Use of perceptual memory as a performance validity indicator: initial validation with simulated mild traumatic brain injury.

INTRODUCTION: Many commonly employed performance validity tests (PVTs) are several decades old and vulnerable to compromise, leading to a need for novel instruments. Because implicit/non-declarative memory may be robust to brain damage, tasks that rely upon such memory may serve as an effective PVT. Using a simulation design, this experiment evaluated whether novel tasks that rely upon perceptual memory hold promise as PVTs. METHOD: Sixty healthy participants were provided instructions to simulate symptoms of mild traumatic brain injury (TBI), and they were compared to a group of 20 honest responding individuals. Simulator groups received varying levels of information concerning TBI symptoms, resulting in naïve, sophisticated, and test-coached groups. The Word Memory Test, Test of Memory Malingering, and California Verbal Learning Test-II Forced Choice Recognition Test were administered. To assess perceptual memory, selected images from the Gollin Incomplete Figures and Mooney Closure Test were presented as visual perception tasks. After brief delays, memory for the images was assessed. RESULTS: No group differences emerged on the perception trials of the Gollin and Mooney figures, but simulators remembered fewer images than the honest responders. Simulator groups differed on the standard PVTs, but they performed equivalently on the Gollin and Mooney figures, implying robustness to coaching. Relying upon a criterion of 90% specificity, the Gollin and Mooney figures achieved at least 90% sensitivity, comparing favorably to the standard PVTs. CONCLUSIONS: The Gollin and Mooney figures hold promise as novel PVTs. As perceptual memory tests, they may be relatively robust to brain damage, but future research involving clinical samples is necessary to substantiate this assertion.

Impaired Neurovascular Coupling and Increased Functional Connectivity in the Frontal Cortex Predict Age-Related Cognitive Dysfunction.

Impaired cerebrovascular function contributes to the genesis of age-related cognitive decline. In this study, the hypothesis is tested that impairments in neurovascular coupling (NVC) responses and brain network function predict cognitive dysfunction in older adults. Cerebromicrovascular and working memory function of healthy young (n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed. To determine NVC responses and functional connectivity (FC) during a working memory (n-back) paradigm, oxy- and deoxyhemoglobin concentration changes from the frontal cortex using functional near-infrared spectroscopy are recorded. NVC responses are significantly impaired during the 2-back task in aged participants, while the frontal networks are characterized by higher local and global connection strength, and dynamic FC (p < 0.05). Both impaired NVC and increased FC correlate with age-related decline in accuracy during the 2-back task. These findings suggest that task-related brain states in older adults require stronger functional connections to compensate for the attenuated NVC responses associated with working memory load.

Cerebral small vessel disease pathology in COVID-19 patients: A systematic review.

Cerebral small vessel disease (CSVD) is the leading cause of vascular cognitive impairment and is associated with COVID-19. However, contributing factors that often accompany CSVD pathology in COVID-19 patients may influence the incidence of cerebrovascular complications. Thus, a mechanism linking COVID-19 and CSVD has yet to be uncovered and differentiated from age-related comorbidities (i.e., hypertension), and medical interventions during acute infection. We aimed to evaluate CSVD in acute and recovered COVID-19 patients and to differentiate COVID-19-related cerebrovascular pathology from the above-mentioned contributing factors by assessing the localization of microbleeds and ischemic lesions/infarctions in the cerebrum, cerebellum, and brainstem. A systematic search was performed in December 2022 on PubMed, Web of Science, and Embase using a pre-established search criterion related to history of, or active COVID-19 with CSVD pathology in adults. From a pool of 161 studies, 59 met eligibility criteria and were included. Microbleeds and ischemic lesions had a strong predilection for the corpus callosum and subcortical/deep white matter in COVID-19 patients, suggesting a distinct CSVD pathology. These findings have important implications for clinical practice and biomedical research as COVID-19 may independently, and through exacerbation of age-related mechanisms, contribute to increased incidence of CSVD.

Gait variability predicts cognitive impairment in older adults with subclinical cerebral small vessel disease.

