Showing papers in "Neuropsychology (journal) in 2016"
TL;DR: WM training produces long-lasting beneficial effects which are strongly pronounced in patients with acquired brain injuries, and this finding supports the application of WM training in clinical settings.
Abstract: OBJECTIVE: Deficits in working memory (WM) are commonly observed after brain injuries and cause severe impairments in patients' everyday life. It is still under debate if training can enhance or rehabilitate WM in case of malfunction. The current meta-analysis investigates this issue from a clinical point of view. It addresses under which conditions and for which target group WM training may be justifiable. METHOD: Relevant WM training studies were identified by searching electronic literature databases with a comprehensive search term. In total, 103 studies, which added up to 112 independent group comparisons (N = 6,113 participants), were included in the analysis. RESULTS: Overall, WM training caused a moderate and long-lasting improvement in untrained WM tasks. Moreover, improvement of WM functioning led to sustainable better evaluation of everyday life functioning, however, effect sizes were small. Concerning transfer effects on other cognitive domains, long-lasting improvements with small effect sizes were observed in cognitive control and reasoning/intelligence. In contrast, small immediate, but no long-term effects were found for attention and long-term memory. Studies with brain injured patients demonstrated long-lasting improvements in WM functions with moderate to large effect sizes. A main moderator variable of intervention efficacy is the number of training sessions applied. CONCLUSION: WM training produces long-lasting beneficial effects which are strongly pronounced in patients with acquired brain injuries. This finding supports the application of WM training in clinical settings. To determine optimal training conditions, future studies must systematically investigate the characteristics of interventions as they are at present inevitably confounded. (PsycINFO Database Record Language: en
114 citations
TL;DR: These findings provide biomarker validation for the greater specificity of declines in category versus letter fluency to underlying AD pathology and suggest that changes in semantic processing occur earlier in the AD trajectory than previously hypothesized.
Abstract: Objective Differentially worse performance on category versus letter fluency suggests greater semantic versus retrieval difficulties. This discrepancy, combined with reduced episodic memory, has widespread clinical utility in diagnosing Alzheimer's disease (AD). Our objective was to investigate whether changes in semantic processing, as measured by the discrepancy between category and letter fluency, was detectable in preclinical AD: in clinically normal older adults with abnormal β-amyloid (Aβ) deposition on positron emission tomography (PET) neuroimaging. Method Clinically normal older adults (mean Mini Mental State Exam (MMSE) score = 29) were classified as Aβ+ (n = 70) or Aβ- (n = 205) using Pittsburgh Compound B-(PET) imaging. Participants completed letter fluency (FAS; word generation to letters F-A-S) and category fluency (CAT; word generation to animals, vegetables, fruits) annually (mean follow-up = 2.42 years). The effect of Aβ status on fluency over time was examined using linear mixed models controlling for age, sex, and education. To dissociate effects related to semantic (CAT) versus retrieval processes (CAT and FAS), we repeated models predicting CAT over time, controlling for FAS and likewise for CAT controlling for FAS. Results At baseline, the Aβ+ group performed better on FAS compared with the Aβ- group but comparably on CAT. Longitudinally, the Aβ+ group demonstrated greater decline on CAT compared with the Aβ- group (p = .0011). This finding remained significant even when covarying for FAS (p = .0107). Aβ+ participants similarly declined compared with Aβ- participants on FAS (p = .0112), but this effect became insignificant when covarying for CAT (p = .1607). Conclusion These findings provide biomarker validation for the greater specificity of declines in category versus letter fluency to underlying AD pathology. Our results also suggest that changes in semantic processing occur earlier in the AD trajectory than previously hypothesized. (PsycINFO Database Record
58 citations
TL;DR: Evidence for WM impairments following TBI is consistent with previous research, and larger verbal STM and verbal WM deficits were related to a longer time postinjury, suggesting that these aspects of memory do not "recover" over time and instead, individuals might show increased rates of cognitive decline.
Abstract: OBJECTIVES: To establish the magnitude of deficits in working memory (WM) and short-term memory (STM) in those with moderate-to-severe traumatic brain injury (TBI) relative to age-matched, healthy controls and to explore the moderating effects of time since injury and age at injury on these impairments. METHOD: Twenty-one studies that compared the WM and/or STM abilities of individuals with at least a moderate TBI relative to healthy controls were included in a random effects meta-analysis. Measures used to examine memory performance were categorized by modality (visuospatial, verbal) and memory system (WM, STM). RESULTS: Individuals with TBI had significant deficits in verbal STM (Cohen's d =.41), visuospatial WM (Cohen's d =.69), and verbal WM (Cohen's d =.37) relative to controls. Greater decrements in verbal STM and verbal WM skills were associated with longer time postinjury. Larger deficits were observed in verbal WM abilities in individuals with older age at injury. CONCLUSION: Evidence for WM impairments following TBI is consistent with previous research. Larger verbal STM and verbal WM deficits were related to a longer time postinjury, suggesting that these aspects of memory do not "recover" over time and instead, individuals might show increased rates of cognitive decline. Age at injury was associated with the severity of verbal WM impairments, with larger deficits evident for injuries that occurred later in life. Further research needs to chart the long-term effects of TBI on WM and to compare the effects of injury on verbal relative to visuospatial memory. (PsycINFO Database Record(c) 2016 APA, all rights reserved). Language: en
55 citations
TL;DR: NAcc and posterior cingulate dysfunctions in SCZ patients may be involved in their impaired effort expenditure decision-making and activity was positively correlated with the willingness to expend high-level effort and concrete consummatory pleasure experience.
