Showing papers in "Journal of Clinical and Experimental Neuropsychology in 2011"
TL;DR: Demographic factors of age, education, gender, and race/ethnicity were found to be significant factors on some indices of all four tests and support the need to consider extended demographic contributions to neuropsychological test performance in clinical and research settings.
Abstract: Memory and executive functioning are two important components of clinical neuropsychological (NP) practice and research. Multiple demographic factors are known to affect performance differentially on most NP tests, but adequate normative corrections, inclusive of race/ethnicity, are not available for many widely used instruments. This study compared demographic contributions for widely used tests of verbal and visual learning and memory (Brief Visual Memory Test-Revised, Hopkins Verbal Memory Test-Revised) and executive functioning (Stroop Color and Word Test, Wisconsin Card Sorting Test-64) in groups of healthy Caucasians (n = 143) and African Americans (n = 103). Demographic factors of age, education, gender, and race/ethnicity were found to be significant factors on some indices of all four tests. The magnitude of demographic contributions (especially age) was greater for African Americans than for Caucasians on most measures. New, demographically corrected T-score formulas were calculated for each race/ethnicity. The rates of NP impairment using previously published normative standards significantly overestimated NP impairment in African Americans. Utilizing the new demographic corrections developed and presented herein, NP impairment rates were comparable between the two race/ethnicities and were unrelated to the other demographic characteristics (age, education, gender) in either race/ethnicity group. Findings support the need to consider extended demographic contributions to neuropsychological test performance in clinical and research settings.
278 citations
TL;DR: The Montreal Cognitive Assessment is a brief cognitive screening instrument with good psychometric features and an excellent sensitivity in the early detection of mild cognitive decline in cognitively healthy adults, with a distribution similar to that observed in the Portuguese population.
Abstract: The Montreal Cognitive Assessment (MoCA) is a brief cognitive screening instrument with good psychometric features and an excellent sensitivity in the early detection of mild cognitive decline. The MoCA was applied to a community-based sample of cognitively healthy adults (n = 650), stratified according to sociodemographic variables (age, gender, educational level, geographic region, geographic localization, and residence area), with a distribution similar to that observed in the Portuguese population. The normative data were determined according to age and education as these were the sociodemographic variables that most significantly contributed to the prediction of the MoCA scores, explaining 49% of their variance.
264 citations
TL;DR: The executive function domains of initiation, plan/organize, inhibit, self-monitor, working memory, task monitor, and organization of materials were significant predictors of academic procrastination in addition to increased age and lower conscientiousness.
Abstract: Procrastination, or the intentional delay of due tasks, is a widespread phenomenon in college settings. Because procrastination can negatively impact learning, achievement, academic self-efficacy, and quality of life, research has sought to understand the factors that produce and maintain this troublesome behavior. Procrastination is increasingly viewed as involving failures in self-regulation and volition, processes commonly regarded as executive functions. The present study was the first to investigate subcomponents of self-reported executive functioning associated with academic procrastination in a demographically diverse sample of college students aged 30 years and below (n = 212). We included each of nine aspects of executive functioning in multiple regression models that also included various demographic and medical/psychiatric characteristics, estimated IQ, depression, anxiety, neuroticism, and conscientiousness. The executive function domains of initiation, plan/organize, inhibit, self-monitor, wo...
238 citations
TL;DR: A new mean span (MS) metric of DS was developed that showed reduced variance, improved test–retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures.
Abstract: We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test-retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with subdigit precision, and elucidated changes in DS performance with age and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.
229 citations
TL;DR: Normative data for repeated neuropsychological assessments using a modified standard regression-based approach improved the consistency of NP impairment classification in a clinically stable longitudinal cohort after baseline.
Abstract: Reliable detection and quantification of longitudinal cognitive change are of considerable importance in many neurological disorders, particularly to monitor central nervous system effects of disease progression and treatment. In the current study, we developed normative data for repeated neuropsychological (NP) assessments (6 testings) using a modified standard regression-based (SRB) approach in a sample that includes both HIV-uninfected (HIV–, N = 172) and neuromedically stable HIV-infected (HIV+, N = 124) individuals. Prior analyses indicated no differences in NP change between the infected and uninfected participants. The norms for change included correction for factors found to significantly affect follow-up performance, using hierarchical regression. The most robust and consistent predictors of follow-up performance were the prior performance on the same test (which contributed in all models) and a measure of prior overall NP competence (predictor in 97% of all models). Demographic variables were pr...
