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1.  An updated version of the Weigl discriminates adults with dementia from those with mild impairment and healthy controls☆ 
Dementia screening batteries often fall short on measures of executive functioning. The Weigl Color Form Sorting Test (WCFST) is a candidate for inclusion in such batteries, but can be insensitive to mild disturbance. The WCFST consists of 12 colored geometric shapes and requires the patient to sort the pieces by color or form, and then shift to the other sorting principle unassisted. We created a modified version of the WCFST (the Weigl-R) with increased conceptual complexity by adding two stimulus dimensions (texture and central shapes). The range of scores was also increased by adding the extent of examiner assistance required to achieve a correct sort, ability to verbalize conceptual strategy, and number of perseverations. We administered the Weigl-R to a group of 30 patients with mixed dementias, 34 adults with cognitive impairment without dementia, and 21 healthy controls. The new measure discriminated well between healthy controls and older adults with either cognitive impairment without dementia, or dementia. The Weigl-R may be a useful adjunct to brief dementia batteries but requires further validation.
PMCID: PMC2760247  PMID: 18093797
Dementia; Executive functioning; Neuropsychology; Conceptual reasoning
2.  Robust norms for selected neuropsychological tests in older adults 
The current study provided longitudinal robust norms for individuals age 70 years and older for several neuropsychological tests. We compared baseline neuropsychological test performance in three groups free of dementia at baseline: a robust normative sample free of dementia for at least two post-follow-up assessments, an incident dementia sample which developed new onset dementia during the follow-up and a Lost to Follow-up (LTF) sample. ANCOVAs showed that the robust sample performed better on all neuropsychological tests compared to the incident dementia and LTF samples. These findings support the argument that individuals in transition to developing dementia may reduce the mean, increase the variability and therefore underestimate cognitive performance in normal aging. We suggest that longitudinal robust norms may help mitigate the limitations inherent in cross-sectional normative samples.
PMCID: PMC2610426  PMID: 18572380
Aging; Norms; Dementia; Attrition
3.  Modified-Symbol Digit Modalities Test for African Americans, Caribbean Black Americans and Non-Latino Whites: Nationally Representative Normative Data from the National Survey of American Life 
Normative neuropsychological data for U.S. racial/ethnic minorities is limited. Extant norms are based on small, regional groups that may not be nationally representative. The objectives of this study were to 1) provide norms for a modified Symbol Digit Modalities Test (M-SDMT) based on a nationally representative sample of African Americans, Caribbean Blacks and non-Latino Whites (NLW) living in areas with large populations of Blacks, and 2) determine significant correlates of M-SDMT performance. The M-SDMT was administered to a subset of respondents from the National Survey of American Life in standard, face-to-face interviews. M-SDMT performance was influenced by race/ethnicity, age, education, and gender. African Americans and NLW groups had similar M-SDMT performances, which differed from Caribbean Blacks. The Black ethnic differences in M-SDMT were not explained by the sociodemographic factors considered in this study. Unlike previous work, this study supports the consideration of Black ethnicity when evaluating Black neuropsychological test performance.
PMCID: PMC2121620  PMID: 17493782
African Americans; Caribbean Blacks; Blacks; Neuropsychological Tests
4.  Psychometric Characteristics of the Postconcussion Symptom Inventory in Children and Adolescents 
Psychometric characteristics of the Postconcussion Symptom Inventory (PCSI) were examined in both concussed (n = 633) and uninjured (n = 1,273) 5 to 18 year olds. Parent- and self-report forms were created with developmentally appropriate wording and content. Factor analyses identified physical, cognitive, emotional, and sleep factors; that did not load strongly or discriminate between groups were eliminated. Internal consistency was strong for the total scales (α = 0.8–0.9). Test–retest reliability for the self-report forms was moderate to strong (intraclass coeffecients, ICCs = 0.65–0.89). Parent and self-report concordance was moderate (r = .44–.65), underscoring the importance of both perspectives. Convergent validity with another symptom measure was good (r = .8). Classification analyses indicated greater discriminability from parent report, but caveats to this are presented. With strong psychometric characteristics, the four versions of the PCSI capture important postconcussion symptoms and can be utilized to track recovery from pediatric concussion and guide treatment recommendations.
