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1

Complex Networks - A Key to Understanding Brain Function  

ScienceCinema

The brain is a complex network of neurons, engaging in spontaneous and evoked activity that is thought to be the main substrate of mental life.  How this complex system works together to process information and generate coherent cognitive states, even consciousness, is not yet well understood.  In my talk I will review recent studies that have revealed characteristic structural and functional attributes of brain networks, and discuss efforts to build computational models of the brain that are informed by our growing knowledge of brain anatomy and physiology.

2

Complex Networks - A Key to Understanding Brain Function  

Microsoft Academic Search

The brain is a complex network of neurons, engaging in spontaneous and evoked activity that is thought to be the main substrate of mental life. How this complex system works together to process information and generate coherent cognitive states, even consciousness, is not yet well understood. In my talk I will review recent studies that have revealed characteristic structural and

Sporns; Olaf

2008-01-01

3

Images of the working brain: understanding human brain function with positron emission tomography  

Microsoft Academic Search

In the past 15 years positron emission tomography (PET) has become a settled method of imaging the functioning human brain, both in normal volunteers and in patients with various disorders. Much of the work on sensory systems has been on the visual system, a conveniently studied and very important part of the brain. The motor system in health and disease

John D. G Watson

1997-01-01

4

To understand brains  

Microsoft Academic Search

``How do we go about understanding brains?'' That was the fundamental question confronting the session, ``To Understand Brains. . . ,'' at the 1968 IEEE International Convention. This report on the views of eight session participants shows a strong consensus on three major points: first, that the popular analogy between brains and computers is ill-taken and perhaps misleading; second, that

Nilo Lindgren

1968-01-01

5

Understanding the potency of stressful early life experiences on brain and body function  

PubMed Central

Early life experiences have powerful effects on the brain and body lasting throughout the entire lifespan and influencing brain function, behavior and the risk for a number of systemic and mental disorders. Animal models of early life adversity are providing mechanistic insights, including glimpses into the fascinating world that is now called “epigenetics” as well as the role of naturally occurring alleles of a number of genes. These studies also provide insights into the adaptive value, as well as the negative consequences, of early life stress, exposure to novelty, and poor vs good quality maternal care. Animal models begin to provide a mechanistic basis for understanding how brain development and physiological functioning is affected in children exposed to early life abuse and neglect, where there is a burgeoning literature on the consequences for physical health and emotional and cognitive development. An important goal is to identify interventions that are likely to be most effective in early life and some guidelines are provided.

McEwen, Bruce S.

2008-01-01

6

Functional and Pharmacological MRI in Understanding Brain Function at a Systems Level  

Microsoft Academic Search

\\u000a Functional magnetic resonance imaging (fMRI) methods have been extensively applied to study the human brain and its functional\\u000a organization in healthy and disease states. A strong rationale exists for the extension of this approach to animal models\\u000a as a translational tool to bridge clinical and preclinical research. Specifically, the development of pharmacological MRI\\u000a (phMRI), i.e., the use of fMRI to

Angelo Bifone; Alessandro Gozzi

7

Understanding Brain and Consciousness?  

Microsoft Academic Search

This is a review of the dissipative quantum model of brain in the form of an extended abstract of recent works addressing\\u000a to the question of the scientific understanding of brain and consciousness in the frame of quantum field theory. The intrinsic\\u000a dissipative character of the brain dynamics appears to be a possible root of consciousness mechanisms.

G. Vitiello

8

Present and future capabilities of molecular imaging techniques to understand brain function  

Microsoft Academic Search

This article focuses on the use of positron emitting tracers and positron emission tomography (PET) as the most specific and sensitive means for imaging molecular interactions and pathways within the human brain. The concept of the imaging science of PET is developed whereby the key components that contribute to the overall accuracy of the image of molecular activity need to

Terry Jones

1999-01-01

9

Understanding the Brain's Emergent Properties  

Microsoft Academic Search

In this paper, we discuss the possibility of applying rule abstraction, a method designed to understand emergent systems, to the physiology of the brain. Rule abstraction reduces complex systems into simpler subsystems, each of which are then understood in terms of their respective subsystems. This process aids in the understanding of complex systems and how behavior emerges from the low-level

Don Miner; Marc Pickett

10

Understanding Vertebrate Brain Evolution1  

Microsoft Academic Search

SYNOPSIS. Four major questions can be asked about vertebrate brain evolution: 1) What major changes have occurred in neural organization and function? 2) When did these changes occur? 3) By what mecha- nisms did these changes occur? 4) Why did these changes occur? Comparative neurobiologists have been very successful in recognizing major changes in brain structure. They have also made

R. GLENN NORTHCUTT

2002-01-01

11

Understanding brain dysfunction in sepsis  

PubMed Central

Sepsis often is characterized by an acute brain dysfunction, which is associated with increased morbidity and mortality. Its pathophysiology is highly complex, resulting from both inflammatory and noninflammatory processes, which may induce significant alterations in vulnerable areas of the brain. Important mechanisms include excessive microglial activation, impaired cerebral perfusion, blood–brain-barrier dysfunction, and altered neurotransmission. Systemic insults, such as prolonged inflammation, severe hypoxemia, and persistent hyperglycemia also may contribute to aggravate sepsis-induced brain dysfunction or injury. The diagnosis of brain dysfunction in sepsis relies essentially on neurological examination and neurological tests, such as EEG and neuroimaging. A brain MRI should be considered in case of persistent brain dysfunction after control of sepsis and exclusion of major confounding factors. Recent MRI studies suggest that septic shock can be associated with acute cerebrovascular lesions and white matter abnormalities. Currently, the management of brain dysfunction mainly consists of control of sepsis and prevention of all aggravating factors, including metabolic disturbances, drug overdoses, anticholinergic medications, withdrawal syndromes, and Wernicke’s encephalopathy. Modulation of microglial activation, prevention of blood–brain-barrier alterations, and use of antioxidants represent relevant therapeutic targets that may impact significantly on neurologic outcomes. In the future, investigations in patients with sepsis should be undertaken to reduce the duration of brain dysfunction and to study the impact of this reduction on important health outcomes, including functional and cognitive status in survivors.

2013-01-01

12

Understanding complexity in the human brain.  

PubMed

Although the ultimate aim of neuroscientific enquiry is to gain an understanding of the brain and how its workings relate to the mind, the majority of current efforts are largely focused on small questions using increasingly detailed data. However, it might be possible to successfully address the larger question of mind-brain mechanisms if the cumulative findings from these neuroscientific studies are coupled with complementary approaches from physics and philosophy. The brain, we argue, can be understood as a complex system or network, in which mental states emerge from the interaction between multiple physical and functional levels. Achieving further conceptual progress will crucially depend on broad-scale discussions regarding the properties of cognition and the tools that are currently available or must be developed in order to study mind-brain mechanisms. PMID:21497128

Bassett, Danielle S; Gazzaniga, Michael S

2011-04-14

13

Understanding complexity in the human brain  

PubMed Central

Although the ultimate aim of neuroscientific enquiry is to gain an understanding of the brain and how its workings relate to the mind, the majority of current efforts are largely focused on small questions using increasingly detailed data. However, it might be possible to successfully address the larger question of mind–brain mechanisms if the cumulative findings from these neuroscientific studies are coupled with complementary approaches from physics and philosophy. The brain, we argue, can be understood as a complex system or network, in which mental states emerge from the interaction between multiple physical and functional levels. Achieving further conceptual progress will crucially depend on broad-scale discussions regarding the properties of cognition and the tools that are currently available or must be developed in order to study mind–brain mechanisms.

Bassett, Danielle S.; Gazzaniga, Michael S.

2011-01-01

14

Brain imaging and brain function  

SciTech Connect

This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage.

Sokoloff, L.

1985-01-01

15

Understanding the changing adolescent brain  

Microsoft Academic Search

Summary Recent brain imaging studies have demonstrated that the human brain continues to develop throughout the adolescent years. Although there are differences between male and female teenagers in terms of the time course of neural development, similar brain areas undergo significant restructuring in both sexes. Brain regions in which development is particularly protracted include the prefrontal cortex and the temporalparietal

Stephanie Burnett; Catherine Sebastian

16

Brain Structure-function Couplings (FY11).  

National Technical Information Service (NTIS)

In FY11, a collaborative team of researchers began a new Director's Strategic Initiative (DSI) to examine brain structure-function couplings. The effort aims to develop a multidisciplinary, multiscale understanding of the relationship between the brain's ...

A. Dagro J. Vettel R. Kraft S. Gordon S. Kerick

2012-01-01

17

Contributions from research on anger and cognitive dissonance to understanding the motivational functions of asymmetrical frontal brain activity  

Microsoft Academic Search

Research has suggested that approach-related positive emotions are associated with greater left frontal brain activity and that withdrawal-related negative emotions are associated with greater right frontal brain activity. Different explanations have been proposed. One posits that frontal asymmetry is due to emotional valence (positivity\\/negativity), one posits that frontal asymmetry is due to motivational direction (approach\\/withdrawal), and one posits that frontal

Eddie Harmon-Jones

2004-01-01

18

Adolescent Brain Development: Implications for Understanding Youth  

Microsoft Academic Search

New scientific discoveries have put a much different perspective on our understanding of adolescent behavior. Research now suggests that the human brain is still maturing during the adolescent years, with significant changes continuing into the early 20s. The developing brain of the teenage years may help explain why adolescents and young adults sometimes make decisions that seem to be quite

Ken C. Winters

2008-01-01

19

Functional Coactivation Map of the Human Brain  

PubMed Central

Understanding the interactions among different brain regions is fundamental to our understanding of brain function. Here we describe a complete map of functional connections in the human brain derived by an automatic meta-analysis of 825 neuroimaging articles, representing 3402 experiments. The likelihood of a functional connection between regions was estimated by studying the interdependence of their “activity,” as reported in each experiment, across all experiments. We obtained a dense coactivation map that recovers some fundamental principles of the brain's functional connectivity, such as the symmetric interhemispheric connections, and important functional networks, such as the fronto-parietal attention network, the resting state network and the motor network.

Fox, Peter T.; Paus, Tomas

2008-01-01

20

Split Brain Functioning.  

ERIC Educational Resources Information Center

|Summarizing recent research, this article defines the functions performed by the left and right sides of the human brain. Attention is given to the right side, or the nondominant side, of the brain and its potential in terms of perception of the environment, music, art, geometry, and the aesthetics. (JC)|

Cassel, Russell N.

1978-01-01

21

COPPER AND BRAIN FUNCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increasing evidence shows that brain development and function are impaired when the brain is deprived of copper either through dietary copper deficiency or through genetic defects in copper transport. A number of copper-dependent enzymes whose activities are lowered by copper deprivation form the ba...

22

Functional Brain Imaging  

PubMed Central

Executive Summary Objective The objective of this analysis is to review a spectrum of functional brain imaging technologies to identify whether there are any imaging modalities that are more effective than others for various brain pathology conditions. This evidence-based analysis reviews magnetoencephalography (MEG), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI) for the diagnosis or surgical management of the following conditions: Alzheimer’s disease (AD), brain tumours, epilepsy, multiple sclerosis (MS), and Parkinson’s disease (PD). Clinical Need: Target Population and Condition Alzheimer’s disease is a progressive, degenerative, neurologic condition characterized by cognitive impairment and memory loss. The Canadian Study on Health and Aging estimated that there will be 97,000 incident cases (about 60,000 women) of dementia (including AD) in Canada in 2006. In Ontario, there will be an estimated 950 new cases and 580 deaths due to brain cancer in 2006. Treatments for brain tumours include surgery and radiation therapy. However, one of the limitations of radiation therapy is that it damages tissue though necrosis and scarring. Computed tomography (CT) and magnetic resonance imaging (MRI) may not distinguish between radiation effects and resistant tissue, creating a potential role for functional brain imaging. Epilepsy is a chronic disorder that provokes repetitive seizures. In Ontario, the rate of epilepsy is estimated to be 5 cases per 1,000 people. Most people with epilepsy are effectively managed with drug therapy; but about 50% do not respond to drug therapy. Surgical resection of the seizure foci may be considered in these patients, and functional brain imaging may play a role in localizing the seizure foci. Multiple sclerosis is a progressive, inflammatory, demyelinating disease of the central nervous system (CNS). The cause of MS is unknown; however, it is thought to be due to a combination of etiologies, including genetic and environmental components. The prevalence of MS in Canada is 240 cases per 100,000 people. Parkinson’s disease is the most prevalent movement disorder; it affects an estimated 100,000 Canadians. Currently, the standard for measuring disease progression is through the use of scales, which are subjective measures of disease progression. Functional brain imaging may provide an objective measure of disease progression, differentiation between parkinsonian syndromes, and response to therapy. The Technology Being Reviewed Functional Brain Imaging Functional brain imaging technologies measure blood flow and metabolism. The results of these tests are often used in conjunction with structural imaging (e.g., MRI or CT). Positron emission tomography and MRS identify abnormalities in brain tissues. The former measures abnormalities through uptake of radiotracers in the brain, while the latter measures chemical shifts in metabolite ratios to identify abnormalities. The potential role of functional MRI (fMRI) is to identify the areas of the brain responsible for language, sensory and motor function (sensorimotor cortex), rather than identifying abnormalities in tissues. Magnetoencephalography measures magnetic fields of the electric currents in the brain, identifying aberrant activity. Magnetoencephalography may have the potential to localize seizure foci and to identify the sensorimotor cortex, visual cortex and auditory cortex. In terms of regulatory status, MEG and PET are licensed by Health Canada. Both MRS and fMRI use a MRI platform; thus, they do not have a separate licence from Health Canada. The radiotracers used in PET scanning are not licensed by Health Canada for general use but can be used through a Clinical Trials Application. Review Strategy The literature published up to September 2006 was searched in the following databases: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Database of Systematic Reviews, CENTRAL, and International Network of Agencies for H

2006-01-01

23

Mechanisms and Functional Brain Areas  

Microsoft Academic Search

Explanations of how psychological capacities are carried out often invoke functional brain areas. I argue that such explanations\\u000a cannot succeed. Psychological capacities are carried out by identifiable entities and their activities in the brain, but functional\\u000a brain areas are not the relevant entities. I proceed by assuming that if functional brain areas did carry out psychological\\u000a capacities, then these brain

Gregory Johnson

2009-01-01

24

Understanding brain, mind and soul: contributions from neurology and neurosurgery.  

PubMed

Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to Broca's area or the movement of limbs to the contralateral motor cortex. Galen's localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units-neurones-lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of 'the cocktail of brain soup and spark' in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here. PMID:21694966

Pandya, Sunil K

2011-01-01

25

[Dehydroepiandrosterone and brain functioning].  

PubMed

The adrenal glands synthesize dehydroepiandrosterone (DHEA) and its sulphate form (DHEAS) more intensively than they do other steroid hormones. Researchers are interested in these hormones for several reasons. Firstly, for some years they have been trying to find the reason for DHEA and DHEAS to be synthesized and present in the organism in such high concentrations. Secondly, their attention have been attracted by age-dependent regression of DHEA, which is strictly determined. Thirdly, despite longstanding efforts of scientists, the physiological role and spectrum of the biological activity of DHEA is still unclear. Evidence of that DHEA and DHEAS can be synthesized in situ in the brain tissue, received in rat experiments, urged researchers to clarify the role of these neurosteroids in the CNS. The presented review covers ways of neurosteroid synthesis, possible mechanisms of the regulation of these processes, and their dynamics under the condition of stress. The authors analyze experimental and clinical observations undertaken with a goal to clarify a possible role of DHEA in the manifestation of various brain functions. Special attention is payed to ambiguous results of modern studies, dedicated to replacement therapy of various disorders of CNS functioning (Alzheimer's disease, depression, age-specific memory impairment, sleep disturbance etc.) with DHEAS. PMID:16149434

Goncharov, N P; Katsiia, G V; Nizhnik, A N

2005-01-01

26

Students’ understanding of trigonometric functions  

Microsoft Academic Search

In this article students’ understanding of trigonometric functions in the context of two college trigonometry courses is investigated.\\u000a The first course was taught by a professor unaffiliated with the study in a lecture-based course, while the second was taught\\u000a using an experimental instruction paradigm based on Gray and Tall’s (1994) notion of procept and current process-object theories\\u000a of learning. Via

Keith Weber

2005-01-01

27

Primate Models for Understanding Brain Mechanisms of Cognitive Behavior  

Microsoft Academic Search

An approach to understanding cognitive brain function is described for behaviors that are best studied in primates. The approach\\u000a begins with the development of an experimental paradigm that exhibits important aspects of the cognitive behavior, can be\\u000a learned by a monkey, and allows quantification and experimental control. Behavioral and neural responses during task performance\\u000a are then recorded and analyzed. Finally,

Ronald E. Kettner; M. Lysetskiy; M. Suh

28

Brain foods: the effects of nutrients on brain function  

PubMed Central

It has long been suspected that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that are responsible for the action of diet on brain health and mental function. Several gut hormones that can enter the brain, or that are produced in the brain itself, influence cognitive ability. In addition, well-established regulators of synaptic plasticity, such as brain-derived neurotrophic factor, can function as metabolic modulators, responding to peripheral signals such as food intake. Understanding the molecular basis of the effects of food on cognition will help us to determine how best to manipulate diet in order to increase the resistance of neurons to insults and promote mental fitness.

Gomez-Pinilla, Fernando

2009-01-01

29

Writing for emotion management: Integrating brain functioning and subjective experience  

Microsoft Academic Search

The brain's emotion processing system is briefly discussed as a model for understanding the emotional benefits of expressive writing. The act of writing integrates both brain functioning and subjective experience.

Beth Jacobs

2010-01-01

30

Functional Plasticity or Vulnerability After Early Brain Injury?  

Microsoft Academic Search

ABSTRACT. Context. Traumatic brain injury (TBI) is a common, acquired, childhood disability that may be used as a model to understand more completely the im- pact of early brain injury on both brain structure and day-to-day function. Contrary to previously held views of the “plasticity” of the young brain, recent research suggests that such early insults may have a profound

Vicki Anderson; Cathy Catroppa; Sue Morse; Flora Haritou; Jeffrey Rosenfeld

2010-01-01

31

Understanding autism: insights from mind and brain.  

PubMed Central

Autism is a developmental disorder characterized by impaired social interaction and communication as well as repetitive behaviours and restricted interests. The consequences of this disorder for everyday life adaptation are extremely variable. The general public is now more aware of the high prevalence of this lifelong disorder, with ca. 0.6% of the population being affected. However, the signs and symptoms of autism are still puzzling. Since a biological basis of autism was accepted, approaches from developmental cognitive neuroscience have been applied to further our understanding of the autism spectrum. The study of the behavioural and underlying cognitive deficits in autism has advanced ahead of the study of the underlying brain abnormalities and of the putative genetic mechanisms. However, advances in these fields are expected as methodological difficulties are overcome. In this paper, recent developments in the field of autism are outlined. In particular, we review the findings of the three main neuro-cognitive theories of autism: theory-of-mind deficit, weak central coherence and executive dysfunction.

Hill, Elisabeth L; Frith, Uta

2003-01-01

32

Understanding brain connectivity from EEG data by identifying systems composed of interacting sources  

Microsoft Academic Search

In understanding and modeling brain functioning by EEG\\/MEG, it is not only important to be able to identify active areas but also to understand interference among different areas. The EEG\\/MEG signals result from the superimposition of underlying brain source activities volume conducted through the head. The effects of volume conduction produce spurious interactions in the measured signals. It is fundamental

Laura Marzetti; Cosimo Del Gratta; Guido Nolte

2008-01-01

33

The Energetic Brain: Understanding and Managing ADHD  

ERIC Educational Resources Information Center

|ADHD affects millions of people-some 3 to 5% of the general population. Written by a neuroscientist who has studied ADHD, a clinician who has diagnosed and treated it for 30 years, and a special educator who sees it daily, "The Energetic Brain" provides the latest information from neuroscience on how the ADHD brain works and shows how to harness…

Reynolds, Cecil R.; Vannest, Kimberly J.; Harrison, Judith R.

2012-01-01

34

Radiotracers for functional brain imaging  

SciTech Connect

The rapid growth of nuclear medicine 25 years ago was in large part related to the success of brain tumor imaging using radiopharmaceuticals designed to detect changes in the blood-brain barrier (BBB). The success of computed tomography, and more recently nuclear magnetic resonance, in imaging these lesions has all but eliminated the use of radioactive agents for brain tumor detection. But, in recent years there has been a new wave of interest in isotope studies of the brain. The recent emphasis has been on agents which enter the brain across the BBB and are designed to provide functional data ranging from regional perfusion and metabolism to the distribution of binding sites for neuroactive compounds. While none of these new radiopharmaceuticals has yet come into widespread clinical application, the research results already achieved clearly indicate that brain imaging will again be an important aspect of nuclear medicine practice. 51 references.

Blau, M.

1985-10-01

35

Understanding the functional neuroanatomy of acquired prosopagnosia  

Microsoft Academic Search

One of the most remarkable disorders following brain damage is prosopagnosia, the inability to recognize faces. While a number of cases of prosopagnosia have been described at the behavioral level, the functional neuroanatomy of this face recognition impairment, and thus the brain regions critically involved in normal face recognition, has never been specified in great detail. Here, we used anatomical

Bettina Sorger; Rainer Goebel; Christine Schiltz; Bruno Rossion

2007-01-01

36

Understanding Traumatic Brain Injury: An Introduction  

ERIC Educational Resources Information Center

This article is the first of a multi-part series on traumatic brain injury (TBI). Historically, TBI has received very limited national public policy attention and support. However since it has become the signature injury of the military conflicts in Iraq and Afghanistan, TBI has gained the attention of elected officials, military leaders,…

Trudel, Tina M.; Scherer, Marcia J.; Elias, Eileen

2009-01-01

37

Understanding Traumatic Brain Injury: An Introduction  

ERIC Educational Resources Information Center

|This article is the first of a multi-part series on traumatic brain injury (TBI). Historically, TBI has received very limited national public policy attention and support. However since it has become the signature injury of the military conflicts in Iraq and Afghanistan, TBI has gained the attention of elected officials, military leaders,…

Trudel, Tina M.; Scherer, Marcia J.; Elias, Eileen

2009-01-01

38

Functional brain mapping of psychopathology  

PubMed Central

In this paper, we consider the impact that the novel functional neuroimaging techniques may have upon psychiatric illness. Functional neuroimaging has rapidly developed as a powerful tool in cognitive neuroscience and, in recent years, has seen widespread application in psychiatry. Although such studies have produced evidence for abnormal patterns of brain response in association with some pathological conditions, the core pathophysiologies remain unresolved. Although imaging techniques provide an unprecedented opportunity for investigation of physiological function of the living human brain, there are fundamental questions and assumptions which remain to be addressed. In this review we examine these conceptual issues under three broad sections: (1) characterising the clinical population of interest, (2) defining appropriate levels of description of normal brain function, and (3) relating these models to pathophysiological conditions. Parallel advances in each of these questions will be required before imaging techniques can impact on clinical decisions in psychiatry.

Honey, G; Fletcher, P; Bullmore, E

2002-01-01

39

Ad cerebrum per scientia: Ira Hirsh, psychoacoustics, and new approaches to understanding the human brain  

Microsoft Academic Search

As Research Director of CID, Ira emphasized the importance of combining information from biology with rigorous studies of behavior, such as psychophysics, to better understand how the brain and body accomplish the goals of everyday life. In line with this philosophy, my doctoral dissertation sought to explain brain functional asymmetries (studied with dichotic listening) in terms of the physical dimensions

Judith Lauter

2002-01-01

40

Supporting Parents with Two Essential Understandings: Attachment and Brain Development.  

ERIC Educational Resources Information Center

Readiness to learn is a constant state. Two critical aspects of early childhood provide parents sufficient understanding of their child's development: attachment and brain development. Children develop attachments to caregivers but need consistent parental care and love. Human brains continue to quickly grow during the first two years of life.…

Berger, Eugenia Hepworth

1999-01-01

41

The Modeling and Functional Connectivity of the Brain  

NASA Astrophysics Data System (ADS)

The brain is considered to be the most complex system, a fertile ground for understanding the complexity of its functions through dynamical modeling. In this talk, we present some biophysical models that help to reveal the complexity of visual functions of the brain through functional self-organization processes. We also present some recent results on how the functional connectivity arises and changes in the brain, reflecting the underlying dynamics of nervous systems. The implications of our work to the brain function are discussed. Note from Publisher: This article contains the abstract only.

Kim, Seunghwan

2008-12-01

42

Understanding human functioning using graphical models  

Microsoft Academic Search

BACKGROUND: Functioning and disability are universal human experiences. However, our current understanding of functioning from a comprehensive perspective is limited. The development of the International Classification of Functioning, Disability and Health (ICF) on the one hand and recent developments in graphical modeling on the other hand might be combined and open the door to a more comprehensive understanding of human

Markus Kalisch; Bernd AG Fellinghauer; Eva Grill; Marloes H Maathuis; Ulrich Mansmann; Peter Bühlmann; Gerold Stucki

2010-01-01

43

[Sleep and brain function].  

PubMed

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) catalyzes the isomerization of PGH2, a common precursor of various prostanoids, to produce PGD2, a potent endogenous somnogen. L-PGDS is localized in the leptomeninges, choroid plexus, and oligodendrocytes of the central nervous system. PGD2 is proposed to be a major humoral sleep-inducing factor accumulated in the brain during wakefulness. PGD2 stimulates DP, receptors localized in the basal forebrain and increases the local extracellular concentration of adenosine, which activates A2A receptor-possessing neurons in the basal forebrain and/or ventrolateral preoptic area (VLPO). The intracerebroventricular infusion of PGD2 or adenosine A2A receptor-agonists induces non-REM sleep and increases the expression of fos protein in VLPO. The activation of VLPO neurons is associated with decreased fos expression in the histaminergic tuberomammillary nucleus (TMN), one of the arousal centers. The GABAergic inhibition of TMN is involved in non-REM sleep induction by PGD2 or adenosine A2A receptor-agonists. The neural network between VLPO and TMN is considered to play a key role in the regulation of vigilance states. PMID:16986732

Urade, Yoshihiro; Mohri, Ikuko

2006-09-01

44

What Is the Function of Mind and Brain?  

Microsoft Academic Search

Byrnes and Fox (1998) provide a useful and important overview of the ways in which cognitive neuroscientific research can inform educational research and practice, but leave unanswered the question: What is the function of mind and brain? An understanding of the function of mind and brain has implications for research in cognitive neuroscience and in educational psychology, and a number

David C. Geary

1998-01-01

45

Understanding the Executive Functioning Heterogeneity in Schizophrenia  

ERIC Educational Resources Information Center

|Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

Raffard, Stephane; Bayard, Sophie

2012-01-01

46

Do Nursing Students Understand the Meaning of Brain Death?  

Microsoft Academic Search

IntroductionCurrently, the concept of “brain death” is central to understanding death. An understanding of this concept could be decisive when information is provided to the general public. Nurses are fundamental players in this area because they measure the vital signs of patients and play important role in therapies such as organ donation and transplantation (ODT). We sought to determine the

L. Martínez-Alarcón; A. Ríos; M. J. López; D. Guzmán; A. López-Navas; P. Parrilla; P. Ramírez

2009-01-01

47

Brain organization and sleep function  

Microsoft Academic Search

A view of brain organization and sleep function is presented. Sleep is hypothesized to begin at the neuronal group level. Sleep results in the use and thus maintenance, of synapses that are insufficiently stimulated during wakefulness thereby serving to preserve a constancy of a synaptic superstructure. It is further hypothesized that sleep at the neuronal group level is regulated by

James M. Krueger; Ferenc Obál; Levente Kapás; Jidong Fang

1995-01-01

48

Optogenetic approaches for functional mouse brain mapping  

PubMed Central

To better understand the connectivity of the brain, it is important to map both structural and functional connections between neurons and cortical regions. In recent years, a set of optogenetic tools have been developed that permit selective manipulation and investigation of neural systems. These tools have enabled the mapping of functional connections between stimulated cortical targets and other brain regions. Advantages of the approach include the ability to arbitrarily stimulate brain regions that express opsins, allowing for brain mapping independent of behavior or sensory processing. The ability of opsins to be rapidly and locally activated allows for investigation of connectivity with spatial resolution on the order of single neurons and temporal resolution on the order of milliseconds. Optogenetic methods for functional mapping have been applied in experiments ranging from in vitro investigation of microcircuits, to in vivo probing of inter-regional cortical connections, to examination of global connections within the whole brain. We review recently developed functional mapping methods that use optogenetic single-point stimulation in the rodent brain and employ cellular electrophysiology, evoked motor movements, voltage sensitive dyes (VSDs), calcium indicators, or functional magnetic resonance imaging (fMRI) to assess activity. In particular we highlight results using red-shifted organic VSDs that permit high temporal resolution imaging in a manner spectrally separated from Channelrhodopsin-2 (ChR2) activation. VSD maps stimulated by ChR2 were dependent on intracortical synaptic activity and were able to reflect circuits used for sensory processing. Although the methods reviewed are powerful, challenges remain with respect to finding approaches that permit selective high temporal resolution assessment of stimulated activity in animals that can be followed longitudinally.

Lim, Diana H.; LeDue, Jeffrey; Mohajerani, Majid H.; Vanni, Matthieu P.; Murphy, Timothy H.

2013-01-01

49

David's Understanding of Functions and Periodicity  

ERIC Educational Resources Information Center

|This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David…

Gerson, Hope

2008-01-01

50

Mechanisms of brain plasticity: From normal brain function to pathology  

Microsoft Academic Search

Since this list of mechanisms covers much of what we know about how brain cells operate, one might object to using such a broad brush in characterizing a purportedly special feature of brain function-“plas ticity.” But that is really just the point. If a significant aspect of brain function is “plasticity,” as I believe to be the case, then all

Philip A. Schwartzkroin

2001-01-01

51

Regulation of brain function by exercise  

Microsoft Academic Search

The effect of excercise on brain function was investigated through animal experiments. Exercise leads to increased serum calcium levels, and the calcium is transported to the brain. This in turn enhances brain dopamine synthesis through a calmodulin-dependent system, and increased dopamine levels regulate various brain functions. There are abnormally low levels of dopamine in the neostriatum and nucleus accumbens of

Den’etsu Sutoo; Kayo Akiyama

2003-01-01

52

Functional expression of SGLTs in rat brain.  

PubMed

This work provides evidence of previously unrecognized uptake of glucose via sodium-coupled glucose transporters (SGLTs) in specific regions of the brain. The current understanding of functional glucose utilization in brain is largely based on studies using positron emission tomography (PET) with the glucose tracer 2-deoxy-2-[F-18]fluoro-D-glucose (2-FDG). However, 2-FDG is only a good substrate for facilitated-glucose transporters (GLUTs), not for SGLTs. Thus, glucose accumulation measured by 2-FDG omits the role of SGLTs. We designed and synthesized two high-affinity tracers: one, ?-methyl-4-[F-18]fluoro-4-deoxy-D-glucopyranoside (Me-4FDG), is a highly specific SGLT substrate and not transported by GLUTs; the other one, 4-[F-18]fluoro-4-deoxy-D-glucose (4-FDG), is transported by both SGLTs and GLUTs and will pass through the blood brain barrier (BBB). In vitro Me-4FDG autoradiography was used to map the distribution of uptake by functional SGLTs in brain slices with a comparable result from in vitro 4-FDG autoradiography. Immunohistochemical assays showed that uptake was consistent with the distribution of SGLT protein. Ex vivo 4-FDG autoradiography showed that SGLTs in these areas are functionally active in the normal in vivo brain. The results establish that SGLTs are a normal part of the physiology of specific areas of the brain, including hippocampus, amygdala, hypothalamus, and cerebral cortices. 4-FDG PET imaging also established that this BBB-permeable SGLT tracer now offers a functional imaging approach in humans to assess regulation of SGLT activity in health and disease. PMID:20826762

Yu, Amy S; Hirayama, Bruce A; Timbol, Gerald; Liu, Jie; Basarah, Ernest; Kepe, Vladimir; Satyamurthy, Nagichettiar; Huang, Sung-Cheng; Wright, Ernest M; Barrio, Jorge R

2010-09-08

53

Brain function, nonlinear coupling, and neuronal transients.  