Abstract: Objective Unwillingness to expend more effort to pursue high value rewards has been associated with motivational anhedonia in schizophrenia (SCZ) and abnormal dopamine activity in the nucleus accumbens (NAcc). The authors hypothesized that dysfunction of the NAcc and the associated forebrain regions are involved in the impaired effort expenditure decision-making of SCZ. Method A 2 (reward magnitude: low vs. high) × 3 (probability: 20% vs. 50% vs. 80%) event-related fMRI design in the effort-expenditure for reward task (EEfRT) was used to examine the neural response of 23 SCZ patients and 23 demographically matched control participants when the participants made effort expenditure decisions to pursue uncertain rewards. Results SCZ patients were significantly less likely to expend high level of effort in the medium (50%) and high (80%) probability conditions than healthy controls. The neural response in the NAcc, the posterior cingulate gyrus and the left medial frontal gyrus in SCZ patients were weaker than healthy controls and did not linearly increase with an increase in reward magnitude and probability. Moreover, NAcc activity was positively correlated with the willingness to expend high-level effort and concrete consummatory pleasure experience. Conclusion NAcc and posterior cingulate dysfunctions in SCZ patients may be involved in their impaired effort expenditure decision-making. (PsycINFO Database Record
54 citations
TL;DR: Higher achievement with older age and pubertal stage in general ability, abstraction, attention, emotion, and balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems.
Abstract: Author(s): Sullivan, Edith V; Brumback, Ty; Tapert, Susan F; Fama, Rosemary; Prouty, Devin; Brown, Sandra A; Cummins, Kevin; Thompson, Wesley K; Colrain, Ian M; Baker, Fiona C; De Bellis, Michael D; Hooper, Stephen R; Clark, Duncan B; Chung, Tammy; Nagel, Bonnie J; Nichols, B Nolan; Rohlfing, Torsten; Chu, Weiwei; Pohl, Kilian M; Pfefferbaum, Adolf | Abstract: ObjectiveTo investigate development of cognitive and motor functions in healthy adolescents and to explore whether hazardous drinking affects the normal developmental course of those functions.MethodParticipants were 831 adolescents recruited across 5 United States sites of the National Consortium on Alcohol and NeuroDevelopment in Adolescence 692 met criteria for no/low alcohol exposure, and 139 exceeded drinking thresholds. Cross-sectional, baseline data were collected with computerized and traditional neuropsychological tests assessing 8 functional domains expressed as composite scores. General additive modeling evaluated factors potentially modulating performance (age, sex, ethnicity, socioeconomic status, and pubertal developmental stage).ResultsOlder no/low-drinking participants achieved better scores than younger ones on 5 accuracy composites (general ability, abstraction, attention, emotion, and balance). Speeded responses for attention, motor speed, and general ability were sensitive to age and pubertal development. The exceeds-threshold group (accounting for age, sex, and other demographic factors) performed significantly below the no/low-drinking group on balance accuracy and on general ability, attention, episodic memory, emotion, and motor speed scores and showed evidence for faster speed at the expense of accuracy. Delay Discounting performance was consistent with poor impulse control in the younger no/low drinkers and in exceeds-threshold drinkers regardless of age.ConclusionsHigher achievement with older age and pubertal stage in general ability, abstraction, attention, emotion, and balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems. Determination of whether low scores by the exceeds-threshold group resulted from drinking or from other preexisting factors requires longitudinal study. (PsycINFO Database Record
54 citations
TL;DR: The rates of GAD increased with injury severity, but "cases" decreased, although neither difference was significant, and anxiety was most prevalent 2 to 5 years postinjury.
Abstract: OBJECTIVE: Anxiety following a traumatic brain injury (TBI) is a common problem; however, disparate prevalence estimates limit the clinical utility of research. The purpose of the current study was to examine how differences in methodological variables and sample characteristics impact on the prevalence of anxiety. METHOD: Data from 41 studies that examined either the prevalence of generalized anxiety disorder (GAD) diagnoses or clinically significant "cases" of self-reported anxiety following adult, nonpenetrating TBI were analyzed, and the impact of diagnostic criteria, measure, postinjury interval and injury severity was evaluated. RESULTS: Overall, 11% of people were diagnosed with GAD and 37% reported clinically significant levels of anxiety following TBI. Prevalence estimates varied for different diagnostic criteria (range: 2%-19%), interview schedules (range: 2%-28%), and self-report measures (range: 36%-50%). GAD and "cases" of anxiety were most prevalent 2 to 5 years postinjury. The rates of GAD increased with injury severity (mild: 11%, severe 15%), but "cases" decreased (mild: 53%, severe: 38%), although neither difference was significant. CONCLUSIONS: Anxiety is common after a TBI and ongoing monitoring and treatment should be provided. Methodological and sample characteristics should be clear and well-defined, as differences across studies (e.g., how anxiety is conceptualized, which measure is used, time since injury, injury severity) impact prevalence rates. (PsycINFO Database Record Language: en
52 citations
TL;DR: There is a significant association between an individual's ability to generate and sustain auditory processing efficiency and their degree of cognitive improvement after TCT, independent of baseline neurocognition.
Abstract: Background Individuals with schizophrenia who engage in targeted cognitive training (TCT) of the auditory system show generalized cognitive improvements. The high degree of variability in cognitive gains maybe due to individual differences in the level of engagement of the underlying neural system target. Method 131 individuals with schizophrenia underwent 40 hours of TCT. We identified target engagement of auditory system processing efficiency by modeling subject-specific trajectories of auditory processing speed (APS) over time. Lowess analysis, mixed models repeated measures analysis, and latent growth curve modeling were used to examine whether APS trajectories were moderated by age and illness duration, and mediated improvements in cognitive outcome measures. Results We observed significant improvements in APS from baseline to 20 hours of training (initial change), followed by a flat APS trajectory (plateau) at subsequent time-points. Participants showed interindividual variability in the steepness of the initial APS change and in the APS plateau achieved and sustained between 20 and 40 hours. We found that participants who achieved the fastest APS plateau, showed the greatest transfer effects to untrained cognitive domains. Conclusions There is a significant association between an individual's ability to generate and sustain auditory processing efficiency and their degree of cognitive improvement after TCT, independent of baseline neurocognition. APS plateau may therefore represent a behavioral measure of target engagement mediating treatment response. Future studies should examine the optimal plateau of auditory processing efficiency required to induce significant cognitive improvements, in the context of interindividual differences in neural plasticity and sensory system efficiency that characterize schizophrenia. (PsycINFO Database Record
51 citations
TL;DR: Children with SLI were found to be impaired on several verbal measures of EF, but these differences were largely due to more fundamental deficits in verbal short-term span.