Introduction: Advanced methods of gait research, including approaches to quantify variability, and orderliness/regularity/predictability, are increasingly used to identify patients at risk for the development of cognitive impairment. Cerebral small vessel disease (CSVD) is highly prevalent in older adults and is known to contribute to the development of vascular cognitive impairment and dementia (VCID). Studies in preclinical models demonstrate that subclinical alterations precede CSVD-related cognitive impairment in gait coordination. In humans, CSVD also associates with gait abnormalities. The present study was designed to test the hypothesis that increased gait variability and gait asymmetry predict a decline in cognitive performance in older adults with CSVD. Methods: To test this hypothesis, we compared cognitive performance and gait function in patients with CSVD (age: 69.8 ± 5.3 years; n = 11) and age- and sex-matched control participants (age: 70.7 ± 5.8 years; n = 11). Based on imaging findings, patients with CSVD were identified [presence of white matter hyperintensities plus silent brain infarcts and/or microhemorrhages on magnetic resonance imaging (MRI) assessment]. Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Gait parameters were measured during the single and dual tasks, during which participants, in addition to the motor task, completed a series of mental arithmetic calculations. Spatial and temporal parameters of gait variability, symmetry, and permutation entropy were determined using a pressure-sensitive gait mat during single and dual cognitive task conditions. Results: Patients with CSVD exhibited lower performance in a visual learning test (p = 0.030) and in a sustained attention test (p = 0.007). CSVD also affected step time variability (p = 0.009) and step length variability (p = 0.017). Step lengths of CSVD participants were more asymmetric (p = 0.043) than that of controls, while the two groups were statistically similar regarding step time symmetry and entropy of step time and length. Gait variability was inversely associated with sustained attention, especially among CSVD patients, and this relationship was significantly different between the two groups. The association of sustained attention with gait symmetry was also significantly different between the two groups. Discussion: Our findings provide additional evidence in support of the concept that increased gait variability and asymmetry may predict cognitive impairment in older adults with CSVD.

The Influence of Processing Speed, Attention, and Inhibition on Texas Functional Living Scale Performance.

OBJECTIVE: Attention, inhibition, and processing speed are related to functional decline among older adults. This study attempts to clarify the relationships between these cognitive factors and adaptive functioning. METHOD: We examined relationships between attention, inhibition, and processing speed, with scores on the Texas Functional Living Scale (TFLS), a performance-based measure of daily functioning, in a mixed clinical sample of 530 older adults who were referred for an outpatient neuropsychological evaluation. RESULTS: The current study used a confirmatory factor analysis (CFA) to derive a three-factor cognitive model consisting of attention, inhibition, and processing speed. Results from a hierarchical regression, which included factor scores from the CFA, revealed that processing speed was the only significant predictor of TFLS performance when all three cognitive factors were included within a single model. CONCLUSION: These results highlight the influence of processing speed as an important indicator of functional decline among a clinical population of older adults.

Classification accuracy of the word memory test genuine memory impairment index.

OBJECTIVE: The Word Memory Test (WMT) assesses non-credible performance in neuropsychological assessment. To mitigate risk of false positives among patients with severe cognitive dysfunction, the Genuine Memory Impairment Profile was derived. Only a modest number of investigations has evaluated classification accuracy among clinical samples, leaving the GMIP's accuracy largely uncertain. Accordingly, a simulation experiment evaluated the classification accuracy of the GMIP in a group of healthy individuals coached to simulate mild traumatic brain injury (TBI) related memory impairment on the WMT. PARTICIPANTS AND METHODS: Eighty healthy individuals were randomly assigned to one of the four experimental groups. One group was provided superficial information concerning TBI symptoms (naïve simulators), another was provided extensive information concerning TBI symptoms (sophisticated simulators), and a third group was provided extensive TBI symptom information and tactics to evade detection by performance validity tests (PVT) (test-coached). An honest responding control group was directed to give their best performance. All participants were administered the California Verbal Learning Test-2 (CVLT-2) and the WMT. RESULTS: Among the TBI simulators, 90% of the test-coached, 95% of the sophisticated simulators, and 100% of the naïve simulators were correctly classified as exaggerating memory impairment on the primary WMT indices. The simulator groups performed worse than the honest responding group on the CVLT-2. Of those who exceeded the WMT cutoffs, 60%, 27%, and 6% of the naïve-, sophisticated-, and test-coached simulators manifested the GMIP profile, respectively. CONCLUSIONS: The GMIP is apt to misclassify individuals as having genuine memory impairment, especially if a naïve or unsophisticated effort is made to exert non-credible performance. Indeed, individuals who employ the least sophisticated efforts to exaggerate cognitive impairment appear most likely to manifest the GMIP. The GMIP should be used cautiously to discriminate genuine impairment from non-credible performance, especially among people with mild TBI.

Memory in multiple sclerosis: A reappraisal using the item specific deficit approach.

