Objectives: Excessive adipose tissue, especially in the abdominal area, is associated with increased risk of dementia in older adults. However, the mechanisms underlying this relationship are poorly understood. As increased adiposity is also associated with lower circulating levels of brain-derived neurotrophic factor (BDNF), a key molecule modulating brain plasticity and neuronal regeneration, we hypothesized that the changes in cognition that occur as a result of excessive abdominal adiposity would be driven by lower levels of circulating BDNF. Methods: Fasting blood samples were obtained from 60 participants aged 40–60 years (mean±SD=52.3±5.6) and BDNF levels were assessed with an enzyme linked immunosorbent assay. Abdominal adiposity was measured using a ratio of waist circumference to hip circumference (WHR). Participants also completed a neuropsychological assessment battery to assess executive function. Statistical mediation was assessed using traditional causal steps and nonparametric bootstrapping. Results: Higher WHR was significantly associated with poorer performance on the Controlled Oral Word Association (COWA) letter fluency test (β=−0.489; p=.003) and lower levels of circulating BDNF (β=−0.345; p=.006). Linear regression and bootstrapping methods indicated that BDNF fully mediated the relationship between WHR and performance on the COWA (β=0.60; 95% confidence interval [−3.79, −0.26]). Conclusions: The relationship between higher WHR and verbal fluency was fully statistically mediated by circulating BDNF levels. The BDNF pathway is thus a useful probable mechanism through which executive function decline occurs in individuals with high abdominal adiposity. BDNF enhancing interventions (physical exercise and dietary restriction) could thus be used to improve executive function in these individuals. (JINS, 2016, 22, 1–8)

Objectives: The cerebellum (CB) is known for its role in supporting processing speed (PS) and cognitive efficiencies. The CB often sustains damage from treatment and resection in pediatric patients with posterior fossa tumors. Limited research suggests that CB atrophy may be associated with the radiation treatment experienced during childhood. The purpose of the study was to measure cerebellar atrophy to determine its neurobehavioral correlates. Methods: Brain magnetic resonance images were collected from 25 adult survivors of CB tumors and age- and gender-matched controls (Mage=24 years (SD=5), 52% female). Average age at diagnosis was 9 years (SD=5) and average time since diagnosis was 15 years (SD=5). PS was measured by the Symbol Digit Modality Test. To quantify atrophy, an objective formula was developed based on prior literature, in which Atrophy=[(CB White+CB Gray Volume)/Intracranial Vault (ICV)]controls-[(CB White+CB Gray+Lesion Size Volume)/ICV]survivors. Results: Regression analyses found that the interaction term (age at diagnosis*radiation) predicts CB atrophy; regression equations included the Neurological Predictor Scale, lesion size, atrophy, and the interaction term and accounted for 33% of the variance in oral PS and 48% of the variance in written PS. Both interactions suggest that individuals with smaller CB lesion size but a greater degree of CB atrophy had slower PS, whereas individuals with a larger CB lesion size and less CB atrophy were less affected. Conclusion: The results of the current study suggest that young age at diagnosis and radiation is associated with CB atrophy, which interacts with lesion size to impact both written and oral PS. (JINS, 2016, 23, 1–11)

Objectives: Following pediatric moderate-to-severe traumatic brain injury (msTBI), few predictors have been identified that can reliably identify which individuals are at risk for long-term cognitive difficulties. This study sought to determine the relative contribution of detailed descriptors of injury severity as well as demographic and psychosocial factors to long-term cognitive outcomes after pediatric msTBI. Methods: Participants included 8- to 19-year-olds, 46 with msTBI and 53 uninjured healthy controls (HC). Assessments were conducted in the post-acute and chronic stages of recovery. Medical record review provided details regarding acute injury severity. Parents also completed a measure of premorbid functioning and behavioral problems. The outcome of interest was four neurocognitive measures sensitive to msTBI combined to create an index of cognitive performance. Results: Results indicated that none of the detailed descriptors of acute injury severity predicted cognitive performance. Only the occurrence of injury, parental education, and premorbid academic competence predicted post-acute cognitive functioning. Long-term cognitive outcomes were best predicted by post-acute cognitive functioning. Discussion: The findings suggest that premorbid factors influence cognitive outcomes nearly as much as the occurrence of a msTBI. Furthermore, of youth with msTBI who initially recover to a level of moderate disability or better, a brief cognitive battery administered within several months after injury can best predict which individuals will experience poor long-term cognitive outcomes and require additional services. (JINS, 2016, 22, 1–8)