PubMed

The brain can be regarded as an ensemble of connected dynamical systems and as such conforms to some simple principles relating the inputs and outputs of its constituent parts. The ensuing implications, for the way we think about, and measure, neuronal interactions, can be quite profound. These range from 1) implications for which aspects of neuronal activity are important to measure and how to characterize coupling among neuronal populations; 2) implication for understanding the emergence of dynamic receptive fields and functionally specialized brain architectures; and 3) teleological implications pertaining to the genesis of dynamic instability and complexity, which is necessary for adaptive self-organization. This review focuses on the first set of implications by looking at neuronal interactions, coupling, and implicit neuronal codes from a dynamical perspective. By considering the brain in this light, one can show that a sufficient description of neuronal activity must comprise activity at the current time and its recent history. This history constitutes a neuronal transient. Such transients represent an essential metric of neuronal interactions and, implicitly, a code employed in the functional integration of brain systems. The nature of transients, expressed conjointly in different neuronal populations, reflects the underlying coupling among brain systems. A complete description of this coupling, or effective connectivity, can be expressed in terms of generalized convolution kernels (Volterra kernels) that embody high-order or nonlinear interactions. This coupling may be synchronous, and possibly oscillatory, or asynchronous. A critical distinction between synchronous and asynchronous coupling is that the former is essentially linear and the latter is nonlinear. The nonlinear nature of asynchronous coupling enables the rich, context-sensitive interactions that characterize real brain dynamics, suggesting that it plays an important role in functional integration. PMID:11597100

Friston, K J

2001-10-01

54

Functional Brain Imaging in Apraxia  

Microsoft Academic Search

Background: An extensive literature describes struc- tural lesions in apraxia, but few studies have used func- tional neuroimaging. We used positron emission tomog- raphy (PET) to characterize relative cerebral glucose metabolism in a 65-year-old, right-handed woman with progressive decline in ability to manipulate objects, write, and articulate speech. Objective: To characterize functional brain organiza- tion in apraxia. Design and Methods:

David A. Kareken; Frederick Unverzagt; Karen Caldemeyer; Martin R. Farlow; Gary D. Hutchins

1998-01-01

55

Brain Gene Ontology and Simulation System (bgos) for a Better Understanding of the Brain  

Microsoft Academic Search

This article presents some preliminary results on a brain-gene ontology project that is concerned with the collection and the presentation, in a form of ontology, of various concepts, facts, data, software simulators, graphs, videos, animations, and other information forms, related to brain functions, brain diseases, their genetic basis and the relationship between all of them. The first version of the

Nikola Kasabov; Vishal Jain; Paulo C. M. Gottgtroy; Lubica Benuskova; Frances Joseph

2007-01-01

56

Towards an understanding of gait control: brain activation during the anticipation, preparation and execution of foot movements  

Microsoft Academic Search

While a detailed understanding of brain activity with hand movements has developed, less is known about the functional anatomy of motor control for foot movements. Here we have used fMRI to define brain activity associated with unilateral foot extension and flexion, component movements of gait. We studied brain responses to visually cued active and passive movements and periods of either

C. Sahyoun; A. Floyer-Lea; H. Johansen-Berg; P. M. Matthews

2004-01-01

57

Nicotine increases brain functional network efficiency.  

PubMed

Despite the use of cholinergic therapies in Alzheimer's disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network's tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer's disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function. PMID:22796985

Wylie, Korey P; Rojas, Donald C; Tanabe, Jody; Martin, Laura F; Tregellas, Jason R

2012-07-14

58

Urban ecological stewardship: understanding the structure, function ...  

Treesearch

... complex and dynamic arrangement of civil society, government and business sectors. To better understand the structure, function and network of these ... Findings include the discovery of a dynamic social network operating within cities , and ...

59

Retinoic Acid Signaling in the Functioning Brain  

NSDL National Science Digital Library

Retinoic acid, an active form of vitamin A, regulates gene expression throughout the body, and many components of the signaling system through which it acts are present in the brain. Very little is known, however, about how retinoic acid functions in neurobiological systems. Several studies have provided evidence that retinoic acid plays a role in sleep, learning, and memory, but the precise mechanisms through which it influences these processes remain unclear. All of these processes involve local or long-range inhibition and synchronized neuronal activity between separate locations in the brain. A critical component in the generation of the synchronized firing of cortical neurons (cortical synchrony) is a network of inhibitory interneurons containing parvalbumin, a cell population affected by retinoid perturbations, such as exposure to a vitamin A overdose. An understanding of the role of retinoids in normal brain function would provide clues to the long-standing question of whether abnormalities in retinoic acid signaling contribute to the pathogenesis of some brain diseases with uncertain etiologies that involve both genetic and environmental factors.

Ursula C. Drager (University of Massachusetts Medical School;Eunice Kennedy Shriver Center REV)

2006-02-28

60

Dynamic geometry, brain function modeling, and consciousness.  

PubMed

Pellionisz and Llinás proposed, years ago, a geometric interpretation towards understanding brain function. This interpretation assumes that the relation between the brain and the external world is determined by the ability of the central nervous system (CNS) to construct an internal model of the external world using an interactive geometrical relationship between sensory and motor expression. This approach opened new vistas not only in brain research but also in understanding the foundations of geometry itself. The approach named tensor network theory is sufficiently rich to allow specific computational modeling and addressed the issue of prediction, based on Taylor series expansion properties of the system, at the neuronal level, as a basic property of brain function. It was actually proposed that the evolutionary realm is the backbone for the development of an internal functional space that, while being purely representational, can interact successfully with the totally different world of the so-called "external reality". Now if the internal space or functional space is endowed with stochastic metric tensor properties, then there will be a dynamic correspondence between events in the external world and their specification in the internal space. We shall call this dynamic geometry since the minimal time resolution of the brain (10-15 ms), associated with 40 Hz oscillations of neurons and their network dynamics, is considered to be responsible for recognizing external events and generating the concept of simultaneity. The stochastic metric tensor in dynamic geometry can be written as five-dimensional space-time where the fifth dimension is a probability space as well as a metric space. This extra dimension is considered an imbedded degree of freedom. It is worth noticing that the above-mentioned 40 Hz oscillation is present both in awake and dream states where the central difference is the inability of phase resetting in the latter. This framework of dynamic geometry makes it possible to distinguish one individual from another. In this paper we shall investigate the role of dynamic geometry in brain function modeling and the neuronal basis of consciousness. PMID:18166391

Roy, Sisir; Llinás, Rodolfo

2008-01-01

61

Sugar for the brain: the role of glucose in physiological and pathological brain function.  

PubMed

The mammalian brain depends upon glucose as its main source of energy, and tight regulation of glucose metabolism is critical for brain physiology. Consistent with its critical role for physiological brain function, disruption of normal glucose metabolism as well as its interdependence with cell death pathways forms the pathophysiological basis for many brain disorders. Here, we review recent advances in understanding how glucose metabolism sustains basic brain physiology. We synthesize these findings to form a comprehensive picture of the cooperation required between different systems and cell types, and the specific breakdowns in this cooperation that lead to disease. PMID:23968694

Mergenthaler, Philipp; Lindauer, Ute; Dienel, Gerald A; Meisel, Andreas

2013-08-20

62

Robust transient dynamics and brain functions.  

PubMed

In the last few decades several concepts of dynamical systems theory (DST) have guided psychologists, cognitive scientists, and neuroscientists to rethink about sensory motor behavior and embodied cognition. A critical step in the progress of DST application to the brain (supported by modern methods of brain imaging and multi-electrode recording techniques) has been the transfer of its initial success in motor behavior to mental function, i.e., perception, emotion, and cognition. Open questions from research in genetics, ecology, brain sciences, etc., have changed DST itself and lead to the discovery of a new dynamical phenomenon, i.e., reproducible and robust transients that are at the same time sensitive to informational signals. The goal of this review is to describe a new mathematical framework - heteroclinic sequential dynamics - to understand self-organized activity in the brain that can explain certain aspects of robust itinerant behavior. Specifically, we discuss a hierarchy of coarse-grain models of mental dynamics in the form of kinetic equations of modes. These modes compete for resources at three levels: (i) within the same modality, (ii) among different modalities from the same family (like perception), and (iii) among modalities from different families (like emotion and cognition). The analysis of the conditions for robustness, i.e., the structural stability of transient (sequential) dynamics, give us the possibility to explain phenomena like the finite capacity of our sequential working memory - a vital cognitive function -, and to find specific dynamical signatures - different kinds of instabilities - of several brain functions and mental diseases. PMID:21716642

Rabinovich, Mikhail I; Varona, Pablo

2011-06-13

63

Robust Transient Dynamics and Brain Functions  

PubMed Central

In the last few decades several concepts of dynamical systems theory (DST) have guided psychologists, cognitive scientists, and neuroscientists to rethink about sensory motor behavior and embodied cognition. A critical step in the progress of DST application to the brain (supported by modern methods of brain imaging and multi-electrode recording techniques) has been the transfer of its initial success in motor behavior to mental function, i.e., perception, emotion, and cognition. Open questions from research in genetics, ecology, brain sciences, etc., have changed DST itself and lead to the discovery of a new dynamical phenomenon, i.e., reproducible and robust transients that are at the same time sensitive to informational signals. The goal of this review is to describe a new mathematical framework – heteroclinic sequential dynamics – to understand self-organized activity in the brain that can explain certain aspects of robust itinerant behavior. Specifically, we discuss a hierarchy of coarse-grain models of mental dynamics in the form of kinetic equations of modes. These modes compete for resources at three levels: (i) within the same modality, (ii) among different modalities from the same family (like perception), and (iii) among modalities from different families (like emotion and cognition). The analysis of the conditions for robustness, i.e., the structural stability of transient (sequential) dynamics, give us the possibility to explain phenomena like the finite capacity of our sequential working memory – a vital cognitive function –, and to find specific dynamical signatures – different kinds of instabilities – of several brain functions and mental diseases.

Rabinovich, Mikhail I.; Varona, Pablo

2011-01-01

64

Functional brain imaging across development.  

PubMed

The developmental cognitive neuroscience literature has grown exponentially over the last decade. This paper reviews the functional magnetic resonance imaging (fMRI) literature on brain function development of typically late developing functions of cognitive and motivation control, timing and attention as well as of resting state neural networks. Evidence shows that between childhood and adulthood, concomitant with cognitive maturation, there is progressively increased functional activation in task-relevant lateral and medial frontal, striatal and parieto-temporal brain regions that mediate these higher level control functions. This is accompanied by progressively stronger functional inter-regional connectivity within task-relevant fronto-striatal and fronto-parieto-temporal networks. Negative age associations are observed in earlier developing posterior and limbic regions, suggesting a shift with age from the recruitment of "bottom-up" processing regions towards "top-down" fronto-cortical and fronto-subcortical connections, leading to a more mature, supervised cognition. The resting state fMRI literature further complements this evidence by showing progressively stronger deactivation with age in anti-correlated task-negative resting state networks, which is associated with better task performance. Furthermore, connectivity analyses during the resting state show that with development increasingly stronger long-range connections are being formed, for example, between fronto-parietal and fronto-cerebellar connections, in both task-positive networks and in task-negative default mode networks, together with progressively lesser short-range connections, suggesting progressive functional integration and segregation with age. Overall, evidence suggests that throughout development between childhood and adulthood, there is progressive refinement and integration of both task-positive fronto-cortical and fronto-subcortical activation and task-negative deactivation, leading to a more mature and controlled cognition. PMID:22729957

Rubia, Katya

2012-06-24

65

The functional neuroanatomy of working memory: Contributions of human brain lesion studies  

Microsoft Academic Search

Studies of patients with focal brain lesions remain critical components of research programs attempting to understand human brain function. Whereas functional imaging typically reveals activity in distributed brain regions that are involved in a task, lesion studies can define which of these brain regions are necessary for a cognitive process. Further, lesion studies are less critical regarding the selection of

N. G. Müller; R. T. Knight

2006-01-01

66

Introductory study of brain function data processing.  

National Technical Information Service (NTIS)

An investigational study was conducted of the brain function aiming at developing an interface with the same function as humans have. In the study, the most up-to-date information/knowledge and future problems were examined on brain measurement, brain mod...

1998-01-01

67

Brain foods: the effects of nutrients on brain function  

Microsoft Academic Search

It has long been suspected that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that are responsible for the action of diet on brain health and mental function. Several gut hormones that can enter the brain, or

Fernando Gómez-Pinilla

2008-01-01

68

Disrupted functional brain networks in autistic toddlers.  

PubMed

Communication and integration of information between brain regions plays a key role in healthy brain function. Conversely, disruption in brain communication may lead to cognitive and behavioral problems. Autism is a neurodevelopmental disorder that is characterized by impaired social interactions and aberrant basic information processing. Aberrant brain connectivity patterns have indeed been hypothesized to be a key neural underpinning of autism. In this study, graph analytical tools are used to explore the possible deviant functional brain network organization in autism at a very early stage of brain development. Electroencephalography (EEG) recordings in 12 toddlers with autism (mean age 3.5 years) and 19 control subjects were used to assess interregional functional brain connectivity, with functional brain networks constructed at the level of temporal synchronization between brain regions underlying the EEG electrodes. Children with autism showed a significantly increased normalized path length and reduced normalized clustering, suggesting a reduced global communication capacity already during early brain development. In addition, whole brain connectivity was found to be significantly reduced in these young patients suggesting an overall under-connectivity of functional brain networks in autism. Our findings support the hypothesis of abnormal neural communication in autism, with deviating effects already present at the early stages of brain development. PMID:23259692

Boersma, Maria; Kemner, Chantal; de Reus, Marcel A; Collin, Guusje; Snijders, Tineke M; Hofman, Dennis; Buitelaar, Jan K; Stam, Cornelis J; van den Heuvel, Martijn P

2013-01-01

69

Intrinsic functional architecture in the anaesthetized monkey brain  

Microsoft Academic Search

The traditional approach to studying brain function is to measure physiological responses to controlled sensory, motor and cognit- ive paradigms. However, most of the brain's energy consumption isdevotedtoongoingmetabolicactivitynotclearlyassociatedwith any particular stimulus or behaviour1. Functional magnetic res- onance imaging studies in humans aimed at understanding this ongoing activity have shown that spontaneous fluctuations of the blood-oxygen-level-dependent signal occur continuously in the

J. L. Vincent; G. H. Patel; M. D. Fox; A. Z. Snyder; J. T. Baker; D. C. Van Essen; J. M. Zempel; L. H. Snyder; M. Corbetta; M. E. Raichle

2007-01-01

70

Culture, Executive Function, and Social Understanding  

ERIC Educational Resources Information Center

Much of the evidence from the West has shown links between children's developing self-control (executive function), their social experiences, and their social understanding (Carpendale & Lewis, 2006, chapters 5 and 6), across a range of cultures including China. This chapter describes four studies conducted in three Oriental cultures, suggesting…

Lewis, Charlie; Koyasu, Masuo; Oh, Seungmi; Ogawa, Ayako; Short, Benjamin; Huang, Zhao

2009-01-01

71

Culture, Executive Function, and Social Understanding  

ERIC Educational Resources Information Center

|Much of the evidence from the West has shown links between children's developing self-control (executive function), their social experiences, and their social understanding (Carpendale & Lewis, 2006, chapters 5 and 6), across a range of cultures including China. This chapter describes four studies conducted in three Oriental cultures, suggesting…

Lewis, Charlie; Koyasu, Masuo; Oh, Seungmi; Ogawa, Ayako; Short, Benjamin; Huang, Zhao

2009-01-01

72

Understanding Transformations of Periodic Functions through Art.  

ERIC Educational Resources Information Center

Presents an interdisciplinary project for precalculus classes that allows students to increase their understanding of the mathematics of transformations of periodic functions and helps them see mathematics in art. Uses an applet that produces high-quality graphs and real works of art by using combinations of transformations of the sine and cosine…

Miller, Syrilda

2001-01-01

73

Ad cerebrum per scientia: Ira Hirsh, psychoacoustics, and new approaches to understanding the human brain  

NASA Astrophysics Data System (ADS)

As Research Director of CID, Ira emphasized the importance of combining information from biology with rigorous studies of behavior, such as psychophysics, to better understand how the brain and body accomplish the goals of everyday life. In line with this philosophy, my doctoral dissertation sought to explain brain functional asymmetries (studied with dichotic listening) in terms of the physical dimensions of a library of test sounds designed to represent a speech-music continuum. Results highlighted individual differences plus similarities in terms of patterns of relative ear advantages, suggesting an organizational basis for brain asymmetries depending on physical dimensions of stimulus and gesture with analogs in auditory, visual, somatosensory, and motor systems. My subsequent work has employed a number of noninvasive methods (OAEs, EPs, qEEG, PET, MRI) to explore the neurobiological bases of individual differences in general and functional asymmetries in particular. This research has led to (1) the AXS test battery for assessing the neurobiology of human sensory-motor function; (2) the handshaking model of brain function, describing dynamic relations along all three body/brain axes; (3) the four-domain EPIC model of functional asymmetries; and (4) the trimodal brain, a new model of individual differences based on psychoimmunoneuroendocrinology.

Lauter, Judith

2002-05-01

74

Exercise enhances and protects brain function.  

PubMed

Physical activity, in the form of voluntary wheel running, induces gene expression changes in the brain. Animals that exercise show an increase in brain-derived neurotrophic factor, a molecule that increases neuronal survival, enhances learning, and protects against cognitive decline. Microarray analysis of gene expression provides further support that exercise enhances and supports brain function. PMID:11991541

Cotman, Carl W; Engesser-Cesar, Christie

2002-04-01

75

From 'understanding the brain by creating the brain' towards manipulative neuroscience.  

PubMed

Ten years have passed since the Japanese 'Century of the Brain' was promoted, and its most notable objective, the unique 'creating the brain' approach, has led us to apply a humanoid robot as a neuroscience tool. Here, we aim to understand the brain to the extent that we can make humanoid robots solve tasks typically solved by the human brain by essentially the same principles. I postulate that this 'Understanding the Brain by Creating the Brain' approach is the only way to fully understand neural mechanisms in a rigorous sense. Several humanoid robots and their demonstrations are introduced. A theory of cerebellar internal models and a systems biology model of cerebellar synaptic plasticity is discussed. Both models are experimentally supported, but the latter is more easily verifiable while the former is still controversial. I argue that the major reason for this difference is that essential information can be experimentally manipulated in molecular and cellular neuroscience while it cannot be manipulated at the system level. I propose a new experimental paradigm, manipulative neuroscience, to overcome this difficulty and allow us to prove cause-and-effect relationships even at the system level. PMID:18375374

Kawato, Mitsuo

2008-06-27

76

Manganese action in brain function  

Microsoft Academic Search

Manganese, an essential trace metal, is supplied to the brain via both the blood–brain and the blood–cerebrospinal fluid barriers. There are some mechanisms in this process and transferrin may be involved in manganese transport into the brain. A large portion of manganese is bound to manganese metalloproteins, especially glutamine synthetase in astrocytes. A portion of manganese probably exists in the

Atsushi Takeda

2003-01-01

77

Understanding the functional neuroanatomy of acquired prosopagnosia.  

PubMed

One of the most remarkable disorders following brain damage is prosopagnosia, the inability to recognize faces. While a number of cases of prosopagnosia have been described at the behavioral level, the functional neuroanatomy of this face recognition impairment, and thus the brain regions critically involved in normal face recognition, has never been specified in great detail. Here, we used anatomical and functional magnetic resonance imaging (fMRI) to present the detailed functional neuroanatomy of a single case of acquired prosopagnosia (PS; Rossion, B., Caldara, R., Seghier, M., Schuller, A.-M., Lazeyras, F., Mayer, E., 2003a. A network of occipito-temporal face-sensitive areas besides the right middle fusiform gyrus is necessary for normal face processing. Brain 126, 2381-95; Rossion, B., Joyce, C.A., Cottrell, G.W., Tarr, M.J., 2003b. Early lateralization and orientation tuning for face, word, and object processing in the visual cortex. Neuroimage 20, 1609-24) with normal object recognition. First, we clarify the exact anatomical location and extent of PS' lesions in relation to (a) retinotopic cortex, (b) face-preferring regions, and (c) other classical visual regions. PS' main lesion - most likely causing her prosopagnosia - is localized in the posterior part of the right ventral occipitotemporal cortex. This lesion causes a left superior paracentral scotoma, as frequently observed in cases of prosopagnosia. While the borders of the early visual areas in the left hemisphere could be delineated well, the extensive posterior right-sided lesion hampered a full specification of the cortical representation of the left visual field. Using multiple scanning runs, face-preferring activation was detected within the right middle fusiform gyrus (MFG) in the so-called 'fusiform face area' ('FFA'), but also in the left inferior occipital gyrus (left 'OFA'), and in the right posterior superior temporal sulcus (STS). The dorsal part of the lateral occipital complex (LOC) and the human middle temporal cortex (hMT+/V5) were localized bilaterally. The color-preferring region V4/V8 was localized only in the left hemisphere. In the right hemisphere, the posterior lesion spared the ventral part of LOC, a region that may be critical for the preserved object recognition abilities of the patient, and the restriction of her deficit to the category of faces. The presumptive functions of both structurally damaged and preserved regions are discussed and new hypotheses regarding the impaired and preserved abilities of the patient during face and non-face object processing are derived. Fine-grained neurofunctional analyses of brain-damaged single cases with isolated recognition deficits may considerably improve our knowledge of the brain regions critically involved in specific visual functions, such as face recognition. PMID:17303440

Sorger, Bettina; Goebel, Rainer; Schiltz, Christine; Rossion, Bruno

2007-02-14

78

Brain death and the historical understanding of bioethics.  

PubMed

In a 1968 Report, the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death promulgated influential criteria for the idea and practice known as "brain death." Before and since the Committee met, brain death has been a focal point of visions and nightmares of medical progress, purpose, and moral authority. Critics of the Committee felt it was deaf to apparently central moral considerations and focused on the self-serving purpose of expanding transplantation. Historical characterizations of the uses and meanings of brain death and the work of the Committee have tended to echo these themes, which means also generally repeating a widely held bioethical self-understanding of how the field appeared-that is, as a necessary antidote of moral expertise. This paper looks at the Committee and finds that historical depictions of it have been skewed by such a bioethical agenda. Entertaining different possibilities as to the motives and historical circumstances behind the Report it famously produced may point to not only different histories of the Committee, but also different perspectives on the historical legacy and role of bioethics as a discourse for addressing anxieties about medicine. PMID:12938717

Belkin, Gary S

2003-07-01

79

Multistability and metastability: understanding dynamic coordination in the brain  

PubMed Central

Multistable coordination dynamics exists at many levels, from multifunctional neural circuits in vertebrates and invertebrates to large-scale neural circuitry in humans. Moreover, multistability spans (at least) the domains of action and perception, and has been found to place constraints upon, even dictating the nature of, intentional change and the skill-learning process. This paper reviews some of the key evidence for multistability in the aforementioned areas, and illustrates how it has been measured, modelled and theoretically understood. It then suggests how multistability—when combined with essential aspects of coordination dynamics such as instability, transitions and (especially) metastability—provides a platform for understanding coupling and the creative dynamics of complex goal-directed systems, including the brain and the brain–behaviour relation.

Kelso, J. A. Scott

2012-01-01

80

A neurogenetics approach to understanding individual differences in brain, behavior, and risk for psychopathology.  

PubMed

Neurogenetics research has begun to advance our understanding of how genetic variation gives rise to individual differences in brain function, which, in turn, shapes behavior and risk for psychopathology. Despite these advancements, neurogenetics research is currently confronted by three major challenges: (1) conducting research on individual variables with small effects, (2) absence of detailed mechanisms, and (3) a need to translate findings toward greater clinical relevance. In this review, we showcase techniques and developments that address these challenges and highlight the benefits of a neurogenetics approach to understanding brain, behavior and psychopathology. To address the challenge of small effects, we explore approaches including incorporating the environment, modeling epistatic relationships and using multilocus profiles. To address the challenge of mechanism, we explore how non-human animal research, epigenetics research and genome-wide association studies can inform our mechanistic understanding of behaviorally relevant brain function. Finally, to address the challenge of clinical relevance, we examine how neurogenetics research can identify novel therapeutic targets and for whom treatments work best. By addressing these challenges, neurogenetics research is poised to exponentially increase our understanding of how genetic variation interacts with the environment to shape the brain, behavior and risk for psychopathology. PMID:22614291

Bogdan, R; Hyde, L W; Hariri, A R

2012-05-22

81

Brain Functional Network for Chewing of Gum  

Microsoft Academic Search

\\u000a Recent studies showed that gum-chewing induced significant increases in cerebral blood flow and blood-oxygenation level in\\u000a the widespread brain regions. However, little is known about the underlying mechanism of chewing-induced regional interconnection\\u000a and interaction within the brain. In this study, we investigated the human brain functional network during chewing of gum\\u000a by using functional magnetic resonance imaging and complex network

Ming Ke; Hui Shen; Zongtan Zhou; Xiaolin Zhou; Dewen Hu; Xuhui Chen

82

Brain Function. Volume IV. Brain Function and Learning.  

National Technical Information Service (NTIS)

Contents: Neurochemical approaches to learning, by John Gaito; Electrical events in the brain and learning, by Robert Galambos; Neurophysiology and learning -- Memory and the organization of attention, by Karl H. Pribram, and A 'model neural system' appro...

D. B. Lindsley A. A. Lumsdaine

1967-01-01

83

A survey of American neurologists about brain death: understanding the conceptual basis and diagnostic tests for brain death  

PubMed Central

Background Neurologists often diagnose brain death (BD) and explain BD to families in the intensive care unit. This study was designed to determine whether neurologists agree with the standard concept of death (irreversible loss of integrative unity of the organism) and understand the state of the brain when BD is diagnosed. Methods A previously validated survey was mailed to a random sample of 500 board-certified neurologists in the United States. Main outcomes were: responses indicating the concept of death that BD fulfills and the empirical state of the brain that would rule out BD. Results After the second mailing, 218 (44%) surveys were returned. Few (n = 52, 27%; 95% confidence interval (CI), 21%, 34%) responded that BD is death because the organism has lost integrative unity. The most common justification was a higher brain concept (n = 93, 48%; 95% CI, 41%, 55%), suggesting that irreversible loss of consciousness is death. Contrary to the recent President's Council on Bioethics, few (n = 22, 12%; 95% CI, 8%, 17%) responded that the irreversible lack of vital work of an organism is a concept of death that the BD criterion may satisfy. Many responded that certain brain functions remaining are not compatible with a diagnosis of BD, including EEG activity, evoked potential activity, and hypothalamic neuroendocrine function. Many also responded that brain blood flow and lack of brainstem destruction are not compatible with a diagnosis of BD. Conclusions American neurologists do not have a consistent rationale for accepting BD as death, nor a clear understanding of diagnostic tests for BD.

2012-01-01

84

What can functional brain imaging studies tell us about typical and atypical cognitive development in children?  

Microsoft Academic Search

Functional brain imaging has been largely reserved for adults. However, in recent years there have been increasing attempts to use functional brain imaging to inform our understanding of child development. These have taken three main forms:(1)Children with known or suspected neurological disorders may undergo brain imaging for medical diagnostic purposes and\\/or for the purpose of research into the nature of

Ann Dowker

2006-01-01

85

Understanding human functioning using graphical models  

PubMed Central

Background Functioning and disability are universal human experiences. However, our current understanding of functioning from a comprehensive perspective is limited. The development of the International Classification of Functioning, Disability and Health (ICF) on the one hand and recent developments in graphical modeling on the other hand might be combined and open the door to a more comprehensive understanding of human functioning. The objective of our paper therefore is to explore how graphical models can be used in the study of ICF data for a range of applications. Methods We show the applicability of graphical models on ICF data for different tasks: Visualization of the dependence structure of the data set, dimension reduction and comparison of subpopulations. Moreover, we further developed and applied recent findings in causal inference using graphical models to estimate bounds on intervention effects in an observational study with many variables and without knowing the underlying causal structure. Results In each field, graphical models could be applied giving results of high face-validity. In particular, graphical models could be used for visualization of functioning in patients with spinal cord injury. The resulting graph consisted of several connected components which can be used for dimension reduction. Moreover, we found that the differences in the dependence structures between subpopulations were relevant and could be systematically analyzed using graphical models. Finally, when estimating bounds on causal effects of ICF categories on general health perceptions among patients with chronic health conditions, we found that the five ICF categories that showed the strongest effect were plausible. Conclusions Graphical Models are a flexible tool and lend themselves for a wide range of applications. In particular, studies involving ICF data seem to be suited for analysis using graphical models.

2010-01-01

86

Understanding the Functions of Proteins and DNA  

NSDL National Science Digital Library

This overview provides a sequence of learning activities to help students understand that proteins and DNA are not just abstract concepts in biology textbooks, but rather crucial components of our bodies that affect functions and characteristics that students are familiar with. Students learn about how proteins contribute to the digestion of food and to characteristics such as albinism, sickle cell anemia and hemophilia. Then, students learn about the relationship between the genetic information in DNA and the different versions of these proteins. The discussion, web-based, and hands-on learning activities presented are appropriate for an introductory unit on biological molecules or as an introduction to a unit on molecular biology.

Waldron, Ingrid

87

Regulation of brain function by exercise.  

PubMed

The effect of excercise on brain function was investigated through animal experiments. Exercise leads to increased serum calcium levels, and the calcium is transported to the brain. This in turn enhances brain dopamine synthesis through a calmodulin-dependent system, and increased dopamine levels regulate various brain functions. There are abnormally low levels of dopamine in the neostriatum and nucleus accumbens of epileptic mice (El mice strain) and spontaneously hypertensive rats (SHR). The low dopamine levels in those animals were improved following intracerebroventricular administration of calcium chloride. Dopamine levels and blood pressure in SHR were also normalized by exercise. In epileptic El mice, convulsions normalized dopamine levels and physiologic function. These findings suggest that exercise or convulsions affect brain function through calcium/calmodulin-dependent dopamine synthesis. This leads to the possibility that some symptoms of Parkinson's disease or senile dementia might be improved by exercise. PMID:12758062

Sutoo, Den'etsu; Akiyama, Kayo

2003-06-01

88

Energetic cost of brain functional connectivity.  

PubMed

The brain's functional connectivity is complex, has high energetic cost, and requires efficient use of glucose, the brain's main energy source. It has been proposed that regions with a high degree of functional connectivity are energy efficient and can minimize consumption of glucose. However, the relationship between functional connectivity and energy consumption in the brain is poorly understood. To address this neglect, here we propose a simple model for the energy demands of brain functional connectivity, which we tested with positron emission tomography and MRI in 54 healthy volunteers at rest. Higher glucose metabolism was associated with proportionally larger MRI signal amplitudes, and a higher degree of connectivity was associated with nonlinear increases in metabolism, supporting our hypothesis for the energy efficiency of the connectivity hubs. Basal metabolism (in the absence of connectivity) accounted for 30% of brain glucose utilization, which suggests that the spontaneous brain activity accounts for 70% of the energy consumed by the brain. The energy efficiency of the connectivity hubs was higher for ventral precuneus, cerebellum, and subcortical hubs than for cortical hubs. The higher energy demands of brain communication that hinges upon higher connectivity could render brain hubs more vulnerable to deficits in energy delivery or utilization and help explain their sensitivity to neurodegenerative conditions, such as Alzheimer's disease. PMID:23898179

Tomasi, Dardo; Wang, Gene-Jack; Volkow, Nora D

2013-07-29

89

The gravitational field and brain function  

NASA Astrophysics Data System (ADS)

The frontal cortex is recognized as the highest adaptive control center of the human brain. The principle of the ``frontalization'' of human brain function offers new possibilities for brain research in space. There is evolutionary and experimental evidence indicating the validity of the principle, including it's role in nervous response to gravitational stimulation. The gravitational field is considered here as one of the more constant and comprehensive factors acting on brain evolution, which has undergone some successive crucial steps: ``encephalization'', ``corticalization'', ``lateralization'' and ``frontalization''. The dominating effects of electrical responses from the frontal cortex have been discovered 1) in experiments under gravitational stimulus; and 2) in processes potentially relating to gravitational adaptation, such as memory and learning, sensory information processing, motor programing, and brain state control. A brain research experiment during space flight is suggested to test the role of the frontal cortex in space adaptation and it's potentiality in brain control.

Mei, Lei; Zhou, Chuan-Dai; Lan, Jing-Quan; Wang, Zhi-Ging; Wu, Wen-Can; Xue, Xin-Min

90

Neuroimaging Studies of Normal Brain Development and Their Relevance for Understanding Childhood Neuropsychiatric Disorders  

PubMed Central

Objective To review the maturational events that occur during prenatal and postnatal brain development and to present neuroimaging findings from studies of healthy individuals that identify the trajectories of normal brain development. Method Histological and postmortem findings of early brain development are presented, followed by a discussion of anatomical, diffusion tensor, proton spectroscopy, and functional imaging findings from studies of healthy individuals, with special emphasis on longitudinal data. Results Early brain development occurs through a sequence of major events, beginning with the formation of the neural tube and ending with myelination. Brain development at a macroscopic level typically proceeds first in sensorimotor areas, spreading subsequently and progressively into dorsal and parietal, superior temporal, and dorsolateral prefrontal cortices throughout later childhood and adolescence. These patterns of anatomical development parallel increasing activity in frontal cortices that subserves the development of higher-order cognitive functions during late childhood and adolescence. Disturbances in these developmental patterns seem to be involved centrally in the pathogenesis of various childhood psychiatric disorders including childhood-onset schizophrenia, attention-deficit/hyperactivity disorder, developmental dyslexia, Tourette’s syndrome, and bipolar disorder. Conclusions Advances in imaging techniques have enhanced our understanding of normal developmental trajectories in the brain, which may improve insight into the abnormal patterns of development in various childhood psychiatric disorders.