PMCID: PMC4030704  PMID: 24739735
Traumatic brain injury; Brain concussion; Symptom checklists
5.  RBANS Memory Indices Are Related to Medial Temporal Lobe Volumetrics in Healthy Older Adults and Those with Mild Cognitive Impairment 
The current study (i) determined whether NeuroQuant® volumetrics are reflective of differences in medial temporal lobe (MTL) volumes between healthy older adults and those with mild cognitive impairment (MCI) and (ii) examined the relationship between RBANS indices and MTL volumes. Forty-three healthy older adults and 57 MCI patients completed the RBANS and underwent structural MRI. Hippocampal and inferior lateral ventricle (ILV) volumes were obtained using NeuroQuant®. Results revealed significantly smaller hippocampal and larger ILV volumes in MCI patients. MTL volumes were significantly related to the RBANS Immediate and Delayed Memory and Language indices but not the Attention or Visuoconstruction indices; findings that demonstrate anatomical specificity. Following discriminant function analysis, we calculated a cutpoint that may prove clinically useful for integrating MTL volumes into the diagnosis of MCI. These findings demonstrate the potential clinical utility of NeuroQuant® and are the first to document the relationship between RBANS indices and MTL volumes.
PMCID: PMC4081621  PMID: 24709384
Aging; Alzheimer's disease; Atrophy; Dementia; Hippocampus; Inferior lateral ventricles
6.  Frontal White Matter Damage Impairs Response Inhibition in Children Following Traumatic Brain Injury 
Inhibition, the ability to suppress inappropriate cognitions or behaviors, can be measured using computer tasks and questionnaires. Inhibition depends on the frontal cortex, but the role of the underlying white matter (WM) is unclear. We assessed the specific impact of frontal WM damage on inhibition in 29 children with moderate-to-severe traumatic brain injury (15 with and 14 without frontal WM damage), 21 children with orthopedic injury, and 29 population controls. We used the Stop Signal Task to measure response inhibition, the Behavior Rating Inventory of Executive Function to assess everyday inhibition, and T2 fluid-attenuated inversion recovery magnetic resonance imaging to identify lesions. Children with frontal WM damage had impaired response inhibition compared with all other groups and poorer everyday inhibition than the orthopedic injury group. Frontal WM lesions most often affected the superior frontal gyrus. These results provide evidence for the critical role of frontal WM in inhibition.
PMCID: PMC4000231  PMID: 24618405
Traumatic brain injury; Response inhibition; Impulsiveness; Brain lesions; White matter; Frontal lobe
7.  Shallow Encoding and Forgetting Are Associated with Dependence in Instrumental Activities of Daily Living Among Older Adults Living with HIV Infection 
Aging and HIV are both risk factors for memory deficits and declines in real-world functioning. However, we know little about the profile of memory deficits driving instrumental activities of daily living (IADL) declines across the lifespan in HIV. This study examined 145 younger (<50 years) and 119 older (≥50 years) adults with HIV who completed the California Verbal Learning Test-Second Edition (CVLT-II), the Wechsler Memory Scale-Third Edition Logical Memory subtest (WMS-III LM), and a modified Lawton and Brody ADL questionnaire. No memory predictors of IADL dependence emerged in the younger cohort. In the older group, IADL dependence was uniquely associated with worse performance on all primary CVLT-II variables, as well as elevated recency effects. Poorer immediate and delayed recall of the WMS-III LM was also associated with IADL dependence, although recognition was intact. Findings suggest older HIV-infected adults with shallow encoding and forgetting are at risk for IADL dependence.
PMCID: PMC4000232  PMID: 24695591
Aging; Disability; Everyday functioning; Learning and memory
8.  Analysis of Verbal Fluency Ability in Alzheimer's Disease: The Role of Clustering, Switching and Semantic Proximities 
The underlying nature of verbal fluency deficits in Alzheimer's disease (AD) was investigated in this study. Participants were 48 individuals with AD and 48 cognitively healthy older adults. Fluency performance on letter and category tasks was analyzed across two 30-s intervals for total words produced, mean cluster size, and total switches. Compared with the control group, AD participants produced fewer words and switches on both fluency tasks and had a reduced category cluster size. The AD group was differentially impaired on category compared with letter fluency and produced more repetitive responses but fewer category exemplars than controls on the category task. A multidimensional scaling approach revealed that AD participants' semantic maps were similar to controls. Overall, the data suggest that executive abilities involving search and retrieval processes and a reduced availability of semantically related words contributed to the AD group's poorer performance despite similar temporal recall and organizational patterns.
