Cognitive abilities can be acutely disrupted in children and adolescents who sustain a mild traumatic brain injury (mTBI), with the potential that these disruptions may be predictive of recovery. The objective of this study was to determine if cognitive abilities in the emergency department (ED) can differentiate and predict poor symptom recovery following a pediatric mTBI. Participants included 77 male and female youth with a mTBI (mean age=13.6; SD=2.6). All participants completed computerized cognitive testing (four subtests from the CNS Vital Signs) when they presented to the ED. Symptom measurement occurred in the ED (for pre-injury), at 7–10 days, 1 month, 2 months, and 3 months post-mTBI using the post-concussion symptom inventory (PCSI). Recovery was determined using reliable change scores for symptom ratings from 28 orthopedic injury controls (mean age=13.9 years; SD=2.1). Significantly worse Reaction Time scores (i.e., rapid information processing) in the ED were found in those who remained symptomatic at 1 month. Performances on the Reaction Time and Cognitive Flexibility domain scores were predictive of symptom outcome at 1 month for youth (above and beyond sex and baseline symptom burden). Youth with low scores on Reaction Time and/or Cognitive Flexibility were nearly 15 times (95%CI=1.8–323.5) more likely to remain symptomatic at 1 month post-mTBI. No significant group differences were found at 7–10 days, 2 months, or 3 months post-injury. Rapid computerized cognitive testing in the ED following a mTBI may help clinicians predict which youth may or may not remain symptomatic at follow-up. (JINS, 2016, 22, 379–387)

Objectives: Although chronic sleep loss is highly common among teens, few objective sleep studies have examined its effects on cognitive performance, and specifically on information processing speed (IPS), a measure of cognitive proficiency. Methods: Forty-five adolescents underwent four consecutive nights of monitored sleep restriction (6–6.5 hr/night) and four nights of sleep extension (10–10.5 hr/night), in counterbalanced order, and separated by a washout period. Following each sleep period, cognitive performance was assessed, at a fixed morning time, using a computerized neuropsychological battery including an IPS task, a timed test providing both accuracy and reaction time outcome measures. Results: Overall IPS performance was poorer in the restricted when compared to the extended condition. Increasing task load and pace were associated with increased accuracy for both sleep conditions. However, a significant pace by load interaction effect was only found in the extended condition, with post hoc tests showing that for medium and hard loads, IPS accuracies were better with increasing pace of task. Differences in IPS reaction times were not found between the sleep conditions. In addition, sleep-related changes in IPS indices were correlated with changes in executive function, motor skill, and attention performance. Conclusions: Adolescents’ ability to process information may be especially vulnerable to sleep loss. Under ideal sleep conditions, however, they seem to be able to achieve optimal performance, particularly on more challenging problems. The functional implications of these findings may be particularly relevant to teens, who are often sleep deprived and are constantly required to process academic, social, and emotional input. (JINS, 2016, 22, 388–398)

Objectives: Numerous studies have shown that individuals with posttraumatic stress disorder (PTSD) display reduced performances on neuropsychological tests, although most prior research has not adequately accounted for comorbidities or performance validity concerns that are common in this population and could partially account for the observed neurocognitive findings. Moreover, few studies have examined the functional implications of neuropsychological results in PTSD. Methods: We examined neuropsychological functioning in 44 veterans with PTSD and 40 veteran trauma comparison (TC) participants with combat exposure and no PTSD. Results: After excluding four veterans with PTSD for performance validity concerns, multivariate analyses of variance by neurocognitive domain revealed significantly worse performance by the PTSD group in the domains of speed of information processing (p=.035) and executive functions (p=.017), but no group differences in attention/working memory, verbal/language functioning, visuoconstruction, or episodic memory. Group differences by PTSD status were still present after covarying for depression, a history of head injuries, and substance use disorders. Executive functioning performance was associated with poorer self-reported occupational functioning and physical health-related quality of life, while speed of information processing performance was associated with poorer physical health-related quality of life. Discussion: These results are generally consistent with a fronto-limbic conceptualization of PTSD-associated neuropsychological dysfunction and show that cognitive functioning may be associated with critical functional outcomes. Taken together, results suggest that consideration of neurocognitive functioning may enhance the clinical management of individuals with PTSD. (JINS, 2016, 22, 399–411)