Abstract: Objective An increasing number of results show that specific language impairment (SLI) is often associated with impairments in executive functions (EF), but the nature, extent, and generality of these deficits is yet unclear. The aim of the paper is to present results from verbal and nonverbal tasks examining EF in children with SLI and their age-matched typically developing (TD) peers. Method 31 children with SLI were tested on verbal and nonverbal versions of simple and complex span, fluency, N-back, and Stroop tasks. Their performance was compared with 31 TD children matched on age and nonverbal IQ. The design allows us to examine whether executive functions are similarly affected in SLI in verbal and nonverbal tasks. Results The SLI group showed difficulties in verbal versions of complex span (listening span task) and fluency but not in inhibition (Stroop tasks) relative to TD age-matched children. Including simple verbal span (digit span) as a covariate eliminated group differences on both verbal tasks. Conclusions Children with SLI were found to be impaired on several verbal measures of EF, but these differences were largely due to more fundamental deficits in verbal short-term span.
48 citations
TL;DR: The hypothesis that late-life depression is associated with dementia-related pathology is not supported and neither dementia nor antidepressant medication modified the relation of pathology to depression.
Abstract: OBJECTIVE: To test the hypothesis that late-life depression is associated with dementia-related pathology. METHOD: Older participants (n = 1,965) in 3 longitudinal clinical-pathologic cohort studies who had no cognitive impairment at baseline underwent annual clinical evaluations for a mean of 8.0 years (SD = 5.0). The authors defined depression diagnostically, as major depression during the study period, and psychometrically, as elevated depressive symptoms during the study period, and established their relation to cognitive outcomes (incident dementia, rate of cognitive decline). A total of 657 participants died and underwent a uniform neuropathologic examination. The authors estimated the association of depression with 6 dementia-related markers (tau tangles, beta-amyloid plaques, Lewy bodies, hippocampal sclerosis, gross and microscopic infarcts) in logistic regression models. RESULTS: In the full cohort, 9.4% were diagnosed with major depression and 8.6% had chronically elevated depressive symptoms, both of which were related to adverse cognitive outcomes. In the 657 persons who died and had a neuropathologic examination, higher beta-amyloid plaque burden was associated with higher likelihood of major depression (present in 11.0%; OR = 1.392, 95% CI = 1.088, 1.780) but not with elevated depressive symptoms (present in 11.3%; OR = 0.919, 95% CI = 0.726, 1.165). None of the other pathologic markers was related to either of the depression measures. Neither dementia nor antidepressant medication modified the relation of pathology to depression. CONCLUSION: The results do not support the hypothesis that major depression is associated with dementia-related pathology. (PsycINFO Database Record Language: en
47 citations
TL;DR: It is hypothesized that training-related increases in control of attention are important for what is termed far transfer of cognitive training to untrained abilities, notably to Gf.
Abstract: Objective General intelligence is important for success in daily life, fueling interest in developing cognitive training as an intervention to improve fluid ability (Gf). A major obstacle to the design of effective cognitive interventions has been the paucity of hypotheses bearing on mechanisms underlying transfer of cognitive training to Gf. Despite the large amounts of money and time currently being expended on cognitive training, there is little scientific agreement on how, or even whether, Gf can be heightened by such training. Method We review the relevant strands of evidence on cognitive-training-related changes in (a) cortical mechanisms of distraction suppression, and (b) activation of the dorsal attention network (DAN). We hypothesize that training-related increases in control of attention are important for what is termed far transfer of cognitive training to untrained abilities, notably to Gf. Results We review the evidence that distraction suppression evident in behavior, neuronal firing, scalp electroencephalography, and hemodynamic change is important for protecting target processing during perception and also for protecting targets held in working memory. Importantly, attentional control also appears to be central to performance on Gf assessments. Consistent with this evidence, forms of cognitive training that increase ability to ignore distractions (e.g., working memory training and perceptual training) not only affect the DAN but also affect transfer to Gf. Conclusions Our hypothesis is supported by existing evidence. However, to advance the field of cognitive training, it is necessary that competing hypotheses on mechanisms of far transfer of cognitive training be advanced and empirically tested. (PsycINFO Database Record
46 citations
TL;DR: This study is the first to objectivize this impairment in social interaction in Alzheimer's disease and confirms that theory of mind is altered in early stages of Alzheimer dementia which is consistent with previous works.
Abstract: The present study aimed to investigate Theory of Mind (the ability to infer others' mental states) deficit in 20 patients with mild Alzheimer's disease and with 20 healthy controls, with two Theory of Mind tasks, one of them being a real interactive task. Previous results concerning preserved or altered Theory of Mind abilities in Alzheimer's disease have been inconsistent and relationships with other cognitive dysfunctions (notably episodic memory and executive functions) are still unclear. Method: The first task we used was a false belief paradigm as frequently used in literature whereas the second task, a referential communication task, assessed Theory of Mind in a real situation of interaction. Participants also underwent neuropsychological evaluation to investigate potential relationships between Theory of Mind and memory deficits. Results: The results showed that Alzheimer patients presented a genuine and significant Theory of Mind deficit compared to control participants characterized notably by difficulties to attribute knowledge to an interlocutor in a real social interaction. Conclusion: These results further confirm that Theory of Mind is altered in early stages of Alzheimer dementia which is consistent with previous works. More specifically, this study is the first one to objectivize this impairment in social interaction.
