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1.
BMC Med Educ ; 23(1): 665, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37710292

RESUMO

BACKGROUND: Ultrasound Guided Regional Anesthesia (UGRA) has become the standard for regional anesthesia practice, but there is not a standardized educational approach for training residents. The objective of this study was to evaluate the efficacy of an UGRA workshop utilizing the theoretical framework of embodied cognition for anesthesiology residents. METHODS: A workshop was developed consisting of didactics, scanning training on standardized patients (SPs) and anatomy reviews on prosected cadavers that focused on the most common UGRA procedures for the upper and lower extremity. At the beginning of the workshop and at the end of the workshop residents completed pre-test and pre-confidence surveys, as well as post-test and post-confidence surveys, respectively to assess the impact of the workshop. RESULTS: 39 residents (100% of the possible residents) participated in the workshop in 2019. Residents' confidence in identifying relevant anatomy for the most common UGRA procedures significantly increased in 13 of the 14 measurements. Residents' knowledge gain was also statistically significant from the pre-test to post-test (20.13 ± 3.61 and 26.13 ± 2.34; p < .0001). The residents found the course overall to be very useful (4.90 ± 0.38) and in particular the cadaveric component was highly rated (4.74 ± 0.55). CONCLUSIONS: In this study, we developed a workshop guided by the embodied cognition framework to aid in shortening the overall learning curve of UGRA for anesthesiology residents. Based on our results this workshop should be replicated by institutions that are hoping to decrease the learning curve associated with UGRA and increase residents' confidence in identifying the relevant anatomy in UGRA nerve blocks.


Assuntos
Anestesia por Condução , Cognição , Humanos , Ultrassonografia , Ultrassom , Escolaridade
2.
J Nutr ; 153(10): 3144-3151, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37315793

RESUMO

BACKGROUND: Carotenoids are plant pigments with light filtering and antioxidant properties that deposit in human tissues, including retina and skin. Descriptive characteristics and covariates of carotenoid status in macula and skin have been examined in adults; however, similar studies in children are limited. Thus, this study aimed to delineate how factors of age, sex, race, weight status, and dietary carotenoid intake relate to macular and skin carotenoids in children. METHODS: Children (7-13 y, N = 375) completed heterochromatic flicker photometry to assess macular pigment optical density (MPOD). Participants underwent anthropometrics to measure weight status (BMI percentile [BMI%]), and parent/guardian provided demographic information. Subsample data were available for skin carotenoids (N = 181), assessed using reflection spectroscopy, and dietary carotenoids (N = 101) using the Block Food Frequency Questionnaire. Relationships between skin and macular carotenoids were assessed using partial Pearson's correlations controlling for age, sex, race, and BMI%. Relationships between dietary carotenoids and macular and skin carotenoids were assessed using stepwise linear regression including age, sex, race, and BMI% in the model. RESULTS: Mean MPOD was 0.56 ± 0.22 and skin carotenoid score was 282 ± 94.6. There was no significant correlation between MPOD and skin carotenoids (r = 0.02, P = 0.76). BMI% was negatively associated with skin (stdß = -0.42, P < 0.001), but not macular carotenoids (stdß = -0.04, P = 0.70). Neither MPOD nor skin carotenoids were associated with age, sex, or race (all P > 0.10). MPOD was positively associated with energy-adjusted reported lutein + zeaxanthin intake (stdß = 0.27, P = 0.01). Skin carotenoids were positively associated with energy-adjusted reported carotenoid intake (stdß = 0.26, P = 0.01). CONCLUSIONS: The mean MPOD values in children were higher than what has been reported in adult populations. Previous studies in adult samples report an average MPOD of 0.21. Although macular and skin carotenoids were not related, they were associated with dietary carotenoids relevant to the respective tissues; however, skin carotenoids may be more susceptible negative influence from higher weight status.


