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1.
Arch Phys Med Rehabil ; 100(10): 1863-1871, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31153854

RESUMO

OBJECTIVE: To examine the validity of factor analytically based summary scores that were developed using the National Institutes of Health Toolbox Emotion Battery (NIHTB-EB); (ie, psychological well-being, social satisfaction, negative affect) normative sample in individuals with neurologic conditions. DESIGN: Cross-sectional, observational cohort. SETTING: Community. PARTICIPANTS: A total of 1036 English-speaking adults from the National Institutes of Health Toolbox (NIHTB) normative project and 604 community-dwelling adults with neurologic conditions including spinal cord injury (SCI n=209), traumatic brain injury (TBI n=184), and stroke (cerebrovascular accident [CVA] n=211) (N=1640). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: The NIHTB-EB. RESULTS: A series of univariate analyses comparing summary scores across the 4 groups (SCI, TBI, CVA, normative group) were conducted to identify group differences. Base rates (defined as >1 SD toward the problematic direction) were also identified. The normative group demonstrated better emotional functioning characterized by greater social satisfaction and psychological well-being (normative group > SCI, TBI, CVA; P's <.0001), and less negative affect (normative group < SCI, P=.016; normative group < TBI, P<.001; normative group < CVA; P=.034) compared with each neurologic group. Using base rates to identify problematic emotions for the 3 summary scores, there were higher rates of problematic emotions on all 3 summary scores for the neurologic groups compared with the normative group. CONCLUSIONS: The NIHTB-EB summary scores demonstrate an increased prevalence of problematic emotions among individuals with 3 neurologic conditions, and might be useful for identifying individuals with similar conditions and potentially in need of psychological support.

2.
Neuroimage Clin ; 20: 1044-1052, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30342393

RESUMO

OBJECTIVE: This study examined the effects of HIV infection, methamphetamine dependence and their interaction on cortical thickness, area and volume, as well as the potential interactive effects on cortical morphometry of HIV and methamphetamine with age. METHOD: T1-weighted structural images were obtained on a 3.0T General Electric MR750 scanner. Freesurfer v5.3.0 was used to derive cortical thickness, area and volume measures in thirty-four regions based on Desikan-Killiany atlas labels. RESULTS: Following correction for multiple statistical tests, HIV diagnosis was not significantly related to cortical thickness or area in any ROI, although smaller global cortical area and volume were seen in those with lower nadir CD4 count. HIV diagnosis, nevertheless, was associated with smaller mean cortical volumes in rostral middle frontal gyrus and in the inferior and superior parietal lobes. Methamphetamine dependence was significantly associated with thinner cortex especially in posterior cingulate gyrus, but was not associated with cortical area or volume following correction for multiple statistical tests. We found little evidence that methamphetamine dependence moderated differences in cortical area, volume or thickness for any ROI in the HIV seropositive group. Interactions with age revealed that HIV diagnosis attenuated the degree of age-related cortical thinning seen in non-infected individuals; intercepts indicated that young HIV seropositive individuals had thinner cortex than non-infected peers. CONCLUSIONS: Methamphetamine dependence does not appear to potentiate a reduction of cortical area, volume or thickness in HIV seropositive individuals. The finding of thinner cortex in young HIV seropositive individuals and the association between CD4 nadir and global cortical area and volume argue for prioritizing early antiretroviral treatment.


Assuntos
Córtex Cerebral/patologia , Lobo Frontal/patologia , Giro do Cíngulo/patologia , Infecções por HIV/virologia , Metanfetamina/farmacologia , Adulto , Antirretrovirais/farmacologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/virologia , Feminino , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/virologia , Giro do Cíngulo/efeitos dos fármacos , Giro do Cíngulo/virologia , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
Psychoneuroendocrinology ; 94: 72-82, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29763783

