27 results match your criteria: "Duke UniversityDurham[Affiliation]"

Despite the population of the noninvasive, economic, comfortable, and easy-to-install photoplethysmography (PPG), it is still lacking a mathematically rigorous and stable algorithm which is able to simultaneously extract from a single-channel PPG signal the instantaneous heart rate (IHR) and the instantaneous respiratory rate (IRR). In this paper, a novel algorithm called deppG is provided to tackle this challenge. deppG is composed of two theoretically solid nonlinear-type time-frequency analyses techniques, the de-shape short time Fourier transform and the synchrosqueezing transform, which allows us to extract the instantaneous physiological information from the PPG signal in a reliable way.

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The problem of estimating neuronal fiber tracts connecting different brain regions is important for various types of brain studies, including understanding brain functionality and diagnosing cognitive impairments. The popular techniques for tractography are mostly sequential-tracts are grown sequentially following principal directions of local water diffusion profiles. Despite several advancements on this basic idea, the solutions easily get stuck in local solutions, and can't incorporate global shape information.

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Visual Form Perception Can Be a Cognitive Correlate of Lower Level Math Categories for Teenagers.

Front Psychol

August 2017

State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal UniversityBeijing, China.

Numerous studies have assessed the cognitive correlates of performance in mathematics, but little research has been conducted to systematically examine the relations between visual perception as the starting point of visuospatial processing and typical mathematical performance. In the current study, we recruited 223 seventh graders to perform a visual form perception task (figure matching), numerosity comparison, digit comparison, exact computation, approximate computation, and curriculum-based mathematical achievement tests. Results showed that, after controlling for gender, age, and five general cognitive processes (choice reaction time, visual tracing, mental rotation, spatial working memory, and non-verbal matrices reasoning), visual form perception had unique contributions to numerosity comparison, digit comparison, and exact computation, but had no significant relation with approximate computation or curriculum-based mathematical achievement.

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As animals evolved to use oxygen as the main strategy to produce ATP through the process of mitochondrial oxidative phosphorylation, the ability to adapt to fluctuating oxygen concentrations is a crucial component of evolutionary pressure. Three mitophagy receptors, FUNDC1, BNIP3 and NIX, induce the removal of dysfunctional mitochondria (mitophagy) under prolonged hypoxic conditions in mammalian cells, to maintain oxygen homeostasis and prevent cell death. However, the evolutionary origins and structure-function relationships of these receptors remain poorly understood.

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The dorsal striatum has two functionally-defined subdivisions: a dorsomedial striatum (DMS) region involved in mediating goal-directed behaviors that require conscious effort, and a dorsolateral striatum (DLS) region involved in the execution of habitual behaviors in a familiar sensory context. Consistent with its presumed role in forming stimulus-response (S-R) associations, neurons in DLS receive massive inputs from sensorimotor cortex and are responsive to both active and passive sensory stimulation. While several studies have established that corticostriatal inputs contribute to the stimulus-induced responses observed in the DLS, there is growing awareness that the thalamus has a significant role in conveying sensory-related information to DLS and other parts of the striatum.

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Automated Detection of Epileptic Biomarkers in Resting-State Interictal MEG Data.

Front Neuroinform

June 2017

Laboratory of Cognitive and Computational Neuroscience, Center of Biomedical Technology, Politechnical University of MadridMadrid, Spain.

Certain differences between brain networks of healthy and epilectic subjects have been reported even during the interictal activity, in which no epileptic seizures occur. Here, magnetoencephalography (MEG) data recorded in the resting state is used to discriminate between healthy subjects and patients with either idiopathic generalized epilepsy or frontal focal epilepsy. Signal features extracted from interictal periods without any epileptiform activity are used to train a machine learning algorithm to draw a diagnosis.