Marsh, Rachel; Gerber, Andrew J.; Peterson, Bradley S.

2009-01-01

91

Brain Function: Implications for Schooling.  

ERIC Educational Resources Information Center

The implications of cerebral dominance for curriculum and instruction are enormous. Cognitive style, sex differences, instructional materials preparation and selection, and testing are affected by right or left brain hemisphere dominance. (CJ)

Edwards, Clifford H.

1982-01-01

92

Thyroid function in brain-dead donors  

Microsoft Academic Search

Twenty brain-dead potential organ donors were studied prospectively to establish thyroid function. Two or three consecutive blood samples were obtained during brain death. Seven times a sample was available before brain death occurred. Free triiodothyronine (FT3) fell in most patients (80%). Very low (<1.6 pmol\\/l) and subnormal levels (between 2 and 3 pmol\\/l) were found in 65% and 15% of

F. Masson; M. Thicoïpe; M. J. Latapie; P. Maurette

1990-01-01

93

Functional Aspects of Creatine Kinase in Brain  

Microsoft Academic Search

The distinct isoenzyme-specific localization of creatine kinase (CK) isoenzymes found recently in brain suggests an important function for CK in brain energetics and points to adaptation of the CK system to the special energy requirements of different neuronal and glial cell types. For example, the presence of brain-type B-CK in Bergmann glial cells and astrocytes is very likely related to

Wolfram Hemmer; Theo Wallimann

1993-01-01

94

Brain Melanocortin Receptors: From Cloning to Function  

Microsoft Academic Search

Adan R. A. H., W. H. Gispen.Brain melanocortin receptors: from cloning to function.Peptides 18(8) 1279–1287, 1997.—The cloning of brain melanocortin (MC) receptors, the mapping of their expression pattern and the identification of MC receptor selective ligands have opened a new avenue towards elucidating the role of the melanocortin system in the brain. MC receptors have now been implicated in melanocortin-induced

Roger A. H Adan; Willem Hendrik Gispen

1997-01-01

95

Brain functional networks analysis and comparison  

Microsoft Academic Search

This study used the complex network analysis to examine the brain functional network involved in right finger movements and compare the deferent functional network involved in left finger and right finger movements. We found that (a)the connections change exponentially as distance between nodes change, the function is Gaussian; (b) the distribution of functional connections was scale-free; (c) the typical path

Fangfeng Zhang; Chunhui Chen; Lu Jiang

2010-01-01

96

Determination of Vascular Dementia Brain in Distinct Frequency Bands with Whole Brain Functional Connectivity Patterns  

PubMed Central

Recent studies have shown that multivariate pattern analysis (MVPA) can be useful for distinguishing brain disorders into categories. Such analyses can substantially enrich and facilitate clinical diagnoses. Using MPVA methods, whole brain functional networks, especially those derived using different frequency windows, can be applied to detect brain states. We constructed whole brain functional networks for groups of vascular dementia (VaD) patients and controls using resting state BOLD-fMRI (rsfMRI) data from three frequency bands - slow-5 (0.01?0.027 Hz), slow-4 (0.027?0.073 Hz), and whole-band (0.01?0.073 Hz). Then we used the support vector machine (SVM), a type of MVPA classifier, to determine the patterns of functional connectivity. Our results showed that the brain functional networks derived from rsfMRI data (19 VaD patients and 20 controls) in these three frequency bands appear to reflect neurobiological changes in VaD patients. Such differences could be used to differentiate the brain states of VaD patients from those of healthy individuals. We also found that the functional connectivity patterns of the human brain in the three frequency bands differed, as did their ability to differentiate brain states. Specifically, the ability of the functional connectivity pattern to differentiate VaD brains from healthy ones was more efficient in the slow-5 (0.01?0.027 Hz) band than in the other two frequency bands. Our findings suggest that the MVPA approach could be used to detect abnormalities in the functional connectivity of VaD patients in distinct frequency bands. Identifying such abnormalities may contribute to our understanding of the pathogenesis of VaD.

Zhang, Delong; Liu, Bo; Chen, Jun; Peng, Xiaoling; Liu, Xian; Fan, Yuanyuan; Liu, Ming; Huang, Ruiwang

2013-01-01

97

Simple models of human brain functional networks  

PubMed Central

Human brain functional networks are embedded in anatomical space and have topological properties—small-worldness, modularity, fat-tailed degree distributions—that are comparable to many other complex networks. Although a sophisticated set of measures is available to describe the topology of brain networks, the selection pressures that drive their formation remain largely unknown. Here we consider generative models for the probability of a functional connection (an edge) between two cortical regions (nodes) separated by some Euclidean distance in anatomical space. In particular, we propose a model in which the embedded topology of brain networks emerges from two competing factors: a distance penalty based on the cost of maintaining long-range connections; and a topological term that favors links between regions sharing similar input. We show that, together, these two biologically plausible factors are sufficient to capture an impressive range of topological properties of functional brain networks. Model parameters estimated in one set of functional MRI (fMRI) data on normal volunteers provided a good fit to networks estimated in a second independent sample of fMRI data. Furthermore, slightly detuned model parameters also generated a reasonable simulation of the abnormal properties of brain functional networks in people with schizophrenia. We therefore anticipate that many aspects of brain network organization, in health and disease, may be parsimoniously explained by an economical clustering rule for the probability of functional connectivity between different brain areas.

Vertes, Petra E.; Alexander-Bloch, Aaron F.; Gogtay, Nitin; Giedd, Jay N.; Rapoport, Judith L.; Bullmore, Edward T.

2012-01-01

98

On development of functional brain connectivity in the young brain  

PubMed Central

Our brain is a complex network of structurally and functionally interconnected regions, shaped to efficiently process and integrate information. The development from a brain equipped with basic functionalities to an efficient network facilitating complex behavior starts during gestation and continues into adulthood. Resting-state functional MRI (rs-fMRI) enables the examination of developmental aspects of functional connectivity (FC) and functional brain networks. This review will discuss changes observed in the developing brain on the level of network FC from a gestational age of 20 weeks onwards. We discuss findings of resting-state fMRI studies showing that functional network development starts during gestation, creating a foundation for each of the resting-state networks (RSNs) to be established. Visual and sensorimotor areas are reported to develop first, with other networks, at different rates, increasing both in network connectivity and size over time. Reaching childhood, marked fine-tuning and specialization takes place in the regions necessary for higher-order cognitive functions.

Hoff, G. E. Anna-Jasmijn; Van den Heuvel, M. P.; Benders, Manon J. N. L.; Kersbergen, Karina J.; De Vries, L. S.

2013-01-01

99

Lead poisoning and brain cell function  

Microsoft Academic Search

Exposure to excessive amounts of inorganic lead during the toddler years may produce lasting adverse effects upon brain function. Maximal ingestion of lead occurs at an age when major changes are occurring in the density of brain synaptic connections. The developmental reorganization of synapses is, in part, mediated by protein kinases, and these enzymes are particularly sensitive to stimulation by

Goldstein

1990-01-01

100

Brain function, injury and disease: an introduction  

Microsoft Academic Search

This paper sets out to provide a brief guide to brain function and the main causes of brain dysfunction likely to be encountered in social care and neurodisability practice. For the first issue of Social Care and Neurodisability, it was felt that such an overview paper serving both as a self-contained aide memoire, and as a ‘signpost’ for other relevant

Keith G Jenkins; Louise Birkett-Swan

2010-01-01

101

Brain spontaneous functional connectivity and intelligence  

Microsoft Academic Search

Many functional imaging studies have been performed to explore the neural basis of intelligence by detecting brain activity changes induced by intelligence-related tasks, such as reasoning or working memory. However, little is known about whether the spontaneous brain activity at rest is relevant to the differences in intelligence. Here, 59 healthy adult subjects (Wechsler Adult Intelligence Scale score, 90–138) were

Ming Song; Yuan Zhou; Jun Li; Yong Liu; Lixia Tian; Chunshui Yu; Tianzi Jiang

2008-01-01

102

Structural and Functional Brain Abnormalities in Schizophrenia  

Microsoft Academic Search

Schizophrenia is associated with changes in the structure and functioning of a number of key brain systems, including prefrontal and medial temporal lobe regions involved in working memory and declarative memory, respectively. Imaging techniques provide an unparalleled window into these changes, allowing repeated assessments across pre- and post-onset stages of the disorder and in relation to critical periods of brain

Katherine H. Karlsgodt; Daqiang Sun; Tyrone D. Cannon

2010-01-01

103

Interpreting Oxygenation-Based Neuroimaging Signals: The Importance and the Challenge of Understanding Brain Oxygen Metabolism  

PubMed Central

Functional magnetic resonance imaging is widely used to map patterns of brain activation based on blood oxygenation level dependent (BOLD) signal changes associated with changes in neural activity. However, because oxygenation changes depend on the relative changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2), a quantitative interpretation of BOLD signals, and also other functional neuroimaging signals related to blood or tissue oxygenation, is fundamentally limited until we better understand brain oxygen metabolism and how it is related to blood flow. However, the positive side of the complexity of oxygenation signals is that when combined with dynamic CBF measurements they potentially provide the best tool currently available for investigating the dynamics of CMRO2. This review focuses on the problem of interpreting oxygenation-based signals, the challenges involved in measuring CMRO2 in general, and what is needed to put oxygenation-based estimates of CMRO2 on a firm foundation. The importance of developing a solid theoretical framework is emphasized, both as an essential tool for analyzing oxygenation-based multimodal measurements, and also potentially as a way to better understand the physiological phenomena themselves. The existing data, integrated within a simple theoretical framework of O2 transport, suggests the hypothesis that an important functional role of the mismatch of CBF and CMRO2 changes with neural activation is to prevent a fall of tissue pO2. Future directions for better understanding brain oxygen metabolism are discussed.

Buxton, Richard B.

2010-01-01

104

FUNCTIONAL IMAGING OF BRAIN TUMORS  

Microsoft Academic Search

Conventional imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MR), are of immeasurable assistance in the diagnosis and characterization of primary intracranial tumors. Factors which can be accurately deduced via these techniques includes the location, size, mass effect and edema associated with brain tumors; usually a differential diagnosis of tumor type can be generated based on characteristics

Ferenc A. Jolesz

105

Functional brain development in humans  

Microsoft Academic Search

There is a continuing debate in developmental neuroscience about the importance of activity-dependent processes. The relatively delayed rate of development of the human brain, compared with that of other mammals, might make it more susceptible to the influence of postnatal experience. The human infant is well adapted to capitalize on this opportunity through primitive biases to attend to relevant stimuli

Mark H. Johnson

2001-01-01

106

Scale-free brain functional networks  

Microsoft Academic Search

Functional magnetic resonance imaging is used to extract functional networks connecting correlated human brain sites. Analysis of the resulting networks in different tasks shows that (a) the distribution of functional connections, and the probability of finding a link versus distance are both scale-free, (b) the characteristic path length is small and comparable with those of equivalent random networks, and (c)

Victor M. Egu ´ õluz; Dante R. Chialvo; Guillermo A. Cecchi; Marwan Baliki; A. Vania Apkarian

2005-01-01

107

Modeling of functional brain imaging data  

NASA Astrophysics Data System (ADS)

The richness and complexity of data sets obtained from functional neuroimaging studies of human cognitive behavior, using techniques such as positron emission tomography and functional magnetic resonance imaging, have until recently not been exploited by computational neural modeling methods. In this article, following a brief introduction to functional neuroimaging methodology, two neural modeling approaches for use with functional brain imaging data are described. One, which uses structural equation modeling, examines the effective functional connections between various brain regions during specific cognitive tasks. The second employs large-scale neural modeling to relate functional neuroimaging signals in multiple, interconnected brain regions to the underlying neurobiological time-varying activities in each region. These two modeling procedures are illustrated using a visual processing paradigm.

Horwitz, Barry

1999-03-01

108

Modeling and function assessing with meditation training on brain functional memory network  

Microsoft Academic Search

Modeling on memory network is an important way to understand the memory mechanism in brain functional complex network. Function assessing is a necessary channel to verify the accuracy of the results that will be applied to the theory strengthening and practice conductions, also the clinical remedy. In order to get abstract memory model, we present the theoretical analysis method by

Lanhua Zhang; Jin Wang; Xiujuan Wang; Shaowei Xue

2012-01-01

109

Affective neuroscience of the emotional BrainMind: evolutionary perspectives and implications for understanding depression  

PubMed Central

Cross-species affective neuroscience studies confirm that primary-process emotional feelings are organized within primitive subcortical regions of the brain that are anatomically, neurochemically, and functionally homologous in all mammals that have been studied. Emotional feelings (affects) are intrinsic values that inform animals how they are faring in the quest to survive. The various positive affects indicate that animals are returning to “comfort zones” that support survival, and negative affects reflect “discomfort zones” that indicate that animals are in situations that may impair survival. They are ancestral tools for living - evolutionary memories of such importance that they were coded into the genome in rough form (as primary brain processes), which are refined by basic learning mechanisms (secondary processes) as well as by higher-order cognitions/thoughts (tertiary processes). To understand why depression feels horrible, we must fathom the affective infrastructure of the mammalian brain. Advances in our understanding of the nature of primary-process emotional affects can promote the development of better preclinical models of psychiatric disorders and thereby also allow clinicians new and useful ways to understand the foundational aspects of their clients' problems. These networks are of clear importance for understanding psychiatric disorders and advancing psychiatric practice.

Panksepp, Jaak

2010-01-01

110

Structure and function of complex brain networks  

PubMed Central

An increasing number of theoretical and empirical studies approach the function of the human brain from a network perspective. The analysis of brain networks is made feasible by the development of new imaging acquisition methods as well as new tools from graph theory and dynamical systems. This review surveys some of these methodological advances and summarizes recent findings on the architecture of structural and functional brain networks. Studies of the structural connectome reveal several modules or network communities that are interlinked by hub regions mediating communication processes between modules. Recent network analyses have shown that network hubs form a densely linked collective called a “rich club,” centrally positioned for attracting and dispersing signal traffic. In parallel, recordings of resting and task-evoked neural activity have revealed distinct resting-state networks that contribute to functions in distinct cognitive domains. Network methods are increasingly applied in a clinical context, and their promise for elucidating neural substrates of brain and mental disorders is discussed.

Sporns, Olaf

2013-01-01

111

Human brain functional MRI and DTI visualization with virtual reality  

PubMed Central

Magnetic resonance diffusion tensor imaging (DTI) and functional MRI (fMRI) are two active research areas in neuroimaging. DTI is sensitive to the anisotropic diffusion of water exerted by its macromolecular environment and has been shown useful in characterizing structures of ordered tissues such as the brain white matter, myocardium, and cartilage. The diffusion tensor provides two new types of information of water diffusion: the magnitude and the spatial orientation of water diffusivity inside the tissue. This information has been used for white matter fiber tracking to review physical neuronal pathways inside the brain. Functional MRI measures brain activations using the hemodynamic response. The statistically derived activation map corresponds to human brain functional activities caused by neuronal activities. The combination of these two methods provides a new way to understand human brain from the anatomical neuronal fiber connectivity to functional activities between different brain regions. In this study, virtual reality (VR) based MR DTI and fMRI visualization with high resolution anatomical image segmentation and registration, ROI definition and neuronal white matter fiber tractography visualization and fMRI activation map integration is proposed. Rationale and methods for producing and distributing stereoscopic videos are also discussed.

Chen, Bin; Moreland, John; Zhang, Jingyu

2011-01-01

112

Mapping brain function in freely moving subjects.  

PubMed

Expression of many fundamental mammalian behaviors such as, for example, aggression, mating, foraging or social behaviors, depend on locomotor activity. A central dilemma in the functional neuroimaging of these behaviors has been the fact that conventional neuroimaging techniques generally rely on immobilization of the subject, which extinguishes all but the simplest activity. Ideally, imaging could occur in freely moving subjects, while presenting minimal interference with the subject's natural behavior. Here we provide an overview of several approaches that have been undertaken in the past to achieve this aim in both tethered and freely moving animals, as well as in nonrestrained human subjects. Applications of specific radiotracers to single photon emission computed tomography and positron emission tomography are discussed in which brain activation is imaged after completion of the behavioral task and capture of the tracer. Potential applications to clinical neuropsychiatry are discussed, as well as challenges inherent to constraint-free functional neuroimaging. Future applications of these methods promise to increase our understanding of the neural circuits underlying mammalian behavior in health and disease. PMID:15465134

Holschneider, Daniel P; Maarek, Jean-Michel I

2004-09-01

113

NIH Researchers Use Brain Imaging to Understand Genetic Link between Parkinson's and a Rare Disease  

MedlinePLUS

... Brain , July 30, 2012 NIH researchers use brain imaging to understand genetic link between Parkinson's and a ... way. The researchers used two types of an imaging technique called positron emission tomography (PET) to study ...

114

Disrupted Functional Brain Connectivity in Partial Epilepsy: A Resting-State fMRI Study  

Microsoft Academic Search

Examining the spontaneous activity to understand the neural mechanism of brain disorder is a focus in recent resting-state fMRI. In the current study, to investigate the alteration of brain functional connectivity in partial epilepsy in a systematical way, two levels of analyses (functional connectivity analysis within resting state networks (RSNs) and functional network connectivity (FNC) analysis) were carried out on

Cheng Luo; Chuan Qiu; Zhiwei Guo; Jiajia Fang; Qifu Li; Xu Lei; Yang Xia; Yongxiu Lai; Qiyong Gong; Dong Zhou; Dezhong Yao

2012-01-01

115

Functional community analysis of brain: a new approach for EEG-based investigation of the brain pathology.  

PubMed

Analysis of structure of the brain functional connectivity (SBFC) is a fundamental issue for understanding of the brain cognition as well as the pathology of brain disorders. Analysis of communities among sub-parts of a system is increasingly used for social, ecological, and other networks. This paper presents a new methodology for investigation of the SBFC and understanding of the brain based on graph theory and community pattern analysis of functional connectivity graph of the brain obtained from encephalograms (EEGs). The methodology consists of three main parts: fuzzy synchronization likelihood (FSL), community partitioning, and decisions based on partitions. As an example application, the methodology is applied to analysis of brain of patients with attention deficit/hyperactivity disorder (ADHD) and the problem of discrimination of ADHD EEGs from healthy (non-ADHD) EEGs. PMID:21586331

Ahmadlou, Mehran; Adeli, Hojjat

2011-05-07

116

Famous Russian brains: historical attempts to understand intelligence  

Microsoft Academic Search

Russian scientists are certainly among those who contributed actively to the search for the neuroanatomical basis of exceptional mental capacity and talent. Research into brain anatomy was one of the topics of special interest in various Russian universities. A number of independent reports on the study of famous Russian brains appeared both in Russia and abroad. Collecting and mapping brains

Alla A. Vein; Marion L. C. Maat-Schieman

2008-01-01

117

Understanding a Brain-Based Approach to Learning and Teaching.  

ERIC Educational Resources Information Center

|Offers 12 principles as a general foundation for brain-based learning, including (1) the brain is a parallel processor; (2) learning engages the entire physiology; (3) the search for meaning is innate and occurs through patterning; (5) emotions are critical to patterning; (6) every brain simultaneously perceives and creates parts and wholes; and…

Caine, Renate Nummela; Caine, Geoffrey

1990-01-01

118

Toward discovery science of human brain function.  

PubMed

Although it is being successfully implemented for exploration of the genome, discovery science has eluded the functional neuroimaging community. The core challenge remains the development of common paradigms for interrogating the myriad functional systems in the brain without the constraints of a priori hypotheses. Resting-state functional MRI (R-fMRI) constitutes a candidate approach capable of addressing this challenge. Imaging the brain during rest reveals large-amplitude spontaneous low-frequency (<0.1 Hz) fluctuations in the fMRI signal that are temporally correlated across functionally related areas. Referred to as functional connectivity, these correlations yield detailed maps of complex neural systems, collectively constituting an individual's "functional connectome." Reproducibility across datasets and individuals suggests the functional connectome has a common architecture, yet each individual's functional connectome exhibits unique features, with stable, meaningful interindividual differences in connectivity patterns and strengths. Comprehensive mapping of the functional connectome, and its subsequent exploitation to discern genetic influences and brain-behavior relationships, will require multicenter collaborative datasets. Here we initiate this endeavor by gathering R-fMRI data from 1,414 volunteers collected independently at 35 international centers. We demonstrate a universal architecture of positive and negative functional connections, as well as consistent loci of inter-individual variability. Age and sex emerged as significant determinants. These results demonstrate that independent R-fMRI datasets can be aggregated and shared. High-throughput R-fMRI can provide quantitative phenotypes for molecular genetic studies and biomarkers of developmental and pathological processes in the brain. To initiate discovery science of brain function, the 1000 Functional Connectomes Project dataset is freely accessible at www.nitrc.org/projects/fcon_1000/. PMID:20176931

Biswal, Bharat B; Mennes, Maarten; Zuo, Xi-Nian; Gohel, Suril; Kelly, Clare; Smith, Steve M; Beckmann, Christian F; Adelstein, Jonathan S; Buckner, Randy L; Colcombe, Stan; Dogonowski, Anne-Marie; Ernst, Monique; Fair, Damien; Hampson, Michelle; Hoptman, Matthew J; Hyde, James S; Kiviniemi, Vesa J; Kötter, Rolf; Li, Shi-Jiang; Lin, Ching-Po; Lowe, Mark J; Mackay, Clare; Madden, David J; Madsen, Kristoffer H; Margulies, Daniel S; Mayberg, Helen S; McMahon, Katie; Monk, Christopher S; Mostofsky, Stewart H; Nagel, Bonnie J; Pekar, James J; Peltier, Scott J; Petersen, Steven E; Riedl, Valentin; Rombouts, Serge A R B; Rypma, Bart; Schlaggar, Bradley L; Schmidt, Sein; Seidler, Rachael D; Siegle, Greg J; Sorg, Christian; Teng, Gao-Jun; Veijola, Juha; Villringer, Arno; Walter, Martin; Wang, Lihong; Weng, Xu-Chu; Whitfield-Gabrieli, Susan; Williamson, Peter; Windischberger, Christian; Zang, Yu-Feng; Zhang, Hong-Ying; Castellanos, F Xavier; Milham, Michael P

2010-02-22

119

Toward discovery science of human brain function  

PubMed Central

Although it is being successfully implemented for exploration of the genome, discovery science has eluded the functional neuroimaging community. The core challenge remains the development of common paradigms for interrogating the myriad functional systems in the brain without the constraints of a priori hypotheses. Resting-state functional MRI (R-fMRI) constitutes a candidate approach capable of addressing this challenge. Imaging the brain during rest reveals large-amplitude spontaneous low-frequency (<0.1 Hz) fluctuations in the fMRI signal that are temporally correlated across functionally related areas. Referred to as functional connectivity, these correlations yield detailed maps of complex neural systems, collectively constituting an individual's “functional connectome.” Reproducibility across datasets and individuals suggests the functional connectome has a common architecture, yet each individual's functional connectome exhibits unique features, with stable, meaningful interindividual differences in connectivity patterns and strengths. Comprehensive mapping of the functional connectome, and its subsequent exploitation to discern genetic influences and brain–behavior relationships, will require multicenter collaborative datasets. Here we initiate this endeavor by gathering R-fMRI data from 1,414 volunteers collected independently at 35 international centers. We demonstrate a universal architecture of positive and negative functional connections, as well as consistent loci of inter-individual variability. Age and sex emerged as significant determinants. These results demonstrate that independent R-fMRI datasets can be aggregated and shared. High-throughput R-fMRI can provide quantitative phenotypes for molecular genetic studies and biomarkers of developmental and pathological processes in the brain. To initiate discovery science of brain function, the 1000 Functional Connectomes Project dataset is freely accessible at www.nitrc.org/projects/fcon_1000/.

Biswal, Bharat B.; Mennes, Maarten; Zuo, Xi-Nian; Gohel, Suril; Kelly, Clare; Smith, Steve M.; Beckmann, Christian F.; Adelstein, Jonathan S.; Buckner, Randy L.; Colcombe, Stan; Dogonowski, Anne-Marie; Ernst, Monique; Fair, Damien; Hampson, Michelle; Hoptman, Matthew J.; Hyde, James S.; Kiviniemi, Vesa J.; Kotter, Rolf; Li, Shi-Jiang; Lin, Ching-Po; Lowe, Mark J.; Mackay, Clare; Madden, David J.; Madsen, Kristoffer H.; Margulies, Daniel S.; Mayberg, Helen S.; McMahon, Katie; Monk, Christopher S.; Mostofsky, Stewart H.; Nagel, Bonnie J.; Pekar, James J.; Peltier, Scott J.; Petersen, Steven E.; Riedl, Valentin; Rombouts, Serge A. R. B.; Rypma, Bart; Schlaggar, Bradley L.; Schmidt, Sein; Seidler, Rachael D.; Siegle, Greg J.; Sorg, Christian; Teng, Gao-Jun; Veijola, Juha; Villringer, Arno; Walter, Martin; Wang, Lihong; Weng, Xu-Chu; Whitfield-Gabrieli, Susan; Williamson, Peter; Windischberger, Christian; Zang, Yu-Feng; Zhang, Hong-Ying; Castellanos, F. Xavier; Milham, Michael P.

2010-01-01

120

Functional Brain Imaging of Nicotinic Effects on Higher Cognitive Processes  

PubMed Central

Significant advances in human functional brain imaging offer new opportunities for direct observation of the effects of nicotine, novel nicotinic agonists and nicotinic antagonists on human cognitive and behavioral performance. Careful research over the last decade has enabled investigators to explore the role of nicotinic systems on the functional neuroanatomy and neural circuitry of cognitive tasks in domains such as selective attention, working memory, episodic memory, cognitive control, and emotional processing. In addition, recent progress in understanding functional connectivity between brain regions utilized during cognitive and emotional processes offers new opportunities for examining drug effects on network-related activity. This review will critically summarize available nicotinic functional brain imaging studies focusing on the specific cognitive domains of attention, memory, behavioral control, and emotional processing. Generally speaking, nicotine appears to increase task-related activity in non-smokers and deprived smokers, but not active smokers. By contrast, nicotine or nicotinic stimulation decreases the activity of structures associated with the default mode network. These particular patterns of activation and/or deactivation may be useful for early drug development and may be an efficient and cost-effective method of screening potential nicotinic agents. Further studies will have to be done to clarify whether such activity changes correlate with cognitive or affective outcomes that are clinically relevant. The use of functional brain imaging will be a key tool for probing pathologic changes related to brain illness and for nicotinic drug development.

Newhouse, Paul A.; Potter, Alexandra S.; Dumas, Julie A.; Thiel, Christiane M.

2011-01-01

121

Brain Research: the Necessity for Separating Sites, Actions and Functions  

Microsoft Academic Search

Some brain research concentrates solely on the study of sites and actions of brain functions but the writer argues that it is essential for research to investigate the functions also. Educators can offer measures of brain function such as the Structure of Intellect (S O I) and psychologists need information about the characteristics of brain functions if accurate diagnosis is

Mary Meeker

1988-01-01

122

Why bother with the brain? A role for decision neuroscience in understanding strategic variability.  

PubMed

Neuroscience, by its nature, seems to hold considerable promise for understanding the fundamental mechanisms of decision making. In recent years, several studies in the domain of "neuroeconomics" or "decision neuroscience" have provided important insights into brain function. Yet, the apparent success and value of each of these domains are frequently called into question by researchers in economics and behavioral decision making. Critics often charge that knowledge about the brain is unnecessary for understanding decision preferences. In this chapter, I contend that knowledge about underlying brain mechanisms helps in the development of biologically plausible models of behavior, which can then help elucidate the mechanisms underlying individual choice biases and strategic preferences. Using a novel risky choice paradigm, I will demonstrate that people vary in whether they adopt compensatory or noncompensatory rules in economic decision making. Importantly, neuroimaging studies using functional magnetic resonance imaging reveal that distinct neural mechanisms support variability in choices and variability in strategic preferences. Converging evidence from a study involving decisions between hypothetical stocks illustrates how knowledge about the underlying mechanisms can help inform neuroanatomical models of cognitive control. Last, I will demonstrate how knowledge about these underlying neural mechanisms can provide novel insights into the effects of decision states like sleep deprivation on decision preferences. Together, these findings suggest that neuroscience can play a critical role in creating robust and flexible models of real-world decision behavior. PMID:23317837

Venkatraman, Vinod

2013-01-01

123

Understanding neural plasticity for programming brain-machine systems  

Microsoft Academic Search

The rapidly emerging field of brain-machine interfaces (BMI) establishes a spectacular convergence between literature and neuroscience. But brain-machine interfaces emerge from two well-defined practical goals: creating more powerful computers and giving new hope to a broad segment of the disabled population. During the last century, the study of computers and of the brain have evolved in a reciprocal metaphor: the

F. Mussa-Ivaldi

2003-01-01

124

Progesterone Receptors: Form and Function in Brain  

PubMed Central

Emerging data indicate that progesterone has multiple non-reproductive functions in the central nervous system to regulate cognition, mood, inflammation, mitochondrial function, neurogenesis and regeneration, myelination and recovery from traumatic brain injury. Progesterone-regulated neural responses are mediated by an array of progesterone receptors (PR) that include the classic nuclear PRA and PRB receptors and splice variants of each, the seven transmembrane domain 7TMPR? and the membrane-associated 25-Dx PR (PGRMC1). These PRs induce classic regulation of gene expression while also transducing signaling cascades that originate at the cell membrane and ultimately activate transcription factors. Remarkably, PRs are broadly expressed throughout the brain and can be detected in every neural cell type. The distribution of PRs beyond hypothalamic borders, suggests a much broader role of progesterone in regulating neural function. Despite the large body of evidence regarding progesterone regulation of reproductive behaviors and estrogen-inducible responses as well as effects of progesterone metabolite neurosteroids, much remains to be discovered regarding the functional outcomes resulting from activation of the complex array of PRs in brain by gonadally and / or glial derived progesterone. Moreover, the impact of clinically used progestogens and developing selective PR modulators for targeted outcomes in brain is a critical avenue of investigation as the non-reproductive functions of PRs have far-reaching implications for hormone therapy to maintain neurological health and function throughout menopausal aging.

Brinton, Roberta Diaz; Thompson, Richard F.; Foy, Michael R.; Baudry, Michel; Wang, JunMing; Finch, Caleb E; Morgan, Todd E.; Stanczyk, Frank Z.; Pike, Christian J.; Nilsen, Jon

2008-01-01

125

Understanding the Role of Neuroscience in Brain Based Products: A Guide for Educators and Consumers  

ERIC Educational Resources Information Center

|The term "brain" based is often used to describe learning theories, principles, and products. Although there have been calls urging educators to be cautious in interpreting and using such material, consumers may find it challenging to understand the role of the brain and to discriminate among brain based products to determine which would be…

Sylvan, Lesley J.; Christodoulou, Joanna A.

2010-01-01

126

Values: Understanding Written Language and the Mind through Brain Biology.  

ERIC Educational Resources Information Center

|Suggesting that neuroscience and the actualities of brain circuitry can provide guidance for what is misunderstood in writing education, namely, the role of subjectivity and values in the composing process, this paper argues that neuroscience provides corporeal evidence for the salience of particular brain structures and processes responsible for…

Brand, Alice G.

127

Changes in Connectivity after Visual Cortical Brain Damage Underlie Altered Visual Function  

ERIC Educational Resources Information Center

|The full extent of the brain's ability to compensate for damage or changed experience is yet to be established. One question particularly important for evaluating and understanding rehabilitation following brain damage is whether recovery involves new and aberrant neural connections or whether any change in function is due to the functional

Bridge, Holly; Thomas, Owen; Jbabdi, Saad; Cowey, Alan

2008-01-01

128

I. Longitudinal changes in aging brain function.  

PubMed

Changes in brain activity over time were evaluated in a group of older adults in the Baltimore Longitudinal Study of Aging who maintained good physical and cognitive health. Participants underwent PET scans during rest and delayed verbal and figural recognition memory performance at year 1 baseline and at year 9. While memory performance remained stable over the 8 years, longitudinal changes in regional cerebral blood flow were observed within each scan condition. Further analyses revealed distinctive patterns of change related specifically to verbal or figural recognition, as well as longitudinal changes common to all scan conditions. These findings demonstrate that the older brain undergoes functional reorganization with increasing age in healthy, cognitively stable individuals. In view of the stable memory performance, the task-dependent results suggest that age-related changes in brain activity help maintain cognitive function with advancing age. PMID:17184881

Beason-Held, L L; Kraut, M A; Resnick, S M

2006-12-20

129

Integrating Retinoic Acid Signaling with Brain Function  

ERIC Educational Resources Information Center

|The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

2009-01-01

130

Classroom Seating and Functional Brain Asymmetry  

ERIC Educational Resources Information Center

|This study examined the relationship between functional brain assymetry, as measured by the characteristic direction of eye movements in response to face-to-face questioning, and sitting on the left or right side of a classroom. Results are congruent with other findings comparing right and left movers. (Author/BJG)|

Gur, Raquel E.; And Others

1975-01-01

131

Superbinding in integrative brain function and memory  

Microsoft Academic Search

A proposal related to the superbinding of the activity of neural populations is outlined. Based on the observation of EEG-oscillations, this proposal aims to replace the Sherrington's single neuron doctrine for interpretation of the mechanisms of complex percepts and integrative brain function.

