling older adults.

The Effect of Deep Micro Vibrotactile Stimulation on Cognitive Function of Mild Cognitive Impairment and Mild Dementia.

Background: The purpose of this study was to clarify the effect of Deep Micro Vibrotactile (DMV) stimulation on the cognitive functions in elderly people with mild cognitive impairment or mild dementia. Methods: A total of 35 participants with dementia from three nursing homes, who had completed treatment with DMV stimulation at 15–40 Hz (hereinafter, 15–40 Hz DMV stimulation) for a month were recruited for this study. The subjects had received continuous 15–40 Hz DMV stimulation for 24 h a day for 1 month. We assessed the effect of the treatment on the cognitive functions (by the word list memory (WM) test, trail making test-part A (TMT-A) and part B (TMT-B), and symbol digit substitution task (SDST)) and physical functions (grip strength (GS) and usual walking speed (UWS)), by comparing the results at the baseline and after the 1-month intervention (DMV stimulation). Results: The results revealed that the performances in the WM test (p < 0.05), TMT-B (p < 0.05), and SDST (p < 0.01) improved significantly after the intervention. Conclusion: Our findings suggest that 15–40 Hz DMV stimulation is might be effective for improving the cognitive functions in elderly people with dementia. Furthermore, our novel findings showed the different effectiveness of the treatment depending on the stage of cognitive impairments.

Air Pollution Exposure Is Associated With Cognitive Performance: Results From the Einstein Aging Study

Prior research has established that those exposed to higher levels of fine particulate matter (PM1, PM2.5) air pollution have higher levels of accumulated amyloid-beta (Aβ) and tau in frontal cortex at autopsy, higher error rates on cognitive function assessments, and lower scores on memory and both verbal and non-verbal intelligence assessments. We explored the relationship between regional air quality monitoring measures (EPA AirData) and baseline cognitive performance of 312 older adults, from the Einstein Aging Study (EAS, NIA P01AG003949). Participants completed neuropsychological assessments at baseline and each followup wave (i.e., delayed free recall and total recall; Trails A & B, Digit Symbol substitution task (DSST), MoCA). For each participant, based on their zipcode, we computed average PM2.5 exposure at various exposure windows (1-15, 30-60, 60-90, 90-120 days prior to baseline). Adjusting for age, education, and gender across all models, mean of daily particulate matter exposure at various exposure windows (30-60, 60-90 days) was significantly related to performance on the MoCA and Trails A & B, in expected directions (i.e., higher pollution, worse cognitive performance - more error, slower speed). Models with memory performance as the outcome indicated that only distant time horizons were related to memory performance (i.e., 60-90, 90-120 days prior). These findings suggest that particulate matter air pollution likely affects different cognitive domains at different timescales. This methodology cannot address contributions from indoor air quality and mobility - an exposure misclassification likely resulting in significant biases towards the null in the estimation of the effects of air pollution.

Altered neuroaxonal integrity in schizophrenia and major depressive disorder assessed with neurofilament light chain in serum

BackgroundSchizophrenia (SZ) and major depressive disorders (MDD) have been frequently linked to anatomical brain alterations. However, the relationship between brain pathology, inflammation and clinical symptoms in these disorders is still unclear. Thus, by applying novel blood markers of neuroaxonal integrity such as neurofilament light chain (NfL), we can now address main issues in psychiatric research and potentially offer innovative diagnostic tools toward better clinical characterizations and monitoring in both SZ and MDD. MethodsNfL levels were measured in serum of 44 patients with SZ and in 41 patients with MDD applying single molecule array technology and compared to a healthy norm population. Main inflammatory markers (C- reactive protein, interleukins IL-6 and IL-10) were measured to define patients with inflammatory phenotype. The Digit Symbol Substitution Task (DSST) and the Letter-Number-Sequencing Task were performed to estimate cognitive function in both groups. ResultsNfL levels in MDD group (but not in SZ group) were significantly higher than reference values of healthy norm population. A higher than expected proportion of patients with NfL levels above age-specific cut-off values was observed in both SZ and MDD groups. No correlation was observed between NfL and inflammatory markers. A negative correlation between DSST and NfL-values was observed in patients with MDD. ConclusionsBoth SZ and MDD showed elevated serum levels of NfL, which were independent from inflammatory markers but associated with cognitive performance.

128 Raw Scores Best Differentiate Resilience and Vulnerability to Sleep Loss for Cognitive Throughput and Working Memory

Abstract Introduction Substantial individual differences exist in cognitive deficits due to sleep restriction (SR) and total sleep deprivation (TSD), but the best approach to define such resilience and vulnerability remains a critical question. We compared multiple approaches and cutoff thresholds to define resilience and vulnerability using the Digit Symbol Substitution Task (DSST) and the Digit Span Task (DST). Methods Forty-one healthy adults (mean±SD ages,33.9±8.9y) participated in a 13-night experiment [two baseline nights (10h-12h time-in-bed, TIB), 5 SR nights (4h TIB), 4 recovery nights (12h TIB), and 36h TSD]. The DSST [measuring cognitive throughput] and DST [measuring working memory] were administered every 2h during wakefulness. Resilient/vulnerable groups were defined by average performance (DSST: number correct; DST: total correct from forward and backward versions) during SR1-5, average performance change from baseline during SR1-5, and variance in performance during SR1-5. Within each approach, groups were defined by +/-1 standard deviation (SD) and the top and bottom 12.5%, 20%, 25%, 33%, 50%. Bias-corrected and accelerated bootstrapped t-tests compared performance between resilient and vulnerable groups during baseline and SR1-5. Kendall’s tau correlations compared the ranking of individuals in each group. Results T-tests showed significant differences between resilient/vulnerable groups at all raw score cutoffs for DSST and DST performance during SR and at baseline. Change from baseline t-tests showed significant differences during SR between the DSST groups only at 12.5%, 20%, and SD whereas DST t-tests showed significant differences at all cutoffs. Variance t-tests revealed a significant difference between the DSST groups only at 25% during SR. For the DSST, the variance vs. change from baseline comparison at all cutoffs and between raw score vs. change from baseline for the SD cutoff showed moderate correlations, and for the DST, the raw score vs. change from baseline correlation was moderate for 25% and 33%. Conclusion The resilient/vulnerable groups defined by raw score were more consistent than those defined by change from baseline or variance, and raw score did not track these approaches well. As such, raw score is the optimal approach to define cognitive throughput and working memory performance resiliency/vulnerability during sleep loss. Support (if any) ONR Award No. N00014-11-1-0361;NIH UL1TR000003;NASA NNX14AN49G and 80NSSC20K0243;NIH R01DK117488