RESUMO

Women and men differ in their risk for developing stress-related conditions such as alcohol use and anxiety disorders and there are gender differences in the typical sequence in which these disorders co-occur. However, the neural systems underlying these gender-biased psychopathologies and clinical course modifiers in humans are poorly understood and may involve both central and peripheral mechanisms regulating the limbic-hypothalamic-pituitary-adrenal axis. In the present randomized, double blind, placebo-controlled, triple-dummy crossover study, we juxtaposed a centrally-acting, citalopram (2 mg/unit BMI) neuroendocrine stimulation test with a peripherally-acting, dexamethasone (Dex) (1.5 mg)/corticotropin-releasing factor (CRF) (1 µg/kg) test in euthymic women (N = 38) and men (N = 44) with (54%) and without histories of alcohol dependence to determine whether sex, alcohol dependence or both influenced the adrenocorticotropic hormone (ACTH) and cortisol responses to the pharmacological challenges and to identify the loci of these effects. We found that central serotonergic mechanisms, along with differences in pituitary and adrenal sensitivity, mediated sexually-diergic ACTH and cortisol responses in a stressor-specific manner regardless of a personal history of alcohol dependence. Specifically, women exhibited a greater response to the Dex/CRF test than they did the citalopram test while men exhibited the opposite pattern of results. Women also had more robust ACTH, cortisol and body temperature responses to Dex/CRF than men, and exhibited a shift in their adrenal glands' sensitivity to ACTH as measured by the cortisol/log (ACTH) ratio during that session in contrast to the other test days. Our findings indicate that central serotonergic and peripheral mechanisms both play roles in mediating sexually dimorphic, stressor-specific endocrine responses in humans regardless of alcohol dependence history.


Assuntos
Hormônio Adrenocorticotrópico/fisiologia , Hidrocortisona/fisiologia , Glândulas Suprarrenais , Hormônio Adrenocorticotrópico/análise , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Alcoolismo , Citalopram/farmacologia , Hormônio Liberador da Corticotropina/metabolismo , Estudos Cross-Over , Dexametasona/farmacologia , Método Duplo-Cego , Sistema Endócrino/metabolismo , Feminino , Humanos , Hidrocortisona/análise , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Hipófise , Sistema Hipófise-Suprarrenal/fisiologia , Fatores Sexuais , Estresse Psicológico/metabolismo
4.
Assessment ; : 1073191118766396, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29618218

RESUMO

The recently released National Institutes of Health Toolbox (NIHTB) batteries for neurological and behavioral function were designed to serve as standardized, common measures in clinical and epidemiological research. The current study aimed to examine constructs assessed by the self-report and parental proxy-report scales in the NIHTB Emotion Battery (NIHTB-EB) for Children by using factor analyses on data from the U.S. national normative sample of 2,916 English-speaking children. This battery contains 31 scales designed to assess both positive and negative aspects of social and emotional functioning that are considered developmentally relevant at each of three age ranges (3-7, 8-12, and 13-17 years). Results revealed four similar self-report factors for ages 8 to 12 years and 13 to 17 years. Proxy reports for ages 3 to 7 years revealed three factors, and for ages 8 to 12 years two factors. Based on the standardization sample data, age- and gender-corrected norms are presented for all NIHTB-EB individual scales and factor-based composites.

5.
Patient Relat Outcome Meas ; 9: 115-127, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29588623

RESUMO

Background: The National Institutes of Health Toolbox Emotion Battery (NIHTB-EB) is a "common currency", computerized assessment developed to measure the full spectrum of emotional health. Though comprehensive, the NIHTB-EB's 17 scales may be unwieldy for users aiming to capture more global indices of emotional functioning. Methods: NIHTB-EB was administered to 1,036 English-speaking and 408 Spanish-speaking adults as a part of the NIH Toolbox norming project. We examined the factor structure of the NIHTB-EB in English- and Spanish-speaking adults and developed factor analysis-based summary scores. Census-weighted norms were presented for English speakers, and sample-weighted norms were presented for Spanish speakers. Results: Exploratory factor analysis for both English- and Spanish-speaking cohorts resulted in the same 3-factor solution: 1) negative affect, 2) social satisfaction, and 3) psychological well-being. Confirmatory factor analysis supported similar factor structures for English- and Spanish-speaking cohorts. Model fit indices fell within the acceptable/good range, and our final solution was optimal compared to other solutions. Conclusion: Summary scores based upon the normative samples appear to be psychometrically supported and should be applied to clinical samples to further validate the factor structures and investigate rates of problematic emotions in medical and psychiatric populations.