Assuntos
Macula Lutea , Pigmento Macular , Adulto , Humanos , Criança , Luteína , Zeaxantinas , Macula Lutea/química , Retina
3.
Am J Clin Nutr ; 118(2): 369-381, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37315924

RESUMO

BACKGROUND: There is evidence that both omega-3 long-chain polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and cocoa flavanols can improve cognitive performance in both healthy individuals and in those with memory complaints. However, their combined effect is unknown. OBJECTIVES: To investigate the combined effect of EPA/DHA and cocoa flavanols (OM3FLAV) on cognitive performance and brain structures in older adults with memory complaints. METHODS: A randomized placebo-controlled trial of DHA-rich fish oil (providing 1.1 g/d DHA and 0.4 g/d EPA) and a flavanol-rich dark chocolate (providing 500 mg/d flavan-3-ols) was conducted in 259 older adults with either subjective cognitive impairment or mild cognitive impairment. Participants underwent assessment at baseline, 3 mo, and 12 mo. The primary outcome was the number of false-positives on a picture recognition task from the Cognitive Drug Research computerized assessment battery. Secondary outcomes included other cognition and mood outcomes, plasma lipids, brain-derived neurotrophic factor (BDNF), and glucose levels. A subset of 110 participants underwent structural neuroimaging at baseline and at 12 mo. RESULTS: 197 participants completed the study. The combined intervention had no significant effect on any cognitive outcomes, with the exception of reaction time variability (P = 0.007), alertness (P < 0.001), and executive function (P < 0.001), with a decline in function observed in the OM3FLAV group (118.6 [SD 25.3] at baseline versus 113.3 [SD 25.4] at 12 mo for executive function) relative to the control, and an associated decrease in cortical volume (P = 0.039). Compared with the control group, OM3FLAV increased plasma HDL, total cholesterol ratio (P < 0.001), and glucose (P = 0.008) and reduced TG concentrations (P < 0.001) by 3 mo, which were sustained to 12 mo, with no effect on BDNF. Changes in plasma EPA and DHA and urinary flavonoid metabolite concentrations confirmed compliance to the intervention. CONCLUSIONS: These results suggest that cosupplementation with ω-3 PUFAs and cocoa flavanols for 12 mo does not improve cognitive outcomes in those with cognitive impairment. This trial was registered at clinicaltrials.gov as NCT02525198.


Assuntos
Chocolate , Ácidos Graxos Ômega-3 , Humanos , Óleos de Peixe , Ácidos Docosa-Hexaenoicos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Método Duplo-Cego , Ácidos Graxos Ômega-3/farmacologia , Ácido Eicosapentaenoico/farmacologia , Cognição , Suplementos Nutricionais , Encéfalo/diagnóstico por imagem
4.
J Exp Psychol Hum Percept Perform ; 49(6): 786-801, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37166935

RESUMO

Humans use eye movements to build visual memories. We investigated how the contributions of specific viewing behaviors to memory formation evolve over individual study epochs. We used dyadic modeling to explain performance on a spatial reconstruction task based on interactions among two gaze measures: (a) the entropy of the scanpath and (b) the frequency of item-to-item gaze transitions. To measure these interactions, our hypothesized model included causal pathways by which early-trial viewing behaviors impacted subsequent memory via downstream effects on later viewing. We found that lower scanpath entropy throughout the trial predicted better memory performance. By contrast, the effect of item-to-item transition frequency changed from negative to positive as the trial progressed. The model also revealed multiple pathways by which early-trial viewing dynamically altered late-trial viewing, thereby impacting memory indirectly. Finally, individual differences in scores on an independent measure of memory ability were found to predict viewing effectiveness, and viewing behaviors partially mediated the relation between memory ability and reconstruction accuracy. In a second experiment, the model showed a good fit for an independent dataset. These results highlight the dynamic nature of memory formation and suggest that the order in which eye movements occur can critically determine their effectiveness. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Movimentos Oculares , Memória , Humanos , Cognição , Individualidade
5.
Nutr Neurosci ; 26(3): 265-274, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35282787

