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ObjectiveMethodResultsConclusionsThis study investigated the relationship between processing speed impairment severity and performance on the Rey 15-Item Test (RFIT) and RFIT + Recognition.Cross-sectional data from 285 examinees (228 valid/57 invalid) referred for neuropsychological assessment who were administered the RFIT, Weschler Adult Intelligence Scale-Fourth Edition (WAIS-IV) Processing Speed Index (PSI), Brief Visuospatial Memory Test – Revised, Rey Auditory Verbal Learning Test, and three independent criterion PVTs were included. PSI bands were operationalized as Intact (≥85SS; n = 163), Reduced/Possibly Impaired (77-84SS; n = 36), or Impaired (≤76 SS; n = 29). Receiver operator characteristic (ROC) curve analyses tested the RFIT and RFIT + Recognition’s classification accuracy for detecting invalid performance for the overall sample and by PSI impairment status.Those with intact processing speed performed significantly better on the RFIT and RFIT + Recognition than those with reduced/possibly impaired and impaired processing speed. Though verbal/visual memory predicted RFIT scores independently, PSI contributed additional variance. ROC curves for RFIT and RFIT + Recognition were significant (AUC=.64-.84). Optimal cut-scores yielded modest sensitivity (30%-63%) and high specificity (89%-93%) among those with intact and reduced processing speed but yielded unacceptable accuracy in those with impaired speed (AUC=.59-.62).Although the RFIT and RFIT + Recognition demonstrated acceptable classification accuracy in those with intact processing speed, accuracy diminished with increasing speed impairment. This finding was more pronounced for RFIT + Recognition compared to the traditional RFIT. As such, the RFIT may have limited clinical utility in examinees with more significant processing speed deficits. [ABSTRACT FROM AUTHOR]

The clinical practice of preschool neuropsychology assumes that our assessment tools are measuring underlying neuropsychological functions, and that these functions are negatively impacted by early life neurological injury, disease, and disorder. This study hypothesized that general intellectual capacity and specific cognitive skills, both "broad" neuropsychological domains and "specific" subdomains within those broader clusters, would be differentiable in a preschool-age clinical population. Using neuropsychological data from 580 children (6 and 71 months) seen for a clinical neuropsychological evaluation in the Preschool and Infant Neuropsychological Testing (PINT) Clinic, exploratory factor analyses (EFA) were conducted. Results: A one-factor model provided a good fit when considering verbal, nonverbal, and adaptive functions. Consideration of one- versus two-factor solutions for broad neuropsychological domains indicated that a 2-factor solution provided a significantly better fit for the data. Factor 1 was defined by motor, language, and nonverbal reasoning abilities; Factor 2 was defined by inhibitory control and attention. Further consideration of specific neuropsychological functions also supported a 2-factor solution. Factor 1 ("thinking") was defined by nonverbal reasoning, receptive language, and expressive language; Factor 2 ("processing") was defined by impulse control, inhibitory control, inattention, visual-motor integration, and visuo-constructional abilities. Motor skills cross-loaded onto both factors. Secondary analyses suggest these models provide the best fit for preschool-aged children with > 70 overall intellectual functioning and no comorbid medical diagnosis. In a clinical sample of preschool-age children, neuropsychological assessment data appears to assess a general level of intellectual capacity or functioning. Further differentiation between assessing "thinking" (knowledge and reasoning skills) and "processing" (cognitive attention and processing of information) can be considered clinically. Next steps include more recent clinical sample replication, consideration of whether neuropsychological profiles are detectable in the preschool-age range and whether the results of early life assessment are predictive of future functioning. [ABSTRACT FROM AUTHOR]