PMCID: PMC4055831  PMID: 24687588
Alzheimer's disease; Fluency; Language and language disorders; Executive functioning
9.  The Impact of Mild Traumatic Brain Injury on Cognitive Functioning Following Co-occurring Spinal Cord Injury 
Meta-analytic studies have shown that mild traumatic brain injury (MTBI) has relatively negligible effects on cognitive functioning at 90 or more days post-injury. Few studies have prospectively examined the effects of MTBI in acute physical trauma populations. This prospective, cohort study compared the cognitive performance of persons who sustained a spinal cord injury (SCI) and a co-occurring MTBI (N = 53) to persons who sustained an SCI alone (N = 64) between 26 and 76 days (mean = 46) post-injury. The presence of MTBI was determined based on acute medical record review using a standardized algorithm. Primary outcome measures were seven neuropsychological tests that evaluated visual, verbal, and working memory, perceptual reasoning, and processing speed that controlled for potential upper extremity impairment. Persons who sustained SCI with or without MTBI had lower than expected performance across all neuropsychological tests, on average about 1 SD below the mean. Analysis of covariance indicated that persons with MTBI did not evidence greater impairment on any neuropsychological test. The aggregated effect size (Cohen's d) was −0.16. The strongest predictors of neuropsychological test scores were education, race, history of learning problems, and days from injury to rehabilitation admission. MTBI did not predict performance on any neuropsychological test. These findings are consistent with other controlled studies that indicate a single MTBI has negligible long-term impacts on cognition.
PMCID: PMC3895971  PMID: 24055885
Assessment; Forensic neuropsychology; Rehabilitation
10.  Blood Pressure and Cognition Among Older Adults: A Meta-Analysis 
Hypertension has adverse effects on cognition, can alter cerebral vasculature integrity, and is associated with the pathogenesis of dementia. Using meta-analysis, we correlated blood pressure to multiple cognitive domains among older adults free of clinical stroke and dementia. We identified 230 studies indexed in PubMed and PsycINFO relating blood pressure and cognition. After applying exclusion criteria, we selected n = 12 articles with n = 4,076 participants (age range 43–91 years). Meta-analysis yielded an association between blood pressure and episodic memory (r = −.18, p < .001) and between blood pressure and global cognition (r = −.07, p < .001). When limiting analyses to studies adjusting for vascular covariates (n = 8, n = 2,141), blood pressure was modestly related to global cognition (r = −.11, p < .001), attention (r = .14, p = .002), and episodic memory (r = −.20, p < .001) with a trend for language (r = −.22, p = .07). Findings underscore the need to manage blood pressure as a key prevention method in minimizing abnormal cognitive aging prior to the onset of clinical dementia.
PMCID: PMC3807830  PMID: 23838685
Cardiovascular disease; Dementia; Learning and episodic memory; Executive functioning; Meta analysis
11.  Amyloid Deposition and Cognition in Older Adults: The Effects of Premorbid Intellect 
Although amyloid deposition remains a marker of the development of Alzheimer's disease, results linking amyloid and cognition have been equivocal. Twenty-five community-dwelling non-demented older adults were examined with 18F-flutemetamol, an amyloid imaging agent, and a cognitive battery, including an estimate of premorbid intellect and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the first model, 18F-flutemetamol uptake significantly correlated with the Delayed Memory Index of the RBANS (r = −.51, p = .02) and premorbid intellect (r = .43, p = .03). In the second model, the relationship between 18F-flutemetamol and cognition was notably stronger when controlling for premorbid intellect (e.g., three of the five RBANS Indexes and its Total score significantly correlated with 18F-flutemetamol, r's = −.41 to −.58). Associations were found between amyloid-binding 18F-flutemetamol and cognitive functioning in non-demented older adults. These associations were greatest with delayed memory and stronger when premorbid intellect was considered, suggesting that cognitive reserve partly compensates for the symptomatic expression of amyloid pathology in community-dwelling elderly.