RESUMO

Objectives: We aimed to determine whether consumption of a fermented dairy beverage containing probiotic microorganisms influences negative mood states, stress, and hippocampal memory performance in healthy adults. Methods: Adults (25-45 yrs, N = 26) free of gastrointestinal and mental illness were enrolled in a single-blind, randomized, controlled, crossover trial. Participants completed testing prior to and after 4-week consumption, with a 2-4 week washout between treatments of: (1) 8 oz of a dairy-based fermented beverage containing 25-30 billion colony forming units of live and active kefir cultures or (2) 8 oz isocaloric, non-fermented, 1% low-fat lactose-free dairy-based control beverage. Hippocampal-dependent relational memory was assessed using a spatial reconstruction task. Negative mood states of depression and anxiety were assessed using the Depression Anxiety Stress Scales-42 (DASS-42). Pooled 24-hour urine samples were analyzed using an enzyme-linked immunosorbent assay to determine urinary free-cortisol (UFC) concentrations. Fecal microbiota composition was assessed using 16S rRNA gene sequencing. Results: Lactobacillus was increased by 235% following fermented dairy consumption compared to the control (p < .01). Furthermore, the fermented dairy beverage improved performance on two metrics of relational memory, misplacement (p = .04) and object-location binding (p = .03). UFC and DASS-42 scores (all p's > .08) were not significantly changed by either arm of the intervention. No correlations were observed between the change in Lactobacillus and memory performance. Conclusions: Fermented dairy consumption increased the presence of certain microorganisms in the gut and improved relational memory in healthy adults. However, the benefits observed for relational memory were not related to changes in Lactobacillus.Trial registration: ClinicalTrials.gov identifier: NCT02849275.


Assuntos
Lactobacillus , Probióticos , Adulto , Humanos , Estudos Cross-Over , RNA Ribossômico 16S/genética , Método Simples-Cego , Bebidas Fermentadas , Bebidas
6.
Contemp Clin Trials ; 122: 106964, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36252934

RESUMO

Lutein and zeaxanthin (L + Z) are carotenoids that accumulate in neural tissue and potentially confer benefits to cognition. Whereas cross-sectional studies have revealed positive associations between macular carotenoids (MC) and cognition, no studies have investigated whether L + Z supplementation impacts MC and cognition in childhood. Accordingly, the Integrated Childhood Ocular Nutrition Study aims to investigate the impact of L + Z supplementation over 9-months on academic abilities, attentional control, memory, and MC among preadolescent children. Children 8-10 years (N = 288) will enroll in a 9-month double-blind, placebo-controlled, randomized trial. The study is registered and approved as a clinical trial on the U.S. National Library of Medicine http://ClinicalTrials.gov registry (NCT05177679). Participants will be randomized into an active (10 mg lutein+2 mg zeaxanthin) or waitlist placebo-controlled group. Primary outcomes include hippocampal-dependent memory, attentional inhibition, and academic achievement using a spatial reconstruction task, an Eriksen flanker task, and the Kaufman Test of Academic and Educational Achievement 3rd edition, respectively. Secondary outcomes include event-related brain potentials of attentional resource allocation and information processing speed (i.e., P3/P300 amplitude and latency) recorded during the flanker task. Macular pigment optical density (MPOD) will be assessed using heterochromatic flicker photometry. Cognitive assessments will be completed prior to and after completion of the supplementation period. MPOD will be quantified prior to, at the mid-point of (4-5 months), and after (9 months) the supplementation period. It is hypothesized that L + Z supplementation will improve cognition and academic achievement. Further, benefits for cognition and achievement are anticipated to be mediated by increases in MC among treatment group participants.