The Delis-Kaplan Executive Function System (D-KEFS) Trail Making Test (TMT) is a commonly used measure of processing speed and executive functioning that may also be useful as an embedded performance validity test (PVT). We evaluated the utility of several multi-condition indices on the D-KEFS TMT in three independent samples to determine an optimal multi-condition index and cutoff on the D-KEFS TMT. Classification accuracy statistics for multiple multi-condition indices on the D-KEFS TMT were evaluated in three independent samples, including a sample with history of mild traumatic brain injury (TBI; n = 267) classified into psychometrically defined performance-valid and performance-invalid subgroups, the D-KEFS national normative sample (n = 1713), and a sample of middle- and older-aged adults diagnosed with mild cognitive impairment (MCI; n = 70). The D-KEFS TMT Conditions 1–5 summation index maximized sensitivity at.31 while maintaining adequate specificity at ≥.9. This index also had acceptable classification accuracy in both the D-KEFS national normative and MCI cross-validation samples, with the exception of the oldest subgroup of the national norming sample (i.e., individuals' ages 80–89), in which the observed failure rates for all multi-condition indices tested were greater than 10%. Our study provides support for the use the D-KEFS TMT Conditions 1–5 summation index as an embedded PVT among individuals younger than 80 years-old and from a range of conditions spanning from cognitively normal to mildly impaired; however, further validation is necessary. [ABSTRACT FROM AUTHOR]

Introduction: Previous studies of neuropsychological performance in electrical injury (EI) patients have produced evidence of deficits in various cognitive domains, but studies have yet to investigate relationships among performance in cognitive domains post-EI. This study examined whether dispersion among neuropsychological test scores was associated with injury parameters and neuropsychological performance in EI patients. Additionally, we examined whether dispersion, processing speed and/or executive abilities explain variance in episodic verbal and visual memory performance among EI patients. Method: Data from 52 post-acute EI patients undergoing outpatient evaluation with objectively-verified valid neuropsychological test performance were examined. Tests included measures of verbal and visual memory, processing speed, and executive functioning. Dispersion was calculated from executive functioning and processing speed scores. Results: Dispersion was not related to mean performance or injury characteristics, but was significantly negatively correlated with performance on a test of processing speed, suggesting that increased dispersion is associated with reduced cognitive efficiency post-EI. Delayed visual memory was related to both dispersion scores and processing speed. Stepwise regression equations predicting delayed memory determined that processing speed most significantly predicted delayed visual memory, even after controlling for immediate visual memory. No significant relationships emerged between verbal memory and non-memory neuropsychological scores. Conclusions: This is the first study to examine neuropsychological dispersion and relationships among domains of cognitive functioning in EI. Current results suggested that neuropsychological dispersion is not a marker of general functioning or severity of injury in EI patients, but may represent more specific processing speed abilities. Processing speed predicts delayed visual memory performance in EI patients, which should be considered in interpreting test scores during evaluations. [ABSTRACT FROM AUTHOR]

The Delis-Kaplan Executive Function System (D-KEFS) is a battery of tests designed to measure executive functions (EF). Additionally, the D-KEFS contains lower-order tasks, designed to control for speed of visual scanning, sequencing, and verbal and graphomotor output. The construct and criterion validities of D-KEFS scores that are time-based are well established. However, the constructs measured by the D-KEFS error scores are poorly understood, making clinical interpretations of such scores difficult. This study examined the construct validity of D-KEFS errors committed on EF tasks and tasks designed to measure lower-order processes (i.e., non-EF tasks), across the adult lifespan. Participants were 427 adults (18–93 years) who completed the timed subtests of the D-KEFS. Four hundred two participants also completed the Push-Turn-Taptap (PTT; a separate measure of EF) to allow cross-validation. General linear regressions showed that D-KEFS errors committed on the EF tests were associated with EF timed performance (assessed using the D-KEFS time-based scores and the PTT), but only among older adults. Importantly, errors committed on the D-KEFS tasks of lower-order processes were also associated with D-KEFS time-based EF performance, and this relationship held across the adult lifespan. These findings suggest that among older adults EF errors on the D-KEFS can be interpreted as indices of EF, but such interpretations are not automatically warranted for younger adults. Additionally, errors committed on non-EF tasks contained within the D-KEFS battery can be interpreted as reflecting EF weaknesses across the adult lifespan. [ABSTRACT FROM AUTHOR]