OBJECTIVE: As many as 65% of people with multiple sclerosis (MS) have clinically significant memory impairment, but the nature of this deficit is controversial. Some investigations suggest that an inability to retrieve newly learned information from memory is prominent, whereas others imply that compromised acquisition accounts for impairment. Prior research has not simultaneously evaluated acquisition and retrieval processes in MS, and fewer have attempted to account for initial acquisition when studying retrieval. The Item Specific Deficit Approach (ISDA) offers a method of quantifying acquisition, retrieval, and retention processes, with the latter two mechanisms being adjusted for initial acquisition. To simultaneously quantify acquisition and retrieval abilities, the ISDA was applied to list learning performance in two independent samples of people with MS and corresponding healthy comparison groups. PARTICIPANTS AND METHODS: Study 1 included 85 people with MS and 47 healthy individuals. Study 2 involved a separate sample of 79 people with MS and 22 healthy people. They were administered neuropsychological batteries, and participants with MS were classified as globally impaired or unimpaired. The California Verbal Learning Test-II was administered to assess new-learning in both studies, and responses were scored using the ISDA. RESULTS: Both studies revealed that cognitively impaired people with MS manifest weaknesses involving acquisition and retrieval. Nearly identical effect sizes emerged across samples, with cognitive impairment achieving a medium effect upon acquisition and a large effect upon retrieval. CONCLUSIONS: These findings accord well with previous research showing diminished acquisition and retrieval among people with MS. The results may also reconcile contradictory findings in the extant literature by showing that memory impairment in MS is not exclusively attributable to either acquisition or retrieval. Rather, both processes may manifest across people with MS. The replication across samples with nearly identical effect sizes implies that these effects are reliable and possess external validity. These data hold implications for memory rehabilitation interventions involving people with MS, and suggest that acquisition and retrieval processes should be addressed in treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Effects of diminished positive mood and depressed mood upon verbal learning and memory among people with multiple sclerosis.

Objective: Cognitive impairment affects as many as 65% of people with multiple sclerosis (PWMS), and memory impairment confers greater severity of disability and functional impairment. Depression is also common among PWMS, and lifetime prevalence rates are as high as 50%. Research has yet to clearly define the relationship between memory dysfunction and depression among PWMS, and may reflect incomplete assessment of depressive symptoms. The present study examined different aspects of depressive symptoms including anhedonia (i.e., diminished positive mood) and their relationships with verbal learning and memory among PWMS.Method: Participants were 48 healthy individuals and 96 PWMS. They were primarily Caucasian (90.3%) and female (75.0%). Participants completed the California Verbal Learning Test-2 (CVLT-2) to assess verbal learning and memory and the Chicago Multiscale Depression inventory to assess depressed mood (CMDI-Mood) and diminished positive mood (CMDI-DPM).Results: Linear regression revealed that the main effect of CMDI-DPM and the interaction of CMDI-DPM and CMDI-Mood significantly explained variance across learning, recall, and recognition CVLT-2 indices. Follow-up analyses indicated that CMDI-DPM was only significant in the absence of high CMDI-Mood scores. CMDI-Mood explained variance in only CVLT-2 Trial B.Conclusions: Depressed mood had little direct effect upon memory performance in PWMS. In the absence of severe depressed mood, higher levels of positive mood corresponded to better memory performance. However, the impact of diminished positive mood was rendered null among those endorsing high levels of depressed mood. These data may imply that anhedonia corresponds with poorer memory function among PWMS, and suggests that investigators and clinicians should assess multiple mood dimensions among PWMS.

Addiction resistance to alcohol: What about heavy drinkers who avoid alcohol problems?

BACKGROUND: Some individuals are resistant to alcohol use disorders despite high levels of intake. Addiction Resistance (AR) measures the disparity between alcohol consumption and alcohol use disorder (AUD) symptoms, such that some persons exhibit few (AUD) symptoms despite higher intake. The validity of the concept and the factors contributing to AR are not well understood. The aim of this study was to predict AR based on variables related to risk for addiction that are measured in the Family Health Patterns Project. METHOD: Participants were healthy young adults (n = 1122) with and without a family history of alcohol and other substance use disorders who were given measures of mood stability and risk-taking tendencies, and were interviewed to determine alcohol intake, AUD symptoms, and other substance use disorders (SUD). AR was calculated using maximal lifetime alcohol intake and number of AUD symptoms. RESULTS: A principal components analysis was run with varimax rotation, which yielded three components: Component 1 indexed behavioral and mood regulation, Component 2 encompassed family and environmental factors, and Component 3 included cognitive factors. A multiple regression analysis revealed that Component 1 and Component 2 were predictive of AR whereas Component 3 was not. DISCUSSION: Individuals who reported greater emotional stability, norm adherence, risk avoidance, and fewer family members with substance use disorders were more resistant to AUD despite higher alcohol intake. These findings suggest that AUD risk and resistance may represent different points of the same continuum.