Assuntos
Luteína , Pigmento Macular , Criança , Humanos , Zeaxantinas/farmacologia , Luteína/uso terapêutico , Luteína/farmacologia , Estudos Transversais , Pigmento Macular/fisiologia , Cognição , Suplementos Nutricionais , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
Sci Rep ; 12(1): 15220, 2022 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-36076053

RESUMO

Nutrition during the first years of life has a significant impact on brain development. This study characterized differences in brain maturation from birth to 6 months of life in infant macaques fed formulas differing in content of lutein, ß-carotene, and other carotenoids using Magnetic Resonance Imaging to measure functional connectivity. We observed differences in functional connectivity based on the interaction of diet, age and brain networks. Post hoc analysis revealed significant diet-specific differences between insular-opercular and somatomotor networks at 2 months of age, dorsal attention and somatomotor at 4 months of age, and within somatomotor and between somatomotor-visual and auditory-dorsal attention networks at 6 months of age. Overall, we found a larger divergence in connectivity from the breastfeeding group in infant macaques fed formula containing no supplemental carotenoids in comparison to those fed formula supplemented with carotenoids. These findings suggest that carotenoid formula supplementation influences functional brain development.


Assuntos
Carotenoides , Macaca , Animais , Alimentos Formulados , Humanos , Luteína/farmacologia , beta Caroteno
8.
Anesth Analg ; 135(4): 697-703, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108183

RESUMO

ADDENDUM: Please note that in the interim since this paper was accepted for publication, new governmental regulations, pertinent to the topic, have been approved for implementation. The reader is thus directed to this online addendum for additional relevant information: http://links.lww.com/AA/E44.


Assuntos
Anestesia , Anestesiologia , Humanos
9.
J Clin Exp Neuropsychol ; 44(3): 210-225, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35876336

RESUMO

INTRODUCTION: Temporal order memory is a core cognitive function that underlies much of our behavior. The ability to bind together information within and across events, and to reconstruct that sequence of information, critically relies upon the hippocampal relational memory system. Recent work has suggested traumatic brain injury (TBI) may particularly impact hippocampally mediated relational memory. However, it is currently unclear whether such deficits extend to temporal order memory, and whether deficits only arise at large memory loads. The present study assessed temporal order memory in individuals with chronic, moderate-severe TBI across multiple set sizes. METHOD: Individuals with TBI and Neurotypical Comparison participants studied sequences of three to nine objects, one a time. At test, all items were re-presented in pseudorandom order, and participants indicated the temporal position (i.e., first, second, etc.) in which each object had appeared. Critically, we assessed both the frequency and the magnitude of errors (i.e., how far from its studied position was an item remembered). RESULTS: Individuals with TBI were not impaired for the smallest set size, but showed significant impairments at 5+ items. Group differences in the error frequency did not increase further with larger set sizes, but group differences in error magnitude did increase with larger memory loads. Individuals with TBI showed spared performance for the first object of each list (primacy) but were impaired on the last object (recency), though error frequency was better for last compared to middle items. CONCLUSIONS: Our findings demonstrate that TBI results in impaired temporal order memory for lists as small as five items, and that impairments are exacerbated with increasing memory loads. Assessments that test only small set sizes may be insufficient to detect these deficits. Further, these data highlight the importance of additional, sensitive measures in the assessment of cognitive impairments in TBI.


Assuntos
Lesões Encefálicas Traumáticas , Transtornos da Memória , Lesões Encefálicas Traumáticas/psicologia , Cognição , Hipocampo , Humanos , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Rememoração Mental
11.
Brain Commun ; 3(2): fcab085, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34007965