PMCID: PMC3807831  PMID: 23817438
Amyloid; Neuroimaging; Neuropsychology; Alzheimer's disease; Premorbid intellect
12.  Performance Lapses in Children with Attention-Deficit/Hyperactivity Disorder Contribute to Poor Reading Fluency 
Children with Attention-Deficit/Hyperactivity Disorder (ADHD) demonstrate increased response variability compared with controls, which is thought to be associated with deficits in attention regulation and response control that subsequently affect performance of more cognitively demanding tasks, such as reading. The present study examined response variability during a computerized simple reaction time (RT) task in 67 children. Ex-Gaussian analyses separated the response time distribution into normal (mu and sigma) and exponential (tau) components; the association of each with reading fluency was examined. Children with ADHD had significantly slower, more variable, and more skewed RTs compared with controls. After controlling for ADHD symptom severity, tau (but not mu or mean RT) was significantly associated with reduced reading fluency, but not with single word reading accuracy. These data support the growing evidence that RT variability, but not simply slower mean response speed, is the characteristic of youth with ADHD and that longer response time latencies (tau) may be implicated in the poorer academic performance associated with ADHD.
PMCID: PMC3807832  PMID: 23838684
Attention; Dyslexia; Variability; Processing speed; Executive function; Ex-Gaussian analyses
13.  Analysis of Verbal Fluency Ability in Amnestic and Non-Amnestic Mild Cognitive Impairment 
The purpose of this study was to investigate the pattern of performance on letter and category fluency tests of individuals with mild cognitive impairment (MCI). Previous research has suggested that organization strategies, including “clustering” (i.e., groups of related words) and “switching” (i.e., shift from one cluster to another), are important for efficient verbal fluency performance. Participants were 25 individuals with single-domain amnestic MCI (aMCI), 49 with multidomain aMCI, 16 with non-amnestic MCI (naMCI), and 90 cognitively healthy older adults. Fluency performances were analyzed across two 30-s intervals for total words produced, cluster size, and switching. Analyses of variance (ANOVAs) with follow-up tests revealed that the single-domain aMCI group performed comparably with healthy controls on each dependent measure across both fluency tasks. In contrast, the multidomain aMCI group showed performance decrements in total words and switching production compared with healthy controls on both fluency tasks, whereas the naMCI group produced fewer words and switches on letter fluency. Each group generated more words and switches during the first 30-s on both fluency tasks, with the exception of the naMCI group, whose switching on letter fluency did not decrease as the task progressed. As indicated by the single-domain aMCI group's unimpaired performance, our findings demonstrate that verbal fluency performance decreases as domains beyond memory become impaired in MCI. Reduced switching ability, which has been linked to prefrontal executive functioning, contributed the most to the poorer performance of individuals with multidomain MCI and naMCI.
PMCID: PMC3888195  PMID: 23917346
Mild cognitive impairment; Fluency; Language and language disorders; Executive functioning
14.  Education Quality, Reading Recognition, and Racial Differences in the Neuropsychological Outcome from Traumatic Brain Injury 
Ethnically diverse examinees tend to perform lower on neuropsychological tests. The practice of adjusting normative comparisons for the education level and/or race to prevent overpathologizing low scores is problematic. Education quality, as measured by reading recognition, appears to be a more accurate benchmark for premorbid functioning in certain populations. The present study aimed to extend this line of research to traumatic brain injury (TBI). We hypothesized that a measure of reading recognition, the Wechsler Test of Adult Reading (WTAR), would account for racial differences in neuropsychological performance after TBI. Fifty participants (72% African American, 28% Caucasian) with moderate to severe TBI underwent neuropsychological testing at 1-year post-injury. Reading recognition accounted for all the same variance in neuropsychological performance as race and education (together), as well as considerable additional variance. Estimation of premorbid functioning in African Americans with TBI could be refined by considering reading recognition.