Embedded performance validity tests (PVTs) allow for continuous and economical validity assessment during neuropsychological evaluations; however, similar to their freestanding counterparts, a limitation of well-validated embedded PVTs is that the majority are memory-based. This study cross-validated several previously identified non-memory-based PVTs derived from language, processing speed, and executive functioning tests within a single mixed clinical neuropsychiatric sample with and without cognitive impairment. This cross-sectional study included data from 124 clinical patients who underwent outpatient neuropsychological evaluation. Validity groups were determined by four independent criterion PVTs (failing ≤1 or ≥2), resulting in 98 valid (68% cognitively impaired) and 26 invalid performances. In total, 23 previously identified embedded PVTs derived from Verbal Fluency (VF), Trail Making Test (TMT), Stroop (SCWT), and Wisconsin Card Sorting Test (WCST) were examined. All VF, SCWT, and TMT PVTs, along with WCST Categories, significantly differed between validity groups (ηp2 =.05-.22) with areas under the curve (AUCs) of.65-.81 and 19-54% sensitivity (≥89% specificity) at optimal cut-scores. When subdivided by impairment status, all PVTs except for WCST Failures to Maintain Set were significant (AUCs =.75–94) with 33-85% sensitivity (≥90% specificity) in the cognitively unimpaired group. Among the cognitively impaired group, most VF, TMT, and SCWT PVTs remained significant, albeit with decreased accuracy (AUCs =.65-.76) and sensitivities (19-54%) at optimal cut-scores, whereas all WCST PVTs were nonsignificant. Across groups, SCWT embedded PVTs evidenced the strongest psychometric properties. VF, TMT, and SCWT embedded PVTs generally demonstrated moderate accuracy for identifying invalid neuropsychological performance. However, performance on these non-memory-based PVTs from processing speed and executive functioning tests are not immune to the effects of cognitive impairment, such that alternate cut-scores (with reduced sensitivity if adequate specificity is maintained) are indicated in cases where the clinical history is consistent with cognitive impairment. In contrast, WCST indices generally had poor accuracy. [ABSTRACT FROM AUTHOR]

Validity indicators embedded within standard neuropsychological tests have received increasing attention as more efficient measures for sampling performance validity throughout an evaluation. This cross-sectional study examined multiple performance validity tests (PVTs) embedded in the Wechsler Adult Intelligence Scale-IV (WAIS-IV) Working Memory (WMI) and Processing Speed (PSI) Indices for detecting invalid test performance. This cross-sectional study examined data from a mixed clinical neuropsychiatric sample of 110 patients referred for outpatient evaluation. The sample was composed of 85 patients with valid neuropsychological performance and 25 with invalid performance based on multiple independent criterion PVTs. Among the patients with valid performance, 54% were cognitively impaired, whereas 46% were cognitively unimpaired. Among the overall sample, performance on WMI, PSI, and 3/4 constituent subtests (i.e., Digit Span, Symbol Search, Coding) was significantly worse among the invalid group compared to the valid group (ηp2 =.06–.16) with areas under the curve (AUCs) of.67–.76 and 24–32% sensitivity (≥88% specificity) for identifying invalid performance at cut-scores that maximized accuracy. When the sample was subdivided by cognitive impairment status, AUCs of.68–.87 and 36–56% sensitivity (≥87% specificity) for detecting invalidity at cut-scores that maximized accuracy were found among those without cognitive impairment. In contrast, for patients with cognitive impairment, Digit Span, Arithmetic, WMI, and Coding were nonsignificant, and AUCs of.66–.67. Further, notably reduced sensitivities of 16–28% (≥91% specificity) were found for the remaining significant indices. Overall, results indicated that embedded WAIS-IV WMI and PSI are useful embedded PVTs in conditions in which cognitive impairment is not expected; however, these embedded PVTs demonstrated questionable utility among patients with cognitive impairment due to poor sensitivity, if adequate specificity is maintained, suggesting limited efficacy among patients with cognitive impairment due to risk of false-positive classification. [ABSTRACT FROM AUTHOR]