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Each year over 16 million older Americans undergo general anesthesia for surgery, and up to 40% develop postoperative delirium and/or cognitive dysfunction (POCD). Delirium and POCD are each associated with decreased quality of life, early retirement, increased 1-year mortality, and long-term cognitive decline. Multiple investigators have thus suggested that anesthesia and surgery place severe stress on the aging brain, and that patients with less ability to withstand this stress will be at increased risk for developing postoperative delirium and POCD.

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Low Cognitive Impulsivity Is Associated with Better Gain and Loss Learning in a Probabilistic Decision-Making Task.

Front Psychol

February 2017

Facultad de Economía y Empresa, Centro de Neuroeconomía, Universidad Diego PortalesSantiago, Chile; Center for Cognitive Neuroscience, Duke UniversityDurham, NC, USA.

Many advances have been made over the last decades in describing, on the one hand, the link between reward-based learning and decision-making, and on the other hand, the link between impulsivity and decision-making. However, the association between reward-based learning and impulsivity remains poorly understood. In this study, we evaluated the association between individual differences in loss-minimizing and gain-maximizing behavior in a learning-based probabilistic decision-making task and individual differences in cognitive impulsivity.

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Editorial: Trust: The Limits of Human Moral.

Front Psychol

February 2017

Interacting Minds Centre, Aarhus UniversityAarhus, Denmark; Department of Clinical Medicine, Center for Functionally Integrative Neuroscience, Aarhus UniversityAarhus, Denmark.

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The functioning of the human brain relies on the interplay and integration of numerous individual units within a complex network. To identify network configurations characteristic of specific cognitive tasks or mental illnesses, functional connectomes can be constructed based on the assessment of synchronous fMRI activity at separate brain sites, and then analyzed using graph-theoretical concepts. In most previous studies, relatively coarse parcellations of the brain were used to define regions as graphical nodes.

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Reward Anticipation Dynamics during Cognitive Control and Episodic Encoding: Implications for Dopamine.

Front Hum Neurosci

November 2016

Center for Cognitive Neuroscience, Duke UniversityDurham, NC, USA; Department of Psychology and Neuroscience, Duke UniversityDurham, NC, USA; Department of Neurobiology, Duke UniversityDurham, NC, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical CenterDurham, NC, USA.

Dopamine (DA) modulatory activity critically supports motivated behavior. This modulation operates at multiple timescales, but the functional roles of these distinct dynamics on cognition are still being characterized. Reward processing has been robustly linked to DA activity; thus, examining behavioral effects of reward anticipation at different timing intervals, corresponding to different putative dopaminergic dynamics, may help in characterizing the functional role of these dynamics.

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Prosocial Reward Learning in Children and Adolescents.

Front Psychol

October 2016

Center for Cognitive Neuroscience, Duke UniversityDurham, NC, USA; Duke Center for Interdisciplinary Decision Sciences, Duke UniversityDurham, NC, USA; Department of Psychology and Neuroscience, Duke UniversityDurham, NC, USA.

Adolescence is a period of increased sensitivity to social contexts. To evaluate how social context sensitivity changes over development-and influences reward learning-we investigated how children and adolescents perceive and integrate rewards for oneself and others during a dynamic risky decision-making task. Children and adolescents ( = 75, 8-16 years) performed the Social Gambling Task (SGT, Kwak et al.

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We have witnessed a rapid development of brain-computer interfaces (BCIs) linking the brain to external devices. BCIs can be utilized to treat neurological conditions and even to augment brain functions. BCIs offer a promising treatment for mental disorders, including disorders of attention.

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Polyamines are small basic compounds present in all living organisms and act in a variety of biological processes. However, the mechanism of polyamine sensing, signaling and response in relation to other metabolic pathways remains to be fully addressed in plant cells. As one approach, we isolated Arabidopsis mutants that show increased resistance to spermine in terms of chlorosis.

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Pharmacometabolomic Assessment of Metformin in Non-diabetic, African Americans.

Front Pharmacol

July 2016

Department of Psychiatry and Behavioral Sciences, Duke UniversityDurham, NC, USA; Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA.

