Bigler (2012) and Larrabee (2012) recently addressed the state of the science surrounding performance validity tests (PVTs) in a dialogue highlighting evidence for the valid and increased use of PVTs, but also for unresolved problems. Specifically, Bigler criticized the lack of guidance from neurocognitive processing theory in the PVT literature. For example, individual PVTs have applied the simultaneous forced-choice methodology using a variety of test characteristics (e.g., word vs. picture stimuli) with known neurocognitive processing implications (e.g., the “picture superiority effect”). However, the influence of such variations on classification accuracy has been inadequately evaluated, particularly among cognitively impaired individuals. The current review places the PVT literature in the context of neurocognitive processing theory, and identifies potential methodological factors to account for the significant variability we identified in classification accuracy across current PVTs. We subsequently evaluated the utility of a well-known cognitive manipulation to provide a Clinical Analogue Methodology (CAM), that is, to alter the PVT performance of healthy individuals to be similar to that of a cognitively impaired group. Initial support was found, suggesting the CAM may be useful alongside other approaches (analogue malingering methodology) for the systematic evaluation of PVTs, particularly the influence of specific neurocognitive processing components on performance. (JINS, 2014, 20, 873–886)

Traumatic brain injury (TBI) is likely to disrupt structural network properties due to diffuse white matter pathology. The present study aimed to detect alterations in structural network topology in TBI and relate them to cognitive and real-world behavioral impairment. Twenty-two people with moderate to severe TBI with mostly diffuse pathology and 18 demographically matched healthy controls were included in the final analysis. Graph theoretical network analysis was applied to diffusion tensor imaging (DTI) data to characterize structural connectivity in both groups. Neuropsychological functions were assessed by a battery of psychometric tests and the Frontal Systems Behavior Scale (FrSBe). Local connection-wise analysis demonstrated reduced structural connectivity in TBI arising from subcortical areas including thalamus, caudate, and hippocampus. Global network metrics revealed that shortest path length in participants with TBI was longer compared to controls, and that this reduced network efficiency was associated with worse performance in executive function and verbal learning. The shortest path length measure was also correlated with family-reported FrSBe scores. These findings support the notion that the diffuse form of neuropathology caused by TBI results in alterations in structural connectivity that contribute to cognitive and real-world behavioral impairment. (JINS, 2014, 20, 1–10)

There is increasing need for early, pro-active programs that can delay dementia diagnosis and enhance well-being of individuals with mild cognitive impairment (MCI) and their care-partners (i.e., care-dyads). This randomized controlled trial evaluated the efficacy of a combined cognitive rehabilitation and multi-family group treatment (CR-MFG) that was designed to facilitate adoption of newly learned cognitive strategies into the care-dyads everyday lives. Analyzed data included 23 care-dyads who participated in CR-MFG treatment and 23 care-dyads in standard care (SC). The 3-month intervention consisted of individual joining sessions, an educational workshop, and 20/twice weekly multifamily memory strategy training and problem-solving sessions. Everyday functioning, memory, and psychological functioning (i.e., quality-of-life, depression, coping) were assessed. The CR-MFG intervention was associated with significant post-test group differences and improved post-test performances by the MCI participants on performance-based measures of everyday functioning and neuropsychological tests of memory. There was also some suggestion that CR-MFG care-partners perceived positive change in the everyday functioning of the MCI participants. In contrast, no post-test group differences were found for either care-dyad member on the self-report psychological measures; care-partners in the treatment group did self-report improved coping behaviors at post-test. These 3-month results are preliminary but suggestive that CR-MFG may produce modest, practical everyday functional benefits for persons with MCI. (JINS, 2014, 20, 1–12)

The effect of low birth weight on children’s development has been documented for a range of neurocognitive outcomes. However, few previous studies have examined the effect of birth weight variability within the normal range on children’s neuropsychological development. The current study examined birth weight variation amongst children weighing ≥2500 g in relation to their language, executive functioning (EF), and theory of mind (ToM), and specified a developmental pathway in which birth weight was hypothesized to be associated with children’s EF and ToM through their intermediary language skills. The current study used a prospective community birth cohort of 468 children. Families were recruited when children were newborns and followed up every 18 months until children were age 4.5. Language was assessed at age 3 using a standardized measure of receptive vocabulary (PPVT), and EF and ToM were measured at age 4.5 using previously validated and developmentally appropriate tasks. After controlling for potential confounding variables (family income, parent education, gestational age), birth weight within the normal range was associated with language ability at age 3 (β=.17; p=.012); and the effect of birth weight on both EF (z=2.09; p=.03) and ToM (z=2.07; p=.03) at age 4.5 operated indirectly through their language ability at age 3. Our findings indicate that the effects of birth weight on child neurocognition extend into the normal range of birth weight, and specific developmental mechanisms may link these skills over time. (JINS, 2014, 20, 1–11)

Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: (i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and (ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite Z-scores of cognition, including attention/information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction: p=.03)—younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=−.46; p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=−.47; p=.03) and older euthymic groups (r=−.51; p=.01). The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics. (JINS, 2014, 20, 1–9)

Cognitive loading aggravates the freezing of gait (FoG), which is observed in approximately 50% of patients with Parkinson’s disease (PD) in the advanced stages. To investigate whether a specific pattern of executive deficits, that is, attentional set-shifting and/or inhibitory control, are associated with FoG in PD, 30 PD patients with FoG (PD-FoG+) and 36 PD patients without FoG (PD-FoG−) and 22 control healthy subjects were examined with a comprehensive neuropsychological battery. Intra-Extra Dimensional Set shifting Test (IED) and Stop Signal Task (SST), selected from the Cambridge Automated Neuropsychological Battery (CANTAB battery), were administered to analyze set-shifting and motor inhibition, respectively. The IED task was significantly sensitive for differentiating between PD-FoG+ and PD-FoG− groups (p<.01), as well Adenbrook’s clock drawing task (p=.033). By contrast, no differences emerged on any aspect of the SST task and other cognitive tasks. The attrition rate during the IED task showed that the problem in the PD-FoG+ group appeared at the pre-ID level, on the discrimination-learning set; the 32% PD-FoG+ subjects did not achieve the ID level of the task in comparison to negligible 4% of the PD-FoG− patients (p=.011). The logistic regression analysis, indicated the higher the IED stage successfully completed, the less likely presence of FoG in PD subjects. These results demonstrate that the complex cognitive–motor interplay might be responsible for FoG in PD and have had real life implication for the patients. (JINS, 2014, 20, 1–8)

Memory impairment affects 50% of multiple sclerosis (MS) patients. Altered resting-state functional connectivity (FC) has been observed in the default network (DN) of MS patients. No study to date has examined the association of DN FC to its behavioral concomitant, memory. The approach of the present study represents a methodological shift allowing straightforward interpretation of FC alterations in MS, as it presupposes specificity of a network to its paired cognitive function. We examined FC from fMRI collected during rest in the DN of 43 MS patients with and without memory-impairment. Memory-intact patients showed increased DN FC relative to memory-impaired patients. There were no regions of higher FC in memory-impaired patients. DN FC was positively correlated with memory function, such that higher FC was associated with better memory performance. Results were unchanged after controlling for cognitive efficiency, supporting specificity of the DN to memory and not cognitive status more generally. These findings support DN FC as a marker of memory function in MS patients that can be targeted by future treatment interventions. Pairing a functional network with its behavioral concomitant represents a straightforward method for interpreting FC alterations in patients with MS. (JINS, 2014, 20, 1–8)

We aimed to identify brain functional correlates of working memory performance in aging, in hopes of facilitating understanding of mechanisms that promote better versus worse working memory in late-life. Among 64 healthy adults, aged 23 to 78, we examined the relationship between age, working memory performance, and brain functional response during task performance. We focused on the association between working memory load-modulated functional response and individual differences in performance and whether these function-performance relationships differed with age. As expected, older age was associated with poorer working memory performance. Older age was also associated with reduced load-modulated activation including in bilateral prefrontal and parietal regions and left caudate as well as reduced deactivation including in the medial prefrontal cortex. Contrary to findings of hyperactivation in aging, we found no evidence of increased activation with older age. Positive associations identified between brain response and performance did not differ with age. Our findings suggest that the neural mechanisms underlying better versus worse working memory performance are age-invariant across adulthood, and argue against a pattern of functional reorganization in aging. Results are discussed within the broader literature, in which significant heterogeneity in findings between studies has been common. (JINS, 2014, 20, 1–6)