E. Basar; M. Ozgoren; S. Karakas

2001-01-01

132

Early Experience Alters Brain Function and Structure  

Microsoft Academic Search

Objective. To investigate the effects of early experience on brain function and structure. Methods. A randomized clinical trial tested the neu- rodevelopmental effectiveness of the Newborn Individ- ualized Developmental Care and Assessment Program (NIDCAP). Thirty preterm infants, 28 to 33 weeks' ges- tational age (GA) at birth and free of known develop- mental risk factors, participated in the trial. NIDCAP

Frank H. Duffy; Gloria B. McAnulty; Michael J. Rivkin; Sridhar Vajapeyam; Robert V. Mulkern; Simon K. Warfield; Petra S. Huppi; Samantha C. Butler; Nikk Conneman; Christine Fischer; Eric C. Eichenwald

2004-01-01

133

Metabolism and functions of glutathione in brain  

Microsoft Academic Search

The tripeptide glutathione is the thiol compound present in the highest concentration in cells of all organs. Glutathione has many physiological functions including its involvement in the defense against reactive oxygen species. The cells of the human brain consume about 20% of the oxygen utilized by the body but constitute only 2% of the body weight. Consequently, reactive oxygen species

Ralf Dringen

2000-01-01

134

The connection between rhythmicity and brain function.  

PubMed

Although rhythm and music are not entirely synonymous terms, rhythm constitutes one of the most essential structural and organizational elements of music. When considering the effect of music on human adaptation, the profound effect of rhythm on the motor system strongly suggests that the time structure of music is the essential element relating music specifically to motor behavior. Why the motor system appears so sensitive to auditory priming and timing stimulation can only be partially answered so far. The high-performance function of the auditory system regarding processing of time information makes good functional sense within the constraints of auditory sensory processing. Thus, the motor system sensitivity to auditory entrainment may simply be an evolutionary useful function of taking advantage of the specific and unique aspects of auditory information processing for enhanced control and organization of motor behavior; e.g, in the time domain. Unlike processes in the motor system, many other physiological processes cannot be effectively entrained by external sensory stimuli. For example, there is probably a very good protective reason why other cyclical physiological processes (e.g., autonomic processes such as heart rate) have only very limited entrainment capacity to external rhythmic cues. Some of the basic auditory-motor arousal connections may also have their basis in adaptive evolutionary processes related to survival behavior; e.g., in fight or flight reactions. Much of the "why" in auditory-motor interactions, however, remains unknown heuristically. In the absence of this knowledge, great care should be taken to not compensate for this lack of understanding of specific cause and effect processes by assigning anthropomorphic descriptions to the behavior of biological and physical systems. The unraveling of the perceptual, physiological, and neuroanatomical basis of the interaction between rhythm and movement has been, and continues to be, a fascinating endeavor with important ramifications for the study of brain function, sensory perception, and motor behavior. One of the most exciting findings in this research, however, may be the evidence that the interaction between auditory rhythm and physical response can be effectively harnessed for specific therapeutic purposes in the rehabilitation of persons with movement disorders. PMID:10101675

Thaut, M H; Kenyon, G P; Schauer, M L; McIntosh, G C

135

See the brain at work: intraoperative laser Doppler functional brain imaging  

NASA Astrophysics Data System (ADS)

During open brain surgery we acquire perfusion images non-invasively using laser Doppler imaging. The regions of brain activity show a distinct signal in response to stimulation providing intraoperative functional brain maps of remarkably strong contrast.

Martin-Williams, E. J.; Raabe, A.; van de Ville, D.; Leutenegger, M.; Szelényi, A.; Hattingen, E.; Gerlach, R.; Seifert, V.; Hauger, C.; Lopez, A.; Leitgeb, R.; Unser, M.; Lasser, T.

2009-07-01

136

Nuclear magnetic resonance imaging and spectroscopy of human brain function.  

PubMed Central

The techniques of in vivo magnetic resonance (MR) imaging and spectroscopy have been established over the past two decades. Recent applications of these methods to study human brain function have become a rapidly growing area of research. The development of methods using standard MR contrast agents within the cerebral vasculature has allowed measurements of regional cerebral blood volume (rCBV), which are activity dependent. Subsequent investigations linked the MR relaxation properties of brain tissue to blood oxygenation levels which are also modulated by consumption and blood flow (rCBF). These methods have allowed mapping of brain activity in human visual and motor cortex as well as in areas of the frontal lobe involved in language. The methods have high enough spatial and temporal sensitivity to be used in individual subjects. MR spectroscopy of proton and carbon-13 nuclei has been used to measure rates of glucose transport and metabolism in the human brain. The steady-state measurements of brain glucose concentrations can be used to monitor the glycolytic flux, whereas subsequent glucose metabolism--i.e., the flux into the cerebral glutamate pool--can be used to measure tricarboxylic acid cycle flux. Under visual stimulation the concentration of lactate in the visual cortex has been shown to increase by MR spectroscopy. This increase is compatible with an increase of anaerobic glycolysis under these conditions as earlier proposed from positron emission tomography studies. It is shown how MR spectroscopy can extend this understanding of brain metabolism. Images Fig. 1 Fig. 2 Fig. 3

Shulman, R G; Blamire, A M; Rothman, D L; McCarthy, G

1993-01-01

137

Modulatory interactions of resting-state brain functional connectivity.  

PubMed

The functional brain connectivity studies are generally based on the synchronization of the resting-state functional magnetic resonance imaging (fMRI) signals. Functional connectivity measures usually assume a stable relationship over time; however, accumulating studies have reported time-varying properties of strength and spatial distribution of functional connectivity. The present study explored the modulation of functional connectivity between two regions by a third region using the physiophysiological interaction (PPI) technique. We first identified eight brain networks and two regions of interest (ROIs) representing each of the networks using a spatial independent component analysis. A voxel-wise analysis was conducted to identify regions that showed modulatory interactions (PPI) with the two ROIs of each network. Mostly, positive modulatory interactions were observed within regions involved in the same system. For example, the two regions of the dorsal attention network revealed modulatory interactions with the regions related to attention, while the two regions of the extrastriate network revealed modulatory interactions with the regions in the visual cortex. In contrast, the two regions of the default mode network (DMN) revealed negative modulatory interactions with the regions in the executive network, and vice versa, suggesting that the activities of one network may be associated with smaller within network connectivity of the competing network. These results validate the use of PPI analysis to study modulation of resting-state functional connectivity by a third region. The modulatory effects may provide a better understanding of complex brain functions. PMID:24023609

Di, Xin; Biswal, Bharat B

2013-08-30

138

Functional Dissociation of Ongoing Oscillatory Brain States  

PubMed Central

The state of a neural assembly preceding an incoming stimulus is assumed to modulate the processing of subsequently presented stimuli. The nature of this state can differ with respect to the frequency of ongoing oscillatory activity. Oscillatory brain activity of specific frequency range such as alpha (8–12 Hz) and gamma (above 30 Hz) band oscillations are hypothesized to play a functional role in cognitive processing. Therefore, a selective modulation of this prestimulus activity could clarify the functional role of these prestimulus fluctuations. For this purpose, we adopted a novel non-invasive brain-computer-interface (BCI) strategy to selectively increase alpha or gamma band activity in the occipital cortex combined with an adaptive presentation of visual stimuli within specific brain states. During training, oscillatory brain activity was estimated online and fed back to the participants to enable a deliberate modulation of alpha or gamma band oscillations. Results revealed that volunteers selectively increased alpha and gamma frequency oscillations with a high level of specificity regarding frequency range and localization. At testing, alpha or gamma band activity was classified online and at defined levels of activity, visual objects embedded in noise were presented instantly and had to be detected by the volunteer. In experiment I, the effect of two levels of prestimulus gamma band activity on visual processing was examined. During phases of increased gamma band activity significantly more visual objects were detected. In experiment II, the effect was compared against increased levels of alpha band activity. An improvement of visual processing was only observed for enhanced gamma band activity. Both experiments demonstrate the specific functional role of prestimulus gamma band oscillations for perceptual processing. We propose that the BCI method permits the selective modulation of oscillatory activity and the direct assessment of behavioral consequences to test for functional dissociations of different oscillatory brain states.

Salari, Neda; Buchel, Christian; Rose, Michael

2012-01-01

139

Electromagnetic inverse applications for functional brain imaging  

SciTech Connect

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This project addresses an important mathematical and computational problem in functional brain imaging, namely the electromagnetic {open_quotes}inverse problem.{close_quotes} Electromagnetic brain imaging techniques, magnetoencephalography (MEG) and electroencephalography (EEG), are based on measurements of electrical potentials and magnetic fields at hundreds of locations outside the human head. The inverse problem is the estimation of the locations, magnitudes, and time-sources of electrical currents in the brain from surface measurements. This project extends recent progress on the inverse problem by combining the use of anatomical constraints derived from magnetic resonance imaging (MRI) with Bayesian and other novel algorithmic approaches. The results suggest that we can achieve significant improvements in the accuracy and robustness of inverse solutions by these two approaches.

Wood, C.C.

1997-10-01

140

Electroencephalographic imaging of higher brain function.  

PubMed Central

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

Gevins, A; Smith, M E; McEvoy, L K; Leong, H; Le, J

1999-01-01

141

Structural and functional neuroimaging studies of the suicidal brain  

Microsoft Academic Search

Suicidality is a major challenge for today's health care. Evidence suggests that there are differences in cognitive functioning of suicidal patients but the knowledge about the underlying neurobiology is limited. Brain imaging offers the advantage of a non-invasive in vivo direct estimation of detailed brain structure, regional brain functioning and estimation of molecular processes in the brain.We have reviewed the

S. Desmyter; C. van Heeringen; K. Audenaert

2011-01-01

142

Using neuroimaging and neuromodulation to study changes in brain functioning with therapy.  

PubMed

This article reviews the concepts underlying functional neuroimaging and its use to study brain function change as a result of recovery and neurorehabilitation for speech, voice, and swallowing. The role of neurovascular coupling for quantifying brain function change in response to behavioral demands is explained. The types of changes in brain function that are measured and how they should be interpreted are addressed for the study of brain function abnormalities in developmental and acquired speech, voice, and swallowing disorders. One challenge is to separate changes in brain function due to recovery from those that are secondary to the development of compensatory skills during therapy. The advantages of functional magnetic resonance imaging and functional near-infrared spectroscopy are compared. The use of transcranial magnetic stimulation for the study of brain function is reviewed. In addition, more recent methods for the modulation of brain function using transcranial magnetic and electrical stimulation over the cortex are examined. These technologies can be used by clinical investigators to gain better understanding of normal brain function and for learning how abnormalities in brain function might be addressed. Both are likely to lead to new therapeutic approaches to neurorehabilitation of speech, voice, and swallowing disorders. PMID:22851340

Ludlow, Christy L

2012-07-31

143

Pro-cognitive drug effects modulate functional brain network organization  

PubMed Central

Previous studies document that cholinergic and noradrenergic drugs improve attention, memory and cognitive control in healthy subjects and patients with neuropsychiatric disorders. In humans neural mechanisms of cholinergic and noradrenergic modulation have mainly been analyzed by investigating drug-induced changes of task-related neural activity measured with functional magnetic resonance imaging (fMRI). Endogenous neural activity has often been neglected. Further, although drugs affect the coupling between neurons, only a few human studies have explicitly addressed how drugs modulate the functional connectome, i.e., the functional neural interactions within the brain. These studies have mainly focused on synchronization or correlation of brain activations. Recently, there are some drug studies using graph theory and other new mathematical approaches to model the brain as a complex network of interconnected processing nodes. Using such measures it is possible to detect not only focal, but also subtle, widely distributed drug effects on functional network topology. Most important, graph theoretical measures also quantify whether drug-induced changes in topology or network organization facilitate or hinder information processing. Several studies could show that functional brain integration is highly correlated with behavioral performance suggesting that cholinergic and noradrenergic drugs which improve measures of cognitive performance should increase functional network integration. The purpose of this paper is to show that graph theory provides a mathematical tool to develop theory-driven biomarkers of pro-cognitive drug effects, and also to discuss how these approaches can contribute to the understanding of the role of cholinergic and noradrenergic modulation in the human brain. Finally we discuss the “global workspace” theory as a theoretical framework of pro-cognitive drug effects and argue that pro-cognitive effects of cholinergic and noradrenergic drugs might be related to higher network integration.

Giessing, Carsten; Thiel, Christiane M.

2012-01-01

144

Pro-cognitive drug effects modulate functional brain network organization.  

PubMed

Previous studies document that cholinergic and noradrenergic drugs improve attention, memory and cognitive control in healthy subjects and patients with neuropsychiatric disorders. In humans neural mechanisms of cholinergic and noradrenergic modulation have mainly been analyzed by investigating drug-induced changes of task-related neural activity measured with functional magnetic resonance imaging (fMRI). Endogenous neural activity has often been neglected. Further, although drugs affect the coupling between neurons, only a few human studies have explicitly addressed how drugs modulate the functional connectome, i.e., the functional neural interactions within the brain. These studies have mainly focused on synchronization or correlation of brain activations. Recently, there are some drug studies using graph theory and other new mathematical approaches to model the brain as a complex network of interconnected processing nodes. Using such measures it is possible to detect not only focal, but also subtle, widely distributed drug effects on functional network topology. Most important, graph theoretical measures also quantify whether drug-induced changes in topology or network organization facilitate or hinder information processing. Several studies could show that functional brain integration is highly correlated with behavioral performance suggesting that cholinergic and noradrenergic drugs which improve measures of cognitive performance should increase functional network integration. The purpose of this paper is to show that graph theory provides a mathematical tool to develop theory-driven biomarkers of pro-cognitive drug effects, and also to discuss how these approaches can contribute to the understanding of the role of cholinergic and noradrenergic modulation in the human brain. Finally we discuss the "global workspace" theory as a theoretical framework of pro-cognitive drug effects and argue that pro-cognitive effects of cholinergic and noradrenergic drugs might be related to higher network integration. PMID:22973209

Giessing, Carsten; Thiel, Christiane M

2012-08-28

145

Functional connectivity hubs in the human brain.  

PubMed

Brain networks appear to have few and well localized regions with high functional connectivity density (hubs) for fast integration of neural processing, and their dysfunction could contribute to neuropsychiatric diseases. However the variability in the distribution of these brain hubs is unknown due in part to the overwhelming computational demands associated to their localization. Recently we developed a fast algorithm to map the local functional connectivity density (lFCD). Here we extend our method to map the global density (gFDC) taking advantage of parallel computing. We mapped the gFCD in the brain of 1031 subjects from the 1000 Functional Connectomes project and show that the strongest hubs are located in regions of the default mode network (DMN) and in sensory cortices, whereas subcortical regions exhibited the weakest hubs. The strongest hubs were consistently located in ventral precuneus/cingulate gyrus (previously identified by other analytical methods including lFCD) and in primary visual cortex (BA 17/18), which highlights their centrality to resting connectivity networks. In contrast and after rescaling, hubs in prefrontal regions had lower gFCD than lFCD, which suggests that their local functional connectivity (as opposed to long-range connectivity) prevails in the resting state. The power scaling of the probability distribution of gFCD hubs (as for lFCD) was consistent across research centers further corroborating the "scale-free" topology of brain networks. Within and between-subject variability for gFCD were twice than that for lFCD (20% vs. 12% and 84% vs. 34%, respectively) suggesting that gFCD is more sensitive to individual differences in functional connectivity. PMID:21609769

Tomasi, Dardo; Volkow, Nora D

2011-05-14

146

Distributed Synchrony - Understanding the Brain at the Single Cell Level  

Microsoft Academic Search

How does the brain process information? Can it be understood at the single cell level? This paper pro- poses a predictive coding model based on the use of distributed synchronous spikes. We test the hypothesis that information is encoded in neurons' probability of firing, which are updated spatial-temporally at precise moments. Therefore, synchronous spikes are distributed across groups of cells

Zuohua Zhang; Dana H. Ballard

147

Understanding and quantifying urban forest structure, functions, and ...  

Treesearch

Unfortunately, there is relatively little data about the structure, health, functions, ... This article was written and prepared by U.S. Government employees on official ... Understanding and quantifying urban forest structure, functions, and value.

148

Approaches to Modelling the Dynamical Activity of Brain Function Based on the Electroencephalogram  

NASA Astrophysics Data System (ADS)

The brain is arguably the quintessential complex system as indicated by the patterns of behaviour it produces. Despite many decades of concentrated research efforts, we remain largely ignorant regarding the essential processes that regulate and define its function. While advances in functional neuroimaging have provided welcome windows into the coarse organisation of the neuronal networks that underlie a range of cognitive functions, they have largely ignored the fact that behaviour, and by inference brain function, unfolds dynamically. Modelling the brain's dynamics is therefore a critical step towards understanding the underlying mechanisms of its functioning. To date, models have concentrated on describing the sequential organisation of either abstract mental states (functionalism, hard AI) or the objectively measurable manifestations of the brain's ongoing activity (rCBF, EEG, MEG). While the former types of modelling approach may seem to better characterise brain function, they do so at the expense of not making a definite connection with the actual physical brain. Of the latter, only models of the EEG (or MEG) offer a temporal resolution well matched to the anticipated temporal scales of brain (mental processes) function. This chapter will outline the most pertinent of these modelling approaches, and illustrate, using the electrocortical model of Liley et al, how the detailed application of the methods of nonlinear dynamics and bifurcation theory is central to exploring and characterising their various dynamical features. The rich repertoire of dynamics revealed by such dynamical systems approaches arguably represents a critical step towards an understanding of the complexity of brain function.

Liley, David T. J.; Frascoli, Federico

149

Physics, Math, and Making Sense: Understanding how brains learn science  

Microsoft Academic Search

Recent developments in neuroscience, cognitive science, and behavioral science are helping physics education researchers develop a theoretical understanding of physics teaching and learning. This understanding helps in two ways. 1). We can make sense of the way students respond (often inappropriately) to our instruction. 2). We can learn to appreciate the difficulties we have as instructors in unpacking and identifying

Edward Redish

2007-01-01

150

Computerized brain atlas in functional neurosurgery.  

PubMed

Computerized brain atlas is a new application area in the practical use of stereotactic neurosurgery. Our approach provides a solution for the straightforward definition of a coordinate system (CA-CP), localization of the selected target point, trepanation points and trajectory transformation of the stereotactic electrode or canula for functional neurosurgery. These problems were solved by comparison of CT, MR and the Schaltenbrand-Wahren atlas. Our original software package integrates all modalities into one system. PMID:9711740

Sramka, M; Ruzicky, E; Novotny, M

1997-01-01

151

Social Functioning in Children with Brain Insult  

PubMed Central

Social dysfunction is commonly reported by survivors of brain insult, and is often rated as the most debilitating of all sequelae, impacting on many areas of daily life, as well as overall quality of life. Within the early brain insult (EBI) literature, physical and cognitive domains have been of primary interest and social skills have received scant attention. As a result it remains unclear how common these problems are, and whether factors predictive of recovery (insult severity, lesion location, age at insult, environment) in other functional domains (motor, speech, cognition) also contribute to social outcome. This study compared social outcomes for children sustaining EBI at different times from gestation to late childhood to determine whether EBI was associated with an increased risk of problems. Children with focal brain insults were categorized according to timing of brain insult: (i) Congenital (n?=?38): EBI: first–second trimester; (ii) Perinatal (n?=?33); EBI: third trimester to 1-month post-natal; (iii) Infancy (n?=?23): EBI: 2?months–2?years post-birth; (iv) Preschool (n?=?19): EBI: 3–6?years; (v) Middle Childhood (n?=?31): EBI: 7–9?years; and (vi) Late Childhood (n?=?19): EBI: after age 10. Children's teachers completed questionnaires measuring social function (Strengths and Difficulties Questionnaire, Walker–McConnell Scale of Social Competence and School Adjustment). Results showed that children with EBI were at increased risk for social impairment compared to normative expectations. EBI before age 2?years was associated with most significant social impairment, while children with EBI in the preschool years and in late childhood recorded scores closer to normal. Lesion location and laterality were not predictive of social outcome, and nor was social risk. In contrast, presence of disability (seizures) and family function were shown to contribute to aspects of social function.

Greenham, Mardee; Spencer-Smith, Megan M.; Anderson, Peter J.; Coleman, Lee; Anderson, Vicki A.

2009-01-01

152

Integrating Functional Brain Neuroimaging and Developmental Cognitive Neuroscience in Child Psychiatry Research  

ERIC Educational Resources Information Center

|The use of cognitive neuroscience and functional brain neuroimaging to understand brain dysfunction in pediatric psychiatric disorders is discussed. Results show that bipolar youths demonstrate impairment in affective and cognitive neural systems and in these two circuits' interface. Implications for the diagnosis and treatment of psychiatric…

Pavuluri, Mani N.; Sweeney, John A.

2008-01-01

153

Integrating Functional Brain Neuroimaging and Developmental Cognitive Neuroscience in Child Psychiatry Research  

ERIC Educational Resources Information Center

The use of cognitive neuroscience and functional brain neuroimaging to understand brain dysfunction in pediatric psychiatric disorders is discussed. Results show that bipolar youths demonstrate impairment in affective and cognitive neural systems and in these two circuits' interface. Implications for the diagnosis and treatment of psychiatric…

Pavuluri, Mani N.; Sweeney, John A.

2008-01-01

154

Non-invasive brain-to-brain interface (BBI): establishing functional links between two brains.  

PubMed

Transcranial focused ultrasound (FUS) is capable of modulating the neural activity of specific brain regions, with a potential role as a non-invasive computer-to-brain interface (CBI). In conjunction with the use of brain-to-computer interface (BCI) techniques that translate brain function to generate computer commands, we investigated the feasibility of using the FUS-based CBI to non-invasively establish a functional link between the brains of different species (i.e. human and Sprague-Dawley rat), thus creating a brain-to-brain interface (BBI). The implementation was aimed to non-invasively translate the human volunteer's intention to stimulate a rat's brain motor area that is responsible for the tail movement. The volunteer initiated the intention by looking at a strobe light flicker on a computer display, and the degree of synchronization in the electroencephalographic steady-state-visual-evoked-potentials (SSVEP) with respect to the strobe frequency was analyzed using a computer. Increased signal amplitude in the SSVEP, indicating the volunteer's intention, triggered the delivery of a burst-mode FUS (350 kHz ultrasound frequency, tone burst duration of 0.5 ms, pulse repetition frequency of 1 kHz, given for 300 msec duration) to excite the motor area of an anesthetized rat transcranially. The successful excitation subsequently elicited the tail movement, which was detected by a motion sensor. The interface was achieved at 94.0±3.0% accuracy, with a time delay of 1.59±1.07 sec from the thought-initiation to the creation of the tail movement. Our results demonstrate the feasibility of a computer-mediated BBI that links central neural functions between two biological entities, which may confer unexplored opportunities in the study of neuroscience with potential implications for therapeutic applications. PMID:23573251

Yoo, Seung-Schik; Kim, Hyungmin; Filandrianos, Emmanuel; Taghados, Seyed Javid; Park, Shinsuk

2013-04-03

155

Brain maturation and its relevance to understanding criminal culpability of juveniles  

Microsoft Academic Search

The purpose of this review is to summarize current understanding of the process of maturation in human brains during the juvenile\\u000a period to young adulthood. We describe the methods used in such investigations, and outline the main findings regarding the\\u000a course of brain development. There is much that we do not know about brain maturation, but there is congruence of

Ruben C. Gur

2005-01-01

156

Traumatic brain injury shows better functional recovery than brain tumor: a rehabilitative perspective.  

PubMed

Background: The similar symptoms seen in the brain tumor (BT) and traumatic brain injury (TBI) population. However, functional comparisons between these two diagnostic groups have been limited. Aim: To compare functional outcomes in patients with supratentorial BT and TBI after early rehabilitation. Design: This was a retrospective database analysis. Setting. Patients admitted to an Acute Care Unit as inpatient (Hacettepe Hospital, Ankara-Turkey). Population. The population included patients with BT and TBI. Methods: Thirty-four patients with BT and TBI were matched one-to-one by lesion side and sex. The Barthel Index was used to assess functional status at the pre- and postrehabilitation. The change rate and efficiency in BI were also calculated. The time between injury onset and admission to rehabilitation (the onset to admission interval, OAI) and length of stay in rehabilitation (LOS rehab) were recorded. In addition, the influence of lesion side (left and right) and age on functional outcome were analyzed. Results: The functional level was significantly lower in TBI patients than in patients BT before rehabilitation (P<0.05). The post-rehabilitation BI score was similar in patients with BT and TBI (P>0.05). Patients with TBI had greater the change rate and efficiency in BI (P<0.05). The OAI and LOS rehab was longer in patients with TBI (P<0.05). In terms of lesion side comparisons, no differences were found (P>0.05). The age had no effect on functional outcome in patients with TBI and BT (P>0.05), expect the age group 45-59 (P<0.05). Conclusion: The early rehabilitation program improved functional ability of patients with brain tumors, as well as patients with traumatic brain injury. Despite the lower functional status, patients with TBI displayed better functional recovery than patients with BT. Lesion side had no effect on functional outcome in patients with TBI and BT. Differences in functional status begin to appear even in patients with TBI between 45 and 59 years. Further investigations with more detailed outcome instruments are required to better understand the qualitative limitations of a patient's recovery. Clinical Rehabilitation Impact: Patients with TBI will make functional gains comparable with patients with brain tumors in a similar rehabilitation setting. PMID:23558698

Bilgin, S; Kose, N; Karakaya, J; Mut, M

2013-04-05

157

New Directions in Brain Imaging Research in Functional Gastrointestinal Disorders  

Microsoft Academic Search

Functional brain imaging has greatly enhanced the ability to investigate brain-gut interactions and to assess the central nervous system role on visceral pain perception. The results of studies using brain imaging in irritable bowel syndrome (IBS) have demonstrated differences in brain activation between patients with IBS and healthy controls. In addition, the more recent studies are starting to shed light

Yehuda Ringel

2006-01-01

158

Significance of epigenetics for understanding brain development, brain evolution and behaviour.  

PubMed

Two major environmental developments have occurred in mammalian evolution which have impacted on the genetic and epigenetic regulation of brain development. The first of these was viviparity and development of the placenta which placed a considerable burden of time and energy investment on the matriline, and which resulted in essential hypothalamic modifications. Maternal feeding, maternal care, parturition, milk letdown and the suspension of fertility and sexual behaviour are all determined by the maternal hypothalamus and have evolved to meet foetal needs under the influence of placental hormones. Viviparity itself provided a new environmental variable for selection pressures to operate via the co-existence over three generations of matrilineal genomes (mother, developing offspring and developing oocytes) in one individual. Also of importance for the matriline has been the evolution of epigenetic marks (imprint control regions) which are heritable and undergo reprogramming primarily in the oocyte to regulate imprinted gene expression according to parent of origin. Imprinting of autosomal genes has played a significant role in mammalian evolutionary development, particularly that of the hypothalamus and placenta. Indeed, many imprinted genes that are co-expressed in the placenta and hypothalamus play an important role in the co-adapted functioning of these organs. Thus the action and interaction of two genomes (maternal and foetal) have provided a template for transgenerational selection pressures to operate in shaping the mothering capabilities of each subsequent generation. The advanced aspects of neocortical brain evolution in primates have emancipated much of behaviour from the determininIBROg effects of hormonal action. Thus in large brain primates, most of the sexual behaviour is not reproductive hormone dependent and maternal care can and does occur outside the context of pregnancy and parturition. The neocortex has evolved to be adaptable and while the adapted changes are not inherited, the epigenetic predisposing processes can be. This provides each generation with the same ability to generate new adaptations while retaining a "cultural" predisposition to retain others. A significant evolutionary contribution to this epigenetic dimension has again been the matriline. The extensive neocortical development which takes place post-natally does so in an environment which is predominantly that of the caring guidance of the mother. Evidence for the epigenetic regulation of neocortical development is best illustrated by the GABA-ergic neurons and their long tangential migratory pathway from the ganglionic eminence, in contrast to the radial migration of principle neurons. GABA-ergic neurons play an integral role both in the developmental formation of canonical localised circuits and in synchronising widespread functional activity by the regulation of network oscillations. Such synchronisation enables distributed regions of the neocortex to coordinate firing. GABA-ergic dysfunction contributes to a broad spectrum of neurological and psychiatric disorders which can differ even across identical monozygotic twins. Moreover, major treatments for schizophrenia over the past 40years have included the drugs lithium and valproate, both of which we now know are histone deacetylases. It is rarely the heritable dysfunctioning of these epigenetic mechanisms that is at fault, but the timing, duration and place where they are deployed. The timing and complexity in the development of the neocortex makes this region of the brain more vulnerable to perturbations. PMID:23201253

Keverne, E B

2012-11-29

159

Physics, Math, and Making Sense: Understanding how brains learn science  

NASA Astrophysics Data System (ADS)

Recent developments in neuroscience, cognitive science, and behavioral science are helping physics education researchers develop a theoretical understanding of physics teaching and learning. This understanding helps in two ways. 1). We can make sense of the way students respond (often inappropriately) to our instruction. 2). We can learn to appreciate the difficulties we have as instructors in unpacking and identifying critical components of our own knowledge. Building on observations of student learning in introductory and advanced physics, I identify critical components for teaching physics with math that are often overlooked in traditional instruction.

Redish, Edward

2007-03-01

160

Understanding your inhibitions: modulation of brain cortical metabolism by GABAB receptors  

Microsoft Academic Search

Although the impact of neuronal excitation on the functional activity of brain is well understood, the nature of functional responses to inhibitory modulation is far from clear. In this work, we investigated the effects of modulation of the metabotropic GABAB receptor on brain metabolism using a targeted neuropharmacological, 1H\\/13C nuclear magnetic resonance spectroscopy, and metabolomic approach. While agonists at GABAB

Fatima A Nasrallah; Julian L Griffin; Vladimir J Balcar; Caroline Rae

2007-01-01

161

Split My Brain: A Case Study of Seizure Disorder and Brain Function  

ERIC Educational Resources Information Center

This case involves a couple deciding whether or not their son should undergo brain surgery to treat a severe seizure disorder. In examining this dilemma, students apply knowledge of brain anatomy and function. They also learn about brain scanning techniques and discuss the plasticity of the brain.

Omarzu, Julia

2004-01-01

162

Split My Brain: A Case Study of Seizure Disorder and Brain Function  

ERIC Educational Resources Information Center

|This case involves a couple deciding whether or not their son should undergo brain surgery to treat a severe seizure disorder. In examining this dilemma, students apply knowledge of brain anatomy and function. They also learn about brain scanning techniques and discuss the plasticity of the brain.|

Omarzu, Julia

2004-01-01

163

Understanding actors and object-goals in the human brain  

Microsoft Academic Search

When another person takes £10 from your hand, it matters if they are a shopkeeper or a robber. That is, the meaning of a simple, goal-directed action can vary depending on the identity of the actors involved. Research examining action understanding has identified an action observation network (AON) that encodes action features such as goals and kinematics. However, it is

Richard Ramsey; Antonia F. de C. Hamilton

2010-01-01

164

Neuroproteomics: understanding the molecular organization and complexity of the brain  

Microsoft Academic Search

Advances in technology have equipped the field of neuroproteomics with refined tools for the study of the expression, interaction and function of proteins in the nervous system. In combination with bioinformatics, neuroproteomics can address the organization of dynamic, functional protein networks and macromolecular structures that underlie physiological, anatomical and behavioural processes. Furthermore, neuroproteomics is contributing to the elucidation of disease

Alex Bayés; Seth G. N. Grant

2009-01-01

165

Fast Optical Imaging of Human Brain Function  

PubMed Central

Great advancements in brain imaging during the last few decades have opened a large number of new possibilities for neuroscientists. The most dominant methodologies (electrophysiological and magnetic resonance-based methods) emphasize temporal and spatial information, respectively. However, theorizing about brain function has recently emphasized the importance of rapid (within 100?ms or so) interactions between different elements of complex neuronal networks. Fast optical imaging, and in particular the event-related optical signal (EROS, a technology that has emerged over the last 15?years) may provide descriptions of localized (to sub-cm level) brain activity with a temporal resolution of less than 100?ms. The main limitations of EROS are its limited penetration, which allows us to image cortical structures not deeper than 3?cm from the surface of the head, and its low signal-to-noise ratio. Advantages include the fact that EROS is compatible with most other imaging methods, including electrophysiological, magnetic resonance, and trans-cranial magnetic stimulation techniques, with which can be recorded concurrently. In this paper we present a summary of the research that has been conducted so far on fast optical imaging, including evidence for the possibility of recording neuronal signals with this method, the properties of the signals, and various examples of applications to the study of human cognitive neuroscience. Extant issues, controversies, and possible future developments are also discussed.