6.
Sleep ; 41(3)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29361107

RESUMO

Study Objectives: Working memory (WM) has been described as a multicomponent process, comprised of the following: attention-driven encoding, maintenance and rehearsal of information, and encoding to and retrieval from episodic memory. Impairments can affect higher-order cognitive processes and many everyday functions. The impact of sleep changes on these cognitive processes across the life span needs to be investigated. The aim of the current study is to examine the effects of sleep deprivation on component processes of WM, comparing younger and older adults across verbal and visuospatial modalities. Methods: Thirty-one younger adults (19-38 years) and 33 older adults (59-82 years) attended two counterbalanced sleep protocols: a regular night of sleep followed by testing the next day (normally rested condition), and 36 hr of total sleep deprivation (TSD), followed by testing (TSD condition). Participants completed matched versions of verbal and visuospatial WM tasks across conditions. Results: Younger adults significantly outperformed older adults on encoding and displacement component processes, for both verbal and visuospatial WM. Following TSD, younger adults showed a significantly larger drop compared with older adults in verbal encoding and in visuospatial displacement. A main effect of condition was observed for verbal displacement. Conclusions: Differences were observed in the performance of younger and older adults on component processes of WM following TSD. This suggests that TSD can have differential effects on each component process when younger and older adults are compared, in both verbal and visuospatial tasks. Understanding this profile of changes is important for the development of possible compensatory strategies or interventions and the differentiation of clinical and healthy populations.


Assuntos
Memória de Curto Prazo/fisiologia , Desempenho Psicomotor/fisiologia , Privação do Sono/fisiopatologia , Privação do Sono/psicologia , Sono/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Atenção/fisiologia , Feminino , Humanos , Masculino , Memória Episódica , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Adulto Jovem
7.
Am J Geriatr Psychiatry ; 25(7): 744-752, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28342644

RESUMO

OBJECTIVES: Bipolar disorder (BD) is associated with compromised white matter (WM) integrity and deficits in processing speed (PS). Few studies, however, have investigated age relationships with WM structure and cognition to understand possible changes in brain health over the lifespan. This investigation explored whether BD and healthy counterpart (HC) participants exhibited differential age-related associations with WM and cognition, which may be suggestive of accelerated brain and cognitive aging. DESIGN: Cross-sectional study. SETTING: University of California San Diego and the Veterans Administration San Diego Healthcare System. PARTICIPANTS: 33 euthymic BD and 38 HC participants. MEASUREMENTS: Diffusion tensor imaging was acquired as a measure of WM integrity, and tract-specific fractional anisotropy (FA) was extracted utilizing the Johns Hopkins University probability atlas. PS was assessed with the Number and Letter Sequencing conditions of the Delis-Kaplan Executive Function System Trail Making Test. RESULTS: BD participants demonstrated slower PS compared with the HC group, but no group differences were found in FA across tracts. Multiple linear regressions revealed a significant group-by-age interaction for the right uncinate fasciculus, the left hippocampal portion of the cingulum, and for PS, such that older age was associated with lower FA values and slower PS in the BD group only. The relationship between age and PS did not significantly change after accounting for uncinate FA, suggesting that the observed age associations occur independently. CONCLUSIONS: Results provide support for future study of the accelerated aging hypothesis by identifying markers of brain health that demonstrate a differential age association in BD.


Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Transtorno Bipolar/patologia , Transtorno Bipolar/fisiopatologia , Cognição/fisiologia , Substância Branca/patologia , Adulto , Idoso , Anisotropia , Encéfalo/patologia , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Teste de Sequência Alfanumérica
8.
Am J Psychiatry ; 174(2): 172-185, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27539487

RESUMO

OBJECTIVE: Underage drinking is widely recognized as a leading public health and social problem for adolescents in the United States. Being able to identify at-risk adolescents before they initiate heavy alcohol use could have important clinical and public health implications; however, few investigations have explored individual-level precursors of adolescent substance use. This prospective investigation used machine learning with demographic, neurocognitive, and neuroimaging data in substance-naive adolescents to identify predictors of alcohol use initiation by age 18. METHOD: Participants (N=137) were healthy substance-naive adolescents (ages 12-14) who underwent neuropsychological testing and structural and functional magnetic resonance imaging (sMRI and fMRI), and then were followed annually. By age 18, 70 youths (51%) initiated moderate to heavy alcohol use, and 67 remained nonusers. Random forest classification models identified the most important predictors of alcohol use from a large set of demographic, neuropsychological, sMRI, and fMRI variables. RESULTS: Random forest models identified 34 predictors contributing to alcohol use by age 18, including several demographic and behavioral factors (being male, higher socioeconomic status, early dating, more externalizing behaviors, positive alcohol expectancies), worse executive functioning, and thinner cortices and less brain activation in diffusely distributed regions of the brain. CONCLUSIONS: Incorporating a mix of demographic, behavioral, neuropsychological, and neuroimaging data may be the best strategy for identifying youths at risk for initiating alcohol use during adolescence. The identified risk factors will be useful for alcohol prevention efforts and in research to address brain mechanisms that may contribute to early drinking.