Millions of individuals are diagnosed with type 2 diabetes mellitus (T2D), which increases the risk for a plethora of adverse outcomes including cardiovascular events and kidney disease. Metformin is the most widely prescribed medication for the treatment of T2D; however, its mechanism is not fully understood and individuals vary in their response to this therapy. Here, we use a non-targeted, pharmacometabolomics approach to measure 384 metabolites in 33 non-diabetic, African American subjects dosed with metformin.

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Music As a Sacred Cue? Effects of Religious Music on Moral Behavior.

Front Psychol

July 2016

Department of Anthropology, University of ConnecticutStorrs, CT, USA; LEVYNA Laboratory for the Experimental Research of Religion, Department for the Study of Religions, Masaryk UniversityBrno, Czech Republic; Interacting Minds Centre, Department of Culture and Society, Aarhus UniversityAarhus, Denmark.

Religion can have an important influence in moral decision-making, and religious reminders may deter people from unethical behavior. Previous research indicated that religious contexts may increase prosocial behavior and reduce cheating. However, the perceptual-behavioral link between religious contexts and decision-making lacks thorough scientific understanding.

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Neural Network Evidence for the Coupling of Presaccadic Visual Remapping to Predictive Eye Position Updating.

Front Comput Neurosci

June 2016

Department of Biomedical Engineering, Pratt School of Engineering, Duke UniversityDurham, NC, USA; Department of Neurobiology, Duke School of Medicine, Duke UniversityDurham, NC, USA; Center for Cognitive Neuroscience, Duke UniversityDurham, NC, USA.

As we look around a scene, we perceive it as continuous and stable even though each saccadic eye movement changes the visual input to the retinas. How the brain achieves this perceptual stabilization is unknown, but a major hypothesis is that it relies on presaccadic remapping, a process in which neurons shift their visual sensitivity to a new location in the scene just before each saccade. This hypothesis is difficult to test in vivo because complete, selective inactivation of remapping is currently intractable.

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Neurocomputational Nosology: Malfunctions of Models and Mechanisms.

Front Psychol

May 2016

Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA; Departments of Neurobiology and Psychology and Neuroscience, Duke UniversityDurham, NC, USA; Departments of Neuroscience, Psychology, and Marketing, University of PennsylvaniaPhiladelphia, PA, USA.

Executive dysfunctions, psychopathologies arising from problems in the control and regulation of behavior, can occur as a result of the faulty execution of formal information processing models or as a result of malfunctioning neural mechanisms. The models correspond to the formal descriptions of how signals in the environment must be transformed in order to behave adaptively, and the mechanisms correspond to the signal transformations that nervous systems implement in order to execute those cognitive functions. Mechanisms in the form of repeated patterns of neural dynamics execute information processing models.

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Discerning Neurogenic vs. Non-Neurogenic Postnatal Lateral Ventricular Astrocytes via Activity-Dependent Input.

Front Neurosci

April 2016

Department of Cell Biology, Duke University School of MedicineDurham, NC, USA; Cellular and Molecular Biology Graduate Training Program, Duke University School of MedicineDurham, NC, USA; Brumley Neonatal Perinatal Research Institute, Duke University School of MedicineDurham, NC, USA; Department of Neurobiology, Duke University School of MedicineDurham, NC, USA; Preston Robert Tisch Brain Tumor Center, Duke University School of MedicineDurham, NC, USA; Duke Institute for Brain Sciences, Duke UniversityDurham, NC, USA.

Throughout development, neural stem cells (NSCs) give rise to differentiated neurons, astrocytes, and oligodendrocytes which together modulate perception, memory, and behavior in the adult nervous system. To understand how NSCs contribute to postnatal/adult brain remodeling and repair after injury, the lateral ventricular (LV) neurogenic niche in the rodent postnatal brain serves as an excellent model system. It is a specialized area containing self-renewing GFAP(+) astrocytes functioning as NSCs generating new neurons throughout life.

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