RESUMO

Docosahexaenoic acid is the main long-chain omega-3 polyunsaturated fatty acids in the brain and accounts for 30-40% of fatty acids in the grey matter of the human cortex. Although the influence of docosahexaenoic acid on memory function is widely researched, its association with brain volumes is under investigated and its association with spatial navigation is virtually unknown. This is despite the fact that spatial navigation deficits are a new cognitive fingerprint for symptomatic and asymptomatic Alzheimer's disease. We investigated the cross-sectional relationship between docosahexaenoic acid levels and the major structural and cognitive markers of preclinical Alzheimer's disease, namely hippocampal volume, entorhinal volume and spatial navigation ability. Fifty-three cognitively normal adults underwent volumetric magnetic resonance imaging, measurements of serum docosahexaenoic acid (DHA, including lysophosphatidylcholine DHA) and APOE ε4 genotyping. Relative regional brain volumes were calculated and linear regression models were fitted to examine DHA associations with brain volume. APOE genotype modulated serum DHA associations with entorhinal cortex volume and hippocampal volume. Linear models showed that greater serum DHA was associated with increased entorhinal cortex volume, but not hippocampal volume, in non APOΕ Îµ4 carriers. APOE also interacted with serum lysophosphatidylcholine DHA to predict hippocampal volume. After testing interactions between DHA and APOE on brain volume, we investigated whether DHA and APOE interact to predict spatial navigation performance on a novel virtual reality diagnostic test for Alzheimer's disease in an independent population of APOE genotyped adults (n = 46). APOE genotype modulated DHA associations with spatial navigation performance, showing that DHA was inversely associated with path integration in APOE ε4 carriers only. This exploratory analysis suggests that interventions aiming to increase DHA blood levels to protect against cognitive decline should consider APOE ε4 carrier status. Future work should focus on replicating our initial findings and establishing whether a specific dose of supplementary DHA, at a particular time in the preclinical disease course can have a positive impact on Alzheimer's disease progression in APOE ε4 carriers.

12.
J Nutr ; 151(9): 2533-2540, 2021 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-34049394

RESUMO

BACKGROUND: High macular pigment optical density (MPOD) has been associated with improved eye health and better cognitive functions. Genetic variations have been associated with MPOD in adults. However, these associations between genetic variations and MPOD have not been studied in children. OBJECTIVES: This was a secondary analysis of the FK2 (Fitness Improves Thinking in Kids 2) trial (n = 134, 41% male). The aim was to determine differences in MPOD among children (aged 7-9 y) based on genetic variants that either are biologically relevant to lutein (L) and zeaxanthin (Z) accumulation or have been associated with MPOD in adults. METHODS: MPOD was measured using customized heterochromatic flicker photometry via a macular densitometer. DXA was used to assess whole-body and visceral adiposity. DNA was extracted from saliva samples and was genotyped for 26 hypothesis-driven single nucleotide polymorphisms and 75 ancestry-informative markers (AIMs). Habitual diet history was obtained via 3-d food logs completed by parents (n = 88). General linear models were used to compare MPOD between different genotypes. Principal component analysis was performed for the AIMs to account for ethnic heterogeneity. RESULTS: Children carrying ≥1 minor allele on ß-carotene-15,15'-monooxygenase (BCO1)-rs7501331 (T allele) (P = 0.045), cluster of differentiation 36(CD36)-rs1527483 (T allele) (P = 0.038), or CD36-rs3173798 (C allele) (P = 0.001) had significantly lower MPOD (range: 14.1%-26.4%) than those who were homozygotes for the major alleles. MPOD differences based on CD36-rs3173798 genotypes persisted after adjustment for dietary L and Z intake. CONCLUSIONS: The findings indicate that genetic variations of CD36 and BCO1 contribute to MPOD in children. The influence of genetic variation in CD36-rs3173798 persisted after adjusting for variation in dietary intake.This trial was registered at clinicaltrials.gov as NCT01619826.


Assuntos
Pigmento Macular , Adulto , Criança , Dieta , Feminino , Humanos , Luteína , Pigmento Macular/genética , Masculino , Polimorfismo de Nucleotídeo Único , Zeaxantinas
13.
Hum Brain Mapp ; 41(18): 5282-5300, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-32931076