150 citations
TL;DR: In this article, the authors address the issue of construct validity (convergent and discriminant) for both brain and cognitive reserve as single or multiple reserve factors, and propose theoretical models that are derived from the current extant reserve literature and empirically testable in order to facilitate establishment of the commonly used, and perhaps misused, brain or cognitive reserve concepts.
Abstract: The concept of "reserve" has traditionally been defined on the basis of a single indicator (e.g., education or intracranial volume) that purports to moderate or buffer the effects of brain damage on different clinical outcomes. While studies have shown modest effects for some indicators, it has left the concept of "reserve" wanting as an explanatory construct. More recently efforts have been made to identify groups of indicators hypothesized to represent a construct for brain or cognitive reserve. These efforts have also proved wanting because of the lack of evidence to justify such a priori groupings of variables into a brain or cognitive reserve construct. This theoretical paper addresses the issue of construct validity (convergent and discriminant) for both brain and cognitive reserve as single or multiple reserve factors. Conceptual models are proposed that are (a) derived from the current extant reserve literature and (b) empirically testable in order to facilitate establishment of construct validity for the commonly used, and perhaps misused, brain and cognitive reserve concepts.
143 citations
TL;DR: Findings support a response inhibition deficit following TBI but suggest factors other than interference control, such as poor processing speed, fatigue, and underarousal, may underlie poor performance in Stroop tasks.
Abstract: The prominent clinical feature of behavioral impulsivity following traumatic brain injury (TBI) suggests impairment of frontal inhibitory control processes. This meta-analysis consolidates the recent surge in studies across two forms of "effortful" inhibition, employing well-defined paradigms of response inhibition (N = 20; i.e., go/no-go, sustained attention to response, stop-signal, Conners' continuous performance tasks) and response interference control (N = 21, i.e., Stroop color word tasks). Across 41 effect sizes involving 989 adults with mild to severe TBI and 969 controls, the overall effect of TBI on reduced inhibitory control was small to moderate (d = 0.3) and significant. The effect was larger in studies measuring response inhibition performance (d = 0.5), while Stroop interference control yielded a nonsignificant overall effect size (d = 0.05). Further analysis of the latter finding revealed a large effect size when Stroop task studies used the outcome measure "total time on task" (d = 1.4), but not "RT per trial" or "number of stimuli" (d = -0.8 and -0.9). Response speed in these tasks was impaired to a large degree (d = 0.96). Together these findings support a response inhibition deficit following TBI but suggest factors other than interference control, such as poor processing speed, fatigue, and underarousal, may underlie poor performance in Stroop tasks.
119 citations
TL;DR: Twenty-four studies utilizing the Wechsler Adult Intelligence Scale Digit Span subtest for malingering detection were meta-analytically reviewed to evaluate their effectiveness in detecting malingered neurocognitive dysfunction.
Abstract: Twenty-four studies utilizing the Wechsler Adult Intelligence Scale (WAIS) Digit Span subtest--either the Reliable Digit Span (RDS) or Age-Corrected Scaled Score (DS-ACSS) variant--for malingering detection were meta-analytically reviewed to evaluate their effectiveness in detecting malingered neurocognitive dysfunction. RDS and DS-ACSS effectively discriminated between honest responders and dissimulators, with average weighted effect sizes of 1.34 and 1.08, respectively. No significant differences were found between RDS and DS-ACSS. Similarly, no differences were found between the Digit Span subtest from the WAIS or Wechsler Memory Scale (WMS). Strong specificity and moderate sensitivity were observed, and optimal cutting scores are recommended.
117 citations
TL;DR: The measure of myelin integrity was significantly correlated with CPS in highly vulnerable late-myelinating regions but not in the splenium, which has implications for the neurobiology of the cognitive changes associated with brain aging.