Objectives: Individuals with major depressive disorder (MDD) demonstrate poorer learning and memory skills relative to never-depressed comparisons (NDC). Previous studies report decreased volume and disrupted function of frontal lobes and hippocampi in MDD during memory challenge. However, it has been difficult to dissociate contributions of short-term memory and executive functioning to memory difficulties from those that might be attributable to long-term memory deficits. Methods: Adult males (MDD, n=19; NDC, n=22) and females (MDD, n=23; NDC, n=19) performed the Semantic List Learning Task (SLLT) during functional magnetic resonance imaging. The SLLT Encoding condition consists of 15 lists, each containing 14 words. After each list, a Distractor condition occurs, followed by cued Silent Rehearsal instructions. Post-scan recall and recognition were collected. Groups were compared using block (Encoding-Silent Rehearsal) and event-related (Words Recalled) models. Results: MDD displayed lower recall relative to NDC. NDC displayed greater activation in several temporal, frontal, and parietal regions, for both Encoding-Silent Rehearsal and the Words Recalled analyses. Groups also differed in activation patterns in regions of the Papez circuit in planned analyses. The majority of activation differences were not related to performance, presence of medications, presence of comorbid anxiety disorder, or decreased gray matter volume in MDD. Conclusions: Adults with MDD exhibit memory difficulties during a task designed to reduce the contribution of individual variability from short-term memory and executive functioning processes, parallel with decreased activation in memory and executive functioning circuits. Ecologically valid long-term memory tasks are imperative for uncovering neural correlates of memory performance deficits in adults with MDD. (JINS, 2016, 22, 412–425)

Objectives: Huntington’s disease (HD) is a neurodegenerative disorder that produces a bias toward risky, reward-driven decisions in situations where the outcomes of decisions are uncertain and must be discovered. However, it is unclear whether HD patients show similar biases in decision-making when learning demands are minimized and prospective risks and outcomes are known explicitly. We investigated how risk decision-making strategies and adjustments are altered in HD patients when reward contingencies are explicit. Methods: HD (N=18) and healthy control (HC; N=17) participants completed a risk-taking task in which they made a series of independent choices between a low-risk/low reward and high-risk/high reward risk options. Results: Computational modeling showed that compared to HC, who showed a clear preference for low-risk compared to high-risk decisions, the HD group valued high-risks more than low-risk decisions, especially when high-risks were rewarded. The strategy analysis indicated that when high-risk options were rewarded, HC adopted a conservative risk strategy on the next trial by preferring the low-risk option (i.e., they counted their blessings and then played the surer bet). In contrast, following a rewarded high-risk choice, HD patients showed a clear preference for repeating the high-risk choice. Conclusions: These results indicate a pattern of high-risk/high-reward decision bias in HD that persists when outcomes and risks are certain. The allure of high-risk/high-reward decisions in situations of risk certainty and uncertainty expands our insight into the dynamic decision-making deficits that create considerable clinical burden in HD. (JINS, 2016, 22, 426–435)

Executive dysfunction is a common consequence of acquired brain injury (ABI), causing significant disability in daily life. This randomized controlled trial investigated the efficacy of Goal Management TrainingTM (GMT) in improving executive functioning in patients with chronic ABI. Seventy patients with a verified ABI and executive dysfunction were randomly allocated to GMT (n=33) or a psycho-educative active control condition, Brain Health Workshop (BHW) (n=37). In addition, all participants received external cueing by text messages. Neuropsychological tests and self-reported questionnaires of executive functioning were administered pre-intervention, immediately after intervention, and at 6 months follow-up. Assessors were blinded to group allocation. Questionnaire measures indicated significant improvement of everyday executive functioning in the GMT group, with effects lasting at least 6 months post-treatment. Both groups improved on the majority of the applied neuropsychological tests. However, improved performance on tests demanding executive attention was most prominent in the GMT group. The results indicate that GMT combined with external cueing is an effective metacognitive strategy training method, ameliorating executive dysfunction in daily life for patients with chronic ABI. The strongest effects were seen on self-report measures of executive functions 6 months post-treatment, suggesting that strategies learned in GMT were applied and consolidated in everyday life after the end of training. Furthermore, these findings show that executive dysfunction can be improved years after the ABI. (JINS, 2016, 22, 436–452)