RESUMO

Standard anatomical atlases are common in neuroimaging because they facilitate data analyses and comparisons across subjects and studies. The purpose of this study was to develop a standardized human brain atlas based on the physical mechanical properties (i.e., tissue viscoelasticity) of brain tissue using magnetic resonance elastography (MRE). MRE is a phase contrast-based MRI method that quantifies tissue viscoelasticity noninvasively and in vivo thus providing a macroscopic representation of the microstructural constituents of soft biological tissue. The development of standardized brain MRE atlases are therefore beneficial for comparing neural tissue integrity across populations. Data from a large number of healthy, young adults from multiple studies collected using common MRE acquisition and analysis protocols were assembled (N = 134; 78F/ 56 M; 18-35 years). Nonlinear image registration methods were applied to normalize viscoelastic property maps (shear stiffness, µ, and damping ratio, ξ) to the MNI152 standard structural template within the spatial coordinates of the ICBM-152. We find that average MRE brain templates contain emerging and symmetrized anatomical detail. Leveraging the substantial amount of data assembled, we illustrate that subcortical gray matter structures, white matter tracts, and regions of the cerebral cortex exhibit differing mechanical characteristics. Moreover, we report sex differences in viscoelasticity for specific neuroanatomical structures, which has implications for understanding patterns of individual differences in health and disease. These atlases provide reference values for clinical investigations as well as novel biophysical signatures of neuroanatomy. The templates are made openly available (github.com/mechneurolab/mre134) to foster collaboration across research institutions and to support robust cross-center comparisons.


Assuntos
Atlas como Assunto , Córtex Cerebral , Técnicas de Imagem por Elasticidade , Substância Cinzenta , Imageamento por Ressonância Magnética , Substância Branca , Adolescente , Adulto , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Feminino , Substância Cinzenta/anatomia & histologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Viscosidade , Substância Branca/anatomia & histologia , Substância Branca/diagnóstico por imagem , Adulto Jovem
14.
Sci Rep ; 10(1): 13993, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32814816

RESUMO

How daily physical activity and sedentary time relate to human judgement and functional connectivity (FC) patterns that support them remains underexplored. We investigated the relationships between accelerometer-measured moderate-to-vigorous physical activity (MVPA) and sedentary time to decision-making competence (DMC) in young adults using a comprehensive Adult-Decision Making Competence battery. We applied graph theory measures of global and local efficiency to test the mediating effects of FC in cognitively salient brain networks (fronto-parietal; dorsal attention, DAN; ventral attention; and default mode), assessed from the resting-state fMRI. Sedentary time was related to lower susceptibility to a framing bias. However, once global and local efficiency of the DAN were considered we observed (1) higher susceptibility to framing with more sedentary time, mediated through lower local and global efficiency in the DAN, and (2) lower susceptibility to framing with more sedentary time. MVPA was not related to DMC or graph theory measures. These results suggest that remaining sedentary may reduce neurofunctional readiness for top-down control and decrease engagement of deliberate thought, required to ignore irrelevant aspects of a problem. The positive effect suggests that the relationship between sedentary time and DMC may be moderated by unmeasured factors such as the type of sedentary behavior.


Assuntos
Atenção/fisiologia , Tomada de Decisões/fisiologia , Exercício Físico/fisiologia , Rede Nervosa/fisiologia , Vias Neurais/fisiologia , Comportamento Sedentário , Adolescente , Adulto , Algoritmos , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Modelos Neurológicos , Adulto Jovem
15.
Front Hum Neurosci ; 14: 270, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32754022

RESUMO

Memory deficits are a common and frequently-cited consequence of moderate-severe traumatic brain injury (TBI). However, we know less about how TBI influences relational memory, which allows the binding of the arbitrary elements of experience and the flexible use and recombination of relational representations in novel situations. Relational memory is of special interest for individuals with TBI, given the vulnerability of the hippocampus to injury mechanisms, as well as a growing body of literature establishing the role of relational memory in flexible and goal-directed behavior. In this study, participants with and without a history of moderate-severe TBI completed a continuous relational memory task for face-scene pairings. Participants with TBI exhibited a disruption in relational memory not only when tested after a delay, but also when tested with no experimenter-imposed delay after stimulus presentation. Further, canonical assessments of working and episodic memory did not correspond with performance on the face-scene task, suggesting that this task may tap into relational memory differently and with greater sensitivity than standardized memory assessments. These results highlight the need for rigorous assessment of relational memory in TBI, which is likely to detect deficits that have specific consequences for community reintegration and long-term functional outcomes.