Abstract: Performance on measures of cognitive processing speed (CPS) slows with age, but the biological basis associated with this cognitive phenomenon remains incompletely understood. We assessed the hypothesis that the age-related slowing in CPS is associated with myelin breakdown in late-myelinating regions in a very healthy elderly population. An in vivo magnetic resonance imaging (MRI) biomarker of myelin integrity was obtained from the prefrontal lobe white matter and the genu of the corpus callosum for 152 healthy elderly adults. These regions myelinate later in brain development and are more vulnerable to breakdown due to the effects of normal aging. To evaluate regional specificity, we also assessed the splenium of the corpus callosum as a comparison region, which myelinates early in development and primarily contains axons involved in visual processing. The measure of myelin integrity was significantly correlated with CPS in highly vulnerable late-myelinating regions but not in the splenium. These result...
113 citations
TL;DR: The concept of EF is revisited and it is suggested that the many proposed subcomponents are not functions per se but rather a number of task-specific behaviors.
Abstract: The concept of executive function (EF) is deemed unclear and difficult to operationalize. We use a multiperspective approach to quantify and reduce the current proliferation of EFs. A literature review of 60 studies identified 68 subcomponents of EF: Through objective statistical techniques, these terms were reduced to 18 by removing semantic overlap (using latent semantic analysis) and psychometric overlap (using hierarchical cluster analysis). However, still such a large number of functions lacks parsimony. We therefore revisit the concept of EF and suggest that the many proposed subcomponents are not functions per se but rather a number of task-specific behaviors.
112 citations
TL;DR: Behavioral markers measured through neuropsychological testing in mild cognitive impairment were analyzed and combined in multivariate ways to predict conversion to Alzheimer's disease (AD) in a longitudinal study of 43 MCI patients.
Abstract: Behavioral markers measured through neuropsychological testing in mild cognitive impairment (MCI) were analyzed and combined in multivariate ways to predict conversion to Alzheimer's disease (AD) in a longitudinal study of 43 MCI patients The test measures taken at a baseline evaluation were first reduced to underlying components (principal component analysis, PCA), and then the component scores were used in discriminant analysis to classify MCI individuals as likely to convert or not When empirically weighted and combined, episodic memory, speeded executive functioning, recognition memory (false and true positives), visuospatial memory processing speed, and visuospatial episodic memory were together strong predictors of conversion to AD These multivariate combinations of the test measures achieved through the PCA were good, statistically significant predictors of MCI conversion to AD (84% accuracy, 86% sensitivity, and 83% specificity) Importantly, the posterior probabilities of group membership that
TL;DR: The interaction of advancing age and cognitive impairment may confer significant functional limitations for HIV individuals that may be better detected by performance-based measures of functional abilities rather than patient self-report.
Abstract: This study examined the effects of aging and cognitive impairment on medication and finance management in an HIV sample. We observed main effects of age (older < younger) and neuropsychological impairment on functional task performance. Interactions between age and cognition demonstrated that older impaired individuals performed significantly more poorly than all other comparison groups. There were no relationships between laboratory performance and self-reported medication and finance management. The interaction of advancing age and cognitive impairment may confer significant functional limitations for HIV individuals that may be better detected by performance-based measures of functional abilities rather than patient self-report.
TL;DR: Findings suggest that the altered neurophysiological index of WM storage might be a more sensitive measure of a latent WM function abnormality which may well worsen with aging, or perhaps additional brain insults.
Abstract: Event-related potentials (ERPs) have been useful to detect subtle, pervasive alterations of cognition-related waveforms in athletes with multiple concussions. This study used the sustained posterior contralateral negativity (SPCN) waveform component recorded while participants performed a visual short-term memory task to investigate how working memory (WM) storage capacity was affected among athletes who differed according to their history of sports concussions. Fifty-five university-level football players were assigned to three groups: 1-2 concussion athletes; 3+ concussion athletes; non-concussed athletes. The main finding of the present study was that athletes with a history of three concussions or more exhibited significantly attenuated SPCN amplitude relative to both concussed athletes with only one or two prior concussions and athletes without concussions. The latter finding adds to previous evidence of disproportionately worse outcome in athletes presenting with a history of three or more concussions relative to those with fewer concussions. In addition, SPCN amplitude was found to correlate significantly with a visual memory capacity estimate (K), but this K value did not significantly differ across groups. This suggests that attenuated SPCN amplitude after three or more concussions did not interfere with apparent WM function. Taken together, these findings suggest that the altered neurophysiological index of WM storage might be a more sensitive measure of a latent WM function abnormality which may well worsen with aging, or perhaps additional brain insults.