Gratton, Gabriele; Fabiani, Monica

2010-01-01

166

Chemical approaches to understanding O-GlcNAc glycosylation in the brain  

PubMed Central

O -GlcNAc glycosylation is a unique, dynamic form of glycosylation found on intracellular proteins of all multicellular organisms. Studies suggest that O-GlcNAc represents a key regulatory modification in the brain, contributing to transcriptional regulation, neuronal communication and neurodegenerative disease. Recently, several new chemical tools have been developed to detect and study the modification, including chemoenzymatic tagging methods, quantitative proteomics strategies and small-molecule inhibitors of O-GlcNAc enzymes. Here we highlight some of the emerging roles for O-GlcNAc in the nervous system and describe how chemical tools have significantly advanced our understanding of the scope, functional significance and cellular dynamics of this modification.

Rexach, Jessica E; Clark, Peter M; Hsieh-Wilson, Linda C

2011-01-01

167

The brain, seizures and epilepsy throughout life: understanding a moving target.  

PubMed

The human brain is a tremendously complex and still enigmatic three-dimensional structure, composed of countless interconnected neurons and glia. The temporal evolution of the brain throughout life provides a fourth dimension, one that influences every element of the brain's function in health and disease. This temporal evolution contributes to the probability of seizure generation and to the type and the nature of these seizures. The age-specific properties of the brain also influence the consequences of seizures on neuronal structure and behavior. These, in turn, govern epileptic activity and cognitive and emotional functions, contributing to the diverse consequences of seizures and epilepsy throughout life. PMID:23476117

Baram, Tallie Z

2012-07-01

168

Split My Brain A Case Study of Seizure Disorder and Brain Function  

NSDL National Science Digital Library

This case study involves a couple deciding whether or not their son should undergo brain surgery to treat a severe seizure disorder. In examining this dilemma, students apply knowledge of brain anatomy and function. They also learn about brain scanning techniques and discuss the plasticity of the brain. The case was written for an introductory psychology course, but could be adapted for any course that covers brain anatomy, neurological disorders, or rehabilitation therapies.

Omarzu, Julia

2004-01-01

169

Dietary boron, brain function, and cognitive performance.  

PubMed Central

Although the trace element boron has yet to be recognized as an essential nutrient for humans, recent data from animal and human studies suggest that boron may be important for mineral metabolism and membrane function. To investigate further the functional role of boron, brain electrophysiology and cognitive performance were assessed in response to dietary manipulation of boron (approximately 0.25 versus approximately 3.25 mg boron/2000 kcal/day) in three studies with healthy older men and women. Within-subject designs were used to assess functional responses in all studies. Spectral analysis of electroencephalographic data showed effects of dietary boron in two of the three studies. When the low boron intake was compared to the high intake, there was a significant (p < 0.05) increase in the proportion of low-frequency activity, and a decrease in the proportion of higher-frequency activity, an effect often observed in response to general malnutrition and heavy metal toxicity. Performance (e.g., response time) on various cognitive and psychomotor tasks also showed an effect of dietary boron. When contrasted with the high boron intake, low dietary boron resulted in significantly poorer performance (p < 0.05) on tasks emphasizing manual dexterity (studies II and III); eye-hand coordination (study II); attention (all studies); perception (study III); encoding and short-term memory (all studies); and long-term memory (study I). Collectively, the data from these three studies indicate that boron may play a role in human brain function and cognitive performance, and provide additional evidence that boron is an essential nutrient for humans.

Penland, J G

1994-01-01

170

Functional transcranial brain imaging by optical-resolution photoacoustic microscopy  

NASA Astrophysics Data System (ADS)

Optical-resolution photoacoustic microscopy (OR-PAM) is applied to functional brain imaging in living mice. A near-diffraction-limited bright-field optical illumination is employed to achieve micrometer lateral resolution, and a dual-wavelength measurement is utilized to extract the blood oxygenation information. The variation in hemoglobin oxygen saturation (sO2) along vascular branching has been imaged in a precapillary arteriolar tree and a postcapillary venular tree, respectively. To the best of our knowledge, this is the first report on in vivo volumetric imaging of brain microvascular morphology and oxygenation down to single capillaries through intact mouse skulls. It is anticipated that: (i) chronic imaging enabled by this minimally invasive procedure will advance the study of cortical plasticity and neurological diseases; (ii) revealing the neuroactivity-dependent changes in hemoglobin concentration and oxygenation will facilitate the understanding of neurovascular coupling at the capillary level; and (iii) combining functional OR-PAM and high-resolution blood flowmetry will have the potential to explore cellular pathways of brain energy metabolism.

Hu, Song; Maslov, Konstantin; Tsytsarev, Vassiliy; Wang, Lihong V.

2009-07-01

171

Understanding adjustment following traumatic brain injury: is the Goodness-of-Fit coping hypothesis useful?  

PubMed

Coping efforts have been recognised as an important aspect of resilience following traumatic brain injury, but little is known about what constitutes effective coping in this population. This longitudinal research examined the usefulness of the Goodness-of-Fit hypothesis, drawn from the Lazarus and Folkman [(1984). Stress, appraisal and coping. NY: Springer.] theory of stress and coping, as a way of understanding coping effectiveness. The hypothesis suggests that the nature and success of specific coping strategies will be associated with the controllability of the event. If an event is relatively uncontrollable, then emotion-focused or perception-focused coping may be more effective than problem-focused coping. In contrast, a controllable event may be best managed through problem-focused coping. Ninety people with traumatic brain injury, drawn from the inpatient rehabilitation unit of a major metropolitan hospital in Australia, and their relatives participated in this longitudinal study. No support was found for the Goodness-of-Fit model, either in the short term or the long term. Although the use of problem-focused coping strategies was positively associated with short-term and long-term role functioning, it was not associated with long-term emotional well-being if the situation was perceived to be controllable. The findings suggest that the persistent use of problem-focused coping in response to the difficulties created by traumatic brain injury can be associated with emotional distress in the long term. Reasons for this finding are explored and its implications are discussed. PMID:18625542

Kendall, Elizabeth; Terry, Deborah J

2008-07-13

172

Evidence from cognitive neuroscience for the role of graphical and algebraic representations in understanding function  

Microsoft Academic Search

Using traditional educational research methods, it is difficult to assess students’ understanding of mathematical concepts,\\u000a even though qualitative methods such as task observation and interviews provide some useful information. It has now become\\u000a possible to use functional magnetic resonance imaging (fMRI) to observe brain activity whilst students think about mathematics,\\u000a although much of this work has concentrated on number. In

Michael O. J. ThomasAnna; Anna J. Wilson; Michael C. CorballisVanessa; Vanessa K. Lim; Caroline Yoon

2010-01-01

173

Understanding the blood–brain barrier using gene and protein expression profiling technologies  

Microsoft Academic Search

The blood–brain barrier (BBB) contributes to the brain homeostasis by regulating the passage of endogenous and exogenous compounds. This function is in part due to well-known proteins such as tight junction proteins, plasma membrane transporters and metabolic barrier proteins. Over the last decade, genomics and proteomics have emerged as supplementary tools for BBB research. The development of genomic and proteomic

Gwënaël Pottiez; Christophe Flahaut; Roméo Cecchelli; Yannis Karamanos

2009-01-01

174

Brain microvascular function during cardiopulmonary bypass  

SciTech Connect

Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass.

Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

1987-11-01

175

Imaging structural and functional brain networks in temporal lobe epilepsy  

PubMed Central

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy.

Bernhardt, Boris C.; Hong, SeokJun; Bernasconi, Andrea; Bernasconi, Neda

2013-01-01

176

Assessing Functional Connectivity in the Human Brain by FMRI  

PubMed Central

Functional magnetic resonance imaging is widely used to detect and delineate regions of the brain that change their level of activation in response to specific stimuli and tasks. Simple activation maps depict only the average level of engagement of different regions within distributed systems. FMRI potentially can reveal additional information about the degree by which components of large-scale neural systems are functionally coupled together to achieve specific tasks. In order to better understand how brain regions contribute to functionally connected circuits, it is necessary to record activation maps either as a function of different conditions, at different times or in different subjects. Data obtained under different conditions may then be analyzed by a variety of techniques to infer correlations and couplings between nodes in networks. Several different multivariate statistical methods have been adapted and applied to analyze the variations within such data. An approach of particular interest that is suited to studies of connectivity within single subjects makes use of acquisitions of runs of MRI images obtained while the brain is in a so-called steady state, either at rest (i.e. without any specific stimulus or task) or in a condition of continuous activation. The interregional correlations between fluctuations of MRI signal potentially reveal functional connectivity. Recent studies have established that interregional correlations between different components of circuits in each of the visual, language, motor and working memory systems can be detected in the resting state. The correlations at baseline are changed during the performance of a continuous task. In this review the various methods available for assessing connectivity are described and evaluated.

Rogers, Baxter P.; Morgan, Victoria L.; Newton, Allen T.; Gore, John C.

2007-01-01

177

kappa-Opioid receptor signaling and brain reward function.  

PubMed

The dynorphin-like peptides have profound effects on the state of the brain reward system and human and animal behavior. The dynorphin-like peptides affect locomotor activity, food intake, sexual behavior, anxiety-like behavior, and drug intake. Stimulation of kappa-opioid receptors, the endogenous receptor for the dynorphin-like peptides, inhibits dopamine release in the striatum (nucleus accumbens and caudate putamen) and induces a negative mood state in humans and animals. The administration of drugs of abuse increases the release of dopamine in the striatum and mediates the concomitant release of dynorphin-like peptides in this brain region. The reviewed studies suggest that chronic drug intake leads to an upregulation of the brain dynorphin system in the striatum and in particular in the dorsal part of the striatum/caudate putamen. This might inhibit drug-induced dopamine release and provide protection against the neurotoxic effects of high dopamine levels. After the discontinuation of chronic drug intake these neuroadaptations remain unopposed which has been suggested to contribute to the negative emotional state associated with drug withdrawal and increased drug intake. kappa-Opioid receptor agonists have also been shown to inhibit calcium channels. Calcium channel inhibitors have antidepressant-like effects and inhibit the release of norepinephrine. This might explain that in some studies kappa-opioid receptor agonists attenuate nicotine and opioid withdrawal symptomatology. A better understanding of the role of dynorphins in the regulation of brain reward function might contribute to the development of novel treatments for mood disorders and other disorders that stem from a dysregulation of the brain reward system. PMID:19804796

Bruijnzeel, Adrie W

2009-10-02

178

Maturation of Widely Distributed Brain Function Subserves Cognitive Development  

Microsoft Academic Search

Cognitive and brain maturational changes continue throughout late childhood and adolescence. During this time, increasing cognitive control over behavior enhances the voluntary suppression of reflexive\\/impulsive response tendencies. Recently, with the advent of functional MRI, it has become possible to characterize changes in brain activity during cognitive development. In order to investigate the cognitive and brain maturation subserving the ability to

Beatriz Luna; Keith R. Thulborn; Douglas P. Munoz; Elisha P. Merriam; Krista E. Garver; Nancy J. Minshew; Matcheri S. Keshavan; Christopher R. Genovese; William F. Eddy; John A. Sweeney

2001-01-01

179

Functional MRI of food-induced brain responses  

Microsoft Academic Search

The ultimate goal of this research was to find central biomarkers of satiety, i.e., physiological measures in the brain that relate to subjectively rated appetite, actual food intake, or both. This thesis describes the changes in brain activity in response to food stimuli as measured by functional MRI, with a focus on the hypothalamus. The hypothalamus is a brain area

P. A. M. Smeets

2006-01-01

180

Organization, development and function of complex brain networks  

Microsoft Academic Search

Recent research has revealed general principles in the structural and functional organization of complex networks which are shared by various natural, social and technological systems. This review examines these principles as applied to the organization, development and function of complex brain networks. Specifically, we examine the structural properties of large-scale anatomical and functional brain networks and discuss how they might

Olaf Sporns; Dante R. Chialvo; Marcus Kaiser; Claus C. Hilgetag

2004-01-01

181

Changes in the Functional Asymmetry of the Brain in Wrestlers  

Microsoft Academic Search

The changes in the functional asymmetry of the brain influenced by the wrestler’s position, a lateacquired automatism, are analyzed in this work. The functional asymmetry of the brain is known to change under the influence of external factors [1, 2]; in sportsmen, it becomes more marked due to the development of the visual and spatial functions of the right hemisphere

S. V. Afanas'ev; M. M. Mikheev; O. P. Trachenko; N. N. Nikolaenko

2000-01-01

182

Brain Maps on the Go: Functional Imaging During Motor Challenge in Animals  

PubMed Central

Brain mapping in the freely-moving animal is useful for studying motor circuits, not only because it avoids the potential confound of sedation or restraints, but because activated brain states may serve to accentuate differences that only manifest partially while a subject is in the resting state. Perfusion or metabolic mapping using autoradiography allows one to examine changes in brain function at the circuit level across the entire brain with a spatial resolution (?100 microns) appropriate for the rat or mouse brain, and a temporal resolution (seconds – minutes) sufficient for capturing acute brain changes. Here we summarize the application of these methods to the functional brain mapping of behaviors involving locomotion of small animals, methods for the three dimensional reconstruction of the brain from autoradiographic sections, voxel based analysis of the whole brain, and generation of maps of the flattened rat cortex. Application of these methods in animal models promises utility in improving our understanding of motor function in the normal brain, and of the effects of neuropathology and treatment interventions such as exercise have on the reorganization of motor circuits.

Holschneider, DP; Maarek, J-M I

2008-01-01

183

Brain maps on the go: functional imaging during motor challenge in animals.  

PubMed

Brain mapping in the freely moving animal is useful for studying motor circuits, not only because it avoids the potential confound of sedation or restraints, but because activated brain states may serve to accentuate differences that only manifest partially while a subject is in the resting state. Perfusion or metabolic mapping using autoradiography allows one to examine changes in brain function at the circuit level across the entire brain with a spatial resolution (approximately 100 micro) appropriate for the rat or mouse brain, and a temporal resolution (seconds-minutes) sufficient for capturing acute brain changes. Here we summarize the application of these methods to the functional brain mapping of behaviors involving locomotion of small animals, methods for the three-dimensional reconstruction of the brain from autoradiographic sections, voxel based analysis of the whole brain, and generation of maps of the flattened rat cortex. Application of these methods in animal models promises utility in improving our understanding of motor function in the normal brain, and of the effects of neuropathology and treatment interventions such as exercise have on the reorganization of motor circuits. PMID:18554522

Holschneider, D P; Maarek, J-M I

2008-06-11

184

Studies of Brain Function and Behavior.  

National Technical Information Service (NTIS)

This study includes single brain cells and their discharge patterns during Pavlovian conditioning to development and evaluation of brain wave recording techniques in pilots flying high performance aircraft on pursuit missions. Much of the work has involve...

J. D. French W. R. Adey H. W. Magoun

1964-01-01

185

Ageing and diabetes: implications for brain function  

Microsoft Academic Search

Diabetes mellitus is associated with moderate cognitive deficits and neurophysiological and structural changes in the brain, a condition that may be referred to as diabetic encephalopathy. Diabetes increases the risk of dementia, particularly in the elderly. The emerging view is that the diabetic brain features many symptoms that are best described as “accelerated brain ageing.” The clinical characteristics of diabetic

Geert Jan Biessels; Lars P van der Heide; Amer Kamal; Ronald L. A. W Bleys; Willem Hendrik Gispen

2002-01-01

186

Ion Channels and Their Neural Functions: Contribution to General Problems from Studies of Brains in Non-Mammalian Species  

Microsoft Academic Search

Ion channels and their neural functions have often been studied in the brains of mammals. However, the brains of some teleost fish species have special features that, at first glance, appear to be atypical and peculiar to that species alone. These teleost fish will contribute considerably to the understanding of general features of the ion channels and their neural functions.

Hidekazu Tsutsui; Yoshitaka Oka

2007-01-01

187

A Review of Functional Brain Imaging Correlates of Successful Cognitive Aging  

PubMed Central

Preserved cognitive performance is a key feature of successful aging. Several theoretical models (compensation, hemispheric asymmetry reduction, and posterior-anterior shift) have been proposed to explain the putative underlying relationship between brain function and performance. We aimed to review imaging studies of the association between brain functional response and cognitive performance among healthy younger and older adults in order to understand the neural correlates of successful cognitive aging. MEDLINE-indexed articles published between January 1989 and May 2008, and bibliographies of these articles and related reviews were searched. Studies that measured brain function using fMRI or PET, evaluated cognitive performance, analyzed how cognitive performance related to brain response, and studied healthy older individuals were included. Forty-seven of 276 articles met these criteria. Eighty-one percent of the studies reported some brain regions in which greater activation related to better cognitive performance among older participants. This association was not universal, however, and was seen mainly in frontal cortex brain response and seemed to be more common among older compared to younger individuals. This review supports the notion of compensatory increases in brain activity in old age resulting in better cognitive performance, as suggested by hemispheric asymmetry reduction and posterior-anterior shift models of functional brain aging. However, a simple model of bigger structure ? greater brain response ? better cognitive performance may not be accurate. Suggestions for future research are discussed.

Eyler, Lisa T.; Sherzai, Abdullah; Jeste, Dilip V.

2013-01-01

188

Functional Brain Networks Develop from a "Local to Distributed" Organization  

PubMed Central

The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward ‘segregation’ (a general decrease in correlation strength) between regions close in anatomical space and ‘integration’ (an increased correlation strength) between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more “distributed” architecture in young adults. We argue that this “local to distributed” developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths) are similar in child and adult graphs, with both showing “small-world”-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults both have relatively efficient systems that may solve similar information processing problems in divergent ways.

Power, Jonathan D.; Dosenbach, Nico U. F.; Church, Jessica A.; Miezin, Francis M.; Schlaggar, Bradley L.; Petersen, Steven E.

2009-01-01

189

Executive Functions in Children with Traumatic Brain Injury  

Microsoft Academic Search

The maturational course of the development of executive functioning abilities is dependent on the functional capacity of the human brain. Unfortunately, there is a dearth of standardized functional assessments of executive functioning abilities for children. The present article describes neurodevelopment of executive functioning and several recent measures of executive functioning that have been developed to assess maturational periods of specific

Arthur MacNeill Horton Jr; Henry V. Soper; Cecil R. Reynolds

2010-01-01

190

Development of Large-Scale Functional Brain Networks in Children  

Microsoft Academic Search

The ontogeny of large-scale functional organization of the human brain is not well understood. Here we use network analysis of intrinsic functional connectivity to characterize the organization of brain networks in 23 children (ages 7-9 y) and 22 young-adults (ages 19-22 y). Comparison of network properties, including path-length, clustering-coefficient, hierarchy, and regional connectivity, revealed that although children and young-adults' brains

Kaustubh Supekar; Mark Musen; Vinod Menon

2009-01-01

191

Brain Chemistry and Behaviour: An Update on Neuroscience Research and Its Implications for Understanding Drug Addiction  

ERIC Educational Resources Information Center

|Psychiatric disorders such as drug addiction represent one of the biggest challenges to society. This article reviews clinical and basic science research to illustrate how developments in research methodology have enabled neuroscientists to understand more about the brain mechanisms involved in addiction biology. Treating addiction represents a…

Robinson, Emma S. J.

2011-01-01

192

Understanding adjustment following traumatic brain injury: Is the Goodness-of-Fit coping hypothesis useful?  

Microsoft Academic Search

Coping efforts have been recognised as an important aspect of resilience following traumatic brain injury, but little is known about what constitutes effective coping in this population. This longitudinal research examined the usefulness of the Goodness-of-Fit hypothesis, drawn from the Lazarus and Folkman [(1984). Stress, appraisal and coping. NY: Springer.] theory of stress and coping, as a way of understanding

Elizabeth Kendall; Deborah J. Terry

2008-01-01

193

Brain Chemistry and Behaviour: An Update on Neuroscience Research and Its Implications for Understanding Drug Addiction  

ERIC Educational Resources Information Center

Psychiatric disorders such as drug addiction represent one of the biggest challenges to society. This article reviews clinical and basic science research to illustrate how developments in research methodology have enabled neuroscientists to understand more about the brain mechanisms involved in addiction biology. Treating addiction represents a…

Robinson, Emma S. J.

2011-01-01

194

Toward Elucidating Language Functions in the Brain  

Microsoft Academic Search

Human intelligence is characterized by the use of language rather than the brain hardware. The human brainware consists of\\u000a a neural system as hardware and a language system as software. Language was created by the brain hardware, and the human brain\\u000a evolved together with language over millions of years. It is, therefore, necessary to take two approaches to create the

Michio Sugeno

2008-01-01

195

Right hemisphere dominance for understanding the intentions of others: evidence from a split-brain patient.  

PubMed

Understanding the actions performed by other people is a key aspect of social interaction, including in clinical settings where patients are learning from therapists and caregivers. While lesions of the left cerebral hemisphere induce praxic disorders, the hemispheric specialisation of intention understanding remains unclear. Do patients with a right hemispheric lesion understand the intentions of other people properly? The present study investigates how a split-brain patient understands the means (what) and intentions (why) of the actions of other people. Results show a significant left hemispheric dominance for understanding what is done, and a significant right hemispheric dominance for understanding why an action is carried out. This discovery might have important clinical implications in neurological patients, especially when those with right hemisphere lesions are faced with important decisions related to the interpretation of other's intentions. PMID:21686731

Ortigue, Stephanie; King, Danielle; Gazzaniga, Michael; Miller, Michael; Grafton, Scott

2009-05-21

196

Right hemisphere dominance for understanding the intentions of others: evidence from a split-brain patient  

PubMed Central

Understanding the actions performed by other people is a key aspect of social interaction, including in clinical settings where patients are learning from therapists and caregivers. While lesions of the left cerebral hemisphere induce praxic disorders, the hemispheric specialisation of intention understanding remains unclear. Do patients with a right hemispheric lesion understand the intentions of other people properly? The present study investigates how a split-brain patient understands the means (what) and intentions (why) of the actions of other people. Results show a significant left hemispheric dominance for understanding what is done, and a significant right hemispheric dominance for understanding why an action is carried out. This discovery might have important clinical implications in neurological patients, especially when those with right hemisphere lesions are faced with important decisions related to the interpretation of other’s intentions.

Ortigue, Stephanie; King, Danielle; Gazzaniga, Michael; Miller, Michael; Grafton, Scott

2009-01-01

197

Partial correlation for functional brain interactivity investigation in functional MRI.  

PubMed

Examination of functional interactions through effective connectivity requires the determination of three distinct levels of information: (1) the regions involved in the process and forming the spatial support of the network, (2) the presence or absence of interactions between each pair of regions, and (3) the directionality of the existing interactions. While many methods exist to select regions (Step 1), very little is available to complete Step 2. The two main methods developed so far, structural equation modeling (SEM) and dynamical causal modeling (DCM), usually require precise prior information to be used, while such information is sometimes lacking. Assuming that Step 1 was successfully completed, we here propose a data-driven method to deal with Step 2 and extract functional interactions from fMRI datasets through partial correlations. Partial correlation is more closely related to effective connectivity than marginal correlation and provides a convenient graphical representation for functional interactions. As an instance of brain interactivity investigation, we consider how simple hand movements are processed by the bihemispheric cortical motor network. In the proposed framework, Bayesian analysis makes it possible to estimate and test the partial statistical dependencies between regions without any prior model on the underlying functional interactions. We demonstrate the interest of this approach on real data. PMID:16777436

Marrelec, Guillaume; Krainik, Alexandre; Duffau, Hugues; Pélégrini-Issac, Mélanie; Lehéricy, Stéphane; Doyon, Julien; Benali, Habib

2006-06-13

198

Oxytocin, brain physiology, and functional connectivity: a review of intranasal oxytocin fMRI studies.  

PubMed

In recent years the neuropeptide oxytocin (OT) has become one of the most studied peptides of the human neuroendocrine system. Research has shown widespread behavioural effects and numerous potential therapeutic benefits. However, little is known about how OT triggers these effects in the brain. Here, we discuss some of the physiological properties of OT in the human brain including the long half-life of neuropeptides, the diffuse projections of OT throughout the brain and interactions with other systems such as the dopaminergic system. These properties indicate that OT acts without clear spatial and temporal specificity. Therefore, it is likely to have widespread effects on the brain's intrinsic functioning. Additionally, we review studies that have used functional magnetic resonance imaging (fMRI) concurrently with OT administration. These studies reveal a specific set of 'social' brain regions that are likely to be the strongest targets for OT's potential to influence human behaviour. On the basis of the fMRI literature and the physiological properties of the neuropeptide, we argue that OT has the potential to not only modulate activity in a set of specific brain regions, but also the functional connectivity between these regions. In light of the increasing knowledge of the behavioural effects of OT in humans, studies of the effects of OT administration on brain function can contribute to our understanding of the neural networks in the social brain. PMID:23159011

Bethlehem, Richard A I; van Honk, Jack; Auyeung, Bonnie; Baron-Cohen, Simon

2012-11-15

199

Network Analysis of Intrinsic Functional Brain Connectivity in Alzheimer's Disease  

Microsoft Academic Search

Functional brain networks detected in task-free (''resting-state'') functional magnetic resonance imaging (fMRI) have a small- world architecture that reflects a robust functional organization of the brain. Here, we examined whether this functional organization is disrupted in Alzheimer's disease (AD). Task-free fMRI data from 21 AD subjects and 18 age-matched controls were obtained. Wavelet analysis was applied to the fMRI data

Kaustubh Supekar; Vinod Menon; Daniel Rubin; Mark Musen; Michael D. Greicius

2008-01-01

200

Graph Analysis of Functional Brain Networks for Cognitive Control of Action in Traumatic Brain Injury  

ERIC Educational Resources Information Center

|Patients with traumatic brain injury show clear impairments in behavioural flexibility and inhibition that often persist beyond the time of injury, affecting independent living and psychosocial functioning. Functional magnetic resonance imaging studies have shown that patients with traumatic brain injury typically show increased and more broadly…

Caeyenberghs, Karen; Leemans, Alexander; Heitger, Marcus H.; Leunissen, Inge; Dhollander, Thijs; Sunaert, Stefan; Dupont, Patrick; Swinnen, Stephan P.

2012-01-01

201

Time-varying functional network information extracted from brief instances of spontaneous brain activity  

PubMed Central

Recent functional magnetic resonance imaging studies have shown that the brain is remarkably active even in the absence of overt behavior, and this activity occurs in spatial patterns that are reproducible across subjects and follow the brain’s established functional subdivision. Investigating the distribution of these spatial patterns is an active area of research with the goal of obtaining a better understanding of the neural networks underlying brain function. One intriguing aspect of spontaneous activity is an apparent nonstationarity, or variability of interaction between brain regions. It was recently proposed that spontaneous brain activity may be dominated by brief traces of activity, possibly originating from a neuronal avalanching phenomenon. Such traces may involve different subregions in a network at different times, potentially reflecting functionally relevant relationships that are not captured with conventional data analysis. To investigate this, we examined publicly available functional magnetic resonance imaging data with a dedicated analysis method and found indications that functional networks inferred from conventional correlation analysis may indeed be driven by activity at only a few critical time points. Subsequent analysis of the activity at these critical time points revealed multiple spatial patterns, each distinctly different from the established functional networks. The spatial distribution of these patterns suggests a potential functional relevance.

Liu, Xiao; Duyn, Jeff H.

2013-01-01

202

Driving and Driven Architectures of Directed Small-World Human Brain Functional Networks  

PubMed Central

Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions. However, most of these studies have only focused on undirected connections between regions in which the directions of information flow are not taken into account. How the brain regions causally influence each other and how the directed network of human brain is topologically organized remain largely unknown. Here, we applied linear multivariate Granger causality analysis (GCA) and graph theoretical approaches to a resting-state functional MRI dataset with a large cohort of young healthy participants (n?=?86) to explore connectivity patterns of the population-based whole-brain functional directed network. This directed brain network exhibited prominent small-world properties, which obviously improved previous results of functional MRI studies showing weak small-world properties in the directed brain networks in terms of a kernel-based GCA and individual analysis. This brain network also showed significant modular structures associated with 5 well known subsystems: fronto-parietal, visual, paralimbic/limbic, subcortical and primary systems. Importantly, we identified several driving hubs predominantly located in the components of the attentional network (e.g., the inferior frontal gyrus, supplementary motor area, insula and fusiform gyrus) and several driven hubs predominantly located in the components of the default mode network (e.g., the precuneus, posterior cingulate gyrus, medial prefrontal cortex and inferior parietal lobule). Further split-half analyses indicated that our results were highly reproducible between two independent subgroups. The current study demonstrated the directions of spontaneous information flow and causal influences in the directed brain networks, thus providing new insights into our understanding of human brain functional connectome.

Yan, Chaogan; He, Yong

2011-01-01

203

Driving and driven architectures of directed small-world human brain functional networks.  

PubMed

Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions. However, most of these studies have only focused on undirected connections between regions in which the directions of information flow are not taken into account. How the brain regions causally influence each other and how the directed network of human brain is topologically organized remain largely unknown. Here, we applied linear multivariate Granger causality analysis (GCA) and graph theoretical approaches to a resting-state functional MRI dataset with a large cohort of young healthy participants (n?=?86) to explore connectivity patterns of the population-based whole-brain functional directed network. This directed brain network exhibited prominent small-world properties, which obviously improved previous results of functional MRI studies showing weak small-world properties in the directed brain networks in terms of a kernel-based GCA and individual analysis. This brain network also showed significant modular structures associated with 5 well known subsystems: fronto-parietal, visual, paralimbic/limbic, subcortical and primary systems. Importantly, we identified several driving hubs predominantly located in the components of the attentional network (e.g., the inferior frontal gyrus, supplementary motor area, insula and fusiform gyrus) and several driven hubs predominantly located in the components of the default mode network (e.g., the precuneus, posterior cingulate gyrus, medial prefrontal cortex and inferior parietal lobule). Further split-half analyses indicated that our results were highly reproducible between two independent subgroups. The current study demonstrated the directions of spontaneous information flow and causal influences in the directed brain networks, thus providing new insights into our understanding of human brain functional connectome. PMID:21858129

Yan, Chaogan; He, Yong

2011-08-12

204

Use of Functional Magnetic Resonance Imaging (Blood Oxygenation Level-Dependent Imaging, Diffusion Tensor Imaging and Magnetic Resonance Spectroscopy) in Brain Development Research  

Microsoft Academic Search

The development of several new magnetic resonance imaging (MRI) techniques has facilitated serial observations of the developing human brain in utero. For example, the noninvasive technique of functional MRI, which is used to study brain anatomy, function and metabolism in both humans and animals, has already enhanced our understanding of brain development and behavior relations. Currently, three main kinds of

Fei Fei Yang; Shu Guang Yuan; David T. Yew

2008-01-01

205

Functional brain connectivity as revealed by singular spectrum analysis.  

PubMed

Correlation based measures have widely been used to characterize brain connectivity. In this paper, a new approach based on singular spectrum analysis is proposed to characterize brain connectivity. It is obtained by deriving the common basis vector of two or more trajectory matrices associated with functional brain responses. This approach has the advantage illustrating the existence of joint variations of the functional brain responses and to characterize the correlation structure. The performance of the method are illustrated on both simulated autoregressive data and real fMRI data. PMID:23367097

Seghouane, Abd-Krim; Shah, Adnan

2012-01-01

206

Understanding the folding-function tradeoff in proteins.  