TL;DR: The relationship between cortical thickness and performance on executive function measures was characterized by a double dissociation between the thickness of cortical regions hypothesized to be involved in executive control and distinct executive processes.
Abstract: Objective This study examined the relationship between cortical thickness in executive control networks and neuropsychological measures of executive function. Method Forty-one community-dwelling older adults completed an MRI scan and a neuropsychological battery including 5 measures of executive function. Results Factor analysis of executive function measures revealed 2 distinct factors: (a) Complex Attention Control (CAC), comprised of tasks that required immediate response to stimuli and involved subtle performance feedback; and (b) Sustained Executive Control (SEC), comprised of tasks that involved maintenance and manipulation of information over time. Neural networks of interest were the frontoparietal network (F-P) and cingulo-opercular network (C-O), which have previously been hypothesized to relate to different components of executive function, based on functional MRI studies, but not neuropsychological factors. Linear regression models revealed that greater cortical thickness in the F-P network, but not the C-O network, predicted better performance on the CAC factor, whereas greater cortical thickness in the C-O network, but not the F-P network, predicted better performance on the SEC factor. Conclusions The relationship between cortical thickness and performance on executive function measures was characterized by a double dissociation between the thickness of cortical regions hypothesized to be involved in executive control and distinct executive processes. Results indicate that fundamentally different executive processes may be predicted by cortical thickness in distinct brain networks.
TL;DR: Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills.
Abstract: OBJECTIVE: Pediatric traumatic brain injury (TBI) may affect children's ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI's effects on adaptive functioning. METHOD: Children (ages 8-13) with severe TBI (STBI; n = 19), mild-moderate TBI (MTBI; n = 50), or orthopedic injury (OI; n = 60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years postinjury (SD = 1.2; range: 1-5.3). Parents rated children's adaptive functioning (ABAS-II, BASC-2, CASP). RESULTS: STBI had lower global adaptive functioning (η2 =.04-.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 =.06-.09). Jointly, executive function and processing speed were mediators of STBI's effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. CONCLUSIONS: Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. (PsycINFO Database Record(c) 2016 APA, all rights reserved). Language: en
TL;DR: Urban/rural differences in cognition for healthy community-dwelling older people while controlling for a comprehensive spectrum of confounding factors suggest higher cognitive functioning for urban residents, although childhood residence modulates this association.
Abstract: OBJECTIVE: Stimulating environments foster cognitive vitality in older age. However, it is not known whether and how geographical and physical characteristics of lived environments contribute to cognitive aging. Evidence of higher prevalence of dementia in rural rather than urban contexts suggests that urban environments may be more stimulating either cognitively, socially, or in terms of lifestyle. The present study explored urban/rural differences in cognition for healthy community-dwelling older people while controlling for a comprehensive spectrum of confounding factors. METHOD: Cognitive performance of 3,765 healthy Irish people aged 50+ years participating in Wave 1 of The Irish Longitudinal Study on Aging was analyzed in relation to current location of residence-urban, other settlements, or rural areas-and its interaction with childhood residence. Regression models controlled for sociodemographic, health, and lifestyle factors. RESULTS: Urban residents showed better performance than the other 2 residence groups for global cognition and executive functions after controlling for covariates. Childhood urban residence was associated with a cognitive advantage especially for currently rural participants. CONCLUSION: Our findings suggest higher cognitive functioning for urban residents, although childhood residence modulates this association. Suggestions for further developments of these results are discussed. (PsycINFO Database Record Language: en
TL;DR: The findings suggest that abnormal activations of multiple cortical regions, especially the frontal lobe, form the neural basis of the cognitive flexibility deficits in children with ASD and an EEG marker of cognitive flexibility is found which could be used to monitor treatment outcomes objectively.
Abstract: Objective Deficits in cognitive flexibility have been suggested to underlie the repetitive and stereotyped behavior in individuals with autism spectrum disorders (ASD). Because cognitive flexibility is primarily mediated by the frontal lobe, where structural and functional abnormalities have been extensively found in these individuals, it is conceivable that their deficits in cognitive flexibility are related to abnormal activations of the frontal lobe. The present study investigates cognitive flexibility and its underlying neurophysiological activities as indicated by theta oscillations in children with ASD. Method Twenty-five children with high-functioning ASD and 25 IQ- and age-matched typically developing (TD) children were subjected to neuropsychological assessments on cognitive flexibility and electroencephalography recordings. Results The children with ASD performed significantly worse than the TD children across the tasks of cognitive flexibility, including the modified Wisconsin Card Sorting Test (WCST). These children also demonstrated a reduced increase of the theta power localized in multiple brain regions, including various sectors of the frontal lobe at the late stage (i.e., 600 ms-900 ms poststimulus interval) but not the early stage (i.e., 250 ms-550 ms poststimulus interval) of the performance of the modified WCST. The suppressed late frontal theta activities were further shown to be significantly correlated with a poorer performance on the cognitive flexibility measures. Conclusion Our findings suggest that abnormal activations of multiple cortical regions, especially the frontal lobe, form the neural basis of the cognitive flexibility deficits in children with ASD. In addition, we found an EEG marker of cognitive flexibility which could be used to monitor treatment outcomes objectively.
TL;DR: The results suggest that the AID and the MID tasks have unique activation patterns and suggest thatThe AID task may be more sensitive in detecting anhedonia in people with traitAnhedonia.