TL;DR: Self-reported depressive symptoms, rather than patients' cognitive complaints, are associated with objective executive function, however, self-reported cognitive complaints may be associated with objectively measured inattention and slow processing speed.
Abstract: Background and objective: We examined the relationship between self-reported pre- and post-injury changes in executive dysfunction, apathy, disinhibition, and depression, and performance on neuropsychological tests of executive function, attention/processing speed, and memory in relation to mood levels and effort test performance in individuals in the early stages of recovery from mild to moderate traumatic brain injury (TBI). Method: Participants were 71 noncombat military personnel who were in a semiacute stage of recovery (<3 months post injury) from mild to moderate TBI. Pre- and post-TBI behaviors were assessed with the Frontal Systems Behavior Scale (FrSBe; Grace & Malloy, 2001) and correlated with levels of depressive symptoms, effort test performance, and performance on objective measures of attention, executive function, and memory. Results: Self-reported symptoms of executive dysfunction generally failed to predict performance on objective measures of executive function and memory, although they...
TL;DR: The results indicate that even among independently living individuals, there is still variability in functionality and self-awareness and better awareness of IADL weaknesses was associated with higher levels of cognitive reserve but, unexpectedly, lower levels of executive abilities.
Abstract: The ability to engage in instrumental activities of daily living (IADLs) is known to rely on cognitive abilities, primarily executive functioning and memory. There is also evidence that good self-awareness, which facilitates the use of compensatory strategies, may prolong functionality and delay the diagnosis of dementia. However, little is known about the mechanisms that mediate self-awareness among healthy elderly. The present study examined the correlates of discrepancies between self-report and performance-based measures of IADLs in a sample of 75 community-dwelling elderly. The results indicate that even among independently living individuals, there is still variability in functionality (i.e., 35% of the sample made IADL performance errors) and self-awareness (i.e., 38% of the sample demonstrated a discrepancy between IADL self-report and performances). Better awareness of IADL weaknesses was associated with higher levels of cognitive reserve but, unexpectedly, lower levels of executive abilities. Additionally, consistent with prior research, better IADL performances were associated with better cognition.
TL;DR: Mild sleep restriction for 5 days impairs reaction times during working memory tasks in adolescents in the absence of increased perception of sleepiness.
Abstract: Objectives: To test the feasibility of using a home-based sleep restriction protocol in adolescents and young adults; and to examine the different effects of chronic sleep restriction on a subjective sleepiness scale and working memory task in adolescents and young adults. Method: Twenty adolescents (ages 13–16 years) and 20 young adults (ages 18–20 years) underwent a 2-week home-based sleep manipulation protocol consisting of a week of 5 school days with 8 hr spent in bed per night and another week of 5 school days with 6 hr spent in bed per night. The protocol used a counterbalanced crossover experimental design. Subjective sleepiness was scored by the participant each morning, and working memory tests were administered during the weekend corresponding to each experimental week. Results: Adherence to the prescribed protocol was similar in the two groups, and both groups achieved the desired differences in total sleep duration across the two sleep conditions. Subjective sleepiness scores significantly in...
TL;DR: This is the first study to determine the normal range of scores on measures of psychomotor speed and executive function among a large group of ethnically and educationally diverse HIV-uninfected, high-risk women, as well as their HIV-infected counterparts.
Abstract: Use of neuropsychological tests to identify HIV-associated neurocognitive dysfunction must involve normative standards that are well suited to the population of interest. Norms should be based on a population of HIV-uninfected individuals as closely matched to the HIV-infected group as possible and must include examination of the potential effects of demographic factors on test performance. This is the first study to determine the normal range of scores on measures of psychomotor speed and executive function among a large group of ethnically and educationally diverse HIV-uninfected, high-risk women, as well as their HIV-infected counterparts. Participants (n = 1,653) were administered the Trail Making Test Parts A and B (Trails A and Trails B), the Symbol Digit Modalities Test (SDMT), and the Wide Range Achievement Test–3 (WRAT–3). Among HIV-uninfected women, race/ethnicity accounted for almost 5% of the variance in cognitive test performance. The proportions ofvariance in cognitive test performance accou...