PubMed

When an amino-acid sequence cannot be optimized for both folding and function, folding can get compromised in favor of function. To understand this tradeoff better, we devise a novel method for extracting the "function-less" folding-motif of a protein fold from a set of structurally similar but functionally diverse proteins. We then obtain the ?-trefoil folding-motif, and study its folding using structure-based models and molecular dynamics simulations. CompariA protein sequence serves two purpson with the folding of wild-type ?-trefoil proteins shows that function affects folding in two ways: In the slower folding interleukin-1?, binding sites make the fold more complex, increase contact order and slow folding. In the faster folding hisactophilin, residues which could have been part of the folding-motif are used for function. This reduces the density of native contacts in functional regions and increases folding rate. The folding-motif helps identify subtle structural deviations which perturb folding. These may then be used for functional annotation. Further, the folding-motif could potentially be used as a first step in the sequence design of function-less scaffold proteins. Desired function can then be engineered into these scaffolds. PMID:23593437

Gosavi, Shachi

2013-04-12

207

Cultural neuroscience of the self: understanding the social grounding of the brain  

PubMed Central

Cultural neuroscience is an interdisciplinary field of research that investigates interrelations among culture, mind and the brain. Drawing on both the growing body of scientific evidence on cultural variation in psychological processes and the recent development of social and cognitive neuroscience, this emerging field of research aspires to understand how culture as an amalgam of values, meanings, conventions, and artifacts that constitute daily social realities might interact with the mind and its underlying brain pathways of each individual member of the culture. In this article, following a brief review of studies that demonstrate the surprising degree to which brain processes are malleably shaped by cultural tools and practices, the authors discuss cultural variation in brain processes involved in self-representations, cognition, emotion and motivation. They then propose (i) that primary values of culture such as independence and interdependence are reflected in the compositions of cultural tasks (i.e. daily routines designed to accomplish the cultural values) and further (ii) that active and sustained engagement in these tasks yields culturally patterned neural activities of the brain, thereby laying the ground for the embodied construction of the self and identity. Implications for research on culture and the brain are discussed.

Park, Jiyoung

2010-01-01

208

BrainKnowledge: A Human Brain Function Mapping Knowledge-Base System  

Microsoft Academic Search

Associating fMRI image datasets with the available literature is crucial for the analysis and interpretation of fMRI data.\\u000a Here, we present a human brain function mapping knowledge-base system (BrainKnowledge) that associates fMRI data analysis\\u000a and literature search functions. BrainKnowledge not only contains indexed literature, but also provides the ability to compare\\u000a experimental data with those derived from the literature. BrainKnowledge

Mei-Yu Hsiao; Chien-Chung Chen; Jyh-Horng Chen

2011-01-01

209

Understanding shoot branching by modelling form and function.  

PubMed

Shoot branching plays a pivotal role in the development of the aboveground plant structure. Therefore, to understand branching in relation to the environment, it is not only necessary to integrate the knowledge on mechanisms that regulate branching at multiple levels of biological organisation, but also to include plant structure explicitly. To this end, we propose the application of an established methodology called functional-structural plant modelling. PMID:21658989

Evers, Jochem B; van der Krol, Alexander R; Vos, Jan; Struik, Paul C

2011-06-12

210

NMDA receptor function, memory, and brain aging  

PubMed Central

An increasing level of N-methyl-D-aspartate (NMDA) receptor hypofunction within the brain is associated with memory and learning impairments, with psychosis, and ultimately with excitotoxic brain injury. As the brain ages, the NMDA receptor system becomes progressively hypofunctional, contributing to decreases in memory and learning performance. In those individuals destined to develop Alzheimer's disease, other abnormalities (eg, amyloidopathy and oxidative stress) interact to increase the NMDA receptor hypofunction (NRHypo) burden. In these vulnerable individuals, the brain then enters into a severe and persistent NRHypo state, which can lead to widespread neurodegeneration with accompanying mental symptoms and further cognitive deterioration. If the hypotheses described herein prove correct, treatment implications may be considerable. Pharmacological methods for preventing the overstimulation of vulnerable corticolimbic pyramidal neurons developed in an animal model may be applicable to the prevention and treatment of Alzheimer's disease.

Newcomer, John W.; Farber, Nuri B.; Olney, John W.

2000-01-01

211

Decoding brain states using functional magnetic resonance imaging  

Microsoft Academic Search

Most leading research in basic and clinical neuroscience has been carried out by functional magnetic resonance imaging (fMRI),\\u000a which detects the blood oxygenation level dependent signals associated with neural activities. Among new fMRI applications,\\u000a brain decoding is an emerging research area, which infers mental states from fMRI signals. Brain decoding using fMRI includes\\u000a classification, identification, and reconstruction of brain states.

Dongha Lee; Changwon Jang; Hae-Jeong Park

2011-01-01

212

Effects of MDMA on Complex Brain Function in Laboratory Animals  

Microsoft Academic Search

FREDERICK, D.L. AND M.G. PAULE. Effects of MDMA on complex brain function in laboratory animals. NEUROSCI BIOBEHAV REV 21(1) 67–78, 1997.—This review surveys experiments that have examined the effects of acute and chronic MDMA exposure on schedule-controlled operant behaviors thought to engender responses that reflect the expression of complex brain functions. Such functions include time estimation, short-term memory, learning, motivation,

DAVID L FREDERICK; MERLE G PAULE

1997-01-01

213

Developmental trajectories during adolescence in males and females: a cross-species understanding of underlying brain changes  

PubMed Central

Adolescence is a transitional period between childhood and adulthood that encompasses vast changes within brain systems that parallel some, but not all, behavioral changes. Elevations in emotional reactivity and reward processing follow an inverted U shape in terms of onset and remission, with the peak occurring during adolescence. However, cognitive processing follows a more linear course of development. This review will focus on changes within key structures and will highlight the relationships between brain changes and behavior, with evidence spanning from functional magnetic resonance imaging (fMRI) in humans to molecular studies of receptor and signaling factors in animals. Adolescent changes in neuronal substrates will be used to understand how typical and atypical behaviors arise during adolescence. We draw upon clinical and preclinical studies to provide a neural framework for defining adolescence and its role in the transition to adulthood.

Brenhouse, Heather C.; Andersen, Susan L.

2011-01-01

214

Constructing human brain-function association models from fMRI literature.  

PubMed

Toward the goal of understanding the human brain function, we have developed a web-based Human Brain Functional Mapping Knowledge Base (HBFMKB) system to mining human brain-function association model from vast Medline abstracts. Since nomenclature and relationships among cognitive functions have no consensus yet, we use rule-based natural language processing methods to extract behavioral task and cognitive function and do n-gram approximate concept mapping by the Unified Medical Language system (UMLS) knowledge source. The HBFMKB system has an automatic PubMed MEDLINE download and import system, name entity extraction system and interactive visualization system. In summary, the HBFMKB system helps scientists to get digest knowledge before design experiments and compare their results with current literature. PMID:18002175

Hsiao, Mei-Yu; Chen, Der-Yow; Chen, Jyh-Horng

2007-01-01

215

PET functional imaging of deep brain stimulation in movement disorders and psychiatry  

Microsoft Academic Search

Deep brain stimulation (DBS) represents a major advance in the treatment of various severe movement disorders or neuropsychiatric diseases. Our understanding of the mechanism of action of this surgical treatment has greatly benefited from functional imaging studies. Most of these studies have been conducted in patients with Parkinson's disease (PD) treated by bilateral subthalamic nucleus (STN) stimulation. These studies have

Benedicte Ballanger; Marjan Jahanshahi; Emmanuel Broussolle; Stéphane Thobois

2009-01-01

216

Connectionist Modeling of the Recovery of Language Functions Following Brain Damage  

Microsoft Academic Search

This paper reviews the contribution of connectionism to our understanding of behavioral changes in language functions after brain damage. Connectionism is founded upon a neural metaphor in that connectionist networks are made up of many simple, neuron-like units. It is possible to lesion these networks and explore the effects of that damage. It is widely held that damaging connectionist networks

Trevor A. Harley

1996-01-01

217

Hierarchical organization of brain functional networks during visual tasks  

NASA Astrophysics Data System (ADS)

The functional network of the brain is known to demonstrate modular structure over different hierarchical scales. In this paper, we systematically investigated the hierarchical modular organizations of the brain functional networks that are derived from the extent of phase synchronization among high-resolution EEG time series during a visual task. In particular, we compare the modular structure of the functional network from EEG channels with that of the anatomical parcellation of the brain cortex. Our results show that the modular architectures of brain functional networks correspond well to those from the anatomical structures over different levels of hierarchy. Most importantly, we find that the consistency between the modular structures of the functional network and the anatomical network becomes more pronounced in terms of vision, sensory, vision-temporal, motor cortices during the visual task, which implies that the strong modularity in these areas forms the functional basis for the visual task. The structure-function relationship further reveals that the phase synchronization of EEG time series in the same anatomical group is much stronger than that of EEG time series from different anatomical groups during the task and that the hierarchical organization of functional brain network may be a consequence of functional segmentation of the brain cortex.

Zhuo, Zhao; Cai, Shi-Min; Fu, Zhong-Qian; Zhang, Jie

2011-09-01

218

Understanding the Role of Nutrition in the Brain & Behavioral Development of Toddlers and Preschool Children: Identifying and Overcoming Methodological Barriers  

PubMed Central

The pre-school years (i.e., 1–5 years of age) is a time of rapid and dramatic postnatal brain development, i.e., neural plasticity, and of fundamental acquisition of cognitive development i.e., working memory, attention and inhibitory control. Also, it is a time of transition from a direct maternal mediation/selection of diet-based nutrition to food selection that is more based on self-selection and self-gratification. However, there have been fewer published studies in pre-school children than in infants or school-aged children that examined the role of nutrition in brain/mental development (i.e., 125 studies vs. 232 and 303 studies, respectively during the last 28 years, Figure 1). This may arise because of age-related variability, in terms of individual differences in temperament, linguistic ability, and patterns of neural activity that may affect assessment of neural and cognitive development in pre-school children. In this review, we suggest several approaches for assessing brain function in children that can be refined. It would be desirable if the discipline developed some common elements to be included in future studies of diet and brain function, with the idea that they would complement more targeted measures based on time of exposure and understanding of data from animal models. Underlining this approach is the concepts of “window of sensitivity” during which nutrients may affect postnatal neural development: investigators and expert panels need to specifically look for region-specific changes and do so with understanding of the likely time window during which the nutrient was, or was not available. (244 words)

Rosales, Francisco J.; Reznick, J. Steven; Zeisel, Steven H.

2009-01-01

219

How should educational neuroscience conceptualise the relation between cognition and brain function? Mathematical reasoning as a network process  

Microsoft Academic Search

Background: There is increasing interest in applying neuroscience findings to topics in education.Purpose: This application requires a proper conceptualisation of the relation between cognition and brain function. This paper considers two such conceptualisations. The area focus understands each cognitive competency as the product of one (and only one) brain area. The network focus explains each cognitive competency as the product

Sashank Varma; Daniel L. Schwartz

2008-01-01

220

The Efficiency of a Small-World Functional Brain Network  

NASA Astrophysics Data System (ADS)

We investigate whether the small-world topology of a functional brain network means high information processing efficiency by calculating the correlation between the small-world measures of a functional brain network and behavioral reaction during an imagery task. Functional brain networks are constructed by multichannel event-related potential data, in which the electrodes are the nodes and the functional connectivities between them are the edges. The results show that the correlation between small-world measures and reaction time is task-specific, such that in global imagery, there is a positive correlation between the clustering coefficient and reaction time, while in local imagery the average path length is positively correlated with the reaction time. This suggests that the efficiency of a functional brain network is task-dependent.

Zhao, Qing-Bai; Zhang, Xiao-Fei; Sui, Dan-Ni; Zhou, Zhi-Jin; Chen, Qi-Cai; Tang, Yi-Yuan

2012-04-01

221

The Effects of Brain Damage on Visual Functioning in Children  

Microsoft Academic Search

Medical and educational professionals arc working with a growing population of in- fants and children who have brain dam- age. This article reviews research on the effects of brain damage on visual function- ing in children, the tests that determine these effects, and the implications of these effects for prognosis and intervention. Background

P. K. Alexander

1990-01-01

222

Functional Brain Imaging Alterations in Acne Patients Treated With Isotretinoin  

Microsoft Academic Search

Objective: Although there have been case reports suggesting a relationship be- tween treatment with the acne medica- tion isotretinoin and the development of depression and suicide, this topic remains controversial. In order for isotretinoin to cause depression, it must have an effect on the brain; however, the effects of isotretinoin on brain functioning in acne patients have not been established.

J. Douglas Bremner; Negar Fani; M. S. Ali Ashraf; John R. Votaw; Marijn E. Brummer; D. Thomas Cummins; Viola Vaccarino; Mark M. Goodman; D. Lai Reed; Sajid Siddiq; Charles B. Nemeroff

2005-01-01

223

Reliability of Individual Functional MRI Brain Mapping of Language  

Microsoft Academic Search

The use of individual brain mapping for a single case study implicitly assumes that the pattern of activation obtained in a single session represents the subject's functional neuroanatomy. It is therefore essential to estimate the potential variability of brain activation in individuals. To this purpose, the authors compared the pattern of activation determined by statistical parametric mapping (SPM 99) in

Hélène Otzenberger; Daniel Gounot; Corinne Marrer; Izzie Jacques Namer; Marie-Noëlle Metz-Lutz

2005-01-01

224

Mapping cognitive brain function with modern high-resolution electroencephalography  

Microsoft Academic Search

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. While electroencephalography (EEG) provides temporal resolution in the millisecond range, which would seem to make it an ideal complement to other imaging modalities, traditional EEG technology and practice provides insufficient spatial detail to identify relationships between brain electrical events and structures and

Alan Gevins; Harrison Leong; Michael E. Smith; Jian Le; Robert Du

1995-01-01

225

Alpha oscillations in brain functioning: an integrative theory  

Microsoft Academic Search

The old concept stating that EEG alpha (10-Hz) activity reflects passive or idling states of the brain is giving way to modern views of 10-Hz oscillations in relation to diverse brain functions comprising sensory, motor, and memory processes: (1) Spontaneous alpha activity is not pure noise as shown by methods of chaos analysis. (2) Evoked alpha oscillations patterns (precisely time-locked

E. Basar; M. Schurmann; C. Basar-eroglu; S. Karakas

1997-01-01

226

Magnetic resonance imaging mapping of brain function. Human visual cortex  

Microsoft Academic Search

Magnetic resonance imaging (MRI) studies of human brain activity are described. Task-induced changes in brain cognitive state were measured using high-speed MRI techniques sensitive to changes in cerebral blood volume (CBV), blood flow (CBF), and blood oxygenation. These techniques were used to generate the first functional MRI maps of human task activation, by using a visual stimulus paradigm. The methodology

J. W. Belliveau; K. K. Kwong; D. N. Kennedy; J. R. Baker; C. E. Stern; R. Benson; D. A. Chesler; R. M. Weisskoff; M. S. Cohen; R. B. Tootell; P. T. Fox; T. J. Brady

1992-01-01

227

Time-varying functional network information extracted from brief instances of spontaneous brain activity.  

PubMed

Recent functional magnetic resonance imaging studies have shown that the brain is remarkably active even in the absence of overt behavior, and this activity occurs in spatial patterns that are reproducible across subjects and follow the brain's established functional subdivision. Investigating the distribution of these spatial patterns is an active area of research with the goal of obtaining a better understanding of the neural networks underlying brain function. One intriguing aspect of spontaneous activity is an apparent nonstationarity, or variability of interaction between brain regions. It was recently proposed that spontaneous brain activity may be dominated by brief traces of activity, possibly originating from a neuronal avalanching phenomenon. Such traces may involve different subregions in a network at different times, potentially reflecting functionally relevant relationships that are not captured with conventional data analysis. To investigate this, we examined publicly available functional magnetic resonance imaging data with a dedicated analysis method and found indications that functional networks inferred from conventional correlation analysis may indeed be driven by activity at only a few critical time points. Subsequent analysis of the activity at these critical time points revealed multiple spatial patterns, each distinctly different from the established functional networks. The spatial distribution of these patterns suggests a potential functional relevance. PMID:23440216

Liu, Xiao; Duyn, Jeff H

2013-02-25

228

Mapping Functional Brain Development: Building a Social Brain Through Interactive Specialization  

Microsoft Academic Search

The authors review a viewpoint on human functional brain development, interactive specialization (IS), and its application to the emerging network of cortical regions referred to as the social brain. They advance the IS view in 2 new ways. First, they extend IS into a domain to which it has not previously been applied—the emergence of social cognition and mentalizing computations

Mark H. Johnson; Tobias Grossmann; Kathrin Cohen Kadosh

2009-01-01

229

Correlation between cognitive brain function and electrical brain activity in dementia of Alzheimer type  

Microsoft Academic Search

Summary Psychometric tests which assess cognitive brain function in dementia disorders are partly prone to artifacts, e.g., the experience of the investigator and the cooperation of the patient influences the results. An objective way to assess the degree of cognitive disturbance could be to measure neuronal activity represented by the electrical brain activity. The aim of the present study was

T. Dierks; L. Frölich; R. Ihl; K. Maurer

1995-01-01

230

BrainMap: A Database of Functional Neuroanatomy Derived from Human Brain Images.  

National Technical Information Service (NTIS)

The goal of the BrainMap project is to promote efficient compilation, analysis, and dissemination of the rapidly growing body of information about the functional organization of the human brain which can be provided by medical imaging techniques such as P...

1991-01-01

231

Dissociable brain networks involved in development of fairness considerations: Understanding intentionality behind unfairness  

Microsoft Academic Search

In this functional magnetic resonance imaging study, we examined developmental changes in the brain regions involved in reactions to unfair allocations. Previous studies on adults suggested that reactions to unfairness are not only affected by the distribution itself but also by the ascribed intentionality of the proposer. In the current study, we employed the mini Ultimatum Game (Falk, Fehr, &

Berna Güro?lu; Wouter van den Bos; Eric van Dijk; Serge A. R. B. Rombouts; Eveline A. Crone

2011-01-01

232

AN INTELLIGENT TOOL TO AID IN UNDERSTANDING CORTICAL BRAIN ANATOMY VISUALIZED BY MEANS OF FLAT MAPS  

Microsoft Academic Search

In the past a versatile medical image analysis environment has been built, that includes a rich set of visualisation functions for 3D atlases and 3D modality images. Later on, the application has been extended with a novel projection method, which unwraps the complete cortical surface of the brain in a 2D plane without severe geometric distortion. This flat map enables

Rudi Deklerck; Marek Suliga; Edgard Nyssen

233

Linking structure and function: Information processing in the brain.  

National Technical Information Service (NTIS)

Traditionally, theories of function in neuroscience have emerged from physiology. Physiologists have suggested a number of means by which information in the brain can be processed, yet the principles underlying the generation of these phenomena are not we...

M. A. V. Gremillion

1990-01-01

234

Functional Imaging of Dolphin Brain Metabolism and Blood Flow.  

National Technical Information Service (NTIS)

This report documents the first use of magnetic resonance images (MRls) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep. Diazepam has been shown to induce unihemispheric s...

S. Ridgway J. Finneran D. Carder M. Keogh W. Van Bonn

2006-01-01

235

Gender Effect on Functional Networks in Resting Brain  

Microsoft Academic Search

Previous studies have witnessed that complex brain networks have the properties of high global and local efficiency. In this\\u000a study, we investigated the gender effect on brain functional networks measured using functional magnetic resonance imaging\\u000a (fMRI). Our experimental results showed that there were no significant difference in global and local efficiency between male\\u000a and female. However, the gender-related effects on

Liang Wang; Chaozhe Zhu; Yong He; Qiuhai Zhong; Yufeng Zang

2007-01-01

236

Improvement of brain function in hemodialysis patients treated with erythropoietin  

Microsoft Academic Search

Improvement of brain function in hemodialysis patients treated with erythropoietin. To evaluate the effects of recombinant human erythropoietin (rHuEPO) on brain function, 15 chronic hemodialysis patients were studied by event-related P300, stimulus-related evoked potentials, and trailmaking before (hematocrit 22.7%) and after rHuEPO (hematocrit 30.6%). P300 peak latency elicited by a tone discrimination paradigm improved (391 before vs. 366 ms after;

Georg Grimm; Felix Stockenhuber; Bruno Schneeweiss; Christian Madl; Josef Zeitlhofer; Barbara Schneider

1990-01-01

237

Efficiency and Cost of Economical Brain Functional Networks  

Microsoft Academic Search

Brain anatomical networks are sparse, complex, and have economical small-world properties. We investigated the efficiency and cost of human brain functional networks measured using functional magnetic resonance imaging (fMRI) in a factorial design: two groups of healthy old (N ¼11; mean age ¼66.5 years) and healthy young (N ¼15; mean age ¼ 24.7 years) volunteers were each scanned twice in

Sophie Achard; Ed Bullmore

2007-01-01

238

Democratic reinforcement: A principle for brain function  

Microsoft Academic Search

We introduce a simple ``toy'' brain model. The model consists of a set of randomly connected, or layered integrate-and-fire neurons. Inputs to and outputs from the environment are connected randomly to subsets of neurons. The connections between firing neurons are strengthened or weakened according to whether the action was successful or not. Unlike previous reinforcement learning algorithms, the feedback from

Dimitris Stassinopoulos; Per Bak

1995-01-01

239

Frontal brain asymmetry and immune function  

Microsoft Academic Search

The relation between brain activity and the immune system was evaluated by assessing immune responses in 20 healthy women who manifested extreme differences in the asymmetry of frontal cortex activation. One group showed extreme and stable left frontal activation; the other group showed extreme and stable right frontal activation. As predicted, women with extreme right frontal activation had significantly lower

Duck-hee Kang; Richard J. Davidson; Christopher L. Coe; Robert E. Wheeler

1991-01-01

240

Yeast sphingolipids: recent developments in understanding biosynthesis, regulation, and function.  

PubMed

Sphingolipids function as required membrane components of virtually all eukaryotic cells. Data indicate that members of the sphingolipid family of lipids, including sphingoid bases, sphingoid base phosphates, ceramides, and complex sphingolipids, serve vital functions in cell biology by both direct mechanisms (e.g., binding to G-protein coupled receptors to transduce an extracellular signal) and indirect mechanisms (e.g., facilitating correct intracellular protein transport). Because of the diverse roles these lipids play in cell biology, it is important to understand not only their biosynthetic pathways and regulation of sphingolipid synthesis, but also the mechanisms by which some sphingolipid species with specific functions are modified or converted to other sphingolipid species with alternate functions. Due to many factors including ease of culture and genetic modification, and conservation of major sphingolipid metabolic pathways, Saccharomyces cerevisiae has served as an ideal model system with which to identify enzymes of sphingolipid biosynthesis and to dissect sphingolipid function. Recent exciting developments in sphingolipid synthesis, transport, signaling, and overall biology continue to fuel vigorous investigation and inspire investigations in mammalian sphingolipid biology. PMID:16997623

Cowart, L Ashley; Obeid, Lina M

2006-08-10

241

Human Brain Language Areas Identified by Functional Magnetic Resonance Imaging  

Microsoft Academic Search

Functional magnetic resonance imaging (FMRI) was used to identify candidate language processing areas in the intact hu- man brain. Language was defined broadly to include both phonological and lexical-semantic functions and to exclude sensory, motor, and general executive functions. The language activation task required phonetic and semantic analysis of aurally presented words and was compared with a control task involving

Jeffrey R. Binder; Julie A. Frost; Thomas A. Hammeke; Robert W. Cox; Stephen M. Rao; Thomas Prieto

1997-01-01

242

Toward a structural understanding of IRES RNA function.  

PubMed

Protein synthesis of an RNA template can start by two different known mechanisms: cap-dependent translation initiation and cap-independent translation initiation. The latter is driven by RNA sequences called internal ribosome entry sites (IRESs) that are found in both viral RNAs and cellular mRNAs. The diverse mechanisms used by IRESs are reflected in their structural diversity, and this structural diversity challenges us to develop a cohesive model linking IRES function to structure. With more direct structural information available for the viral IRESs, data suggest an inverse correlation between the degree to which an IRES RNA can form a stable structure on its own and the number of factors that it requires to function. Lessons learned from the viral IRESs may help understand the cellular IRESs, although more structural data are needed before any strong links can be made. PMID:19362464

Filbin, Megan E; Kieft, Jeffrey S

2009-04-09

243

Towards a structural understanding of IRES RNA function  

PubMed Central

Protein synthesis of an RNA template can initiate by two different known mechanisms: cap-dependent translation initiation and cap-independent translation initiation. The latter is driven by RNA sequences called internal ribosome entry sites (IRESs) that are found in both viral RNAs and cellular mRNAs. The diverse mechanisms used by IRESs are reflected in their structural diversity, and this structural diversity challenges us to develop a cohesive model linking IRES function to structure. With more direct structural information available for the viral IRESs, data suggest an inverse correlation between the degree to which an IRES RNA can form a stable structure on its own, and the number of factors that it requires to function. Lessons learned from the viral IRESs may help understand the cellular IRESs, although more structural data is needed before any strong links can be made.

Filbin, Megan E.; Kieft, Jeffrey S.

2009-01-01

244

Neuroecology of cartilaginous fishes: the functional implications of brain scaling.  

PubMed

It is a widely accepted view that neural development can reflect morphological adaptations and sensory specializations. The aim of this review is to give a broad overview of the current status of brain data available for cartilaginous fishes and examine how perspectives on allometric scaling of brain size across this group of fishes has changed within the last 50 years with the addition of new data and more rigorous statistical analyses. The current knowledge of neuroanatomy in cartilaginous fishes is reviewed and data on brain size (encephalization, n = 151) and interspecific variation in brain organization (n = 84) has been explored to ascertain scaling relationships across this clade. It is determined whether similar patterns of brain organization, termed cerebrotypes, exist in species that share certain lifestyle characteristics. Clear patterns of brain organization exist across cartilaginous fishes, irrespective of phylogenetic grouping and, although this study was not a functional analysis, it provides further evidence that chondrichthyan brain structures might have developed in conjunction with specific behaviours or enhanced cognitive capabilities. Larger brains, with well-developed telencephala and large, highly foliated cerebella are reported in species that occupy complex reef or oceanic habitats, potentially identifying a reef-associated cerebrotype. In contrast, benthic and benthopelagic demersal species comprise the group with the smallest brains, with a relatively reduced telencephalon and a smooth cerebellar corpus. There is also evidence herein of a bathyal cerebrotype; deep-sea benthopelagic sharks possess relatively small brains and show a clear relative hypertrophy of the medulla oblongata. Despite the patterns observed and documented, significant gaps in the literature have been highlighted. Brain mass data are only currently available on c. 16% of all chondrichthyan species, and only 8% of species have data available on their brain organization, with far less on subsections of major brain areas that receive distinct sensory input. The interspecific variability in brain organization further stresses the importance of performing functional studies on a greater range of species. Only an expansive data set, comprised of species that span a variety of habitats and taxonomic groups, with widely disparate behavioural repertoires, combined with further functional analyses, will help shed light on the extent to which chondrichthyan brains have evolved as a consequence of behaviour, habitat and lifestyle in addition to phylogeny. PMID:22497414

Yopak, K E

2012-03-27

245

Understanding the benefits of musical training: effects on oscillatory brain activity.  

PubMed

A number of studies suggest that musical training has benefits for other cognitive domains, such as language and mathematics, and studies of children and adults indicate structural as well as functional differences between the brains of musicians and nonmusicians. The induced gamma-band response has been associated with attentional, expectation, memory retrieval, and integration of top-down, bottom-up, and multisensory processes. Here we report data indicating that the induced gamma-band response to musical sounds is larger in adult musicians than in nonmusicians and that it develops in children after 1 year of musical training beginning at age 4.5 years, but not in children of this age who are not engaged in musical lessons. We conclude that musical training affects oscillatory networks in the brain associated with executive functions, and that superior executive functioning could enhance learning and performance in many cognitive domains. PMID:19673769

Trainor, Laurel J; Shahin, Antoine J; Roberts, Larry E

2009-07-01

246

The impact of alcohol dependence on social brain function.  

PubMed

The impact of alcoholism (ALC) or alcohol dependence on the neural mechanisms underlying cognitive and affective empathy (i.e. the different routes to understanding other people's minds) in schizophrenic patients and non-schizophrenic subjects is still poorly understood. We therefore aimed at determining the extent to which the ability to infer other people's mental states and underlying neural mechanisms were affected by ALC. We examined 48 men, who suffered either from ALC, schizophrenia, both disorders or none of these disorders, using functional magnetic resonance imaging while performing on a mind reading task that involves both cognitive and affective aspects of empathy. Using voxel-based morphometry, we additionally examined whether between-group differences in functional activity were associated with deficits in brain structural integrity. During mental state attribution, all clinical groups as compared with healthy controls exhibited poor performance as well as reduced right-hemispheric insular function with the highest error rate and insular dysfunction seen in the schizophrenic patients without ALC. Accordingly, both behavioral performance and insular functioning revealed schizophrenia × ALC interaction effects. In addition, schizophrenic patients relative to non-schizophrenic subjects (regardless of ALC) exhibited deficits in structural integrity and task-related recruitment of the left ventrolateral prefrontal cortex (vlPFC). Our data suggest that ALC-related impairment in the ability to infer other people's mental states is limited to insular dysfunction and thus deficits in affective empathy. By contrast, mentalizing in schizophrenia (regardless of ALC) may be associated with insular dysfunction as well as a combination of structural and functional deficits in the left vlPFC. PMID:22340281

Gizewski, Elke R; Müller, Bernhard W; Scherbaum, Norbert; Lieb, Bodo; Forsting, Michael; Wiltfang, Jens; Leygraf, Norbert; Schiffer, Boris

2012-02-17

247

Human brain activity with functional NIR optical imager  

NASA Astrophysics Data System (ADS)

In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

Luo, Qingming

2001-08-01

248

Cytochrome P450 in the brain: neuroendocrine functions.  

PubMed

The effectiveness of steroid hormone metabolites as sedatives and anesthetics has been known for many years. More recently, their interaction with neurotransmitter receptors has helped to elucidate their mechanism of action, but their physiological functions and their role in disturbances of behavior, anxiety, and sleep/wakefulness have yet to be elucidated. Until 1981 it was assumed that metabolites of steroid hormones arose from the adrenals and gonads and that their action on neurotransmitter receptors was a mechanism of communication between the brain and the periphery. The evidence that the brain could accumulate steroids independently of the adrenals and gonads in 1981 and later the evidence for the presence of the cholesterol side chain cleavage enzyme (P450scc) in the brain have challenged this concept and stimulated a great deal of interest in the possibility that the brain could be making its own steroids from cholesterol for some as yet undefined purpose. In this review we examine the data pertaining to the role of brain P450 in the synthesis and degradation of neurosteroids. We summarize the data on the presence of P450scc in the brain and try to answer the following questions: (1) Does P450scc in the brain contribute significantly to the synthesis of GABAA receptor active steroids? (2) Can the P450scc in the brain account for the accumulation of pregnenolone in the brain? (3) Is there evidence for special functions of the pregnenolone synthesized in the brain? (4) Is there a role for other forms of brain P450 in neurosteroid action? PMID:7556851

Warner, M; Gustafsson, J A

1995-07-01

249

The brain basis for episodic memory: Insights from functional MRI, intracranial EEG, and patients with epilepsy  

Microsoft Academic Search

This article reviews the contributions that functional magnetic resonance imaging (fMRI), intracranial electroencephalography (iEEG), and patient studies have made to our current understanding of how memory functions arise from the brain. First, we briefly discuss the current classification of different memory systems and their neuroanatomical correlates, focusing on episodic memory and evidence from lesion studies. We then survey both fMRI

David Y. Hwang; Alexandra J. Golby

2006-01-01

250

Oxidative damage in brain from human mutant APP\\/PS1 double knock-in mice as a function of age ? [1] This manuscript is dedicated to the life of Earl R. Stadtman (1919–2008), a dear friend who gave such elegant understanding of protein oxidation to the scientific community  

Microsoft Academic Search

Oxidative stress is strongly implicated in the progressive decline of cognition associated with aging and neurodegenerative disorders. In the brain, free radical-mediated oxidative stress plays a critical role in the age-related decline of cellular function as a result of the oxidation of proteins, lipids, and nucleic acids. A number of studies indicate that an increase in protein oxidation and lipid

Hafiz Mohmmad Abdul; Rukhsana Sultana; Daret K. St. Clair; William R. Markesbery; D. Allan Butterfield

2008-01-01

251

Evolving knowledge of sex differences in brain structure, function, and chemistry.  