Abstract: Objective: Anticipatory and consummatory dissociation of hedonic experience may manifest as trait anhedonia in healthy and clinical populations. It is still unclear whether the underlying neural mechanisms of the monetary-based and affect-based incentive delay paradigms are distinct from each other. The present study aimed to examine the similarities and differences between the Affect Incentive Delay (AID) and the Monetary Incentive Delay (MID) imaging paradigms in relation to brain activations. Method: We administered the AID and the MID imaging tasks to 28 adolescent participants. A cue signaling the type of forthcoming feedback (reward or punishment) was displayed to the participants, followed by a target-hit task with corresponding reward or punishment. Results: The striatal and limbic regions were activated during the anticipatory phase of MID, while there was no brain activation during the anticipatory phase of AID. In the consummatory phase, the MID task activated the medial frontal cortex, while the AID task activated the frontal and dorsal limbic regions. We further found that the anhedonic group exhibited significant hypoactivation than the nonanhedonic group at the left pulvinar, the left claustrum and the left insula to positive cues in the anticipatory phase of the AID task. Conclusions: The results suggest that the AID and the MID tasks have unique activation patterns. Our findings also suggest that the AID task may be more sensitive in detecting anhedonia in people with trait anhedonia.
TL;DR: It is shown that cranial-spinal radiation may have a negative impact on information processing speed via insult to the right optic radiations.
Abstract: OBJECTIVE We compared the structure of specific white matter tracts and information processing speed between children treated for posterior fossa tumors with cranial-spinal radiation (n = 30), or with surgery +/- focal radiation (n = 29), and healthy children (n = 37). METHOD Probabilistic diffusion tensor imaging (DTI) tractography was used to delineate the inferior longitudinal fasciculi, optic radiation, inferior frontal occipital fasciculi, and uncinate fasciculi bilaterally. Information processing speed was measured using the coding and symbol search subtests of the Wechsler Intelligence Scales, and visual matching, pair cancellation, and rapid picture naming subtests of the Woodcock-Johnson Test of Cognitive Ability, 3rd revision. We examined group differences using repeated measures MANOVAs and path analyses were used to test the relations between treatment, white matter structure of the tracts, and information processing speed. RESULTS DTI indices of the optic radiations, the inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi differed between children treated with cranial-spinal radiation and children treated with surgery +/- focal radiation, and healthy controls (p = .045). Children treated with cranial-spinal radiation also exhibited lower processing speed scores relative to healthy control subjects (p = .002). Notably, we observed that group differences in information processing speed were related to the structure of the right optic radiation (p = .002). CONCLUSION We show that cranial-spinal radiation may have a negative impact on information processing speed via insult to the right optic radiations. (PsycINFO Database Record
TL;DR: It is demonstrated that increasing brain activity by HF-rTMS over the left DLPFC can help attenuating physiological stress reactions, indicative of the positive effects of rTMS on stress resilience and underscore the possible benefit of HF-RTMS as a transdiagnostic intervention.
Abstract: OBJECTIVE Previous research has demonstrated that prefrontal activity is related to control over stress responses. However, the causal mechanisms are not well understood. In this study we investigated the possible influence of brain stimulation on the physiological stress response system. Because an increased stress response is known to precipitate psychiatric disorders, further inquiry can have important clinical implications. METHOD In 38 healthy, right-handed female participants, we examined the effects of a single sham-controlled high-frequency (HF) repetitive Transcranial Magnetic Stimulation (rTMS) session over the left (n = 19) and right (n = 19) dorsolateral prefrontal cortex (DLPFC) on the autonomic nervous system stress response, as measured by heart rate variability (HRV). Stress was transiently induced through evaluative negative feedbacks. RESULTS Although the induction procedure was efficient in increasing self-reported distress in all groups and conditions, only after real HF-rTMS over the left DLPFC the physiological stress response was diminished, as indicated by a significant increase in HRV. No effects were found in the sham or right side stimulation condition. CONCLUSIONS These findings demonstrate that increasing brain activity by HF-rTMS over the left DLPFC can help attenuating physiological stress reactions. Results are indicative of the positive effects of rTMS on stress resilience and underscore the possible benefit of HF-rTMS as a transdiagnostic intervention. Finally, the results also show that effects only occur when stimulating the left DLPFC, which is in line with the therapeutic effects of HF-rTMS in affective disorders. (PsycINFO Database Record
TL;DR: The presence of a family history of AD confers a subtle cognitive deficit in episodic memory as reflected by decreased drift rate that cannot be attributed to APOE, which may serve as a novel cognitive marker of preclinical AD.
Abstract: Objective: A family history of Alzheimer’s disease (AD) increases the risk of developing AD and can influence the accumulation of well-established AD biomarkers. There is some evidence that family history can influence episodic memory performance even in cognitively normal individuals. We attempted to replicate the effect of family history on episodic memory and used a specific computational model of binary decision making (the diffusion model) to understand precisely how family history influences cognition. Finally, we assessed the sensitivity of model parameters to family history controlling for standard neuropsychological test performance. Method: Across 2 experiments, cognitively healthy participants from the Adult Children Study completed an episodic recognition test consisting of high- and low-frequency words. The diffusion model was applied to decompose accuracy and reaction time (RT) into latent parameters which were analyzed as a function of family history. Results: In both experiments, individuals with a family history of AD exhibited lower recognition accuracy and this occurred in the absence of an apolipoprotein E (APOE) e4 allele. The diffusion model revealed this difference was due to changes in the quality of information accumulation (the drift rate) and not differences in response caution or other model parameters. This difference remained after controlling for several standard neuropsychological tests. Conclusions: These results confirm that the presence of a family history of AD confers a subtle cognitive deficit in episodic memory as reflected by decreased drift rate that cannot be attributed to APOE. This measure may serve as a novel cognitive marker of preclinical AD.
TL;DR: The Computerized Neurocognitive Battery can be used to assess specific neurocognitive performance, as well as to obtain a reliable proxy of general intelligence.