TL;DR: Results highlight the executive component of semantic fluency and the importance of using this task when assessing cognitive functioning after TBI.
Abstract: This paper examines switching and clustering in phonemic and semantic fluency tasks in individuals with traumatic brain injury (TBI). Fluency tasks were administered to 30 Hebrew-speaking patients with TBI and 30 age-matched control participants. Significant group differences were found in total output, number of switches, and number of clusters on both tasks, but not in mean cluster size. Unlike prediction, z scores of the number of semantic switches and clusters were lower than the equivalent z scores on the phonemic test. Results highlight the executive component of semantic fluency and the importance of using this task when assessing cognitive functioning after TBI.
TL;DR: Results indicate that handling probabilities, as in the PAG task, is an important ingredient of GDT performance and may compensate for the effects of weak executive functions in decisions under risk.
Abstract: In two experiments with healthy subjects, we used the Game of Dice Task (GDT), the Probability-Associated Gambling (PAG) task, the Iowa Gambling Task (IGT), and executive-function and logical thinking tasks to shed light on the underlying processes of decision making under risk. Results indicate that handling probabilities, as in the PAG task, is an important ingredient of GDT performance. Executive functions and logical thinking also play major roles in deciding in the GDT. Implicit feedback learning, as measured by the IGT, has little impact. Results suggest that good probability handling may compensate for the effects of weak executive functions in decisions under risk.
TL;DR: A higher mean level of parental education was associated with significantly higher AVF and DF structured test scores, and sex was not associated with any of the outcomes.
Abstract: The Animal Verbal Fluency (AVF) and Design Fluency (DF) structured and unstructured test versions were administered to N = 294 healthy native Dutch-speaking children who were aged between 6.56 and 15.85 years. The AVF and DF structured test scores increased linearly as a function of age, whilst the relation between age and the DF unstructured test score was curvilinear (i.e., the improvement in test scores was much more pronounced for younger children than for older children). A higher mean level of parental education was associated with significantly higher AVF and DF structured test scores. Sex was not associated with any of the outcomes. Demographically corrected norms for the AVF and DF tests were established, and an automatic scoring program was provided.
TL;DR: The findings indicate that conceptually distinctive dimensions with differential relationships to vmPFC can be derived from the Iowa Scales of Personality Change.
Abstract: This study employed a multistep, rational-empirical approach to identify dimensions of personality disturbance in brain-damaged individuals: (a) Five dimensions were hypothesized based on empirical literature and conceptual grounds; (b) principal components analysis was performed on the Iowa Scales of Personality Change (ISPC) to determine the pattern of covariance among 30 personality characteristics; (c) when discrepancies existed between principal components analysis results and conceptually based dimensions, empirical findings and clinical considerations were weighed to determine assignment of ISPC scales to dimensions; (d) the fit of data to the refined dimensions was assessed by examination of intercorrelations; (e) differential predictions concerning the relationship of dimensions to ventromedial prefrontal cortex (vmPFC) damage were tested. This process resulted in the specification of five dimensions: Disturbed Social Behavior, Executive/Decision-Making Deficits, Diminished Motivation/Hypo-Emotionality, Irascibility, and Distress. In accord with predictions, the 28 participants with vmPFC lesions, compared to 96 participants with focal lesions elsewhere in the brain, had significantly more Disturbed Social Behavior and Executive/Decision-Making Deficits and tended to have more Diminished Motivation/Hypo-Emotionality. Irascibility was not significantly higher among the vmPFC group, and the groups had very similar levels of Distress. The findings indicate that conceptually distinctive dimensions with differential relationships to vmPFC can be derived from the Iowa Scales of Personality Change.
TL;DR: The findings may have clinical implications for the management of individuals with WS and show similar patterns of neuropsychological functioning, particularly in working memory (WM) strategy use and delayed short-term memory (STM).