PubMed

Clinical and epidemiologic evidence demonstrates sex differences in the prevalence and course of various psychiatric disorders. Understanding sex-specific brain differences in healthy individuals is a critical first step toward understanding sex-specific expression of psychiatric disorders. Here, we evaluate evidence on sex differences in brain structure, chemistry, and function using imaging methodologies, including functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), and structural magnetic resonance imaging (MRI) in mentally healthy individuals. MEDLINE searches of English-language literature (1980-November 2006) using the terms sex, gender, PET, SPECT, MRI, fMRI, morphometry, neurochemistry, and neurotransmission were performed to extract relevant sources. The literature suggests that while there are many similarities in brain structure, function, and neurotransmission in healthy men and women, there are important differences that distinguish the male from the female brain. Overall, brain volume is greater in men than women; yet, when controlling for total volume, women have a higher percentage of gray matter and men a higher percentage of white matter. Regional volume differences are less consistent. Global cerebral blood flow is higher in women than in men. Sex-specific differences in dopaminergic, serotonergic, and gamma-aminobutyric acid (GABA)ergic markers indicate that male and female brains are neurochemically distinct. Insight into the etiology of sex differences in the normal living human brain provides an important foundation to delineate the pathophysiological mechanisms underlying sex differences in neuropsychiatric disorders and to guide the development of sex-specific treatments for these devastating brain disorders. PMID:17544382

Cosgrove, Kelly P; Mazure, Carolyn M; Staley, Julie K

2007-06-04

252

Structural, functional and developmental convergence of the insect mushroom bodies with higher brain centers of vertebrates.  

PubMed

Convergence of higher processing centers has been proposed for insects and vertebrates, but the extent of these similarities remains controversial. The present study demonstrates that one higher brain center of insects, the mushroom bodies, displays a number of similarities with mammalian higher brain centers that are arguably the products of adaptation to common behavioral ecologies, despite their deeply divergent origins. Quantitative neuroanatomy, immunohistochemistry, fluorescent tract tracing and BrdU labeling are employed to investigate the relationships among behavioral ecology and mushroom body size, sensory input and mode of development in one taxon, the scarab beetles (Coleoptera: Scarabaeidae). Comparisons are extended to a taxon in which similar mushroom body architectures have arisen independently, the cockroaches (Dictyoptera), and to published accounts of vertebrate brain evolution. This study demonstrates that evolutionary increases in higher brain center size and intrinsic neuron number are associated with flexibility in food acquisition behaviors in both vertebrates and insects. These evolutionarily expanded higher brain centers are divided into novel structural subcompartments that acquire novel processing functions. Increased numbers of neurons comprising enlarged higher brain centers are generated by expanded neural precursor pools, and the time for development of these brain centers is protracted. Taken together, these findings extend our understanding of how evolutionarily constrained neural substrates might converge under shared adaptive landscapes, even after 600 million years of divergence, and even at the level of higher brain centers that generate complex behaviors. PMID:18560208

Farris, Sarah M

2008-06-17

253

ABCD: a functional database for the avian brain.  

PubMed

Here we present the first database developed for storing, retrieving and cross-referencing neuroscience information about the connectivity of the avian brain. The Avian Brain Circuitry Database (ABCD) contains entries about the new and old terminology of the areas and their hierarchy, data on connections between brain regions, as well as a functional keyword system linked to brain regions and connections. Data were collected from the primary literature and textbooks, and an online submission system was developed to facilitate further data collection directly from researchers. The database aims to help spread the results of avian connectivity studies, the recently revised nomenclature and also to provide data for brain network research. ABCD is freely available at http://www.behav.org/abcd. PMID:17889371

Schrott, Aniko; Kabai, Peter

2007-08-19

254

Mining the brain metabolome to understand behavioural disruptions induced in mouse fed Hypochoeris radicata (L.), a neurotoxic plant for horse.  

PubMed

Mining the brain metabolome to understand behavioural disruptions induced in mouse fed Hypochoeris radicata (L.), a neurotoxic plant for horse. C57BL/6J mice orally exposed to 9% H. radicata (HR) are metabolically competent laboratory animals which can be used as model of Australian stringhalt, a neurological horse disease induced by HR ingestion. So, the present study was conducted to assess the brain metabolome and the behavioural performances of mice fed with a 9%-HR-based diet for 21 days. By the end of the period of exposure, mice were investigated for motor activity and coordination, anxiety level, learning and memory performances, social behaviour and rewarding properties of for the plant. Thus, the animals were sacrificed and the brain metabolome was studied using (1)H NMR spectroscopy. HR-exposed mice displayed a motor hyperactivity in several tasks, a less resignation in the forced swimming test, and paradigm place preference for the plant. A bootstrap-based regularized canonical analysis performed on merged behavioural and metabolic datasets showed a clear relationship in HR-treated mice between an increase in cerebral scyllo-inositol, an increased motor activity, and seemingly rewarding properties of HR. These results underlie the interest of such a dual approach to characterize functional end-points of a pathophysiological model of the Australian stringhalt in equine species. PMID:23811200

Domange, Céline; Schroeder, Henri; Violle, Nicolas; Peiffer, Julie; Canlet, Cécile; Paris, Alain; Priymenko, Nathalie

2013-06-28

255

Pattern Classification of Large-Scale Functional Brain Networks: Identification of Informative Neuroimaging Markers for Epilepsy  

PubMed Central

The accurate prediction of general neuropsychiatric disorders, on an individual basis, using resting-state functional magnetic resonance imaging (fMRI) is a challenging task of great clinical significance. Despite the progress to chart the differences between the healthy controls and patients at the group level, the pattern classification of functional brain networks across individuals is still less developed. In this paper we identify two novel neuroimaging measures that prove to be strongly predictive neuroimaging markers in pattern classification between healthy controls and general epileptic patients. These measures characterize two important aspects of the functional brain network in a quantitative manner: (i) coordinated operation among spatially distributed brain regions, and (ii) the asymmetry of bilaterally homologous brain regions, in terms of their global patterns of functional connectivity. This second measure offers a unique understanding of brain asymmetry at the network level, and, to the best of our knowledge, has not been previously used in pattern classification of functional brain networks. Using modern pattern-recognition approaches like sparse regression and support vector machine, we have achieved a cross-validated classification accuracy of 83.9% (specificity: 82.5%; sensitivity: 85%) across individuals from a large dataset consisting of 180 healthy controls and epileptic patients. We identified significantly changed functional pathways and subnetworks in epileptic patients that underlie the pathophysiological mechanism of the impaired cognitive functions. Specifically, we find that the asymmetry of brain operation for epileptic patients is markedly enhanced in temporal lobe and limbic system, in comparison with healthy individuals. The present study indicates that with specifically designed informative neuroimaging markers, resting-state fMRI can serve as a most promising tool for clinical diagnosis, and also shed light onto the physiology behind complex neuropsychiatric disorders. The systematic approaches we present here are expected to have wider applications in general neuropsychiatric disorders.

Zhang, ZhiQiang; Lu, WenLian; Lu, GuangMing; Feng, Jianfeng

2012-01-01

256

What is the role of brain mechanisms underlying arousal in recovery of motor function after structural brain injuries?  

PubMed Central

Purpose of review Standard neurorehabilitation approaches have limited impact on motor recovery in patients with severe injuries. Consideration of the contributions of impaired arousal offers a novel approach to understand and enhance recovery. Recent findings Animal and human neuroimaging studies are elucidating the neuroanatomical bases of arousal and of arousal regulation, the process by which the cerebrum mobilizes resources. Studies of patients with disorders of consciousness have revealed that recovery of these processes is associated with marked improvements in motor performance. Recent studies have also demonstrated that patients with less severe brain injuries also have impaired arousal, manifesting as diminished sustained attention, fatigue and apathy. In these less severely injured patients it is difficult to connect disorders of arousal with motor recovery due to a lack of measures of arousal independent of motor function. Summary Arousal impairment is common after brain injury and likely plays a significant role in recovery of motor function. A more detailed understanding of this connection will help to develop new therapeutic strategies applicable for a wide range of patients. This requires new tools that continuously and objectively measure arousal in patients with brain injury, to correlate with detailed measures of motor performance and recovery.

Schiff, Nicholas D.

2013-01-01

257

Functional Brain Networks Develop from a “Local to Distributed” Organization  

Microsoft Academic Search

The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze

Damien A. Fair; Alexander L. Cohen; Jonathan D. Power; Nico U. F. Dosenbach; Jessica A. Church; Francis M. Miezin; Bradley L. Schlaggar; Steven E. Petersen

2009-01-01

258

Functional MRI and intraoperative brain mapping to evaluate brain plasticity in patients with brain tumours and hemiparesis  

Microsoft Academic Search

OBJECTIVETo support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours.METHODSRetrospective analysis was carried out on the results of functional MRI (fMRI) of a selected group of five paretic patients with Rolandic brain tumours who exhibited an abnormally high ipsilateral\\/contralateral ratio of activation—that is, movements of the paretic hand

F E Roux; K Boulanouar; D Ibarrola; M Tremoulet; F Chollet; I Berry

2000-01-01

259

The neural basis of functional brain imaging signals  

Microsoft Academic Search

The haemodynamic responses to neural activity that underlie the blood-oxygen-level-dependent (BOLD) signal used in functional magnetic resonance imaging (fMRI) of the brain are often assumed to be driven by energy use, particularly in presynaptic terminals or glia. However, recent work has suggested that most brain energy is used to power postsynaptic currents and action potentials rather than presynaptic or glial

David Attwell; Costantino Iadecola

2002-01-01

260

Structure and function of the blood–brain barrier  

Microsoft Academic Search

Neural signalling within the central nervous system (CNS) requires a highly controlled microenvironment. Cells at three key interfaces form barriers between the blood and the CNS: the blood–brain barrier (BBB), blood–CSF barrier and the arachnoid barrier. The BBB at the level of brain microvessel endothelium is the major site of blood–CNS exchange. The structure and function of the BBB is

N. Joan Abbott; Adjanie A. K. Patabendige; Diana E. M. Dolman; Siti R. Yusof; David J. Begley

2010-01-01

261

Transforming Growth Factor-? in Brain Functions and Dysfunctions  

Microsoft Academic Search

Transforming growth factor-?s (TGF-?s) belong to a superfamily of related peptides that play pivotal roles in intercellular\\u000a communication. Among these biological agents, TGF-?1 has been involved in a number of brain functions and dysfunctions throughout\\u000a life, ranging from neurogenesis to neurodegeneration. Animal models mimicking some aspects of human brain pathologies have\\u000a led to the idea that TGF-? may be a

Denis Vivien; Karim Benchenane; Carine Ali

262

Investigating brain dynamics and connectivity with functional MRI  

Microsoft Academic Search

Functional magnetic resonance imaging (fMRI) scans provide a record of ongoing neural processing through the measurement of changes in regional levels of blood oxygenation. While subjects are resting, fMRI has revealed networks of brain regions exhibiting synchronised 0.02-0.12 Hz fluctuations in spontaneous, low frequency brain activity. The physiology underlying these 'resting state' fluctuations is poorly understood. Our current research investigates

Eugene Duff; Gary Egan; Ross Cunnington; Iven Mareels; Binquan Wang; Peter Fox; Jinhu Xiong

2004-01-01

263

Drug addiction: Functional neurotoxicity of the brain reward systems  

Microsoft Academic Search

Drug addiction is a chronic relapsing brain disorder characterized by a compulsion to take a drug with loss of control over\\u000a drug intake. The hypothesis under discussion here is that chronic drug use produces long-lasting dysfunctions in neurons associated\\u000a with the brain reward circuitry, and this “functional neurotoxicity” of drugs of abuse leads to vulnerability to relapse and\\u000a continued drug

Friedbert Weiss; George F. Koob

2001-01-01

264

Functional brain imaging of nicotinic effects on higher cognitive processes  

Microsoft Academic Search

Significant advances in human functional brain imaging offer new opportunities for direct observation of the effects of nicotine, novel nicotinic agonists and nicotinic antagonists on human cognitive and behavioral performance. Careful research over the last decade has enabled investigators to explore the role of nicotinic systems on the functional neuroanatomy and neural circuitry of cognitive tasks in domains such as

Paul A. Newhouse; Alexandra S. Potter; Julie A. Dumas; Christiane M. Thiel

2011-01-01

265

Imaging Body Structure and Mapping Brain Function: A Historical Approach  

Microsoft Academic Search

Now in its second decade, functional magnetic resonance imaging (fMRI) localizes changes in blood oxygenation that occur in the brain when an individual performs a mental task. Physicians and scientists use fMRI not only to map sensory, motor, and cognitive functions, but also to study the neural correlates of a range of sensitive and potentially stigmatizing conditions, behaviors, and characteristics.

Stacey A. Tovino

2007-01-01

266

Functional magnetic resonance imaging (FMRI) of the human brain  

Microsoft Academic Search

Functional magnetic resonance imaging (FMRI) can provide detailed images of human brain that reflect localized changes in cerebral blood flow and oxygenation induced by sensory, motor, or cognitive tasks. This review presents methods for gradient-recalled echo-planar functional magnetic resonance imaging (FMRI). Also included is a discussion of the hypothesized basis of FMRI, imaging hardware, a unique visual stimulation apparatus, image

Edgar A. DeYoe; Peter Bandettini; Jay Neitz; David Miller; Paula Winans

1994-01-01

267

Altered Sleep Brain Functional Connectivity in Acutely Depressed Patients  

Microsoft Academic Search

Recent evidence suggests that problems in information processing within neural networks may underlie depressive disease. In this study, we investigated whether sleep functional brain net- works are abnormally organized during a major depressive episode (MDE). We characterized spatial patterns of functional connectivity by computing the ''synchronization likelihood'' (SL) of 19 sleep EEG channels in 11 acutely depressed patients (42 (20-51)

Samuël J. J. Leistedt; Nathalie Coumans; Martine Dumont; Jean-Pol Lanquart; Cornelis J. Stam; Paul Linkowski

2009-01-01

268

Executive Functioning and Adaptive Living Skills after Acquired Brain Injury  

Microsoft Academic Search

Executive dysfunction is common following brain injury, with impairments involving attention, social pragmatics, higher-order thinking, judgment, and reasoning. Executive function impairments may have a direct impact on an individual's ability to return to instrumental activities of daily living (IADL), including employment, money management, driving, and maintaining a residence. Research has shown that neuropsychological executive function measures may be able to

Robert Perna; Ashlee R. Loughan; Kristin Talka

2012-01-01

269

Resting-State Brain Organization Revealed by Functional Covariance Networks  

PubMed Central

Background Brain network studies using techniques of intrinsic connectivity network based on fMRI time series (TS-ICN) and structural covariance network (SCN) have mapped out functional and structural organization of human brain at respective time scales. However, there lacks a meso-time-scale network to bridge the ICN and SCN and get insights of brain functional organization. Methodology and Principal Findings We proposed a functional covariance network (FCN) method by measuring the covariance of amplitude of low-frequency fluctuations (ALFF) in BOLD signals across subjects, and compared the patterns of ALFF-FCNs with the TS-ICNs and SCNs by mapping the brain networks of default network, task-positive network and sensory networks. We demonstrated large overlap among FCNs, ICNs and SCNs and modular nature in FCNs and ICNs by using conjunctional analysis. Most interestingly, FCN analysis showed a network dichotomy consisting of anti-correlated high-level cognitive system and low-level perceptive system, which is a novel finding different from the ICN dichotomy consisting of the default-mode network and the task-positive network. Conclusion The current study proposed an ALFF-FCN approach to measure the interregional correlation of brain activity responding to short periods of state, and revealed novel organization patterns of resting-state brain activity from an intermediate time scale.

Wang, Zhengge; Yuan, Cuiping; Jiao, Qing; Chen, Huafu; Biswal, Bharat B.; Lu, Guangming; Liu, Yijun

2011-01-01

270

Tracing Activity Across the Whole Brain Neural Network with Optogenetic Functional Magnetic Resonance Imaging  

PubMed Central

Despite the overwhelming need, there has been a relatively large gap in our ability to trace network level activity across the brain. The complex dense wiring of the brain makes it extremely challenging to understand cell-type specific activity and their communication beyond a few synapses. Recent development of the optogenetic functional magnetic resonance imaging (ofMRI) provides a new impetus for the study of brain circuits by enabling causal tracing of activities arising from defined cell types and firing patterns across the whole brain. Brain circuit elements can be selectively triggered based on their genetic identity, cell body location, and/or their axonal projection target with temporal precision while the resulting network response is monitored non-invasively with unprecedented spatial and temporal accuracy. With further studies including technological innovations to bring ofMRI to its full potential, ofMRI is expected to play an important role in our system-level understanding of the brain circuit mechanism.

Lee, Jin Hyung

2011-01-01

271

Sustained deep-tissue pain alters functional brain connectivity.  

PubMed

Recent functional brain connectivity studies have contributed to our understanding of the neurocircuitry supporting pain perception. However, evoked-pain connectivity studies have employed cutaneous and/or brief stimuli, which induce sensations that differ appreciably from the clinical pain experience. Sustained myofascial pain evoked by pressure cuff affords an excellent opportunity to evaluate functional connectivity change to more clinically relevant sustained deep-tissue pain. Connectivity in specific networks known to be modulated by evoked pain (sensorimotor, salience, dorsal attention, frontoparietal control, and default mode networks: SMN, SLN, DAN, FCN, and DMN) was evaluated with functional-connectivity magnetic resonance imaging, both at rest and during a sustained (6-minute) pain state in healthy adults. We found that pain was stable, with no significant changes of subjects' pain ratings over the stimulation period. Sustained pain reduced connectivity between the SMN and the contralateral leg primary sensorimotor (S1/M1) representation. Such SMN-S1/M1 connectivity decreases were also accompanied by and correlated with increased SLN-S1/M1 connectivity, suggesting recruitment of activated S1/M1 from SMN to SLN. Sustained pain also increased DAN connectivity to pain processing regions such as mid-cingulate cortex, posterior insula, and putamen. Moreover, greater connectivity during pain between contralateral S1/M1 and posterior insula, thalamus, putamen, and amygdala was associated with lower cuff pressures needed to reach the targeted pain sensation. These results demonstrate that sustained pain disrupts resting S1/M1 connectivity by shifting it to a network known to process stimulus salience. Furthermore, increased connectivity between S1/M1 and both sensory and affective processing areas may be an important contribution to interindividual differences in pain sensitivity. PMID:23718988

Kim, Jieun; Loggia, Marco L; Edwards, Robert R; Wasan, Ajay D; Gollub, Randy L; Napadow, Vitaly

2013-04-11

272

Democratic reinforcement: A principle for brain function  

SciTech Connect

We introduce a simple ``toy`` brain model. The model consists of a set of randomly connected, or layered integrate-and-fire neurons. Inputs to and outputs from the environment are connected randomly to subsets of neurons. The connections between firing neurons are strengthened or weakened according to whether the action was successful or not. Unlike previous reinforcement learning algorithms, the feedback from the environment is democratic: it affects all neurons in the same way, irrespective of their position in the network and independent of the output signal. Thus no unrealistic back propagation or other external computation is needed. This is accomplished by a global threshold regulation which allows the system to self-organize into a highly susceptible, possibly ``critical`` state with low activity and sparse connections between firing neurons. The low activity permits memory in quiescent areas to be conserved since only firing neurons are modified when new information is being taught.

Stassinopoulos, D.; Bak, P. [Brookhaven National Laboratory, Upton, New York 11973 (United States)

1995-05-01

273

Reorganization of functional brain networks during the recovery of stroke: a functional MRI study.  

PubMed

Studies have demonstrated that reorganization of the cortex after stroke contributed to the recovery of motor function. However, these studies paid much more attention to the reorganization of motor-related brain regions and motor executive network which only contained tens of brain regions, ignoring the change in brain-wide network during the restoration of motor function. Based on this consideration, this paper investigated the functional reorganization of brain-wide network during the recovery after stroke from the perspective of graph theory. At four time points (less than 10 days, around 2 weeks, 1 month and 3 months) after stroke onset, we obtained the functional MRI (fMRI) data of stroke patients when they were doing finger tapping task. Based on the fMRI data, we constructed the brain-wide functional network which consisted of 264 putative functional areas for each subject at each time point. Then the topological parameters (e.g., characteristic path length and cluster coefficient) of these brain networks were examined. Results showed that the brain networks shifted towards a non-optimal topological configuration with low small-worldness during the process of recovery. And this finding may broaden our knowledge about the reorganization of brain function during recovery after stroke. PMID:23366837

Cheng, Lin; Wu, Zhiyuan; Fu, Yi; Miao, Fei; Sun, Junfeng; Tong, Shanbao

2012-01-01

274

Organization of Cognitive Functions in the Brain.  

ERIC Educational Resources Information Center

Neuropsychological research on the effects of hemispherectomy-the excision of one of the cerebral hemispheres-in children and adults adds to knowledge about the division of labor between the left cerebral hemisphere, which specializes in language and verbal cognitive functions, and the right hemisphere, which specializes in nonlanguage functions.…

Smith, Aaron

275

Decreased Functional Brain Connectivity in Adolescents with Internet Addiction  

PubMed Central

Background Internet addiction has become increasingly recognized as a mental disorder, though its neurobiological basis is unknown. This study used functional neuroimaging to investigate whole-brain functional connectivity in adolescents diagnosed with internet addiction. Based on neurobiological changes seen in other addiction related disorders, it was predicted that connectivity disruptions in adolescents with internet addiction would be most prominent in cortico-striatal circuitry. Methods Participants were 12 adolescents diagnosed with internet addiction and 11 healthy comparison subjects. Resting-state functional magnetic resonance images were acquired, and group differences in brain functional connectivity were analyzed using the network-based statistic. We also analyzed network topology, testing for between-group differences in key graph-based network measures. Results Adolescents with internet addiction showed reduced functional connectivity spanning a distributed network. The majority of impaired connections involved cortico-subcortical circuits (?24% with prefrontal and ?27% with parietal cortex). Bilateral putamen was the most extensively involved subcortical brain region. No between-group difference was observed in network topological measures, including the clustering coefficient, characteristic path length, or the small-worldness ratio. Conclusions Internet addiction is associated with a widespread and significant decrease of functional connectivity in cortico-striatal circuits, in the absence of global changes in brain functional network topology.

Hong, Soon-Beom; Zalesky, Andrew; Cocchi, Luca; Fornito, Alex; Choi, Eun-Jung; Kim, Ho-Hyun; Suh, Jeong-Eun; Kim, Chang-Dai; Kim, Jae-Won; Yi, Soon-Hyung

2013-01-01

276

Stereotactic PET atlas of the human brain: Aid for visual interpretation of functional brain images  

SciTech Connect

In the routine analysis of functional brain images obtained by PET, subjective visual interpretation is often used for anatomic localization. To enhance the accuracy and consistency of the anatomic interpretation, a PET stereotactic atlas and localization approach was designed for functional brain images. The PET atlas was constructed from a high-resolution [{sup 18}F]fluorodeoxyglucose (FDG) image set of a normal volunteer (a 41-yr-ld woman). The image set was reoriented stereotactically, according to the intercommissural (anterior and posterior commissures) line and transformed to the standard stereotactic atlas coordinates. Cerebral structures were annotated on the transaxial planes using a proportional grid system and surface-rendered images. The stereotactic localization technique was applied to image sets from patients with Alzheimer`s disease, and areas of functional alteration were localized visually by referring to the PET atlas. Major brain structures were identified on both transaxial planes and surface-rendered images. In the stereotactic system, anatomic correspondence between the PET atlas and stereotactically reoriented individual image sets of patients with Alzheimer`s disease facilitated both indirect and direct localization of the cerebral structures. Because rapid stereotactic alignment methods for PET images are now available for routine use, the PET atlas will serve as an aid for visual interpretation of functional brain images in the stereotactic system. Widespread application of stereotactic localization may be used in functional brain images, not only in the research setting, but also in routine clinical situations. 41 refs., 3 figs.

Minoshima, S.; Koeppe, R.A.; Frey, A.; Ishihara, M.; Kuhl, D.E. [Univ. of Michigan, Ann Arbor, MI (United States)

1994-06-01

277

Spatiotemporal reconfiguration of large-scale brain functional networks during propofol-induced loss of consciousness.  

PubMed

Applying graph theoretical analysis of spontaneous BOLD fluctuations in functional magnetic resonance imaging (fMRI), we investigated whole-brain functional connectivity of 11 healthy volunteers during wakefulness and propofol-induced loss of consciousness (PI-LOC). After extraction of regional fMRI time series from 110 cortical and subcortical regions, we applied a maximum overlap discrete wavelet transformation and investigated changes in the brain's intrinsic spatiotemporal organization. During PI-LOC, we observed a breakdown of subcortico-cortical and corticocortical connectivity. Decrease of connectivity was pronounced in thalamocortical connections, whereas no changes were found for connectivity within primary sensory cortices. Graph theoretical analyses revealed significant changes in the degree distribution and local organization metrics of brain functional networks during PI-LOC: compared with a random network, normalized clustering was significantly increased, as was small-worldness. Furthermore we observed a profound decline in long-range connections and a reduction in whole-brain spatiotemporal integration, supporting a topological reconfiguration during PI-LOC. Our findings shed light on the functional significance of intrinsic brain activity as measured by spontaneous BOLD signal fluctuations and help to understand propofol-induced loss of consciousness. PMID:22973006

Schröter, Manuel S; Spoormaker, Victor I; Schorer, Anna; Wohlschläger, Afra; Czisch, Michael; Kochs, Eberhard F; Zimmer, Claus; Hemmer, Bernhard; Schneider, Gerhard; Jordan, Denis; Ilg, Rüdiger

2012-09-12

278

Subcortical aphasia and the problem of attributing functional responsibility to parts of distributed brain processes.  

PubMed

N&C's discussion is, in places, an exemplar of the sort of rigor and attention to detail that will bring us closer to an understanding of the functional organization of the brain. Indeed, it is this level of work that pushes us to reflect on the assumptions that undergird our research efforts. Our criticisms have developed four main points. First, the level of rigor applied to the consideration of basal ganglionic aphasia should extend to each application of the CPC method (thalamic aphasia included). Second, in our haste to identify specific brain systems with distinct cognitive functions we should not neglect the more basic question of the causal mechanisms by which the brain organizes behavior. Questions of "direct" versus "indirect" involvement of a particular organ in a cognitive function are only likely to distract our attention from this more basic and less inferentially perilous issue. Third, pure cases should no longer be considered touchstones against which all behavioral disturbances are measured. Reifying such ideals is more likely to shroud than reveal the brain's true complexity. Finally, the functions that we enshrine in particular brain regions should explain the particular character of the symptoms observed when they are damaged and should admit of independent verification. PMID:9222523

Craver, C F; Small, S L

1997-07-01

279

Understanding the human parental brain: A critical role of the orbitofrontal cortex.  

PubMed

The bond between a parent and an infant often appears to form effortlessly and intuitively, and this relationship is fundamental to infant survival and development. Parenting is considered to depend on specific brain networks that are largely conserved across species and in place even before parenthood. Efforts to understand the neural basis of parenting in humans have focused on the overlapping networks implicated in reward and social cognition, within which the orbitofrontal cortex (OFC) is considered to be a crucial hub. This review examines emerging evidence that the OFC may be engaged in several phases of parent-infant interactions, from early, privileged orienting to infant cues, to ongoing monitoring of interactions and subsequent learning. Specifically, we review evidence suggesting that the OFC rapidly responds to a range of infant communicative cues, such as faces and voices, supporting their efficient processing. Crucially, this early orienting response may be fundamental in supporting adults to respond rapidly and appropriately to infant needs. We suggest a number of avenues for future research, including investigating neural activity in disrupted parenting, exploring multimodal cues, and consideration of neuroendocrine involvement in responsivity to infant cues. An increased understanding of the brain basis of caregiving will provide insight into our greatest challenge: parenting our young. PMID:24171901

Parsons, Christine E; Stark, Eloise A; Young, Katherine S; Stein, Alan; Kringelbach, Morten L

2013-11-01

280

Assortative mixing in functional brain networks during epileptic seizures  

NASA Astrophysics Data System (ADS)

We investigate assortativity of functional brain networks before, during, and after one-hundred epileptic seizures with different anatomical onset locations. We construct binary functional networks from multi-channel electroencephalographic data recorded from 60 epilepsy patients; and from time-resolved estimates of the assortativity coefficient, we conclude that positive degree-degree correlations are inherent to seizure dynamics. While seizures evolve, an increasing assortativity indicates a segregation of the underlying functional network into groups of brain regions that are only sparsely interconnected, if at all. Interestingly, assortativity decreases already prior to seizure end. Together with previous observations of characteristic temporal evolutions of global statistical properties and synchronizability of epileptic brain networks, our findings may help to gain deeper insights into the complicated dynamics underlying generation, propagation, and termination of seizures.

Bialonski, Stephan; Lehnertz, Klaus

2013-09-01

281

Laterality patterns of brain functional connectivity: gender effects.  

PubMed

Lateralization of brain connectivity may be essential for normal brain function and may be sexually dimorphic. Here, we study the laterality patterns of short-range (implicated in functional specialization) and long-range (implicated in functional integration) connectivity and the gender effects on these laterality patterns. Parallel computing was used to quantify short- and long-range functional connectivity densities in 913 healthy subjects. Short-range connectivity was rightward lateralized and most asymmetrical in areas around the lateral sulcus, whereas long-range connectivity was rightward lateralized in lateral sulcus and leftward lateralizated in inferior prefrontal cortex and angular gyrus. The posterior inferior occipital cortex was leftward lateralized (short- and long-range connectivity). Males had greater rightward lateralization of brain connectivity in superior temporal (short- and long-range), inferior frontal, and inferior occipital cortices (short-range), whereas females had greater leftward lateralization of long-range connectivity in the inferior frontal cortex. The greater lateralization of the male's brain (rightward and predominantly short-range) may underlie their greater vulnerability to disorders with disrupted brain asymmetries (schizophrenia, autism). PMID:21878483

Tomasi, Dardo; Volkow, Nora D

2011-08-30

282

Linking structure and function: Information processing in the brain  

SciTech Connect

Traditionally, theories of function in neuroscience have emerged from physiology. Physiologists have suggested a number of means by which information in the brain can be processed, yet the principles underlying the generation of these phenomena are not well understood. A complex systems approach would be to examine the overall structure and function of the system and to attempt to establish a common framework for information processing interactions. This paper will use the structure-function relationship as a basis for exploring units of information processing. It will examine the brain as a whole, first providing the non-specialists with an short overview of the structure and some of the functions or outputs of the brain. It then very briefly reviews three of the prominent theoretical concepts that have emerged in the last few decades: receptive fields, feature extraction, and parallel processing. Next, it addresses the question of information processing and outlines the structures which have traditionally been proposed to be the basic unit of information processing. An alternative unit on which information processing in the brain might be based is then proposed, and data outlined to support it. Finally, the implications of this different mode of processing are discussed, both for the brain and for other complex systems. 40 refs., 4 figs., 2 tabs.

Gremillion, M.A.V.

1990-01-01

283

Nutrition, Brain Function and Cognitive Performance.  

National Technical Information Service (NTIS)

Military interest in the effects of nutritional factors on cognitive function has stimulated considerable research on a variety of food constituents. This paper will review the research on the amino acids tryptophan and tyrosine, caffeine and carbohydrate...

H. R. Lieberman

2003-01-01

284

MR atlas of the baboon brain for functional neuroimaging  

Microsoft Academic Search

Mathematical co-registration of functional image data (e.g., positron emission tomography, PET) to anatomical magnetic resonance (MR) imaging data allows for objective associations between function and anatomy. Baboons are often used as non-human primate models for functional neuroimaging studies. In this work, a digital MR-based high-resolution atlas of the baboon brain was generated and evaluated for PET. The atlas was generated

Phil J Greer; Victor L Villemagne; James Ruszkiewicz; Angela K Graves; Carolyn Cidis Meltzer; Chester A Mathis; Julie C Price

2002-01-01

285

SSVEP Response Is Related to Functional Brain Network Topology Entrained by the Flickering Stimulus  

PubMed Central

Previous studies have shown that the brain network topology correlates with the cognitive function. However, few studies have investigated the relationship between functional brain networks that process sensory inputs and outputs. In this study, we focus on steady-state paradigms using a periodic visual stimulus, which are increasingly being used in both brain-computer interface (BCI) and cognitive neuroscience researches. Using the graph theoretical analysis, we investigated the relationship between the topology of functional networks entrained by periodic stimuli and steady state visually evoked potentials (SSVEP) using two frequencies and eleven subjects. First, the entire functional network (Network 0) of each frequency for each subject was constructed according to the coherence between electrode pairs. Next, Network 0 was divided into three sub-networks, in which the connection strengths were either significantly (positively for Network 1, negatively for Network 3) or non-significantly (Network 2) correlated with the SSVEP responses. Our results revealed that the SSVEP responses were positively correlated to the mean functional connectivity, clustering coefficient, and global and local efficiencies, while these responses were negatively correlated with the characteristic path length of Networks 0, 1 and 2. Furthermore, the strengths of these connections that significantly correlated with the SSVEP (both positively and negatively) were mainly found to be long-range connections between the parietal-occipital and frontal regions. These results indicate that larger SSVEP responses correspond with better functional network topology structures. This study may provide new insights for understanding brain mechanisms when using SSVEPs as frequency tags.

Zhang, Yangsong; Xu, Peng; Huang, Yingling; Cheng, Kaiwen; Yao, Dezhong

2013-01-01

286

Darwin's evolution theory, brain oscillations, and complex brain function in a new "Cartesian view".  