Assuntos
Alcoolismo/fisiopatologia , Alcoolismo/psicologia , Consumo de Álcool por Menores/psicologia , Adolescente , Fatores Etários , Encéfalo/fisiopatologia , Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Cultura , Feminino , Seguimentos , Humanos , Controle Interno-Externo , Aprendizado de Máquina , Imagem por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Valor Preditivo dos Testes , Fatores de Risco , Fatores Sexuais , Fatores Socioeconômicos , Estados Unidos
9.
Psychiatry Res Neuroimaging ; 249: 27-37, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-27000304

RESUMO

Methamphetamine (METH) is an addictive psychostimulant inducing neurotoxicity. Human magnetic resonance imaging and diffusion tensor imaging (DTI) of METH-dependent participants find various structural abnormities. Animal studies demonstrate immunohistochemical changes in multiple cellular pathways after METH exposure. Here, we characterized the long-term effects of METH on brain microstructure in mice exposed to an escalating METH binge regimen using in vivo DTI, a methodology directly translatable across species. Results revealed four patterns of differential fractional anisotropy (FA) and mean diffusivity (MD) response when comparing METH-exposed (n=14) to saline-treated mice (n=13). Compared to the saline group, METH-exposed mice demonstrated: 1) decreased FA with no change in MD [corpus callosum (posterior forceps), internal capsule (left), thalamus (medial aspects), midbrain], 2) increased MD with no change in FA [posterior isocortical regions, caudate-putamen, hypothalamus, cerebral peduncle, internal capsule (right)], 3) increased FA with decreased MD [frontal isocortex, corpus callosum (genu)], and 4) increased FA with no change or increased MD [hippocampi, amygdala, lateral thalamus]. MD was negatively associated with calbindin-1 in hippocampi and positively with dopamine transporter in caudate-putamen. These findings highlight distributed and differential METH effects within the brain suggesting several distinct mechanisms. Such mechanisms likely change brain tissue differentially dependent upon neural location.


Assuntos
Encéfalo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/efeitos adversos , Imagem de Tensor de Difusão/métodos , Metanfetamina/efeitos adversos , Animais , Anisotropia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/patologia , Cápsula Interna/diagnóstico por imagem , Cápsula Interna/efeitos dos fármacos , Cápsula Interna/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tálamo/diagnóstico por imagem , Tálamo/efeitos dos fármacos , Tálamo/patologia
10.
J Int Neuropsychol Soc ; 21(5): 330-41, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26037664

RESUMO

Evidence for abnormal brain function as measured with diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) and cognitive dysfunction have been observed in inter-episode bipolar disorder (BD) patients. We aimed to create a joint statistical model of white matter integrity and functional response measures in explaining differences in working memory and processing speed among BD patients. Medicated inter-episode BD (n=26; age=45.2±10.1 years) and healthy comparison (HC; n=36; age=46.3±11.5 years) participants completed 51-direction DTI and fMRI while performing a working memory task. Participants also completed a processing speed test. Tract-based spatial statistics identified common white matter tracts where fractional anisotropy was calculated from atlas-defined regions of interest. Brain responses within regions of interest activation clusters were also calculated. Least angle regression was used to fuse fMRI and DTI data to select the best joint neuroimaging predictors of cognitive performance for each group. While there was overlap between groups in which regions were most related to cognitive performance, some relationships differed between groups. For working memory accuracy, BD-specific predictors included bilateral dorsolateral prefrontal cortex from fMRI, splenium of the corpus callosum, left uncinate fasciculus, and bilateral superior longitudinal fasciculi from DTI. For processing speed, the genu and splenium of the corpus callosum and right superior longitudinal fasciculus from DTI were significant predictors of cognitive performance selectively for BD patients. BD patients demonstrated unique brain-cognition relationships compared to HC. These findings are a first step in discovering how interactions of structural and functional brain abnormalities contribute to cognitive impairments in BD.