PMCID: PMC3858031  PMID: 23858087
traumatic brain injury; premorbid functioning; racial differences; neuropsychological testing; psychometrics
15.  Depressive Symptoms and Concussions in Aging Retired NFL Players 
We examined the relationship between a remote history of concussions with current symptoms of depression in retired professional athletes. Thirty retired National Football League (NFL) athletes with a history of concussion and 29 age- and IQ-matched controls without a history of concussion were recruited. We found a significant correlation between the number of lifetime concussions and depressive symptom severity using the Beck Depression Inventory II. Upon investigating a three-factor model of depressive symptoms (affective, cognitive, and somatic; Buckley et al., 2001) from the BDI-II, the cognitive factor was the only factor that was significantly related to concussions. In general, NFL players endorsed more symptoms of depression on all three Buckley factors compared with matched controls. Findings suggest that the number of self-reported concussions may be related to later depressive symptomology (particularly cognitive symptoms of depression).
PMCID: PMC4007104  PMID: 23644673
Concussion; Depression; Cognition; Aging; Football; NFL
16.  Similar Verbal Fluency Patterns in Amnestic Mild Cognitive Impairment and Alzheimer's Disease 
Disproportionately greater deficits in semantic relative to phonemic verbal fluency are seen in Alzheimer's disease (AD) and have been attributed to neurodegenerative changes in the temporal lobe. Amnestic (AMN) mild cognitive impairment (MCI), which often represents incipient AD, is also characterized by early temporal lobe neuropathology, but previous comparisons of verbal fluency between AD and AMN MCI have yielded mixed results. We examined semantic and phonemic verbal fluency performance in 399 individuals (78 AD, 138 AMN MCI, 72 non-amnestic MCI, and 111 cognitively normal controls). Similar verbal fluency patterns were seen in AMN MCI and AD; both groups exhibited disproportionately poorer performance on semantic verbal fluency relative to normal controls. However, relative verbal fluency indices performed more poorly than individual semantic or phonemic verbal fluency indices for discriminating AMN MCI or AD participants from normal controls, suggesting that they are unlikely to provide additional utility for predicting progression from MCI to AD.
PMCID: PMC3711375  PMID: 23752677
Mild cognitive impairment; Alzheimer's disease; Verbal fluency; Dementia; Assessment; Cognition
17.  Confirmatory Factor Analysis of the Behavior Rating Inventory of Executive Function-Adult Version in Healthy Adults and Application to Attention-Deficit/Hyperactivity Disorder 
The Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) is a questionnaire measure designed to assess executive functioning in everyday life. Analysis of data from the BRIEF-A standardization sample yielded a two-factor solution (labeled Behavioral Regulation and Metacognition). The present investigation employed confirmatory factor analysis (CFA) to evaluate four alternative models of the factor structure of the BRIEF-A self-report form in a sample of 524 healthy young adults. Results indicated that a three-factor model best fits the data: a Metacognition factor, a Behavioral Regulation factor consisting of the Inhibit and Self-Monitor scales, and an Emotional Regulation factor composed of the Emotional Control and Shift scales. The three factors contributed 14%, 19%, and 24% of unique variance to the model, respectively, and a second-order general factor accounted for 41% of variance overall. This three-factor solution is consistent with recent CFAs of the Parent report form of the BRIEF. Furthermore, although the Behavioral Regulation factor score in the two-factor model did not differ between adults with attention-deficit/hyperactivity disorder and a matched healthy comparison group, greater impairment on the Behavioral Regulation factor but not the Emotional Regulation factor was found using the three-factor model. Together, these findings support the multidimensional nature of executive function and the clinical relevance of a three-factor model of the BRIEF-A.
PMCID: PMC3711374  PMID: 23676185
Executive function; Factor analysis; Psychometrics; Self-regulation; Neuropsychology; ADHD
18.  Predictors of Neuropsychological Change in Patients with Chronic Myelogenous Leukemia and Myelodysplastic Syndrome 
This study examined the course of neuropsychological functioning in patients with chronic myelogeous leukemia (n = 91) or myelodysplastic syndrome (n = 15) who underwent standard treatment for their disease or allogeneic hematopoietic stem cell transplantation (HSCT) at baseline, 12 months, and 18 months post-treatment. At baseline, 23% of the participants (n = 75) in the longitudinal sample had Z-scores on at least one of the neuropsychological tests that were <1.4. Participants in the study showed improvement over baseline at the 12 and 18 months assessments. The average Z-scores for the six cognitive domains in the longitudinal data set over the course of the study ranged from −0.89 to 0.59. Significant predictors of change in neuropsychological test scores included age, with older participants showing less improvement over time. Other predictors included baseline cognitive domains (language, memory, and attention), previous cocaine use, disease status, intelligence quotient, and quality of life measures. Findings support previous studies in patients with hematological malignancies who showed cognitive impairments at baseline prior to HSCT. However, there was little evidence for further cognitive decline over the course of 18 months.