Objectives: This study aims to compare verbal and motor implicit sequence learning abilities in children with and without specific language impairment (SLI). Methods: Forty-eight children (24 control and 24 SLI) were administered the Serial Search Task (SST), which enables the simultaneous assessment of implicit spoken words and visuomotor sequences learning. Results: Results showed that control children implicitly learned both the spoken words as well as the motor sequences. In contrast, children with SLI showed deficits in both types of learning. Moreover, correlational analyses revealed that SST performance was linked with grammatical abilities in control children but with lexical abilities in children with SLI. Conclusions: Overall, this pattern of results supports the procedural deficit hypothesis and suggests that domain general implicit sequence learning is impaired in SLI. (JINS, 2016, 22, 1–10)

Objectives: Chemotherapy has adverse effects on cognitive performance in women treated for breast cancer, but less is known about the period before chemotherapy. Studies have focused on mean level of performance, yet there is increasing recognition that variability in performance within an individual is also an important behavioral indicator of cognitive functioning and underlying neural integrity. Methods: We examined intraindividual variability (IIV) before chemotherapy and surgery in women diagnosed with breast cancer (n=31), and a healthy control group matched on age and education (n=25). IIV was calculated across trials of a computerized Stroop task, including an examination of the slowest and fastest trials of reaction time (RT) responses. Results: The groups were equivalent on overall accuracy and speed, and participants in both groups were less accurate and slower on incongruent trials compared with congruent trials. However, women with breast cancer became more variable with increased task difficulty relative to healthy controls. Among the slowest RT responses, women with breast cancer were significantly more variable than healthy controls on incongruent trials. This suggests that a specific variability-producing process (e.g., attentional lapses) occurs in task conditions that require executive control (e.g., incongruent trials). Conclusions: Results are consistent with other evidence of executive dysfunction among women treated for breast cancer. These findings highlight the importance of pretreatment assessment and show that variability in performance provides information about cognition that measures of central tendency do not. (JINS, 2016, 23, 1–10)

Objectives: Parkinson’s disease (PD) is associated with deficits in social cognition and visual perception, but little is known about how the disease affects perception of socially complex biological motion, specifically motion-defined communicative and non-communicative gestures. We predicted that individuals with PD would perform more poorly than normal control (NC) participants in discriminating between communicative and non-communicative gestures, and in describing communicative gestures. We related the results to the participants’ gender, as there are gender differences in social cognition in PD. Methods: The study included 23 individuals with PD (10 men) and 24 NC participants (10 men) matched for age and education level. Participants viewed point-light human figures that conveyed communicative and non-communicative gestures and were asked to describe each gesture while discriminating between the two gesture types. Results: PD as a group were less accurate than NC in describing non-communicative but not communicative gestures. Men with PD were impaired in describing and discriminating between communicative as well as non-communicative gestures. Conclusions: The present study demonstrated PD-related impairments in perceiving and inferring the meaning of biological motion gestures. Men with PD may have particular difficulty in understanding the communicative gestures of others in interpersonal exchanges. (JINS, 2016, 22, 1–11)

Objectives: Executive dysfunction is associated with impaired memory performance, but controversies remain about which aspects of memory are involved and how general intelligence influences these connections. We aimed to clarify these connections in stroke patients by comparing various memory measures in patients with and without executive impairment. Methods: Our consecutive cohort included patients with a first-ever ischemic stroke. Neuropsychological assessments were completed 6 months and 2 years after stroke. We classified patients as executively impaired, when at least two of five executive measures were defective at 6 months. At both 6 months and 2 years, we compared list learning of unrelated words, story recall, and recall of geometric figures in patients with and without executive impairment, while controlling for general intelligence. Results: Patients with executive impairment (n=66; 37%) performed worse in list learning (p=.001; partial η2=.058) and immediate recall of a logical passage (p=.010; partial η2=.037) 6 months after stroke compared to executively intact patients (n=113). At the end of the 2-year follow-up period, the patients who were executively impaired at 6 months (n=53; 37%) still performed worse than executively intact patients (n=92) in list learning (p<.001; partial η2=.096), and additionally in delayed recall of the list (p=.006; partial η2=.052) and immediate recall of geometric figures (p=.007; partial η2=.050). Conclusions: In our working-aged stroke patients, executive impairment was common. Executive impairment was associated with memory tasks that provided less inherent structure and required the use of active memory strategies. Clinicians should remember this role of executive dysfunction when interpreting memory performance. (JINS, 2016, 22, 1–10)