Assuntos
Transtorno Bipolar/complicações , Transtorno Bipolar/patologia , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Transtornos da Memória/etiologia , Memória de Curto Prazo/fisiologia , Adulto , Idoso , Anisotropia , Imagem de Tensor de Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Tempo de Reação/fisiologia , Análise de Regressão
11.
J Int Neuropsychol Soc ; 21(2): 105-15, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25771682

RESUMO

Impairment on inhibitory tasks has been well documented in bipolar disorder (BD). Differences in cerebral blood flow (CBF) between BD patients and healthy comparison (HC) participants have also been reported. Few studies have examined the relationship between cognitive performance and regional CBF in this patient population. We hypothesized that group differences on an inhibitory task (the Delis-Kaplan Executive Function Scale's Color-Word Inhibition task) would be associated with differential CBF in bilateral anterior cingulate cortex (ACC), inferior parietal lobule (IPL) and dorsolateral prefrontal cortex (DLPFC) regions. Whole brain resting CBF was measured using Multiphase Pseudocontinuous Arterial Spin Labeling MR imaging for 28 euthymic BD and 36 HC participants. Total gray matter (GM) CBF was measured, and regional CBF values were extracted for each region of interest (ROI) using Freesurfer-based individual parcellations. Group, CBF, and group-by-CBF interaction were examined as predictors of inhibition performance. Groups did not differ in age, gender or education. BD patients performed significantly worse on Color-Word inhibition. There were no significant group differences in CBF in either total GM or in any ROI. There was a group by CBF interaction in the bilateral ACC, right IPL and right DLPFC such that better inhibitory performance was generally associated with higher resting state CBF in BD subjects, but not HC participants. Although CBF was not abnormal in this euthymic BD sample, results confirm previous reports of inter-episode inhibitory deficits and indicate that the perfusion-cognition relationship is different in BD compared to HC individuals.


Assuntos
Transtorno Bipolar/complicações , Transtorno Bipolar/patologia , Circulação Cerebrovascular/fisiologia , /etiologia , Adulto , Idoso , Feminino , Substância Cinzenta/patologia , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Marcadores de Spin
12.
J Affect Disord ; 164: 101-6, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24856561

RESUMO

BACKGROUND: Working memory and underlying functional brain deficits have been observed in euthymic bipolar disorder (BD) patients, though there is heterogeneity in the degree of deficits. Sleep/circadian rhythm abnormalities are thought to be a core component of BD and may explain some of the heterogeneity in functional abnormalities. This preliminary study examined associations between sleep/circadian rhythm abnormalities and functional magnetic resonance imaging (fMRI) brain response on a working memory task among BD patients. METHODS: Fourteen euthymic medicated BD patients wore an actigraph for 7 days before undergoing fMRI with a working memory task. Two matched healthy comparison (HC) groups were used (14 in each sample). One group completed the actigraphy portion and the other completed the fMRI portion of the study. Circadian activity rhythm and sleep variables were calculated and compared between BD and HC participants. Variables that significantly differed were used to examine the association between activity rhythms/sleep abnormalities and fMRI working memory brain response in anatomically defined regions. RESULTS: Sleep efficiency and the rhythm robustness, mesor, and amplitude-to-width ratio were significantly abnormal in BD patients. Individual variability in all the sleep/circadian variables was significantly associated with the degree of abnormality of brain response in the dorsolateral prefrontal cortex and supramarginal gyri. LIMITATIONS: Small sample size and multiple comparison groups limit the interpretability of these findings. CONCLUSIONS: BD patients have abnormal activity rhythms and sleep efficiency, which are associated with abnormal working memory brain response. These preliminary findings support the notion that the sleep/circadian system is important in the functional brain deficits among BD patients.


Assuntos
Transtorno Bipolar/fisiopatologia , Encéfalo/fisiopatologia , Ritmo Circadiano , Adulto , Transtorno Bipolar/psicologia , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Memória de Curto Prazo , Pessoa de Meia-Idade , Córtex Pré-Frontal/fisiopatologia , Sono
13.
Bipolar Disord ; 16(3): 289-99, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24119150