Abstract: We compared verbally matched attention-deficit/hyperactivity disorder (ADHD), Williams syndrome (WS), and typically developing individuals (N = 19 each group) on behavioral symptoms (Conners ADHD rating scale) and neuropsychological functioning. Neuropsychological tasks included those that assessed short-term memory and executive functions from the CANTAB (Cambridge Neuropsychological Test Automated Battery) neuropsychological battery. Children with WS scored within the abnormal range and did not differ in severity from ADHD children on the Conners Oppositionality, Cognitive Problems/Inattention, Hyperactivity, and ADHD Index subscales. The WS and ADHD groups also showed similar patterns of neuropsychological functioning, particularly in working memory (WM) strategy use and delayed short-term memory (STM). The findings may have clinical implications for the management of individuals with WS, highlighting the potential significance of behavioral, educational, and pharmacological strategies and treatments known to be useful in the treatment of children with ADHD for individuals with WS.
TL;DR: It is suggested that anosognosia is a multifaceted disorder, with diverse neuroanatomical and psychopathological origins, and management should be multidimensional to address problems with motor function, awareness, and emotional/motivational disturbance.
Abstract: How should stroke patients with poor motor awareness be managed? This question is important because unawareness (or anosognosia) is related to poor rehabilitation and prognosis. This narrative review provides a guide for clinicians and (applied) academics to understanding, assessing and managing anosognosia. Questions addressed are: What is anosognosia? What causes anosognosia? How can anosognosia be assessed? And how can anosognosia be managed? We suggest that anosognosia is a multifaceted disorder, with diverse neuroanatomical and psychopathological origins. Assessment should measure various aspects of awareness, and management should be multidimensional to address problems with motor function, awareness, and emotional/motivational disturbance.
TL;DR: Standardized norms for the Freedman version of the CDT were collected in a large sample of healthy individuals and could increase the use of this comprehensive tool in the detection of dementia.
Abstract: Background: The Clock Drawing Test (CDT) is a valid screening tool for the evaluation of cognitive decline. This study aimed to compute standardized norms for the Freedman version of the CDT in a population of 248 healthy Italian individuals aged from 20 to 89 years. Method: The effects of age, education, and gender on performance were assessed. Three conditions were administered: free-drawn clock (FD), which required participants to draw the contour, numbers, hands, and center of the clock; predrawn clock (PD), in which numbers, hands, and center had to be included in a predrawn contour; examiner-drawn clock (ED), in which only hands and center had to be inserted in a template including a predrawn contour and numbers. Scores for each of the single conditions and a total score were calculated. Results: Age had no effect on the FD condition, whereas a significant effect of age was found for the PD and ED conditions and the total score. Gender and education had no influence on any of the scores. Correction ...
TL;DR: It is suggested that spaced retrieval may be the stronger memory rehabilitation principle when it comes to learning face–name associations in people with mild to moderate memory impairment.
Abstract: While errorless learning and spaced retrieval have both proved effective in helping many patients with acquired brain injury (ABI) and dementia learn novel information, it is not clear which of these principles we should apply to target treatment most effectively. To address this issue we conducted a systematic comparison of these principles in three experiments, comparing their effectiveness in healthy controls (N = 60), patients with ABI (N = 30), and patients with dementia (N = 15). Participants were asked to learn face-name associations, and the relative effectiveness of the principles over and above trial-and-error learning was investigated. The results were remarkably consistent across experiments: Both errorless learning and spaced retrieval produced greater accuracy in name recall than did trial-and-error learning, but recall under conditions of spaced retrieval was significantly better than that under errorless learning. We discuss the implications of these findings and suggest that spaced retrieval may be the stronger memory rehabilitation principle when it comes to learning face-name associations in people with mild to moderate memory impairment.
TL;DR: The results in combination suggest that the performance difference, at least in the present shift task, is caused by reduced novelty processing in ASD participants.
Abstract: Autism spectrum disorders (ASD) are associated with impaired attentional set shifting, which may reflect enhanced perseverative responding, enhanced learned irrelevance, and/or reduced novelty processing. We assessed the contribution of these potential error sources in ASD adults. A total of 17 ASD and 19 matched comparison individuals first solved a discrimination learning task. Thereafter, the participants faced three types of attentional shift, specifically designed to isolate the effect of the three possible error sources. ASD participants made more errors than comparison individuals in a shift implying a choice between a novel relevant stimulus attribute and a familiar attribute that was previously relevant but now irrelevant. However, they made fewer errors in a shift involving a choice between a novel irrelevant attribute and a familiar, previously irrelevant but now relevant attribute. The results in combination suggest that the performance difference, at least in the present shift task, is caused by reduced novelty processing in ASD participants.