16.
J Cogn Neurosci ; 32(9): 1704-1713, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32379003

RESUMO

The hippocampus is necessary for binding and reconstituting information in relational memory. These essential memory functions are supported by the distinct cytoarchitecture of the hippocampal subfields. Magnetic resonance elastography is an emerging tool that provides sensitive estimates of microstructure vis-à-vis tissue mechanical properties. Here, we report the first in vivo study of human hippocampal subfield viscoelastic stiffness and damping ratio. Stiffness describes resistance of a viscoelastic tissue to a stress and is thought to reflect the relative composition of tissue at the microscale; damping ratio describes relative viscous-to-elastic behavior and is thought to generally reflect microstructural organization. Measures from the subiculum (combined with presubiculum and parasubiculum), cornu ammonis (CA) 1-2, and CA3-dentate gyrus (CA3-DG) were collected in a sample of healthy, cognitively normal men (n = 20, age = 18-33 years). In line with known cytoarchitecture, the subiculum demonstrated the lowest damping ratio, followed by CA3-DG and then combined CA1-CA2. Moreover, damping ratio of the CA3-DG-potentially reflective of number of cells and their connections-predicted relational memory accuracy and alone replicated most of the variance in performance that was explained by the whole hippocampus. Stiffness did not differentiate the hippocampal subfields and was unrelated to task performance in this sample. Viscoelasticity measured with magnetic resonance elastography appears to be sensitive to microstructural properties relevant to specific memory function, even in healthy younger adults, and is a promising tool for future studies of hippocampal structure in aging and related diseases.


Assuntos
Técnicas de Imagem por Elasticidade , Adolescente , Adulto , Envelhecimento , Giro Denteado , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
17.
Metab Brain Dis ; 35(6): 999-1007, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32350752

RESUMO

Magnetic Resonance Spectroscopy provides measures of brain chemistry that are sensitive to cardiorespiratory fitness and body composition. The concentration of N-acetyl aspartic acid (NAA) is of interest because it is a marker of neuronal integrity. The ratio of NAA to creatine, a standard reference metabolite, has been shown to correlate with measures of both cardiorespiratory fitness and body composition. However, previous studies have explored these effects in isolation, making it impossible to know which of these highly correlated measures drive the correlations with NAA/Cr. As a result, the mechanisms underlying their association remain to be established. We therefore conducted a comprehensive study to investigate the relative contributions of cardiorespiratory fitness and percent body fat in predicting NAA/Cr. We demonstrate that NAA/Cr in white matter is correlated with percent body fat, and that this relationship largely subsumes the correlation of NAA/Cr with cardiorespiratory fitness. These results underscore the association of body composition with axonal integrity and suggests that this relationship drives the association of NAA/Cr with physical fitness in young adults.


Assuntos
Índice de Massa Corporal , Química Encefálica/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Aptidão Cardiorrespiratória/fisiologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Adulto Jovem
18.
Trends Neurosci Educ ; 18: 100123, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32085907

RESUMO

BACKGROUND: Fluid intelligence (Gf) is a critical cognitive ability that is predictive of real-world outcomes, and it has been a persistent aim to characterize its neural architecture. PROCEDURE: We advance our prior research by applying latent class analysis to evaluate individual differences in the neural and cognitive foundations of Gf over the course of a 16-week randomized, multi-modal intervention trial in neurologically healthy, younger adults (N = 424). RESULTS: Controlling for pre-intervention ability, three latent classes described individual performance at post-intervention and one group (n = 71) showed greater gains in visuospatial reasoning and high performance at post-intervention. The high performance group was predicted by larger anterior cingulate cortex, caudate and hippocampus volumes, and smaller middle frontal, insula and parahippocampal cortex volumes. CONCLUSION: Regions that support cognitive control, working memory, and relational processes differentiated individuals who had higher Gf ability at pre-intervention and demonstrated a cumulative better response to the intervention.