RESUMO

OBJECTIVES: Individuals with bipolar disorder (BD) have trait-like deficits in attention and working memory (WM). A fundamental dissociation for most verbal WM theories involves the separation of sensory-perceptual encoding, reliant upon attention, from the maintenance of this information in WM proper. The present study examined if patients with BD demonstrate differential neural changes in encoding and maintenance WM processes that underlie cognitive impairment. METHODS: Event-related functional magnetic resonance imaging during a delayed match-to-sample WM paradigm was employed in 23 inter-episode medicated patients with BD and 23 demographically similar healthy comparison participants. We examined brain regions during encoding and maintenance task intervals to identify regions that demonstrated differential effects between groups. Medication effects and functional connectivity between prefrontal cortex and basal ganglia/thalamus were examined during the encoding interval due to the importance of these regions and the connection among them for encoding into WM. RESULTS: Patients with BD exhibited deficits in task accuracy and attenuated brain response during the encoding interval in areas of the prefrontal cortex, caudate, thalamus, and posterior visual regions. In contrast, patients with BD exhibited hyperactivation in posterior sensory regions during the maintenance interval. Among the BD group, those with greater medication load exhibited the greatest brain response within the prefrontal cortex. CONCLUSIONS: Reduction in activation during the encoding interval suggests that attentional deficits underlie WM deficits in patients with BD. These deficits appear to be trait-like in so far as they were observed during periods of euthymia in patients with BD. Medication effects remain to be further explored as there was evidence of prefrontal changes dependent on medication load.


Assuntos
Transtorno Bipolar/complicações , Transtorno Bipolar/patologia , Encéfalo/patologia , Transtornos da Memória/etiologia , Memória de Curto Prazo/fisiologia , Aprendizagem Verbal/fisiologia , Adulto , Idoso , Análise de Variância , Transtorno Bipolar/tratamento farmacológico , Encéfalo/irrigação sanguínea , Estudos de Casos e Controles , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio
14.
Brain Res ; 1537: 59-68, 2013 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-24012876

RESUMO

BACKGROUND: Significant cortical thinning and neural resource allocation changes emerge during adolescence; however, little is known of how morphometric changes influence neural response to cognitive demands. This study used a novel multimodal imaging registration technique to examine the relationship between brain structure and function during adolescence. METHODS: 156 healthy 12-14 year-olds (44% female) participants underwent structural and functional magnetic resonance imaging. Cortical surface reconstruction was performed via FreeSurfer, and neural activation was measured from a blood oxygen level dependent (BOLD) contrast during visual working memory (VWM) via AFNI. AFNI Surface Mapper aligned segmented volumetric and functional datasets to a common template space. Hierarchical linear regressions determined the effect of cortical thickness on VWM BOLD contrast in brain regions that activated during the VWM task, controlling for age, pubertal development, gender, IQ, and intracranial volume. RESULTS: Power analyses suggest this study was able to detect small effect sizes. However, in no region was cortical thickness related to BOLD activation (ps>.01; R(2)Δ<.02). Gender did not moderate effects. CONCLUSIONS: Cortical thickness, although variable across individuals, was not related to BOLD response, suggesting that structural and functional maturation do not have the same developmental trajectory during early adolescence. These findings are important, as imaging studies that report group differences in regards to cortical thickness should not necessarily assume co-occurring behavioral or functional changes. The methodology used in this study could be of interest to other developmental neuroimaging researchers using multimodal imaging to understand adolescent brain development.


Assuntos
Córtex Cerebral/fisiologia , Memória de Curto Prazo/fisiologia , Oxigênio/sangue , Percepção Visual/fisiologia , Adolescente , Mapeamento Encefálico/métodos , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Testes Neuropsicológicos
15.
Psychiatry Res ; 212(3): 183-91, 2013 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-23570915

RESUMO

Vigilance, which requires attending to relevant while ignoring irrelevant stimuli, is a cognitive domain impacted by schizophrenia and bipolar disorder. Various continuous performance tests (CPT) have been used to examine neural correlates of vigilance within people with and without severe mental illness, though there are limited cross-species paradigms available. The 5-choice CPT (5C-CPT) was designed for use in rodents as a cross-species translational paradigm. Here, we evaluate construct validity of a reverse-translated human analog of the 5C-CPT in assessing the neural correlates of vigilance. Functional magnetic resonance imaging during the 5C-CPT was used to examine activation of healthy individuals during target and non-target trials separately. We found activation in brain regions implicated in sustained attention processes including premotor cortex, inferior parietal lobe, basal ganglia, and thalamus during target trials. For non-target trials, we found expected activation in inferior frontal cortex, premotor cortex, presupplementary motor area, and inferior parietal lobe. Results support the construct validity of the 5C-CPT in measuring attentional and inhibitory systems within a single task paradigm enabling the assessment of vigilance across species. This task can be used for powerful parallel human and animal investigations of the biological basis of vigilance deficits in populations with severe mental illness.