Introduction: Many medical facilities and research institutes start using digital assessment methods to assess cognitive abilities, such as processing speed, instead of the traditional pen and paper versions. Even though many of the new digital assessment methods have shown to have a stable internal validity, the comparability of results across assessment modes is unclear. The study investigated whether results for assessing processing speed via (i) the traditional pen and paper version, (ii) a tablet and pen version, and (iii) a tablet and finger version are comparable. Methods: In a within-subject design, each participant (N= 30) completed the 90-number version by Oswald and Roth (1987) of the trail-making test (TMT) in three different assessment modes in randomized order. Each participant completed four TMT versions in each assessment mode (3 × 4 within-subject design). Results: Repeated measures ANOVA and mixed-effects analyses adjusted for age, gender, mode order, and trial number reveal significantly faster test TMT completion times (about 5 s) for the tablet and pen version compared to the pen and paper and the tablet and finger version. Conclusions: Our findings indicate that assessing processing speed can lead to different results with different digital versions depending on their setup, especially different input devices. Medical professionals and researchers who use digital assessment methods to assess cognitive abilities need to be aware of mode effects, even within the digital assessment domain, because the results may not be comparable and the available norms may not be applicable. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to test the theoretical relationships between smell identification and cognitive tasks based on existing neuroimaging and anatomical findings. Method: Utilizing data collected from a memory assessment clinic, theory-derived mediation and moderation models were tested. The sample used in this study consisted of 103 (39 male, 64 female) individuals referred for memory assessments. The sample’s mean education was 12.4 years (SD = 3.2), and the mean age of the sample was 77.2 years (SD = 6.3). Results: The University of Pennsylvania Smell Identification Test (UPSIT) was a significant, partial mediator of the relationship between the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Immediate and Delayed Memory indexes. Olfactory identification did not mediate list learning and retrieval; however, olfactory identification was a significant partial mediator of the relationship between story encoding and later memory retrieval of the story. Olfactory identification also fully mediated the relationship between a visuospatial construction task and its reconstruction from memory after a short delay. The relationship between processing speed and the olfactory identification was significantly mediated by semantic memory. Finally, the UPSIT moderated the relationship between a measure of premorbid ability, the Wechsler Test of Adult Reading, and current global cognitive functioning. Conclusions: Our results support theoretical relationships between olfaction and neuropsychological domains. Additionally, our results suggest that the UPSIT may serve as a proxy for cerebral integrity and is likely related to the duration of neurodegeneration. [ABSTRACT FROM AUTHOR]

Introduction: Although disorders of mood and cognition are frequently observed in multiple sclerosis, their relationship remains unclear. We aimed to investigate whether this mood–cognition relationship is mediated by inefficient processing speed, a deficit typically associated with mood symptomatology in the psychiatric literature and a common deficit observed in multiple sclerosis patients.Method: In this study, comprehensive cognitive data and self-reported mood data were retrospectively analyzed from 349 patients with relapsing remitting multiple sclerosis. We performed a bootstrapping analysis to examine whether processing speed provided an indirect means by which depressive symptoms influenced cognitive functioning, specifically memory and executive function.Results: We observed that processing speed mediated the relationship between depressive symptoms and measures of memory and executive function. Interestingly, exploratory analyses revealed that this mediational role of processing speed was specific to MS patients who were younger, had a lower disability level, and had fewer years since MS diagnosis.Conclusions: Together, these findings have implications for mood and cognitive intervention with multiple sclerosis patients. [ABSTRACT FROM PUBLISHER]

Objective: The aim was to examine the severity and prevalence of cognitive difficulties in persons with rheumatoid arthritis (RA) within the first three years of diagnosis.Method: One hundred consecutive RA patients aged 28–67 years (90% women) were administered a battery of 6 neuropsychological tests yielding 14 cognitive indices. Self-reported measures of trait anxiety, depression, impact of disease on daily activities, and pain severity were also obtained along with physician-rated disease severity.Results: Twenty percent of RA patients were classified as cognitively impaired, defined as age- and education-adjusted scores at least 1.5 standard deviations below the population mean on 3 or more cognitive indices. Impaired performance, controlling for age, education, and premorbid cognitive capacity, was detected primarily on measures of short-term memory, immediate and delayed episodic recall, and phonemic fluency. There were modest negative associations between cognitive indices and measures of perceived disease severity (pain level, impact of disease on daily functionality, and overall health quality).Conclusions: Cognitive deficits on several domains are frequently encountered in relatively young RA patients during the first few years of the disease and may need to be taken into account as important correlates of disease severity and progression. [ABSTRACT FROM PUBLISHER]

