Search

Introduction: Continuous recognition tasks (CRTs) assess episodic memory (EM), the central functional disturbance in Alzheimer's disease and several related disorders. The online MemTrax computerized CRT provides a platform for screening and assessment that is engaging and can be repeated frequently. MemTrax presents complex visual stimuli, which require complex involvement of the lateral and medial temporal lobes and can be completed in less than 2 min. Results include number of correct recognitions (HITs), recognition failures (MISSes = 1-HITs), correct rejections (CRs), false alarms (FAs = 1-CRs), total correct (TC = HITs + CRs), and response times (RTs) for each HIT and FA. Prior analyses of MemTrax CRT data show no effects of sex but an effect of age on performance. The number of HITs corresponds to faster RT-HITs more closely than TC, and CRs do not relate to RT-HITs. RT-HITs show a typical skewed distribution, and cumulative RT-HITs fit a negative survival curve (RevEx). Thus, this study aimed to define precisely the effects of sex and age on HITS, CRs, RT-HITs, and the dynamics of RTs in an engaged population. Methods: MemTrax CRT online data on 18,255 individuals was analyzed for sex, age, and distributions of HITs, CRs, MISSes, FAs, TC, and relationships to both RT-HITs and RT-FAs. Results: HITs corresponded more closely to RT-HITs than did TC because CRs did not relate to RT-HITs. RT-FAs had a broader distribution than RT-HITs and were faster than RT-HITs in about half of the sample, slower in the other half. Performance metrics for men and women were the same. HITs declined with age as RT-HITs increased. CRs also decreased with age and RT-FAs increased, but with no correlation. The group over aged 50 years had RT-HITs distributions slower than under 50 years. For both age ranges, the RevEx model explained more than 99% of the variance in RT-HITs. Discussion: The dichotomy of HITs and CRs suggests opposing cognitive strategies: (1) less certainty about recognitions, in association with slower RTHITs and lower HIT percentages suggests recognition difficulty, leading to more MISSes, and (2) decreased CRs (more FAs) but faster RTs to HITs and FAs, suggesting overly quick decisions leading to errors. MemTrax CRT performance provides an indication of EM (HITs and RT-HITs may relate to function of the temporal lobe), executive function (FAs may relate to function of the frontal lobe), processing speed (RTs), cognitive ability, and age-related changes. This CRT provides potential clinical screening utility for early Alzheimer's disease and other conditions affecting EM, other cognitive functions, and more accurate impairment assessment to track changes over time. [ABSTRACT FROM AUTHOR]

PURPOSES: To establish a normative range of MemTrax (MTx) metrics in the Chinese population. METHODS: The correct response percentage (MTx‐%C) and mean response time (MTx‐RT) were obtained and the composite scores (MTx‐Cp) calculated. Generalized additive models for location, shape and scale (GAMLSS) were applied to create percentile curves and evaluate goodness of fit, and the speed‐accuracy trade‐off was investigated. RESULTS: 26,633 subjects, including 13,771 (51.71%) men participated in this study. Age‐ and education‐specific percentiles of the metrics were generated. Q tests and worm plots indicated adequate fit for models of MTx‐RT and MTx‐Cp. Models of MTx‐%C for the low and intermediate education fit acceptably, but not well enough for a high level of education. A significant speed‐accuracy trade‐off was observed for MTx‐%C from 72 to 94. CONCLUSIONS: GAMLSS is a reliable method to generate smoothed age‐ and education‐specific percentile curves of MTx metrics, which may be adopted for mass screening and follow‐ups addressing Alzheimer's disease or other cognitive diseases. Highlights: GAMLSS was applied to establish nonlinear percentile curves of cognitive decline.Subjects with a high level of education demonstrate a later onset and slower decline of cognition.Speed‐accuracy trade‐off effects were observed in a subgroup with moderate accuracy.MemTrax can be used as a mass‐screen instrument for active cognition health management advice. [ABSTRACT FROM AUTHOR]