Assuntos
Encéfalo/fisiologia , Neuroimagem Funcional , Imagem por Ressonância Magnética , Desempenho Psicomotor/fisiologia , Adulto , Atenção/fisiologia , Mapeamento Encefálico , Comportamento de Escolha/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Tempo de Reação/fisiologia
16.
Neuropsychology ; 27(2): 243-55, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23527652

RESUMO

OBJECTIVE: A fundamental dissociation for most working memory (WM) theories involves the separation of sensory-perceptual encoding of stimulus information from the maintenance of this information. The present paper reports tests of this separability hypothesis for visually presented pseudowords at both mathematical and neuroimaging levels of analysis. METHOD: Levels of analysis were linked by two experimental manipulations-visual degradation and pseudoword length variation-that coupled findings from a mathematical modeling study of WM performed in a separate sample to findings from an event-related functional MRI (fMRI) study reported in the present paper. Results from the mathematical modeling study generated parametric signatures of stimulus encoding and WM rehearsal and displacement. These signatures led to specific predictions about neurophysiological responses to study manipulations in a priori regions of interest (ROI). RESULTS: Results demonstrated predicted dissociations of activation signatures in several ROIs. Significant patterns of brain response mirroring the encode signature were observed only during the task encode interval and only in the visual cortex and posterior fusiform gyrus. In contrast, significant brain response mirroring the rehearsal/displacement signature was observed only in the dorsolateral prefrontal cortex, inferior frontal gyrus, and supramarginal gyrus. CONCLUSIONS: Present findings support the separability hypothesis insofar as brain regions that underlie sensory-perceptual processes demonstrated encode signatures whereas brain regions that support WM maintenance demonstrated the rehearsal/displacement signature. These results also provide evidence for the utility of combining mathematical modeling with fMRI to integrate information across cognitive and neural levels of analysis.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Memória de Curto Prazo/fisiologia , Modelos Neurológicos , Modelos Teóricos , Aprendizagem Verbal/fisiologia , Adulto , Análise de Variância , Córtex Cerebral/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Imagem por Ressonância Magnética , Masculino , Oxigênio/sangue , Estimulação Luminosa , Valor Preditivo dos Testes , Tempo de Reação/fisiologia , Adulto Jovem
17.
Clin Psychol Rev ; 32(7): 650-63, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22926687

RESUMO

Prefrontal cortex (PFC) mediated cognitive and emotional processing deficits in bipolar disorder lead to functional limitations even during periods of mood stability. Alterations of sleep and circadian functioning are well-documented in bipolar disorder, but there is little research directly examining the mechanistic role of sleep and/or circadian rhythms in the observed cognitive and emotional processing deficits. We systematically review the cognitive and emotional processing deficits reliant upon PFC functioning of euthymic patients with bipolar disorder and in healthy individuals deprived of sleep. The evidence from two parallel lines of investigation suggests that sleep and circadian rhythms may be involved in the cognitive and emotional processing deficits seen in bipolar disorder through overlapping neurobiological systems. We discuss current models of bipolar highlighting the PFC-limbic connections and discuss inclusion of sleep-related mechanisms. Sleep and circadian dysfunction is a core feature of bipolar disorder and models of neurobiological abnormalities should incorporate chronobiological measures. Further research into the role of sleep and circadian rhythms in cognition and emotional processing in bipolar disorder is warranted.


Assuntos
Transtorno Bipolar/fisiopatologia , Cognição/fisiologia , Emoções/fisiologia , Córtex Pré-Frontal/fisiopatologia , Privação do Sono/fisiopatologia , Transtorno Bipolar/psicologia , Mapeamento Encefálico , Neuroimagem Funcional , Humanos , Privação do Sono/psicologia
18.
Front Neurol ; 3: 49, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22493590