Introduction: There is evidence that the e4 allele of the apolipoprotein E (APOE) gene is detrimental to cognitive function, but results from traumatic brain injury (TBI) populations are mixed. A possible explanation is that APOEe2 carriers have routinely been incorporated into APOEe4 and non-e4 groups, despite APOEe2 being proposed to have an ameliorative effect. Our primary aim was to investigate the influence of APOEe4 on cognitive impairment during early recovery following TBI, excluding the potential confound of APOEe2 possession. A secondary objective was to explore whether APOEe4 displays more pronounced effects in moderate to severe TBI and to consider the potential postinjury protective influence of the APOEe2 allele.Method: Participants who recently sustained a TBI (posttraumatic amnesia > 5 minutes) were assessed on measures of information processing speed, executive function, and working memory upon remission of posttraumatic amnesia. APOE genotype was determined by buccal saliva DNA extraction (APOEe4n= 37, APOEe3n= 92, APOEe2n= 13).Results: Stepwise multiple regressions were performed to compare APOEe4 carriers to APOEe3 homozygotes, with injury severity, age, and estimated premorbid IQ included in the first step. This model was found to significantly predict performance on all tasks, accounting for 17.3–24.3% of the variance. When APOEe4 status was added for the second step, there were no significant changes on any tasks (additional variance <1%). The effect of APOEe4 in moderate to severe TBI and the effect of APOEe2 were explored by analysis of covariance (ANCOVA), with no significant effects revealed.Conclusions: It is unlikely that APOE genotype influences cognitive function in the initial recovery period following TBI, regardless of injury severity. However, a more nuanced and long-term exploration of the effect of APOE genotype in the TBI population is warranted. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the extent and pattern of brain activation elicited by a functional magnetic resonance imaging version of the Symbol Digit Modalities Test (fMRI–SDMT), a task of information processing speed, in pediatric-onset multiple sclerosis (MS) patients as compared to sex- and age-matched non-MS self-reported healthy individuals. Method: Participants included 20 right-handed individuals aged 13–24 years with pediatric-onset MS (mean age = 19 years, 15 female) and 16 non-MS self-reported healthy individuals. All participants underwent a 3.0-tesla MRI scan with structural (T1; T2; proton density, PD; fluid-attenuated inversion recovery, FLAIR) and fMRI–SDMT acquisition. Participants were instructed to indicate with a button press whether a single pairing of a symbol to a number matched any of those shown in a key that displays nine possible pairings. Results: Response time (p=.909) and accuracy (p=.832) on the fMRI–SDMT did not differ between groups. However, the MS group demonstrated lower overall activation than the non-MS group in the right middle frontal gyrus (p=.003). Within the MS group, faster response time was associated with greater activation of the right inferior occipital, anterior cingulate, right superior parietal, thalamus, and left superior occipital cortices (all p <.05). A significant interaction effect was demonstrated, indicating that faster response time was associated with greater activation of the left superior occipital region in the pediatric MS group than in the non-MS group (p=.002). Conclusions: Attenuated activation of frontal regions was observed in this cohort of pediatric-onset MS patients when performing the fMRI–SDMT, even in the absence of behaviorally detectable deficits. Within the MS group only, faster response time elicited greater activation, suggesting this to be an adaptive mechanism that may contribute to limiting the impact of disease-related structural pathology. [ABSTRACT FROM AUTHOR]