Assuntos
Córtex Cerebral/fisiologia , Exercício Físico/psicologia , Inteligência/fisiologia , Meditação/psicologia , Atenção Plena , Adulto , Função Executiva/fisiologia , Feminino , Humanos , Testes de Inteligência , Masculino , Memória de Curto Prazo/fisiologia
19.
Nutr Neurosci ; 23(10): 791-802, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30558494

RESUMO

Objectives: Creativity requires the ability to combine existing mental representations in new ways and depends, in part, on the hippocampus. Hippocampal function is, in turn, affected by a number of health factors, including aerobic fitness, excess adiposity, and diet. Specifically, in rodent studies, diets high in saturated fatty acids and sugar - hallmarks of a western diet- have been shown to negatively impact hippocampal function and thereby impair performance on cognitive tasks that require the hippocampus. Yet relatively few studies have examined the relationship between diet and hippocampal-dependent cognition in children. Methods: The current study therefore sought to explore the relationship of several diet quality markers including dietary lipids (saturated fatty acids and omega-3 fatty acids), simple carbohydrates (added sugars), and dietary fiber with creativity in preadolescent children. Participants (N = 57; mean age = 9.1 years) completed the Verbal Form of the Torrance Test of Creative Thinking (TTCT), a standardized test of creativity known to require the hippocampus. Additionally, participants completed a 3-day food intake record with the assistance of a parent, underwent dual energy x-ray absorptiometry (DXA) to assess central adiposity, and VO2max testing to assess aerobic fitness. Results: Added sugar intake was negatively associated, and dietary fiber was positively associated with overall TTCT performance. These relationships were sustained even after controlling for key covariates. Discussion: These findings are among the first to report an association between added sugar consumption and hippocampal-dependent cognition during childhood and, given the key role of the hippocampus in learning and memory, as well as creative thinking, have potential educational and public health implications.


Assuntos
Criatividade , Fibras na Dieta/administração & dosagem , Açúcares da Dieta/administração & dosagem , Adiposidade , Antropometria , Criança , Dieta , Dieta Ocidental , Exercício Físico , Feminino , Hipocampo , Humanos , Masculino , Testes Neuropsicológicos
20.
J Clin Exp Neuropsychol ; 42(1): 14-27, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31475607

RESUMO

Introduction: Relational memory is the ability to bind arbitrary relations between elements of experience into durable representations and the flexible expression of these representations. It is well known that individuals with traumatic brain injury (TBI) have declarative memory impairments, but less is known about how TBI affects relational memory binding, the deficit at the heart of declarative, or relational, memory impairment. The aim of the current study is to examine such deficits.Method: We used a spatial reconstruction task (SRT) with 29 individuals with TBI and 23 normal comparison (NC) participants to investigate four different types of spatial relations: (A) identity-location relations, i.e., the relationship between a specific item and its known location; (B) item-item relations, or the relationship between one item and another; (C) item-display relations, or the relationship between an item and its position in the display; and (D) compound-item relations, i.e., relations that involve combinations of A, B, and C.Results: Our data revealed that individuals with TBI showed impairments in learning identity-location relations and increased compound errors compared to NCs. We also found evidence that when item identity is disregarded, individuals with TBI do not perform differently from NCs. An exploratory analysis revealed that while relational memory performance was significantly correlated with scores on the California Verbal Learning Test (CVLT), more participants with TBI exhibited impairment on the SRT than of the CVLT.Conclusions: Our findings show that relational memory is impaired following TBI, and provide preliminary evidence for an easy-to-administer task with increased sensitivity to memory impairment.


Assuntos
Associação , Lesões Encefálicas Traumáticas/fisiopatologia , Transtornos da Memória/fisiopatologia , Aprendizagem Espacial/fisiologia , Memória Espacial/fisiologia , Adulto , Lesões Encefálicas Traumáticas/complicações , Feminino , Humanos , Masculino , Transtornos da Memória/etiologia
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