PMCID: PMC3656510  PMID: 23391504
Cancer; Neuropsychology; Hematological malignancy; Cognition; Cancer treatment; Hematopoietic stem cell transplantation
19.  The Influence of Semantic Processing on Odor Identification Ability in Schizophrenia 
Despite the well-documented observation of odor identification deficits in schizophrenia, less is known about where the disruption in the process of correctly identifying an odor occurs. This study aimed to determine the potential moderating effects of semantic processing on the observed olfactory dysfunction in schizophrenia. Schizophrenia patients and healthy comparison subjects completed two versions of the University of Pennsylvania Smell Identification Test (UPSIT): an uncued free-response version and the standard multiple-choice paradigm, as well as three semantic measures: The Boston Naming Test, Animal Naming, and Pyramids and Palm Tree Test. Schizophrenia patients yielded significantly lower scores than the comparison group on the standard UPSIT and on semantic measures. No relationship was observed between olfactory and semantic task performance in patients. These data suggest that odor identification deficits may not be primarily due to semantic processing deficits in schizophrenia.
PMCID: PMC3631780  PMID: 23537559
Schizophrenia; Semantic processing; Olfactory; Olfaction; Smell; Boston naming test
20.  Executive Dysfunction Is the Primary Cognitive Impairment in Progressive Supranuclear Palsy 
Cognitive difficulties appear to be a more prevalent clinical feature in progressive supranuclear palsy (PSP) than previously thought, and significant cognitive impairment is prevalent in a majority of patients PSP patients not considered clinically demented. The neurocognitive performance of 200 patients with PSP across multiple sites was examined with a variety of commonly used neuropsychological tests. Results indicate primary executive dysfunction (e.g., 74% impaired on the Frontal Assessment Battery, 55% impaired on Initiation/Perseveration subscale of the Dementia Rating Scale), with milder difficulties in memory, construction, and naming. These results have important clinical implications for providers following patients with PSP.
PMCID: PMC3569947  PMID: 23127882
Progressive supranuclear palsy; Frontal-executive; Parkinsonism; Dementia; Memory
21.  Neuropsychological Patterns Differ by Type of Left Ventricle Dysfunction in Heart Failure 
Cognitive impairment is common among individuals with heart failure. The purpose of this study was to compare cognitive profiles of individuals with systolic and diastolic dysfunction. Eighty individuals with heart failure completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Mini-Mental State Examination, Trail Making Test, and letter fluency. Approximately 25% of individuals with systolic dysfunction were impaired on the RBANS Total Scale score, compared with only 3% in the diastolic group. Additionally, individuals with systolic dysfunction scored lower than those with diastolic dysfunction on tests of immediate and delayed memory. The groups did not differ on tests of visuospatial skills, but there were mixed results on the RBANS Attention and Language subtests. Overall, the results of this study suggest that individuals with different types of cardiac dysfunction (systolic and diastolic dysfunction) demonstrate differential patterns of performance on neuropsychological tests. These findings have important clinical implications.
PMCID: PMC3569948  PMID: 23257366
Cardiovascular disease; Executive function; Learning and memory; Mild cognitive impairment; Assessment
22.  Executive Functioning as a Mediator of the Relationship Between Premorbid Verbal Intelligence and Health Risk Behaviors in a Rural-Dwelling Cohort: A Project FRONTIER Study 
Limited research is available regarding the impact of neuropsychological functioning on health risk behaviors in rural-dwelling elderly populations. This cross-sectional study examined the relationships between estimated premorbid verbal IQ (AMNART), executive functioning impairment (EXIT25), and health risk behaviors including alcohol use (AUDIT), smoking, compliance with recommended cancer screenings, and obesity (BMI). The total sample included 456 English-speaking adults and older adults of non-Hispanic White and Hispanic origin seen as part of an ongoing study of rural cognitive aging, Project FRONTIER. Regression analyses revealed significant independent effects of AMNART and EXIT25 on most health risk behaviors, and supported the hypothesized mediating role of EXIT25 on the relationships between AMNART and smoking, cancer screenings, and BMI in both cognitively impaired and healthy subgroups. This study clarifies the relationships between executive functioning, premorbid IQ, and health risk behaviors in diverse groups, and confirms that premorbid IQ represents an important determinant of health behaviors and neurocognitive outcomes.