Background Many investigators are interested in recruiting veterans from recent conflicts in Afghanistan and Iraq with Traumatic Brain Injury (TBI) and/or Post Traumatic Stress Disorder (PTSD). Researchers pursuing such studies may experience problems in recruiting sufficient numbers unless effective strategies are used. Currently, there is very little information on recruitment strategies for individuals with TBI and/or PTSD. It is known that groups of patients with medical conditions may be less likely to volunteer for clinical research. This study investigated the feasibility of recruiting veterans returning from recent military conflicts--Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) - using a population-based sampling method. Methods Individuals were sampled from a previous epidemiological study. Three study sites focused on recruiting survey respondents (n = 445) who lived within a 60 mile radius of one of the sites. Results Overall, the successful recruitment of veterans using a population-based sampling method was dependent on the ability to contact potential participants following mass mailing. Study enrollment of participants with probable TBI and/or PTSD had a recruitment yield (enrolled/total identified) of 5.4%. We were able to contact 146 individuals, representing a contact rate of 33%. Sixty-six of the individuals contacted were screened. The major reasons for not screening included a stated lack of interest in the study (n = 37), a failure to answer screening calls after initial contact (n = 30), and an unwillingness or inability to travel to a study site (n = 10). Based on the phone screening, 36 veterans were eligible for the study. Twenty-four veterans were enrolled, (recruitment yield = 5.4%) and twelve were not enrolled for a variety of reasons. Conclusions Our experience with a population-based sampling method for recruitment of recent combat veterans illustrates the challenges encountered, particularly contacting and screening potential participants. The screening and enrollment data will help guide recruitment for future studies using population-based methods. [ABSTRACT FROM AUTHOR]

Purposes: To establish a normative range of MemTrax (MTx) metrics in the Chinese population., Methods: The correct response percentage (MTx-%C) and mean response time (MTx-RT) were obtained and the composite scores (MTx-Cp) calculated. Generalized additive models for location, shape and scale (GAMLSS) were applied to create percentile curves and evaluate goodness of fit, and the speed-accuracy trade-off was investigated., Results: 26,633 subjects, including 13,771 (51.71%) men participated in this study. Age- and education-specific percentiles of the metrics were generated. Q tests and worm plots indicated adequate fit for models of MTx-RT and MTx-Cp. Models of MTx-%C for the low and intermediate education fit acceptably, but not well enough for a high level of education. A significant speed-accuracy trade-off was observed for MTx-%C from 72 to 94., Conclusions: GAMLSS is a reliable method to generate smoothed age- and education-specific percentile curves of MTx metrics, which may be adopted for mass screening and follow-ups addressing Alzheimer's disease or other cognitive diseases., Highlights: GAMLSS was applied to establish nonlinear percentile curves of cognitive decline. Subjects with a high level of education demonstrate a later onset and slower decline of cognition. Speed-accuracy trade-off effects were observed in a subgroup with moderate accuracy. MemTrax can be used as a mass-screen instrument for active cognition health management advice., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Background: Posttraumatic stress disorder (PTSD) is a frequent problem of veterans receiving care and is often associated with cognitive deficits. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a well-validated cognitive screening measure often used in the US Department of Veterans Affairs (VA), particularly in neurorehabilitation settings. However, the influence of PTSD on RBANS performance is unclear, particularly within a heterogeneous VA outpatient population in which PTSD and traumatic brain injury (TBI) may not be the primary focus of care., Methods: Participants included 153 veterans with complex deployment-related health problems, including a diagnosis of PTSD (n = 98) and a history of TBI (n = 92). All veterans completed a targeted cognitive battery that included the Wechsler Test of Adult Reading, the Wechsler Adults Intelligence Scale, measure assessing processing speed, attention, and cognitive flexibility, and RBANS., Results: A diagnosis of PTSD was associated with worse performance on the Story Recall subtest of the RBANS, but not on any other cognitive measures. A diagnosis of mild TBI, or co-occurring PTSD and TBI did not predict cognitive performance on any measures., Conclusions: The RBANS best captured cognitive deficits associated with PTSD compared with a history of mild TBI or co-occurring mild TBI and PTSD. These findings may provide insight into the interpretation and attribution of cognitive deficits in the veteran population., Competing Interests: Author disclosures The authors report no actual or potential conflicts of interest with regard to this article., (Copyright © 2021 Frontline Medical Communications Inc., Parsippany, NJ, USA.)