Response Validity in Forensic Neuropsychology: Exploratory Factor Analytic Evidence of Distinct Cognitive and Psychological Constructs

Forensic neuropsychology studies usually address either cognitive effort or psychological response validity. Whether these are distinct constructs is unclear. In 122 participants evaluated in a compensation-seeking context, the present Exploratory Factor Analysis examined whether forced-choice cognitive effort measures (Victoria Symptom Validity Test, Test of Memory Malingering, Letter Memory Test) and Minnesota Multiphasic Personality Inventory, Second Edition (MMPI-2) validity scales (L, F, K, FBS, Fp, RBS, Md, Dsr2, S) load on independent factors. Regardless of factor rotation strategy (orthogonal or oblique), four response validity factors emerged by means of both Principal Components Analysis (82.7% total variance) and Principal-Axis Factor Analysis (74.1% total variance). The four factors were designated as follows: Factor I, with large loadings from L, K, and S—underreporting of psychologicalsymptoms; Factor II, with large loadings from FBS, RBS, and Md—overreporting of neurotic symptoms; Factor III, with large loadings from VSVT, TOMM, and LMT—insufficient cognitive effort; and Factor IV, with the largest loadings from F, Fp, and Dsr2—overreporting of psychotic/rarely endorsed symptoms. Results reflect the heterogeneity of response validity in forensic samples referred for neuropsychological evaluation. Administration of both cognitive effort measures and psychological validity scales is imperative to accurate forensic neuropsychological assessment. (JINS, 2007, 13, 440–449.

Cognitive-postural multitasking training in older adults: Effects of input-output modality mappings on cognitive performance and postural control

Older adults exhibit impaired cognitive and balance performance, particularly under multi-task conditions, which can be improved through training. Compatibility of modality mappings in cognitive tasks (i.e., match between stimulus modality and anticipated sensory effects of motor responses), modulates physical and cognitive dual-task costs. However, the effects of modality specific training programs have not been evaluated yet. Here, we tested the effects of cognitive-postural multi-tasking training on the ability to coordinate task mappings under high postural demands in healthy older adults. Twenty-one adults aged 65-85 years were assigned to one of two groups. While group 1 performed cognitive-postural triple-task training with compatible modality mappings (i.e., visual-manual and auditory-vocal dual n-back tasks), group 2 performed the same tasks with incompatible modality mappings (i.e., visual-vocal and auditory-manual n-back tasks). Throughout the 6-weeks balance training intervention, working-memory load was gradually increased while base-of-support was reduced. Before training (T0), after a 6-week passive control period (T1), and immediately after the intervention (T2), participants performed spatial dual one-back tasks in semi-tandem stance position. Our results indicate improved working-memory performance and reduced dual-task costs for both groups after the passive control period, but no training-specific performance gains. Furthermore, balance performance did not improve in response to training. Notably, the cohort demonstrated meaningful interindividual variability in training responses. Our findings raise questions about practice effects and age-related heterogeneity of training responses following cognitive-motor training. Following multi-modal balance training, neither compatible nor incompatible modality mappings had an impact on the observed outcomes

Use of MMPI-2 to Predict Cognitive Effort: A Hierarchically Optimal Classification Tree Analysis

Neuropsychologists routinely rely on response validity measures to evaluate the authenticity of test performances. However, the relationship between cognitive and psychological response validity measures is not clearly understood. It remains to be seen whether psychological test results can predict the outcome of response validity testing in clinical and civil forensic samples. The present analysis applied a unique statistical approach, classification tree methodology (Optimal Data Analysis: ODA), in a sample of 307 individuals who had completed the MMPI-2 and a variety of cognitive effort measures. One hundred ninety-eight participants were evaluated in a secondary gain context, and 109 had no identifiable secondary gain. Through recurrent dichotomous discriminations, ODA provided optimized linear decision trees to classify either sufficient effort (SE) or insufficient effort (IE) according to various MMPI-2 scale cutoffs. After “pruning” of an initial, complex classification tree, the Response Bias Scale (RBS) took precedence in classifying cognitive effort. After removing RBS from the model, Hy took precedence in classifying IE. The present findings provide MMPI-2 scores that may be associated with SE and IE among civil litigants and claimants, in addition to illustrating the complexity with which MMPI-2 scores and effort test results are associated in the litigation context. (JINS, 2008, 14, 842–852.