PMCID: PMC3569949  PMID: 23192834
Executive functioning; Diversity; Cognition; Health risk behaviors; Premorbid verbal IQ; geriatrics
23.  Measuring Executive Dysfunction Longitudinally and in Relation to Genetic Burden, Brain Volumetrics, and Depression in Prodromal Huntington Disease 
Executive dysfunction (ED) is a characteristic of Huntington disease (HD), but its severity and progression is less understood in the prodromal phase, e.g., before gross motor abnormalities. We examined planning and problem-solving abilities using the Towers Task in HD mutation-positive individuals without motor symptoms (n = 781) and controls (n = 212). Participants with greater disease progression (determined using mutation size and current age) performed more slowly and with less accuracy on the Towers Task. Performance accuracy was negatively related to striatal volume while both accuracy and working memory were negatively related to frontal white matter volume. Disease progression at baseline was not associated with longitudinal performance over 4 years. Whereas the baseline findings indicate that ED becomes more prevalent with greater disease progression in prodromal HD and can be quantified using the Towers task, the absence of notable longitudinal findings indicates that the Towers Task exhibits limited sensitivity to cognitive decline in this population.
PMCID: PMC3569950  PMID: 23246934
Huntington's disease; Genetic disorders; Executive functions; Neuroimaging (structural); Norms/normative studies; Practice effects/reliable change; longitudinal change
24.  Global Processing Training to Improve Visuospatial Memory Deficits after Right-Brain Stroke 
Visuospatial stimuli are normally perceived from the global structure to local details. A right-brain stroke often disrupts this perceptual organization, resulting in piecemeal encoding and thus poor visuospatial memory. Using a randomized controlled design, the present study examined whether promoting the global-to-local encoding improves retrieval accuracy in right-brain-damaged stroke survivors with visuospatial memory deficits. Eleven participants received a single session of the Global Processing Training (global-to-local encoding) or the Rote Repetition Training (no encoding strategy) to learn the Rey–Osterrieth Complex Figure. The result demonstrated that the Global Processing Training significantly improved visuospatial memory deficits after a right-brain stroke. On the other hand, rote practice without a step-by-step guidance limited the degree of memory improvement. The treatment effect was observed both immediately after the training procedure and 24 h post-training. Overall, the present findings are consistent with the long-standing principle in cognitive rehabilitation that an effective treatment is based on specific training aimed at improving specific neurocognitive deficits. Importantly, visuospatial memory deficits after a right-brain stroke may improve with treatments that promote global processing at encoding.
PMCID: PMC3589919  PMID: 23070314
Stroke rehabilitation; Visuospatial disorder; Cognitive rehabilitation; Memory rehabilitation; Complex figure; Learning and memory
25.  Evidence of Change in Brain Activity among Childhood Cancer Survivors Participating in a Cognitive Remediation Program 
Increased understanding of the underlying mechanisms of cognitive remediation is needed to facilitate development of intervention strategies for childhood cancer survivors experiencing cognitive late effects. Accordingly, a pilot functional magnetic resonance imaging (fMRI) study was conducted with 14 cancer survivors (12.02 ± 0.09 years old), who participated in a cognitive remediation clinical trial, and 28 healthy children (12.7 ± 0.6 years old). The ventral visual areas, cerebellum, supplementary motor area, and left inferior frontal cortex were significantly activated in the healthy participants during a continuous performance task. In survivors, brain activation in these regions was diminished at baseline, and increased upon completion of remediation and at a 6-month follow-up. The fMRI activation index for each region of interest was inversely associated with the Conners' Clinical Competence Index (p<.01). The pilot study suggests that fMRI is useful in evaluating neural responses to cognitive remediation.
PMCID: PMC3500501  PMID: 23079152
Attention; Brain tumor; Childhood brain insult; Neuroimaging (functional); Rehabilitation

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