TL;DR: Results indicate that motor signs only mildly affected Part A, and psychiatric symptoms did not affect either part, and TMT scores differentiated between healthy comparisons and prodromal HD individuals as far as 9–15 years before estimated diagnosis.
Abstract: We examined the Trail Making Test (TMT) in a sample of 767 participants with prodromal Huntington disease (prodromal HD) and 217 healthy comparisons to determine the contributions of motor, psychiatric, and cognitive changes to TMT scores. Eight traditional and derived TMT scores were also evaluated for their ability to differentiate prodromal participants closer to estimated age of diagnosis from those farther away and prodromal individuals from healthy comparisons. Results indicate that motor signs only mildly affected Part A, and psychiatric symptoms did not affect either part. Tests of perceptual processing, visual scanning, and attention were primarily associated with Part A, and executive functioning (response inhibition, set-shifting), processing speed, and working memory were associated with Part B. Additionally, TMT scores differentiated between healthy comparisons and prodromal HD individuals as far as 9-15 years before estimated diagnosis. In participants manifesting prodromal motor signs and psychiatric symptoms, the TMT primarily measures cognition and is able to discriminate between groups based on health status and estimated time to diagnosis.
TL;DR: Retention weighted scoring improved the discrimination of MCI and AD groups and no alternative scoring system was better than standard scoring of word-list recall in distinguishing MCI patients from controls.
Abstract: Mild cognitive impairment (MCI) is often associated with the preclinical phase of Alzheimer's disease (AD). Special scoring of word-list recall data for serial position has been suggested to improve discrimination of normal aging from dementia. We examined serial position effects in word-list recall for MCI participants compared to Alzheimer patients and controls. Individuals with MCI, like Alzheimer patients, had a diminished primacy effect in recalling words from a list. No alternative scoring system was better than standard scoring of word-list recall in distinguishing MCI patients from controls. Retention weighted scoring improved the discrimination of MCI and AD groups.
TL;DR: The authors observed activations in the left frontal and parietal areas during both tasks; however, the PASAT activated more frontal areas than did the SDMT, and these tasks require an efficient transfer of information among large areas.
Abstract: The Paced Auditory Serial Addition Test (PASAT) and the Symbol Digit Modalities Test (SDMT) are generally used to detect cognitive impairments in multiple sclerosis patients. Although both seem to be sensitive to the slow information-processing speed, some results suggest that they do not involve the same cognitive functions. The aim of the present study is to observe possible differences between these tasks to help understand their utility to cognitive assessment. A total of 17 participants were recruited for the study and completed a block-design version of each task. Comparisons between tasks were calculated using an analysis of variance (ANOVA; p < .05, familywise error, FWE, corrected). We observed activations in the left frontal and parietal areas during both tasks; however, the PASAT activated more frontal areas than did the SDMT. These tasks require an efficient transfer of information among large areas. Moreover, the PASAT requires more executive functions to be executed.
TL;DR: While both tools are brief and specific for the detection of early executive dysfunction in dementia, the IFS is more and specific in differentiating bvFTD from AD, and its use in everyday clinical practice can contribute to the differential diagnosis between types of dementia.
Abstract: We compared the utility of two executive-function brief screening tools, the Institute of Cognitive Neurology (INECO) Frontal Screening (IFS) and the Frontal Assessment Battery (FAB), in their ability to detect executive dysfunction in a group of behavioral variant frontotemporal dementia (bv-FTD, n = 25) and Alzheimer's disease (AD, n = 25) patients in the early stages of their disease and in comparison to a group of age-, gender-, and education-matched controls (n = 26). Relative to the FAB, the IFS showed (a) better capability to differentiate between types of dementia; (b) higher sensitivity and specificity for the detection of executive dysfunction; (c) stronger correlations with standard executive tasks. We conclude that while both tools are brief and specific for the detection of early executive dysfunction in dementia, the IFS is more sensitive and specific in differentiating bvFTD from AD, and its use in everyday clinical practice can contribute to the differential diagnosis between types of dementia.