Abstract: Objective The Computerized Neurocognitive Battery (CNB) enables efficient neurocognitive assessment. The authors aimed to (a) estimate validity and reliability of the battery's Dutch translation, (b) investigate effects of age across cognitive domains, and (c) estimate heritability of the CNB tests. Method A population-representative sample of 1,140 participants (aged 10-86), mainly twin-families, was tested on the CNB, providing measures of speed and accuracy in 14 cognitive domains. In a subsample (246 subjects aged 14-22), IQ data (Wechsler Intelligence Scale for Adults; WAIS) were available. Validity and reliability were assessed by Cronbach's alpha, comparisons of scores between Dutch and U.S. samples, and investigation of how a CNB-based common factor compared to a WAIS-based general factor of intelligence (g). Linear and nonlinear age dependencies covering the life span were modeled through regression. Heritability was estimated from twin data and from entire pedigree data. Results Internal consistency of all tests was moderate to high (median = 0.86). Effects of gender, age, and education on cognitive performance closely resembled U.S. Samples The CNB-based common factor was completely captured by the WAIS-based g. Some domains, like nonverbal reasoning accuracy, peaked in young adulthood and showed steady decline. Other domains, like language reasoning accuracy, peaked in middle adulthood and were spared decline. CNB-test heritabilities were moderate (median h2 = 31%). Heritability of the CNB common factor was 70%, similar to the WAIS-based g-factor. Conclusion The CNB can be used to assess specific neurocognitive performance, as well as to obtain a reliable proxy of general intelligence. Effects of aging and heritability differed across cognitive domains.
TL;DR: It is demonstrated that maltreated adolescents are more likely to have a range of cognitive deficits that can only be identified with thorough neuropsychological assessment, and have the potential to significantly impair adaptive, social, emotional, and academic functioning.
Abstract: OBJECTIVE: Studies of adolescents with histories of maltreatment typically report specific cognitive deficits in higher order functioning and attention. Emerging evidence suggests that the cognitive difficulties seen in maltreated adolescents are much broader, and go beyond executive functioning impairments. This study examined whether maltreated adolescents exhibited cognitive deficits across a number of cognitive domains, in addition to executive functioning. METHOD: A group of 39 adolescents with documented histories of severe maltreatment were compared with 43 controls on measures of learning and memory, executive function, processing speed, working memory, visuoperceptual function, and language. Groups were matched demographically and on the Wechsler Intelligence Scale for Children-IV (WISC-IV) Full Scale Intelligence Quotient (FSIQ; Wechsler, 2003). RESULTS: Using multivariate analyses, the maltreated group showed significant impairments on measures of executive function and attention, working memory, learning, visuospatial function and visual processing speed. Effect sizes ranged from medium to large. CONCLUSIONS: The FSIQ indicated that these adolescents were performing comparably with their nonmaltreated peers, though this was not the case when specific cognitive functions were measured. This demonstrates that maltreated adolescents are more likely to have a range of cognitive deficits that can only be identified with thorough neuropsychological assessment. Such deficits have the potential to significantly impair adaptive, social, emotional, and academic functioning, explaining many of the typical difficulties seen in maltreated adolescents. (PsycINFO Database Record Language: en
TL;DR: The hypothesis that the OFC plays a key role in explicit hedonic judgment is supported, as an activation likelihood estimation (ALE) meta-analysis on 16 functional imaging studies that examined brain activation in olfactory hedonics processing-related tasks in healthy adults support the hypothesis.
Abstract: Objective: Pleasure is essential to normal healthy life. Olfaction, as 1 of the neurobehavioral probes of hedonic capacity, has a unique advantage compared to other sensory modalities. However, it is unclear how olfactory hedonic information is processed in the brain. This study aimed to investigate olfactory hedonic processing in the human brain. Method: We conducted an activation likelihood estimation (ALE) meta-analysis on 16 functional imaging studies that examined brain activation in olfactory hedonic processing-related tasks in healthy adults. Results: The results show that there is a core olfactory hedonic processing network, which consists of the bilateral parahippocampal gyrus/amygdala (BA34), the left middle frontal gyrus (BA6), the right middle frontal gyrus/lateral orbitofrontal cortex (OFC; BA10), the bilateral cingulate gyrus (BA32), the right lentiform nucleus/lateral globus pallidus, the right medial frontal gyrus/medial OFC (BA11), the left superior frontal gyrus (BA10), and the right insula (BA13). Moreover, our findings highlight that the right hemisphere is predominant in explicit odor hedonic judgment. Finally, the results indicate that there are significant differences in brain activation for hedonic judgment and passive smelling. Conclusion: These results support the hypothesis that the OFC plays a key role in explicit hedonic judgment.
TL;DR: PD leads to a deficit in perceiving biological motion, which is independent of gait dysfunction and low-level vision changes, and may therefore arise from difficulty perceptually integrating form and motion cues in posterior superior temporal sulcus.