Objectives: In addition to neuropsychological difficulties, patients with cerebral small vessel disease (SVD) can have reduced activities of daily living and a poorer quality of life compared to healthy adults. The Brief Memory and Executive Test (BMET), is a cognitive screening tool designed to be sensitive to the neuropsychological profile of patients with SVD. While the BMET is sensitive to the cognitive consequences of SVD, it is unclear how well scores on this measure relate to functional outcomes. The aims of this study are to investigate the relationship between scores on the BMET and functional outcomes (activities of daily living and quality of life) in SVD, and to compare this with other commonly used cognitive screening tools. Methods: This study included 184 participants with SVD (mean age=63.2; SD=9.9) and 299 healthy controls (mean age=62.4; SD=13.8) who were tested using the BMET, Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Stroke Specific - Quality of Life Scale (SS-QoL), Geriatric Depression Scale (GDS), and measures of both instrumental activities of daily living (IADL) and basic activities of daily living (BADL). Results: After controlling for covariates the scores on the BMET, but not the MoCA or MMSE, were significantly related to poorer IADL and quality of life in the SVD group. In addition to the BMET scores, symptoms of depression were found to be significant associated with functional outcome. Conclusion: These results support the clinical utility of using of the BMET, in combination with a standardized depression questionnaire, during the early assessment of patients with SVD. (JINS, 2016, 22, 1–9)

Objectives: It is widely believed that phonemic fluency is more difficult than naming exemplars from a semantic category. Normative data in this regard are scarce, and there is considerable disagreement in the literature regarding the pattern in normal ageing and neurodegenerative conditions. Our objective was to provide normative data for semantic phonemic discrepancy scores from a large sample of older adults. Methods: A total of 5780 community-dwelling older adults were included in this prospective, longitudinal study. Discrepancy scores were calculated by subtracting phonemic fluency score from semantic fluency score for each participant. Quantile regression was used to estimate normative values stratified for age. Results: Subjects did better on testing of semantic fluency. The average discrepancy score was 9.18±6.89 words, (range, −20 to 37; n=5780). At the fiftieth percentile, those in their fifth decade produced 10 more “animals” than “letter F” words. Subjects scored one word less per decade, with an average of seven more “animal” words produced by those in their eighth decade. Conclusions: Our study is the first to provide normative data and confirms that, for animal versus letter F fluency, the semantic advantage persists into later life in a population-based sample of community-dwelling older adults. Given that a majority of clinical samples have confirmed a reverse of this pattern in Alzheimer’s dementia (i.e., loss of semantic advantage in Alzheimer’s disease, yielding a phonemic advantage), our findings support the clinical utility of brief fluency tests and encourage further research into their use in diagnosis and prediction of progression to dementia. (JINS, 2016, 22, 1–7)

Objectives: This research retrospectively analyzed the effect of education on cognitive interventions carried out in patients with mild Alzheimer’s disease (AD). Methods: The total sample consisted of 75 patients with mild AD receiving treatment with cholinesterase inhibitors. The participants were divided into two groups: cognitive intervention (IG; n=45) and waiting list (WLG; n=30). Patients in the IG received either the Big Brain Academy (n=15) or the Integrated Psychostimulation Program (n=30) during 12 weeks. The influence of education on intervention effect was analyzed comparing mean change scores of the two study groups in the cognitive subscale of the Alzheimer’s Disease Assessment Scale (ADAS-cog), stratified by educational level. The potential effect of age, sex, cognitive status, and type of intervention was examined using post hoc stratification analyses. Results: Higher education was associated with faster cognitive decline in the WLG (effect size=0.51; p<.01). However, cognitive evolution was not influenced by education in the IG (effect size=0.12; p=.42). Conclusions: Our results suggest that cognitive intervention might delay accelerated cognitive decline in higher educated individuals with mild AD. (JINS, 2016, 23, 1–6)