Although cognitive decline is typically associated with decreasing practice effects (PEs) (presumably due to declining memory), some studies show increased PEs with declines in cognition. One explanation for these inconsistencies is that PEs reflect not only memory, but also rebounds from adapting to task novelty (i.e., novelty effect), leading to increased PEs. We examined a theoretical model of relationships among novelty effects, memory, cognitive decline, and within-session PEs. Sixty-six older adults ranging from normal to severely impaired completed measures of memory, novelty effects, and two trials each of Wechsler Adult Intelligence Scale, 4thEdition Symbol Search and Coding. Interrelationships among variables were examined using regression analyses. PEs for Symbol Search and Coding (a) were related to different proposed PE components (i.e., memory and novelty effects), such that novelty effect predicted Symbol Search PE (R2=.239, p<.001) and memory predicted Coding PE (R2=.089, p=.015), and (b) showed different patterns across stages of cognitive decline, such that the greatest cognitive decline was associated with smallest Coding PE (R2=.125, p=.004), whereas intermediate cognitive decline was associated with the greatest Symbol Search PE (R2=.097, p=.040). The relationship between cognitive decline and PE for Symbol Search was partially mediated by novelty effect among older adults with abnormal cognitive decline (model R2=.286, p<.001). These findings (a) suggest that PE is not a unitary construct, (b) offer an explanation for contradictory findings in the literature, and (c) highlight the need for a better understanding of component processes of PE across different neuropsychological measures. (JINS, 2016, 22, 453–466)

Objectives: An increasing number of studies have presented evidence that various patient groups with acquired brain injury suffer from navigation problems in daily life. This skill is, however, scarcely addressed in current clinical neuropsychological practice and suitable diagnostic instruments are lacking. Real-world navigation tests are limited by geographical location and associated with practical constraints. It was, therefore, investigated whether virtual navigation might serve as a useful alternative. Methods: To investigate the convergent validity of virtual navigation testing, performance on the Virtual Tübingen test was compared to that on an analogous real-world navigation test in 68 chronic stroke patients. The same eight subtasks, addressing route and survey knowledge aspects, were assessed in both tests. In addition, navigation performance of stroke patients was compared to that of 44 healthy controls. Results: A correlation analysis showed moderate overlap (r=.535) between composite scores of overall real-world and virtual navigation performance in stroke patients. Route knowledge composite scores correlated somewhat stronger (r=.523) than survey knowledge composite scores (r=.442). When comparing group performances, patients obtained lower scores than controls on seven subtasks. Whereas the real-world test was found to be easier than its virtual counterpart, no significant interaction-effects were found between group and environment. Conclusions: Given moderate overlap of the total scores between the two navigation tests, we conclude that virtual testing of navigation ability is a valid alternative to navigation tests that rely on real-world route exposure. (JINS, 2016, 22, 467–477)

Objectives: Patients with Parkinson’s disease often experience significant decline in verbal fluency over time; however, deep brain stimulation of the subthalamic nucleus (STN-DBS) is also associated with post-surgical declines in verbal fluency. The purpose of this study was to determine if Parkinson’s patients who have undergone bilateral STN-DBS have greater impairment in verbal fluency compared to Parkinson’s patients treated by medication only. Methods: A literature search yielded over 140 articles and 10 articles met inclusion criteria. A total of 439 patients with Parkinson’s disease who underwent bilateral STN-DBS and 392 non-surgical patients were included. Cohen’s d, a measure of effect size, was calculated using a random effects model to compare post-treatment verbal fluency in patients with Parkinson’s disease who underwent STN-DBS versus those in the non-surgical comparison group. Results: The random effects model demonstrated a medium effect size for letter fluency (d=−0.47) and a small effect size for category fluency (d=−0.31), indicating individuals with bilateral STN-DBS had significantly worse verbal fluency performance than the non-surgical comparison group. Conclusions: Individuals with Parkinson’s disease who have undergone bilateral STN-DBS experience greater deficits in letter and category verbal fluency compared to a non-surgical group. (JINS, 2016, 22, 478–485)

Objectives: The aim of this study was to explore the relationship between cognitive and white matter deterioration in a group of participants with spinocerebellar ataxia type 2 (SCA2). Methods: Fourteen genetically confirmed participants with SCA2 and 14 aged-matched controls participated in the study. Diffusion tensor imaging tract-based spatial statistics were performed to analyze structural white matter integrity. Significant group differences in the mean diffusivity were correlated with SCA2 cognitive deficits. Results: Our analysis revealed higher mean diffusivity in the SCA2 group in cerebellar white matter, medial lemniscus, and middle cerebellar peduncle, among other regions. Cognitive scores correlated with white matter mean diffusivity in the parahippocampal area, inferior frontal and supramarginal gyri and the stria terminalis. Conclusions: Our findings show significant correlations between white matter microstructural damage in key areas affected in SCA2 and cognitive deficits. These findings result in a more comprehensive understanding of the effect of the neurodegenerative process in people with SCA2. (JINS, 2016, 22, 486–491)