The effects of aerobic exercise and transcranial direct current stimulation on cognitive function in older adults with and without cognitive impairment:A systematic review and meta-analysis

Background: Aerobic exercise (AE) may slow age-related cognitive decline. However, such cognition-sparing effects are not uniform across cognitive domains and studies. Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation and is also emerging as a potential alternative to pharmaceutical therapies. Like AE, the effectiveness of tDCS is also inconsistent for reducing cognitive impairment in ageing. The unexplored possibility exists that pairing AE and tDCS could produce synergistic effects and reciprocally augment cognition-improving effects in older individuals with and without cognitive impairments.Previous research found such synergistic effects on cognition when cognitive training is paired with tDCS in older individuals with and without mild cognitive impairment (MCI) or dementia.Aim: The purpose of this systematic review with meta-analysis was to explore if pairing AE with tDCS could augment singular effects of AE and tDCS on global cognition (GC), working memory (WM) and executive function (EF) in older individuals with or without MCI and dementia.Methods: Using a PRISMA-based systematic review, we compiled studies that examined the effects of AE alone, tDCS alone, and AE and tDCS combined on cognitive function in older individuals with and without mild cognitive impairment (MCI) or dementia. Using a PICOS approach, we systematically searched PubMed, Scopus and Web of Science searches up to December 2021, we focused on ‘MoCA’, ‘MMSE’, ‘Mini-Cog’ (measures) and ‘cognition’, ‘cognitive function’, ‘cognitive’, ‘cognitive performance’, ‘executive function’, ‘executive process’, ‘attention’, ‘memory’, ‘memory performance’ (outcome terms). We included only randomized controlled trials (RTC) in humans if available in English full text over the past 20 years, with participants’ age over 60. We assessed the methodological quality of the included studies (RTC) by the Physiotherapy Evidence Database (PEDro) scale.Results: Overall, 68 studies were included in the meta-analyses. AE (ES = 0.56 [95% CI: 0.28–0.83], p = 0.01) and tDCS (ES = 0.69 [95% CI: 0.12–1.26], p = 0.02) improved GC in all three groups of older adults combined (healthy, MCI, demented). In healthy population, AE improved GC (ES = 0.46 [95% CI: 0.22–0.69], p = 0.01) and EF (ES = 0.27 [95% CI: 0.05–0.49], p = 0.02). AE improved GC in older adults with MCI (ES = 0.76 [95% CI: 0.21–1.32], p = 0.01). tDCS improved GC (ES = 0.69 [90% CI: 0.12–1.26], p = 0.02), all three cognitive function (GC, WM and EF) combined in older adults with dementia (ES = 1.12 [95% CI: 0.04–2.19], p = 0.04) and improved cognitive function in older adults overall (ES = 0.69 [95% CI: 0.20–1,18], p = 0.01).Conclusion: Our systematic review with meta-analysis provided evidence that beyond the cardiovascular and fitness benefits of AE, pairing AE with tDCS may have the potential to slow symptom progression of cognitive decline in MCI and dementia. Future studies will examine the hypothesis of this present review that a potentiating effect would incrementally improve cognition with increasing severity of cognitive impairment.</p

The effects of aerobic exercise and transcranial direct current stimulation on cognitive function in older adults with and without cognitive impairment:A systematic review and meta-analysis