Abstract: OBJECTIVE We examined biological motion perception in Parkinson's disease (PD). Biological motion perception is related to one's own motor function and depends on the integrity of brain areas affected in PD, including posterior superior temporal sulcus. If deficits in biological motion perception exist, they may be specific to perceiving natural/fast walking patterns that individuals with PD can no longer perform, and may correlate with disease-related motor dysfunction. METHOD Twenty-six nondemented individuals with PD and 24 control participants viewed videos of point-light walkers and scrambled versions that served as foils, and indicated whether each video depicted a human walking. Point-light walkers varied by gait type (natural, parkinsonian) and speed (0.5, 1.0, 1.5 m/s). Participants also completed control tasks (object motion, coherent motion perception), a contrast sensitivity assessment, and a walking assessment. RESULTS The PD group demonstrated significantly less sensitivity to biological motion than the control group (p < .001, Cohen's d = 1.22), regardless of stimulus gait type or speed, with a less substantial deficit in object motion perception (p = .02, Cohen's d = .68). There was no group difference in coherent motion perception. Although individuals with PD had slower walking speed and shorter stride length than control participants, gait parameters did not correlate with biological motion perception. Contrast sensitivity and coherent motion perception also did not correlate with biological motion perception. CONCLUSION PD leads to a deficit in perceiving biological motion, which is independent of gait dysfunction and low-level vision changes, and may therefore arise from difficulty perceptually integrating form and motion cues in posterior superior temporal sulcus. (PsycINFO Database Record
TL;DR: Results indicate that older adults engaging in high-level mental stimulation display an increase in CR over a 4-year period, indicating that increasing mental activity in older adulthood may be a viable strategy to improve cognitive function and offset cognitive decline associated with normal aging.
Abstract: OBJECTIVE : Increasing an individual's level of cognitive reserve (CR) has been suggested as a nonpharmacological approach to reducing the risk for Alzheimer's disease. We examined changes in CR in older adults participating over 4 years in the Tasmanian Healthy Brain Project. METHOD : A sample of 459 healthy older adults between 50 and 79 years of age underwent a comprehensive annual assessment of current CR, neuropsychological function, and psychosocial factors over a 4-year period. The intervention group of 359 older adults (M = 59.61 years, SD = 6.67) having completed a minimum of 12 months part-time university study were compared against a control reference group of 100 adults (M = 62.49 years, SD = 6.24) who did not engage in further education. RESULTS: Growth mixture modeling demonstrated that 44.3% of the control sample showed no change in CR, whereas 92.5% of the further education participants displayed a significant linear increase in CR over the 4 years of the study. These results indicate that older adults engaging in high-level mental stimulation display an increase in CR over a 4-year period. CONCLUSION: Increasing mental activity in older adulthood may be a viable strategy to improve cognitive function and offset cognitive decline associated with normal aging.
TL;DR: Young adults reporting early onset marijuana use had learning weaknesses, which accounted for the association between early onsetarijuana use and delayed recall, and no amnestic effect of marijuana use was observed.
Abstract: OBJECTIVE: Verbal memory difficulties are the most widely reported and persistent cognitive deficit associated with early onset marijuana use. Yet, it is not known what memory stages are most impaired in those with early marijuana use. METHOD: Forty-eight young adults, aged 18-25, who used marijuana at least once per week and 48 matched nonusing controls (CON) completed the California Verbal Learning Test, Second Edition (CVLT-II). Marijuana users were stratified by age of initial use: early onset users (EMJ), who started using marijuana at or before age 16 (n = 27), and late onset marijuana user group (LMJ), who started using marijuana after age 16 (n = 21). Outcome variables included trial immediate recall, total learning, clustering strategies (semantic clustering, serial clustering, ratio of semantic to serial clustering, and total number of strategies used), delayed recall, and percent retention. RESULTS: Learning improved with repetition, with no group effect on the learning slope. EMJ learned fewer words overall than LMJ or CON. There was no difference between LMJ and CON in total number of words learned. Reduced overall learning mediated the effect on reduced delayed recall among EMJ, but not CON or LMJ. Learning improved with greater use of semantic versus serial encoding, but this did not vary between groups. EMJ was not related to delayed recall after adjusting for encoding. CONCLUSIONS: Young adults reporting early onset marijuana use had learning weaknesses, which accounted for the association between early onset marijuana use and delayed recall. No amnestic effect of marijuana use was observed. (PsycINFO Database Record(c) 2016 APA, all rights reserved). Language: en
TL;DR: Rule inference on WCST-like card-sorting tasks appeared to be selectively impaired when the amount of information to be integrated in working memory increases or when working memory capacity is reduced (as in older individuals).
Abstract: OBJECTIVE The Wisconsin Card Sorting Test (WCST) is often regarded as a prototypical neuropsychological test of set-shifting ability However, it has been proposed that WCST performance involves cognitive processes other than set shifting, such as set maintenance and rule inference Distinguishing between these processes is necessary for the meaningful interpretation of WCST performance deficits in neuropsychological populations In the present studies, we aimed to concurrently measure processes of set shifting, set maintenance and rule inference in a computerized version of the WCST, and to dissociate these processes based on their dependence on working memory capacity METHOD AND RESULTS In Study 1, we manipulated the number of card-sorting rules to vary the demands placed on working memory-dependent processes of rule inference As predicted, integration errors as a novel measure of rule-inference efficiency were selectively affected by increasing the number of rules from 3 to 4 In Study 2, we examined age-related changes in set shifting, set maintenance, and rule inference We found a specific association between age and integration errors, indicating that rule inference, but not set shifting or set maintenance, is affected in older individuals CONCLUSIONS Rule inference on WCST-like card-sorting tasks appeared to be selectively impaired when the amount of information to be integrated in working memory increases or when working memory capacity is reduced (as in older individuals) Our findings indicate that measuring integration errors as an index of a distinct rule-inference process can improve the understanding and interpretability of WCST performance (PsycINFO Database Record
TL;DR: Neurodegenerative processes are differentially related to cognitive trajectories, with TDP-43 pathology most potently impacting incipient cognitive decline, AD pathology and hippocampal sclerosis affecting the progression of Cognitive decline, and Lewy bodies impacting terminal decline.