RESUMO

Disrupted sleep is more common in older adults (OLD) than younger adults (YOUNG), often co-morbid with other conditions. How these sleep disturbances affect cognitive performance is an area of active study. We examined whether brain activation during verbal encoding correlates with sleep quantity and quality the night before testing in a group of healthy OLD and YOUNG. Twenty-seven OLD (ages 59-82) and 27 YOUNG (ages 19-36) underwent one night of standard polysomnography. Twelve hours post-awakening, subjects performed a verbal encoding task while undergoing functional magnetic resonance imaging. Analyses examined the group (OLD vs. YOUNG) by prior sleep quantity (total sleep time, TST) or quality (sleep efficiency, SE) interaction on cerebral activation, controlling for performance. Longer TST promoted higher levels of activation in the bilateral anterior parahippocampal in OLD and lower activation levels in the left anterior parahippocampus in YOUNG. Greater SE promoted higher activation levels in the left posterior parahippocampus and right inferior frontal gyrus in YOUNG, but not in OLD. The roles of these brain regions in verbal encoding suggest, in OLD, longer sleep duration may be linked to the ability to engage in functional compensation during cognitive challenges. By contrast, in YOUNG, shorter sleep duration may necessitate functional compensation to maintain cognitive performance, similar to what is seen following acute sleep deprivation. Additionally, in YOUNG, better sleep quality may improve semantic retrieval processes, thereby aiding encoding.

19.
Sleep ; 32(3): 373-81, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19294957

RESUMO

STUDY OBJECTIVES: The objectives of this study were to (1) characterize cognitive and cerebral correlates of attention and response speed in patients with obstructive sleep apnea (OSA) and (2) assess the association of performance and brain activation with measures of OSA severity. DESIGN: Patients with OSA and controls were compared on performance and brain activation during a sustained attention task. The association of reaction time and brain activation with apnea-hypopnea index, nocturnal hypoxia, and arousals was assessed. SETTING: Functional magnetic resonance imaging was conducted while participants performed a Go-No-Go task. The 'Go' trials of the Go-No-Go task were used to index attention processing. PARTICIPANTS: Fourteen patients with OSA and 14 normal control subjects with equivalent age, body mass index, blood pressure, and education. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Patients with OSA showed decreased brain activation in cingulate, frontal, and parietal regions typically involved in attention tasks, compared with control subjects. Within the patients with OSA, increasing arousal index, but not desaturation index, was associated with slower mean reaction time and with decreased brain activation in areas involved in arousal and attention, response selection, motor response, and decision making. The apnea-hypopnea index, by itself, was not associated with changes in cerebral response. CONCLUSIONS: Patients with OSA showed decreased brain activation compared with control subjects during an attention task. The association of arousal index (but not hypoxia) with slow reaction times and brain activation suggests that alertness and reaction times show greater correlations with measures of sleep disruption than with measures of hypoxia.


Assuntos
Atenção/fisiologia , Encéfalo/fisiopatologia , Processamento de Imagem Assistida por Computador , Imagem por Ressonância Magnética , Tempo de Reação/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Adulto , Nível de Alerta/fisiologia , Mapeamento Encefálico , Tomada de Decisões/fisiologia , Dominância Cerebral/fisiologia , Feminino , Lobo Frontal/fisiopatologia , Giro do Cíngulo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Lobo Parietal/fisiopatologia , Reconhecimento Visual de Modelos/fisiologia , Desempenho Psicomotor/fisiologia , Apneia Obstrutiva do Sono/diagnóstico
20.
J Sleep Res ; 16(3): 245-52, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17716272

RESUMO

Sleep deprivation has been shown to alter decision-making abilities. The majority of research has utilized fairly complex tasks with the goal of emulating 'real-life' scenarios. Here, we use a Lottery Choice Task (LCT) which assesses risk and ambiguity preference for both decisions involving potential gains and those involving potential losses. We hypothesized that one night of sleep deprivation would make subjects more risk seeking in both gains and losses. Both a control group and an experimental group took the LCT on two consecutive days, with an intervening night of either sleep or sleep deprivation. The control group demonstrated that there was no effect of repeated administration of the LCT. For the experimental group, results showed significant interactions of night (normal sleep versus total sleep deprivation, TSD) by frame (gains versus losses), which demonstrate that following as little as 23 h of TSD, the prototypical response to decisions involving risk is altered. Following TSD, subjects were willing to take more risk than they ordinarily would when they were considering a gain, but less risk than they ordinarily would when they were considering a loss. For ambiguity preferences, there seems to be no direct effect of TSD. These findings suggest that, overall, risk preference is moderated by TSD, but whether an individual is willing to take more or less risk than when well-rested depends on whether the decision is framed in terms of gains or losses.


Assuntos
Tomada de Decisões , Jogo de Azar , Assunção de Riscos , Privação do Sono/psicologia , Vigília , Adulto , Afeto , Análise de Variância , Ritmo Circadiano , Feminino , Humanos , Masculino , Inquéritos e Questionários
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