Background: Aerobic exercise (AE) may slow age-related cognitive decline. However, such cognition-sparing effects are not uniform across cognitive domains and studies. Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation and is also emerging as a potential alternative to pharmaceutical therapies. Like AE, the effectiveness of tDCS is also inconsistent for reducing cognitive impairment in ageing. The unexplored possibility exists that pairing AE and tDCS could produce synergistic effects and reciprocally augment cognition-improving effects in older individuals with and without cognitive impairments. Previous research found such synergistic effects on cognition when cognitive training is paired with tDCS in older individuals with and without mild cognitive impairment (MCI) or dementia. Aim: The purpose of this systematic review with meta-analysis was to explore if pairing AE with tDCS could augment singular effects of AE and tDCS on global cognition (GC), working memory (WM) and executive function (EF) in older individuals with or without MCI and dementia. Methods: Using a PRISMA-based systematic review, we compiled studies that examined the effects of AE alone, tDCS alone, and AE and tDCS combined on cognitive function in older individuals with and without mild cognitive impairment (MCI) or dementia. Using a PICOS approach, we systematically searched PubMed, Scopus and Web of Science searches up to December 2021, we focused on ‘MoCA’, ‘MMSE’, ‘Mini-Cog’ (measures) and ‘cognition’, ‘cognitive function’, ‘cognitive’, ‘cognitive performance’, ‘executive function’, ‘executive process’, ‘attention’, ‘memory’, ‘memory performance’ (outcome terms). We included only randomized controlled trials (RTC) in humans if available in English full text over the past 20 years, with participants’ age over 60. We assessed the methodological quality of the included studies (RTC) by the Physiotherapy Evidence Database (PEDro) scale. Results: Overall, 68 studies were included in the meta-analyses. AE (ES = 0.56 [95% CI: 0.28–0.83], p = 0.01) and tDCS (ES = 0.69 [95% CI: 0.12–1.26], p = 0.02) improved GC in all three groups of older adults combined (healthy, MCI, demented). In healthy population, AE improved GC (ES = 0.46 [95% CI: 0.22–0.69], p = 0.01) and EF (ES = 0.27 [95% CI: 0.05–0.49], p = 0.02). AE improved GC in older adults with MCI (ES = 0.76 [95% CI: 0.21–1.32], p = 0.01). tDCS improved GC (ES = 0.69 [90% CI: 0.12–1.26], p = 0.02), all three cognitive function (GC, WM and EF) combined in older adults with dementia (ES = 1.12 [95% CI: 0.04–2.19], p = 0.04) and improved cognitive function in older adults overall (ES = 0.69 [95% CI: 0.20–1,18], p = 0.01). Conclusion: Our systematic review with meta-analysis provided evidence that beyond the cardiovascular and fitness benefits of AE, pairing AE with tDCS may have the potential to slow symptom progression of cognitive decline in MCI and dementia. Future studies will examine the hypothesis of this present review that a potentiating effect would incrementally improve cognition with increasing severity of cognitive impairment

Functional Relevance of Resistance Training-Induced Neuroplasticity in Health and Disease

[Abstract] Repetitive, monotonic, and effortful voluntary muscle contractions performed for just a few weeks, i.e., resistance training, can substantially increase maximal voluntary force in the practiced task and can also increase gross motor performance. The increase in motor performance is often accompanied by neuroplastic adaptations in the central nervous system. While historical data assigned functional relevance to such adaptations induced by resistance training, this claim has not yet been systematically and critically examined in the context of motor performance across the lifespan in health and disease. A review of muscle activation, brain and peripheral nerve stimulation, and imaging data revealed that increases in motor performance and neuroplasticity tend to be uncoupled, making a mechanistic link between neuroplasticity and motor performance inconclusive. We recommend new approaches, including causal mediation analytical and hypothesis-driven models to substantiate the functional relevance of resistance training-induced neuroplasticity in the improvements of gross motor function across the lifespan in health and disease

Home-based exercise programmes improve physical fitness of healthy older adults: A PRISMA-compliant systematic review and meta-analysis with relevance for COVID-19

This systematic review and meta-analysis aimed to examine the effects of home-based exercise programmes on measures of physical-fitness in healthy older adults. Seventeen randomized-controlled trials were included with a total of 1,477 participants. Results indicated small effects of home-based training on muscle strength (between-study standardised-mean-difference [SMD]=0.30), muscle power (SMD=0.43),muscular endurance (SMD=0.28), and balance (SMD=0.28). We found no statistically significant effects for single-mode strength vs. multimodal training (e.g., combined balance, strength, and flexibility exercises) on measures of muscle strength and balance. Single-mode strength training had moderate effects on muscle strength (SMD=0.51) and balance (SMD=0.65) while multimodal training had no statistically significant effects on muscle strength and balance. Irrespective of the training type, >3 weekly sessions produced larger effects on muscle strength (SMD=0.45) and balance(SMD=0.37) compared with ≤3 weekly sessions (muscle strength: SMD=0.28; balance:SMD=0.24). For session-duration, only ≤30min per-session produced small effects on muscle strength (SMD=0.35) and balance (SMD=0.34). No statistically significant differences were observed between all independently-computed single-training factors. Home-based exercise appears effective to improve components of health- (i.e., muscle strength and muscular endurance) and skill-related (i.e., muscle power, balance) physical-fitness. Therefore, in times of restricted physical activity due to pandemics, home-based exercises constitute an alternative to counteract physical inactivity and preserve/improve the health and fitness of healthy older adults aged 65-to-83 years