Introduction: Mild traumatic brain injuries (MTBI) or concussions often result in problems with attention, executive functions, and motor control. For better identification of these diverse problems, novel approaches integrating tests of cognitive and motor functioning are needed. The aim was to characterize minor changes in motor and cognitive performance after sports-related concussions with a novel test battery, including balance tests and a computerized multilimb reaction time test. The cognitive demands of the battery gradually increase from a simple stimulus response to a complex task requiring executive attention.Method: A total of 113 male ice hockey players (mean age = 24.6 years,SD= 5.7) were assessed before a season. During the season, nine concussed players were retested within 36 hours, four to six days after the concussion, and after the season. A control group of seven nonconcussed players from the same pool of players with comparable demographics were retested after the season. Performance was measured using a balance test and the Motor Cognitive Test battery (MotCoTe) with multilimb responses in simple reaction, choice reaction, inhibition, and conflict resolution conditions.Results: The performance of the concussed group declined at the postconcussion assessment compared to both the baseline measurement and the nonconcussed controls. Significant changes were observed in the concussed group for the multilimb choice reaction and inhibition tests. Tapping and balance showed a similar trend, but no statistically significant difference in performance.Conclusion: In sports-related concussions, complex motor tests can be valuable additions in assessing the outcome and recovery. In the current study, using subtasks with varying cognitive demands, it was shown that while simple motor performance was largely unaffected, the more complex tasks induced impaired reaction times for the concussed subjects. The increased reaction times may reflect the disruption of complex and integrative cognitive function in concussions. [ABSTRACT FROM PUBLISHER]

Huntington disease (HD) is a neurodegenerative condition with prominent motor (including oculomotor), cognitive, and psychiatric effects. While neuropsychological deficits are present in HD, motor impairments may impact performance on neuropsychological measures, especially those requiring a speeded response, as has been demonstrated in multiple sclerosis and schizophrenia. The current study is the first to explore associations between oculomotor functions and neuropsychological performance in HD. Participants with impaired oculomotor functioning performed worse than those with normal oculomotor functioning on cognitive tasks requiring oculomotor involvement, particularly on psychomotor speed tasks, controlling for covariates. Consideration of oculomotor dysfunction on neuropsychological performance is critical, particularly for populations with motor deficits. [ABSTRACT FROM PUBLISHER]

Introduction:There is a lack of population-based data on specific cognitive profiles in childhood epilepsy. This study sought to determine the frequency of impairments in global cognition and aspects of working memory and processing speed in a population-based sample of children with “active” epilepsy (on antiepileptic Drugs (AEDs), and/or had a seizure in the last year). Factors significantly associated with global and specific difficulties in cognition were also identified.Method:A total of 85 (74% of eligible population) school-aged children (5–15 years) with “active” epilepsy underwent comprehensive psychological assessment including assessment of global cognition, working memory, and processing speed. Scores on cognitive subtests were compared via paired-samplesttests. The factors associated with cognitive difficulties were analyzed via linear regression.Results:A total of 24% of children were functioning below IQ 50, and 40% had IQ scores below 70. Scores on the Processing Speed Index were significantly lower than scores on the Verbal or Performance indexes on Wechsler instruments. The Coding subtest was a significant weakness compared with the other Wechsler subtests. A total of 58% of children displayed “memory underachievement” (memory score 1SDbelow assessed IQ) on at least one of the four administered working memory subtests. Factors significantly associated with globally impaired cognition included being on polytherapy (β = –13.0; 95% CI [–19.3, –6.6],p= .000) and having attention-deficit/hyperactivity disorder (ADHD; β = –11.1, 95% CI [–3.0, –19.3],p= .008). Being on polytherapy was also associated with lower scores on the working memory and processing speed composite scores. Having developmental coordination disorder (DCD) was associated with a lower score on the processing speed composite.Conclusions:There is a high rate of global and specific cognitive difficulties in childhood epilepsy. Difficulties are most pronounced in aspects of working memory and processing speed. Predictors of cognitive impairment in childhood epilepsy include epilepsy-related and behavioral factors, which may differ depending on the domain of cognition assessed. [ABSTRACT FROM PUBLISHER]

Between 40–65% of multiple sclerosis patients experience cognitive deficits, with processing speed and working memory most commonly affected. This pilot study investigated the effect of computerized cognitive training focused on improving processing speed and working memory. Participants were randomized into either an active or a sham training group and engaged in six weeks of training. The active training group improved on a measure of processing speed and attention following cognitive training, and data trended toward significance on measures of other domains. Results provide preliminary evidence that cognitive training with multiple sclerosis patients may produce moderate improvement in select areas of cognitive functioning. [ABSTRACT FROM PUBLISHER]