Abstract: Objective To test the hypothesis that different forms of neurodegeneration are differentially related to longitudinal cognitive trajectories in old age. Methods Participants are 420 older persons from 2 clinical-pathologic studies without cognitive impairment at study onset. They completed a battery of 17 cognitive tests annually for a minimum of 5 years, died, and underwent a neuropathologic examination to quantify neuronal neurofibrillary tangles and transactive response DNA-binding protein 43 (TDP-43) pathology and to identify Lewy bodies and hippocampal sclerosis. The authors used sigmoid mixed models based on the 4-parameter logistic distribution to decompose nonlinear global cognitive trajectories into components and assess the relation of each neuropathologic marker to each trajectory component. Results Cognitive function was assessed for a mean of 10.5 years before death. In the absence of pathology, global cognition was relatively stable before declining moderately in the last 3 to 4 years of life. Tangles were related to all trajectory components except initial level. TDP-43 pathology was the only marker related to initial level of function. It was also associated with an earlier midpoint of decline but not to slope of decline. Hippocampal sclerosis was related to an earlier midpoint of decline and more rapid slope of decline. Lewy bodies were associated with faster slope of decline and lower level of function proximate to death. Conclusion Neurodegenerative processes are differentially related to cognitive trajectories, with TDP-43 pathology most potently impacting incipient cognitive decline, AD pathology and hippocampal sclerosis affecting the progression of cognitive decline, and Lewy bodies impacting terminal decline. (PsycINFO Database Record
TL;DR: The results suggest that ALS compromises the frontoparietal brain networks involved in anticipatory set-shifting, rendering patients unable to flexibly adapt to changes in environmental contingencies.
Abstract: Objective Executive dysfunctions in patients suffering from amyotrophic lateral sclerosis (ALS) are often described but poorly understood. Specifically, research on patients' ability to flexibly shift between cognitive sets is still scarce and unsystematic. The present study set out to compensate for this lack by providing an in-depth analysis of ALS-related set-shifting impairments. Method We first present a quantitative overview of the literature revealing that the Wisconsin Card Sorting Test (WCST) is sensitive to set-shifting impairments in ALS. Moreover, we evaluated patients' performance on a computerized task-switching paradigm modeled after the WCST to elucidate the neurocognitive processes underlying their set-shifting impairments. Twenty-one ALS patients and 21 age- and education-matched controls were required to respond to changing task demands while their EEG was being measured. Results Behavioral results revealed significant set-shifting deficits in patients suffering from ALS. Executive deficits were accompanied by substantial alterations of event-related brain activity. While switch cues elicited a more positive posterior event-related potential (ERP) waveform than repeat cues in healthy controls, ERP amplitudes did not vary as a function of switching demand in ALS patients. Individual differences in posterior switch positivity were reliably associated with patients' performance on neuropsychological tests of executive functioning. Conclusions The absence of switch-related ERP modulations appears to be a sensitive indicator of executive deficits in ALS patients. Our results suggest that ALS compromises the frontoparietal brain networks involved in anticipatory set-shifting, rendering patients unable to flexibly adapt to changes in environmental contingencies.
TL;DR: Use of a virtual reality-based NP platform can detect lingering cognitive abnormalities resulting from concussion in clinically asymptomatic participants and may compliment the traditional concussion assessment battery by providing novel information.
Abstract: OBJECTIVE: Computer-based neuropsychological (NP) evaluation is an effective clinical tool used to assess cognitive function which complements the clinical diagnosis of a concussion. However, some researchers and clinicians argue its lack of ecological validity places limitations on externalizing results to a sensory rich athletic environment. Virtual reality-based NP assessment offers clinical advantages using an immersive environment and evaluating domains not typically assessed by traditional NP assessments. The sensitivity and specificity of detecting lingering cognitive abnormalities was examined on components of a virtual reality-based NP assessment battery to cohort affiliation (concussed vs. controls). METHOD: Data were retrospectively gathered on 128 controls (no concussion) and 24 concussed college-age athletes on measures of spatial navigation, whole body reaction, attention, and balance in a virtual environment. Concussed athletes were tested within 10 days (M = 8.33, SD = 1.06) of concussion and were clinically asymptomatic at the time of testing. RESULTS: A priori alpha level was set at 0.05 for all tests. Spatial navigation (sensitivity 95.8%/specificity 91.4%, d = 1.89), whole body reaction time (sensitivity 95.2%/specificity 89.1%, d = 1.50) and combined virtual reality modules (sensitivity 95.8%,/specificity 96.1%, d = 3.59) produced high sensitivity/specificity values when determining performance-based variability between groups. CONCLUSIONS: Use of a virtual reality-based NP platform can detect lingering cognitive abnormalities resulting from concussion in clinically asymptomatic participants. Virtual reality NP platforms may compliment the traditional concussion assessment battery by providing novel information. Language: en
TL;DR: Examining the combination of sleep-related symptoms and reduced sleep duration effectively identified adolescents at risk for poor neurocognitive performance than sleep duration alone.
Abstract: Typically, the effects of sleep duration on cognition are examined in isolation. OBJECTIVE: This study examined the effects of restricted sleep and related symptoms on neurocognitive performance. METHOD: Baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and postconcussion symptom scale (PCSS) were administered to athletes (N = 7,150) ages 14-17 (M = 15.26, SD = 1.09) prior to sport participation. Three groups of athletes were derived from total sleep duration: sleep restriction (≤5 hours), typical sleep (5.5-8.5 hours), and optimal sleep (≥9 hours). A MANCOVA (age and sex as covariates) was conducted to examine differences across ImPACT/PCSS. Follow-up MANOVA compared ImPACT/PCSS performance among symptomatic (e.g., trouble falling asleep, sleeping less than usual) adolescents from the sleep restriction group (n = 78) with asymptomatic optimal sleepers (n = 99). RESULTS: A dose-response effect of sleep duration on ImPACT performance and PCSS was replicated (Wilk's λ =.98, F2,7145 = 17.25, p CONCLUSION: Examining the combination of sleep-related symptoms and reduced sleep duration effectively identified adolescents at risk for poor neurocognitive performance than sleep duration alone. (PsycINFO Database Record Language: en