Executive dysfunction is common in early stage Parkinson’s disease (PD). We evaluated the relationship between self- and informant-report measurement of real-world executive functions as well as performance-based neuropsychological measures in mildly cognitively impaired individuals with PD and healthy controls. The PD group reported more difficulty with initiation of complex tasks compared to caregiver ratings, and processing speed was a strong predictor of self-reported executive dysfunction for the PD group, followed by depression. Processing speed and semantic verbal fluency predicted informant-reported executive dysfunction in PD. These findings highlight the contribution of speeded processing for performance of everyday executive tasks in PD. [ABSTRACT FROM PUBLISHER]

The primary purpose of the current study was to examine the relationship between performance on executive tasks and white matter integrity, assessed by diffusion tensor imaging (DTI) in multiple sclerosis (MS). A second aim was to examine how processing speed affects the relationship between executive functioning and fractional anisotropy (FA). This relationship was examined in two executive tasks that rely heavily on processing speed: the Color–Word Interference Test and the Trail Making Test (Delis–Kaplan Executive Function System). It was hypothesized that reduced FA is related to poor performance on executive tasks in MS, but that this relationship would be affected by the statistical correction of processing speed from the executive tasks. A total of 15 healthy controls and 25 persons with MS participated. Regression analyses were used to examine the relationship between executive functioning and FA, both before and after processing speed was removed from the executive scores. Before processing speed was removed from the executive scores, reduced FA was associated with poor performance on the Color–Word Interference Test and Trail Making Test in a diffuse network including corpus callosum and superior longitudinal fasciculus. However, once processing speed was removed, the relationship between executive functions and FA was no longer significant on the Trail Making Test, and significantly reduced and more localized on the Color–Word Interference Test. [ABSTRACT FROM PUBLISHER]

The most common cognitive impairments in multiple sclerosis (MS) have been documented in specific domains, including new learning and memory, working memory, and information processing speed. However, little attempt has been made to increase our understanding of their relationship to one another. While recent studies have shown that processing speed impacts new learning and memory abilities in MS, the role of working memory in this relationship has received less attention. The present study examines the relative contribution of impaired working memory versus processing speed in new learning and memory functions in MS. Participants consisted of 51 individuals with clinically definite MS. Participants completed two measures of processing speed, two measures of working memory, and two measures of episodic memory. Data were analyzed via correlational and multiple regression analysis. Results indicate that the variance in new learning abilities in this sample was primarily associated with processing speed, with working memory exerting much less of an influence. Results are discussed in terms of the role of cognitive rehabilitation of new learning and memory abilities in persons with MS. [ABSTRACT FROM AUTHOR]

The present study aimed to examine the association between frequency and quantity of alcohol consumption and cognitive functioning following traumatic brain injury (TBI). Sixty moderately to severely injured individuals had completed the Alcohol Use Disorders Identification Test (AUDIT) to measure preinjury alcuhol use soon after injury and were recruited and assessed with AUDIT and Time Line Follow-Back (TLFB), as a measure of frequency and quantity of alcohol consumption at 6--9 moths post injury. Fifty participants completed both AUDIT and TLFB at a follow-up assessment at 12--15 months post injury. Measures of processing speed/attention, memory, and executive function were also administered. Regression anlyses were used to examine the relationships between alcohol use and cognition at the two occasions of measurement. harmful or hazardous alcohol use preinjury was associated with poorer memory performance on the California Verbal Learning Test (CVLT--II) and slower processing speed on Symbol Digit Modalities Test on average across postinjury measurement occasions, but not with executive functioning, measured by the Modified Six Elements Test (MSET) at 6--9 months postinjury. On the other hand, executive functioning on MSET 6--9 months post injury was significantly poorer in participants who were consuming any alcohol at all in the month prior to follow-up assessment. The current study provides evidence showing that pre- and postinjury alcohol use is negatively associated with different aspects of cognitive functioning following TBI. In addition to providing some support for the provision of advice to abstain from alcohol after injury, these findings suggest that interventions to reduse postinjury alcohol use may be useful. [ABSTRACT FROM AUTHOR]

There is a lack of consensus upon a conclusive cognitive profile characterizing unipolar major depression. Currently depressed (n = 37), recovered previously depressed (n = 81), and never depressed controls (n = 50) underwent assessment of executive functions, working memory, attention, and psychomotor speed. Currently depressed yielded significantly lower test scores than previously and never depressed subjects on a measure of working memory. Both currently depressed and previously depressed scored significantly lower than never depressed subjects on measures of processing speed. Recurrent depressed performed similarly to subjects with a single depressive episode. These findings indicate a mild and limited cognitive impairment during the course of a mild to moderate major depressive disorder among relatively young adults. Impaired processing speed should be considered in further studies as a potential irreversible marker for recurrent depression. [ABSTRACT FROM PUBLISHER]

Cognitive symptoms of multiple sclerosis (MS) include processing-speed deficits and working memory impairment. The precise manner in which these deficits interact in individuals with MS remains to be explicated. We hypothesized that providing more time on a complex working memory task would result in performance benefits for individuals with MS relative to healthy controls. Fifty-three individuals with clinically definite MS and 36 matched healthy controls performed a computerized task that systematically manipulated cognitive load. The interval between stimuli presentations was manipulated to provide increasing processing time. The results confirmed that individuals with MS who have processing-speed deficits significantly improve in performance accuracy when given additional time to process the information in working memory. Implications of these findings for developing appropriate cognitive rehabilitation interventions are discussed. [ABSTRACT FROM AUTHOR]

This study investigated the effects of endocrine therapy (i.e., tamoxifen and anastrozole) on cognitive functioning by comparing 28 postmenopausal women with breast cancer to 37 healthy age-equivalent controls. Participants completed neuropsychological tests previously shown to be estrogen sensitive (e.g., verbal memory, letter fluency). A significant treatment effect was observed on speeded measures of letter fluency, complex visuomotor attention, and manual dexterity, but not on measures of verbal or object-location memory, or on tests presumed to be estrogen insensitive (e.g., spatial ability). In partial support of previous research, these results indicate that endocrine therapy can have detrimental effects on speeded higher brain functions but not necessarily on memory. [ABSTRACT FROM AUTHOR]

Cognitive reserve theory helps to explain the neuropsychological expression of neurologic disease (e.g., Alzheimer's disease; Stern, 2006). Multiple sclerosis (MS) is a neurologic disease characterized by information processing inefficiency and verbal learning and memory deficits. The current study is the first to investigate whether higher cognitive reserve moderates the relationship between MS and cognitive functioning. A word-reading proxy of premorbid intelligence was used to estimate cognitive reserve for 58 persons with MS and 43 healthy controls. Dependent measures of simple processing efficiency, complex information processing efficiency, and verbal learning and memory were administered. There were significant Group × Cognitive Reserve interactions for complex information processing efficiency and verbal learning and memory, such that persons with MS demonstrated deficits relative to controls at lower, but not higher, levels of reserve. No such interaction was found for simple processing efficiency. The protective influence of higher cognitive reserve against disease-related cognitive deficits is discussed. [ABSTRACT FROM AUTHOR]

Previous research had shown that processing speed and premorbid IQ are predictors of verbal-memory efficiency in patients with schizophrenia. We investigated whether the same factors are involved in visual memory. A total of 49 patients with schizophrenia and 43 healthy controls were administered a picture recognition task. Half of the pictures were black and white, and half were in color, in order to vary the depth of encoding. Processing speed was measured by three standard tasks, and premorbid IQ was measured by the National Adult Reading Test (NART). Patients were significantly impaired in picture recognition. Regression analyses revealed that NART score was a significant predictor of the recognition of both types of picture in patients. Processing speed was a significant predictor of the recognition of the colored pictures. The effect of diagnosis on the recognition of colored pictures was reduced to nonsignificance when processing speed was entered in the regression. These data suggest that premorbid IQ is involved in visual-recognition efficiency. However, the deficit observed in patients is accounted for by decreased processing speed. [ABSTRACT FROM AUTHOR]