PubMed

Comparatively analyses of electrophysiological correlates across species during evolution, alpha activity during brain maturation, and alpha activity in complex cognitive processes are presented to illustrate a new multidimensional "Cartesian System" brain function. The main features are: (1) The growth of the alpha activity during evolution, increase of alpha during cognitive processes, and decrease of the alpha entropy during evolution provide an indicator for evolution of brain cognitive performance. (2) Human children younger than 3 years are unable to produce higher cognitive processes and do not show alpha activity till the age of 3 years. The mature brain can perform higher cognitive processes and demonstrates regular alpha activity. (3) Alpha activity also is significantly associated with highly complex cognitive processes, such as the recognition of facial expressions. The neural activity reflected by these brain oscillations can be considered as constituent "building blocks" for a great number of functions. An overarching statement on the alpha function is presented by extended analyzes with multiple dimensions that constitute a "Cartesian Hyperspace" as the basis for oscillatory function. Theoretical implications are considered. PMID:18805445

Ba?ar, Erol; Güntekin, Bahar

2008-07-31

287

Typical and Atypical Development of Functional Human Brain Networks: Insights from Resting-State fMRI  

PubMed Central

Over the past several decades, structural MRI studies have provided remarkable insights into human brain development by revealing the trajectory of gray and white matter maturation from childhood to adolescence and adulthood. In parallel, functional MRI studies have demonstrated changes in brain activation patterns accompanying cognitive development. Despite these advances, studying the maturation of functional brain networks underlying brain development continues to present unique scientific and methodological challenges. Resting-state fMRI (rsfMRI) has emerged as a novel method for investigating the development of large-scale functional brain networks in infants and young children. We review existing rsfMRI developmental studies and discuss how this method has begun to make significant contributions to our understanding of maturing brain organization. In particular, rsfMRI has been used to complement studies in other modalities investigating the emergence of functional segregation and integration across short and long-range connections spanning the entire brain. We show that rsfMRI studies help to clarify and reveal important principles of functional brain development, including a shift from diffuse to focal activation patterns, and simultaneous pruning of local connectivity and strengthening of long-range connectivity with age. The insights gained from these studies also shed light on potentially disrupted functional networks underlying atypical cognitive development associated with neurodevelopmental disorders. We conclude by identifying critical gaps in the current literature, discussing methodological issues, and suggesting avenues for future research.

Uddin, Lucina Q.; Supekar, Kaustubh; Menon, Vinod

2010-01-01

288

Loss of functional GABAA receptors in the Alzheimer diseased brain  

PubMed Central

The cholinergic and glutamatergic neurotransmission systems are known to be severely disrupted in Alzheimer's disease (AD). GABAergic neurotransmission, in contrast, is generally thought to be well preserved. Evidence from animal models and human postmortem tissue suggest GABAergic remodeling in the AD brain. Nevertheless, there is no information on changes, if any, in the electrophysiological properties of human native GABA receptors as a consequence of AD. To gain such information, we have microtransplanted cell membranes, isolated from temporal cortices of control and AD brains, into Xenopus oocytes, and recorded the electrophysiological activity of the transplanted GABA receptors. We found an age-dependent reduction of GABA currents in the AD brain. This reduction was larger when the AD membranes were obtained from younger subjects. We also found that GABA currents from AD brains have a faster rate of desensitization than those from non-AD brains. Furthermore, GABA receptors from AD brains were slightly, but significantly, less sensitive to GABA than receptors from non-AD brains. The reduction of GABA currents in AD was associated with reductions of mRNA and protein of the principal GABA receptor subunits normally present in the temporal cortex. Pairwise analysis of the transcripts within control and AD groups and analyses of the proportion of GABA receptor subunits revealed down-regulation of ?1 and ?2 subunits in AD. In contrast, the proportions of ?2, ?1, and ?1 transcripts were up-regulated in the AD brains. Our data support a functional remodeling of GABAergic neurotransmission in the human AD brain.

Limon, Agenor; Reyes-Ruiz, Jorge Mauricio; Miledi, Ricardo

2012-01-01

289

Topological Organization of Functional Brain Networks in Healthy Children: Differences in Relation to Age, Sex, and Intelligence  

PubMed Central

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence.

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C.; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

290

A multidimensional approach to understanding floral function and form1.  

PubMed

• Premise of the study: Variation in plant mating systems is a fundamental component of the diversity of floral form and function. Mating systems have a strong influence on the distribution and expression of genetic variation, which in turn can influence the course of mating system evolution. It has long been appreciated, however, that ecological interactions may provide much of the impetus behind these evolutionary changes. • Methods: This commentary reviews the Special Section in the American Journal of Botany (vol. 100, issue 6) that features novel research on the role of interactions between plants and their pollinators, seed dispersers, herbivores, and interspecific competitors in the evolution of selfing rates and gender. These studies vary in approach from empirical experiments, to phylogenetic comparisons, to theoretical models, to literature reviews as they each attempt to shed new light on longstanding questions about the selective forces and evolutionary pathways that have led to the diversified means by which plants promote or discourage self-fertilization. • Key results: Evidence is provided that indicates that ecological interactions (e.g., herbivory and heterospecific pollen deposition by pollinators) can strongly influence the relative advantages of selfing and outcrossing. Ecological interactions can also influence allocation to sexual functions, which will influence individual and population outcrossing rates and possibly the evolutionary path of gender expression. • Conclusions: Mating systems evolution is clearly a multidimensional problem. Research that places the study of mating and sexual systems within a more realistic ecological context will no doubt reveal more complexity as we move toward a better understanding of plant diversity. PMID:23720428

Carr, David E

2013-05-29

291

Using computational biophysics to understand protein evolution and function  

NASA Astrophysics Data System (ADS)

Understanding how proteins evolve and function is vital for human health (e.g., developing better drugs, predicting the outbreak of disease, etc.). In spite of its importance, little is known about the underlying molecular mechanisms behind these biological processes. Computational biophysics has emerged as a useful tool in this area due to its unique ability to obtain a detailed, atomistic view of proteins and how they interact. I will give two examples from our studies where computational biophysics has provided valuable insight: (i) Protein evolution in viruses. Our results suggest that the amino acid changes that occur during high temperature evolution of a virus decrease the binding free energy of the capsid, i.e., these changes increase capsid stability. (ii) Determining realistic structural ensembles for intrinsically disordered proteins. Most methods for determining protein structure rely on the protein folding into a single conformation, and thus are not suitable for disordered proteins. I will describe a new approach that combines experiment and simulation to generate structures for disordered proteins.

Ytreberg, F. Marty

2010-10-01

292

New approaches for exploring anatomical and functional connectivity in the human brain  

Microsoft Academic Search

Information processing in the primate brain is based on the complementary principles of modular and distributed information processing. The former emphasizes the specialization of functions within different brain areas. The latter emphasizes the massively parallel nature of brain networks and the fact that function also emerges from the flow of information between brain areas. The localization of function to specific

Narender Ramnani; Timothy E. J. Behrens; Will Penny; Paul M. Matthews

2004-01-01

293

The functional brain architecture of human morality.  

PubMed

Human morality provides the foundation for many of the pillars of society, informing political legislation and guiding legal decisions while also governing everyday social interactions. In the past decade, researchers in the field of cognitive neuroscience have made tremendous progress in the effort to understand the neural basis of human morality. The emerging insights from this research point toward a model in which automatic processing in parallel neural circuits, many of which are associated with social emotions, evaluate the actions and intentions of others. Through various mechanisms of competition, only a subset of these circuits ultimately causes a decision or an action. This activity is experienced consciously as a subjective moral sense of right or wrong, and an interpretive process offers post hoc explanations designed to link the social stimulus with the subjective moral response using whatever explicit information is available. PMID:19889532

Funk, Chadd M; Gazzaniga, Michael S

2009-11-04

294

Understanding the Unconscious Brain: Can Humans process Emotional Information in a Non-Linear Way?  

Microsoft Academic Search

In the late seventies, the cognitive approach to emotion was more or less the only approach. Much of contemporary psychology has come to recognize that a great deal of human emotional functioning is rooted in unconscious processes. Evidence was found in many behavioral and neuroimaging studies. Although we are beginning to understand some of the mechanisms behind unconscious emotional information

Maurits van den Noort; Peggy Bosch; Kenneth Hugdahl

295

Genome-brain-behavior interdependencies as a framework to understand hormone effects on learned behavior.  

PubMed

Hormones have profound effects on the maturation and function of the zebra finch song system. Hormones often signal through receptors that directly or indirectly regulate transcription. In this way, hormones and the genome are functionally connected. Genome-brain-behavior interdependencies are often studied on evolutionary timescales but we can now apply and test these relationships on short timescales, relevant to an individual. Here, we begin to place patterns of hormone-related gene expression into the timeframe of an individual's lifespan to consider how hormones contribute to organization of neural systems necessary for learned behavior, and how they might signal during experience in ways that affect future behavior. This framework illustrates both how much investigations into genome and hormone function are intertwined, and how much we still need to learn. PMID:23684969

London, Sarah E

2013-05-14

296

Neuroimaging Studies of Normal Brain Development and Their Relevance for Understanding Childhood Neuropsychiatric Disorders  

ERIC Educational Resources Information Center

|Neuroimaging findings which identify normal brain development trajectories are presented. Results show that early brain development begins with the neural tube formation and ends with myelintation. How disturbances in brain development patterns are related to childhood psychiatric disorders is examined.|

Marsh, Rachel; Gerber, Andrew J.; Peterson, Bradley S.

2008-01-01

297

Social behavior following traumatic brain injury and its association with emotion recognition, understanding of intentions, and cognitive flexibility.  

PubMed

Although the adverse consequences of changes in social behavior following traumatic brain injury (TBI) are well documented, relatively little is known about possible underlying neuropsychological deficits. Following a model originally developed for social behavior deficits in schizophrenia, we investigated whether impairments in emotion recognition, understanding of other people's intentions ("theory of mind"), and cognitive flexibility soon after first TBI or 1 year later were associated with self and proxy ratings of behavior following TBI. Each of the three functions was assessed with two separate tests, and ratings of behavior were collected on three questionnaires. Patients with TBI (n = 33) were impaired in emotion recognition, "theory of mind," and cognitive flexibility compared with matched orthopedic controls (n = 34). Proxy ratings showed increases in behavioral problems 1 year following injury in the TBI group but not in the control group. However, test performance was not associated with questionnaire data. Severity of the impairments in emotion recognition, understanding intention, and flexibility were unrelated to the severity of behavioral problems following TBI. These findings failed to confirm the used model for social behavior deficits and may cast doubt on the alleged link between deficits in emotion recognition or theory of mind and social functioning. PMID:18282329

Milders, Maarten; Ietswaart, Magdalena; Crawford, John R; Currie, David

2008-03-01

298

The extrinsic and intrinsic functional architectures of the human brain are not equivalent.  

PubMed

The brain's intrinsic functional architecture, revealed in correlated spontaneous activity, appears to constitute a faithful representation of its repertoire of evoked, extrinsic functional interactions. Here, using broad task contrasts to probe evoked patterns of coactivation, we demonstrate tight coupling between the brain's intrinsic and extrinsic functional architectures for default and task-positive regions, but not for subcortical and limbic regions or for primary sensory and motor cortices. While strong correspondence likely reflects persistent or recurrent patterns of evoked coactivation, weak correspondence may exist for regions whose patterns of evoked functional interactions are more adaptive and context dependent. These findings were independent of task. For tight task contrasts (e.g., incongruent vs. congruent trials), evoked patterns of coactivation were unrelated to the intrinsic functional architecture, suggesting that high-level task demands are accommodated by context-specific modulations of functional interactions. We conclude that intrinsic approaches provide only a partial understanding of the brain's functional architecture. Appreciating the full repertoire of dynamic neural responses will continue to require task-based functional magnetic resonance imaging approaches. PMID:22298730

Mennes, Maarten; Kelly, Clare; Colcombe, Stan; Castellanos, F Xavier; Milham, Michael P

2012-01-31

299

Large-scale functional brain network abnormalities in Alzheimer's disease: Insights from functional neuroimaging  

Microsoft Academic Search

Functional MRI (fMRI) studies of mild cognitive impairment (MCI) and Alzheimer's disease (AD) have begun to reveal abnormalities in large-scale memory and cognitive brain networks. Since the medial temporal lobe (MTL) memory system is a site of very early pathology in AD, a number of studies have focused on this region of the brain. Yet it is clear that other

Bradford C. Dickerson; Reisa A. Sperling

300

Decreased in vitro mitochondrial function is associated with enhanced brain metabolism, blood flow, and memory in Surf1-deficient mice.  

PubMed

Recent studies have challenged the prevailing view that reduced mitochondrial function and increased oxidative stress are correlated with reduced longevity. Mice carrying a homozygous knockout (KO) of the Surf1 gene showed a significant decrease in mitochondrial electron transport chain Complex IV activity, yet displayed increased lifespan and reduced brain damage after excitotoxic insults. In the present study, we examined brain metabolism, brain hemodynamics, and memory of Surf1 KO mice using in vitro measures of mitochondrial function, in vivo neuroimaging, and behavioral testing. We show that decreased respiration and increased generation of hydrogen peroxide in isolated Surf1 KO brain mitochondria are associated with increased brain glucose metabolism, cerebral blood flow, and lactate levels, and with enhanced memory in Surf1 KO mice. These metabolic and functional changes in Surf1 KO brains were accompanied by higher levels of hypoxia-inducible factor 1 alpha, and by increases in the activated form of cyclic AMP response element-binding factor, which is integral to memory formation. These findings suggest that Surf1 deficiency-induced metabolic alterations may have positive effects on brain function. Exploring the relationship between mitochondrial activity, oxidative stress, and brain function will enhance our understanding of cognitive aging and of age-related neurologic disorders. PMID:23838831

Lin, Ai-Ling; Pulliam, Daniel A; Deepa, Sathyaseelan S; Halloran, Jonathan J; Hussong, Stacy A; Burbank, Raquel R; Bresnen, Andrew; Liu, Yuhong; Podlutskaya, Natalia; Soundararajan, Anuradha; Muir, Eric; Duong, Timothy Q; Bokov, Alex F; Viscomi, Carlo; Zeviani, Massimo; Richardson, Arlan G; Van Remmen, Holly; Fox, Peter T; Galvan, Veronica

2013-07-10

301

Functional brain mapping of the relaxation response and meditation  

Microsoft Academic Search

Meditation is a conscious mental process that induces a set of integrated physiologic changes termed the relaxation response. Functional magnetic resonance imaging (fMRI) was used to identify and characterize the brain regions that are active during a simple form of meditation. Significant ( p , 10?7) signal increases were observed in the group-averaged data in the dorsolateral prefrontal and parietal

Sara W. Lazar; George Bush; Randy L. Gollub; Gregory L. Fricchione; Gurucharan Khalsa; Herbert Benson

2000-01-01

302

Function Testing for Chemical Brain Damage: A Review  

Microsoft Academic Search

Testing of neurobehavioral functions for evaluation of the effects of chemicals on the human brain from community (i.e., environmental) exposures is logical and may be a preferred initial step. Sensitivity is improved (1) by adjusting individual tests for influential factors, found by regression modeling and by retaining significant coefficients; and (2) by the calculation of predicted values for each test

Kaye H. Kilburn

2001-01-01

303

Complexity in Quantum System and Its Application to Brain Function  

Microsoft Academic Search

The complexity and the chaos degree can be used to examine the chaotic aspects of not only several nonlinear classical and quantum physical physics but also life sciences. We will construct a model describing the function of brain in the context of Quantum Information Dynamics.

Masanori Ohya

2004-01-01

304

An Examination of the Functional Relationship between Brain and Language.  

ERIC Educational Resources Information Center

Focuses on the structure/function relationship of the brain and language. Reviews the basic theories concerning cortical structures and language representation. Presents a call that highlights the need to examine the areas of listening, memory, and information retrieval for a more sophisticated analysis of the complex relationship between cortical…

McQuillen, Jeffrey S.; Strong, William F.

2000-01-01

305

Steroid Hormones: Effect on Brain Development and Function  

Microsoft Academic Search

Hormones secreted by the adrenals, gonads and thyroid play an important role in mediating how the environment shapes the structure and function of the brain during early development, adult life and senescence. Many of these hormone effects occur at the level of gene transcription, via the actions of intracellular hormone receptors which are DNA-binding proteins. Other effects occur at the

B. S. McEwen

1992-01-01

306

An Examination of the Functional Relationship between Brain and Language.  

ERIC Educational Resources Information Center

|Focuses on the structure/function relationship of the brain and language. Reviews the basic theories concerning cortical structures and language representation. Presents a call that highlights the need to examine the areas of listening, memory, and information retrieval for a more sophisticated analysis of the complex relationship between…

McQuillen, Jeffrey S.; Strong, William F.

2000-01-01

307

Binding in models of perception and brain function  

Microsoft Academic Search

The development of the concept of feature binding as fundamental to neural dynamics has made possible recent advances in the modeling of difficult problems of perception and brain function. Major weaknesses of past neural modeling (most prominently its inability to work with natural stimuli and its ‘learning-time’ barrier) have been traced back to improper treatment of the binding issue. Signal

Christoph von der Malsburg

1995-01-01

308

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients  

Microsoft Academic Search

Background  Delirium (acute brain dysfunction) is a potentially life threatening disturbance in brain function that frequently occurs\\u000a in critically ill patients. While this area of brain dysfunction in critical care is rapidly advancing, striking limitations\\u000a in use of terminology related to delirium internationally are hindering cross-talk and collaborative research. In the English\\u000a literature, synonyms of delirium such as the Intensive Care

A. Morandi; P. Pandharipande; M. Trabucchi; R. Rozzini; G. Mistraletti; A. C. Trompeo; C. Gregoretti; L. Gattinoni; M. V. Ranieri; L. Brochard; D. Annane; C. Putensen; U. Guenther; P. Fuentes; E. Tobar; A. R. Anzueto; A. Esteban; Y. Skrobik; J. I. F. Salluh; M. Soares; C. Granja; A. Stubhaug; S. E. de Rooij; E. Wesley Ely

2008-01-01

309

Abnormal brain functional connectivity of the hypothalamus in cluster headaches.  

PubMed

The aim of this study was to detect the abnormality of the brain functional connectivity of the hypothalamus during acute spontaneous cluster headache (CH) attacks ('in attack') and headache-free intervals ('out of attack') using resting-state functional magnetic resonance imaging (RS-fMRI) technique. The RS-fMRI data from twelve male CH patients during 'in attack' and 'out of attack' periods and twelve age- and sex-matched normal controls were analyzed by the region-of-interest -based functional connectivity method using SPM5 software. Abnormal brain functional connectivity of the hypothalamus is present in CH, which is located mainly in the pain system during the spontaneous CH attacks. It extends beyond the pain system during CH attack intervals. PMID:23460913

Qiu, Enchao; Wang, Yan; Ma, Lin; Tian, Lixia; Liu, Ruozhuo; Dong, Zhao; Xu, Xian; Zou, Zhitong; Yu, Shengyuan

2013-02-27

310

Abnormal Brain Functional Connectivity of the Hypothalamus in Cluster Headaches  

PubMed Central

The aim of this study was to detect the abnormality of the brain functional connectivity of the hypothalamus during acute spontaneous cluster headache (CH) attacks (‘in attack’) and headache-free intervals (‘out of attack’) using resting-state functional magnetic resonance imaging (RS-fMRI) technique. The RS-fMRI data from twelve male CH patients during ‘in attack’ and ‘out of attack’ periods and twelve age- and sex-matched normal controls were analyzed by the region-of-interest -based functional connectivity method using SPM5 software. Abnormal brain functional connectivity of the hypothalamus is present in CH, which is located mainly in the pain system during the spontaneous CH attacks. It extends beyond the pain system during CH attack intervals.

Qiu, Enchao; Wang, Yan; Ma, Lin; Tian, Lixia; Liu, Ruozhuo; Dong, Zhao; Xu, Xian; Zou, Zhitong; Yu, Shengyuan

2013-01-01

311

Dynamic regulation of NMDAR function in the adult brain by the stress hormone corticosterone  

PubMed Central

Stress and corticosteroids dynamically modulate the expression of synaptic plasticity at glutamatergic synapses in the developed brain. Together with alpha-amino-3-hydroxy-methyl-4-isoxazole propionic acid receptors (AMPAR), N-methyl-D-aspartate receptors (NMDAR) are critical mediators of synaptic function and are essential for the induction of many forms of synaptic plasticity. Regulation of NMDAR function by cortisol/corticosterone (CORT) may be fundamental to the effects of stress on synaptic plasticity. Recent reports of the efficacy of NMDAR antagonists in treating certain stress-associated psychopathologies further highlight the importance of understanding the regulation of NMDAR function by CORT. Knowledge of how corticosteroids regulate NMDAR function within the adult brain is relatively sparse, perhaps due to a common belief that NMDAR function is stable in the adult brain. We review recent results from our laboratory and others demonstrating dynamic regulation of NMDAR function by CORT in the adult brain. In addition, we consider the issue of how differences in the early life environment may program differential sensitivity to modulation of NMDAR function by CORT and how this may influence synaptic function during stress. Findings from these studies demonstrate that NMDAR function in the adult hippocampus remains sensitive to even brief exposures to CORT and that the capacity for modulation of NMDAR may be programmed, in part, by the early life environment. Modulation of NMDAR function may contribute to dynamic regulation of synaptic plasticity and adaptation in the face of stress, however, enhanced NMDAR function may be implicated in mechanisms of stress-related psychopathologies including depression.

Tse, Yiu Chung; Bagot, Rosemary C.; Wong, Tak Pan

2012-01-01

312

The prairie vole: an emerging model organism for understanding the social brain  

PubMed Central

Unlike most mammalian species, the prairie vole is highly affiliative, forms enduring social bonds between mates, and displays biparental behavior. Over two decades of research in this species has enhanced our understanding of the neurobiological basis not only of monogamy, social attachment and nurturing behaviors, but also other aspects of social cognition. Because social cognitive deficits are hallmarks of many psychiatric disorders, discoveries made in prairie voles may direct novel treatment strategies for disorders such as autism spectrum disorder and schizophrenia. With the ongoing development of molecular, genetic and genomic tools for this species, prairie voles will likely maintain their current trajectory becoming an unprecedented model organism for basic and translational research focusing on the biology of the social brain.

McGraw, Lisa A.; Young, Larry J.

2009-01-01

313

Functional Brain Image Analysis Using Joint Function-Structure Priors  

Microsoft Academic Search

\\u000a We propose a new method for context-driven analysis of functional magnetic resonance images (fMRI) that incorporates spatial\\u000a relationships between functional parameter clusters and anatomical structure directly for the first time. We design a parametric\\u000a scheme that relates functional and structural spatially-compact regions in a single unified manner. Our method is motivated\\u000a by the fact that the fMRI and anatomical MRI

Jing Yang; Xenophon Papademetris; Lawrence H. Staib; Robert T. Schultz; James S. Duncan

2004-01-01

314

Functional Brain Imaging of Young, Nondemented, and Demented Older Adults  

Microsoft Academic Search

Brain imaging based on functional MRI (fMRI) provides a powerful tool for characterizing age-related changes in functional anatomy. However, between-population comparisons confront potential differences in measurement properties. The present experiment explores the feasibility of conducting fMRI studies in nondemented and demented older adults by measuring hemodynamic response properties in an event-related design. A paradigm involving repeated presentation of sensory-motor response

Randy L. Buckner; Abraham Z. Snyder; Amy L. Sanders; Marcus E. Raichle; John C. Morris

2000-01-01

315

The automatic brain: studies on practice and brain function in healthy subjects and patients with schizophrenia  

Microsoft Academic Search

Practice makes perfect. The neural mechanisms behind the behavioral improvement of practice (automatization) however are largely unknown. Here we investigate how practice changes brain function and how this can improve our processing capacity. We also examine whether a deficit in automatization can explain the severely limited processing capacity in schizophrenia. Previous research implicates working memory (WM) in the development of

T. R. van Raalten

2009-01-01

316

Moderate doses of alcohol disrupt the functional organization of the human brain  

Microsoft Academic Search

Acute alcohol administration decreases overall brain glucose metabolism, which serves as a marker of brain activity. The behavioral effects of alcohol, however, are likely to reflect not only changes in regional brain activity but also the patterns of brain functional organization. Here we assessed the effects of a moderate dose of alcohol on the patterns of brain activity and cerebral

Nora D. Volkow; Yeming Ma; Wei Zhu; Joanna S. Fowler; Juan Li; Manlong Rao; Klaus Mueller; Kith Pradhan; Christopher Wong; Gene-Jack Wang

2008-01-01

317

Suicidal brains: a review of functional and structural brain studies in association with suicidal behaviour.  

PubMed

Evidence of an association between a vulnerability to suicidal behaviour and neurobiological abnormalities is accumulating. Post-mortem studies have demonstrated structural and biochemical changes in the brains of suicide victims. More recently, imaging techniques have become available to study changes in the brain in vivo. This systematic review of comparative imaging studies of suicidal brains shows that changes in the structure and functions of the brain in association with suicidal behaviour are mainly found in the orbitofrontal and dorsolateral parts of the prefrontal cortex. Correlational studies suggest that these changes relate to neuropsychological disturbances in decision-making, problem solving and fluency, respectively. As a consequence, the findings from these studies suggest that suicidal behaviour is associated with (1) a particular sensitivity to social disapproval (2) choosing options with high immediate reward and (3) a reduced ability to generate positive future events. Further study is needed to elaborate these findings and to investigate to what extent changes in the structure and function of suicidal brains are amenable to psychological and/or biological interventions. PMID:20826179

van Heeringen, C; Bijttebier, S; Godfrin, K

2010-09-06

318

Neuroimaging Studies of Brain Activation for Language, with an Emphasis on Functional Magnetic Resonance Imaging: A Review  

Microsoft Academic Search

Neuroimaging studies have greatly enhanced the potential to understand brain-behavior relationships in complex behaviors such as language. The method of functional magnetic resonance imaging (fMRI) is one of the newest tools for neuroimaging, and it will in all likelihood contribute substantially to new knowledge about brain activation for language processing. This review summarizes basic information about fMRI, including principles of

Raymond D. Kent

1998-01-01

319

Cytokines for Psychologists: Implications of Bidirectional Immune-to-Brain Communication for Understanding Behavior, Mood, and Cognition  

Microsoft Academic Search

The brain and immune system form a bidirectional communication network in which the immune system operates as a diffuse sense organ, informing the brain about events in the body. This allows the activation of immune cells to produce physiological, behavioral, affective, and cognitive changes that are collectively called sickness, which function to promote recuperation. Fight–flight evolved later and coopted this

Steven F. Maier; Linda R. Watkins

1998-01-01

320

Using knowledge of development to promote recovery of function after brain damage.  

PubMed

Knowledge of normal development of brain-behavior relations plays an important role in understanding how the plasticity of the nervous system can be used to promote recovery of function following brain damage. Aspects of the other articles in this issue are used in justification of the value of such developmental knowledge. Also, the development of amblyopia and its remediation in adulthood is discussed as a model for developing other techniques for ensuring recovery of function after stroke. Although the articles in this issue establish an excellent context for improving actual recovery of function (rather than compensation for deficits), much still needs to be discovered about how we can use developmental knowledge, along with knowledge of the plasticity of the nervous system, to improve remediation techniques. PMID:22415922

Michel, George F

2012-04-01

321

Mental time travel and default-mode network functional connectivity in the developing brain  

PubMed Central

A core brain network is engaged in remembering the past and envisioning the future. This network overlaps with the so-called default-mode network, the activity of which increases when demands for focused attention are low. Because of their shared brain substrates, an intriguing hypothesis is that default-mode activity, measured at rest, is related to performance in separate attention-focused recall and imagination tasks. However, we do not know how functional connectivity of the default-mode network is related to individual differences in reconstruction of the past and imagination of the future. Here, we show that functional connectivity of the default-mode network in children and adolescents is related to the quality of past remembering and marginally to future imagination. These results corroborate previous findings of a common neuronal substrate for memory and imagination and provide evidence suggesting that mental time travel is modulated by the task-independent functional architecture of the default-mode network in the developing brain. A further analysis showed that local cortical arealization also contributed to explain recall of the past and imagination of the future, underscoring the benefits of studying both functional and structural properties to understand the brain basis for complex human cognition.

?stby, Ylva; Walhovd, Kristine B.; Tamnes, Christian K.; Grydeland, Hakon; Westlye, Lars Tjelta; Fjell, Anders M.

2012-01-01

322

Mental time travel and default-mode network functional connectivity in the developing brain.  

PubMed

A core brain network is engaged in remembering the past and envisioning the future. This network overlaps with the so-called default-mode network, the activity of which increases when demands for focused attention are low. Because of their shared brain substrates, an intriguing hypothesis is that default-mode activity, measured at rest, is related to performance in separate attention-focused recall and imagination tasks. However, we do not know how functional connectivity of the default-mode network is related to individual differences in reconstruction of the past and imagination of the future. Here, we show that functional connectivity of the default-mode network in children and adolescents is related to the quality of past remembering and marginally to future imagination. These results corroborate previous findings of a common neuronal substrate for memory and imagination and provide evidence suggesting that mental time travel is modulated by the task-independent functional architecture of the default-mode network in the developing brain. A further analysis showed that local cortical arealization also contributed to explain recall of the past and imagination of the future, underscoring the benefits of studying both functional and structural properties to understand the brain basis for complex human cognition. PMID:23027942

Østby, Ylva; Walhovd, Kristine B; Tamnes, Christian K; Grydeland, Håkon; Westlye, Lars Tjelta; Fjell, Anders M

2012-10-01

323

Whole brain functional connectivity in the early blind.  

PubMed

Early visual deprivation can lead to changes in the brain, which may be explained by either of two hypotheses. The general loss hypothesis has been proposed to explain maladjustments, while the compensatory plasticity hypothesis may explain a superior ability in the use of the remaining senses. Most previous task-based functional MRI (fMRI) studies have supported the compensatory plasticity hypothesis, but it has been difficult to provide evidence to support the general loss hypothesis, since the blind cannot execute visual tasks. The study of resting state fMRI data may provide an opportunity to simultaneously detect the two aspects of changes in the blind. In this study, using a whole brain perspective, we investigated the decreased and increased functional connectivities in the early blind using resting state fMRI data. The altered functional connectivities were identified by comparing the correlation coefficients of each pair of brain regions of 16 early blind subjects (9 males; age range: 15.6-29.3 years, mean age: 22.1 years) with the corresponding coefficients of gender- and age-matched sighted volunteers. Compared with the sighted subjects, the blind demonstrated the decreased functional connectivities within the occipital visual cortices as well as between the occipital visual cortices and the parietal somatosensory, frontal motor and temporal multisensory cortices. Such differences may support the general loss hypothesis. However, we also found that the introduction of Braille earlier in life and for longer daily practice times produced stronger functional connectivities between these brain areas. These findings may support the compensatory plasticity hypothesis. Additionally, we found several increased functional connectivities between the occipital cortices and frontal language cortices in those with early onset of blindness, which indicate the predominance of compensatory plasticity. Our findings indicate that changes in the functional connectivities in the resting state may be an integrated reflection of general loss and compensatory plasticity when a single sensory modality is deprived. PMID:17533167

Liu, Yong; Yu, Chunshui; Liang, Meng; Li, Jun; Tian, Lixia; Zhou, Yuan; Qin, Wen; Li, Kuncheng; Jiang, Tianzi

2007-05-28

324

Development of structure and function in the infant brain: Implications for cognition, language and social behaviour  

PubMed Central

Recent advances in cognitive neuroscience have allowed us to begin investigating the development of both structure and function in the infant brain. However, despite the rapid evolution of technology, surprisingly few studies have examined the intersection between brain and behaviour over the first years of life. Even fewer have done so in the context of a particular research question. This paper aims to provide an overview of four domains that have been studied using techniques amenable to elucidating the brain/behaviour interface: language, face processing, object permanence, and joint attention, with particular emphasis on studies focusing on early development. The importance of the unique role of development and the interplay between structure and function is stressed throughout. It is hoped that this review will serve as a catalyst for further thinking about the substantial gaps in our understanding of the relationship between brain and behaviour across development. Further, our aim is to provide ideas about candidate brain areas that are likely to be implicated in particular behaviours or cognitive domains.

Paterson, Sarah J.; Heim, Sabine; Friedman, Jennifer Thomas; Choudhury, Naseem; Benasich, April A.

2007-01-01

325

Developing high-performance cross-functional teams: Understanding motivations, functional loyalties, and teaming fundamentals  

SciTech Connect

Teamwork is the key to the future of effective technology management. Today`s technologies and markets have become too complex for individuals to work alone. Global competition, limited resources, cost consciousness, and time pressures have forced organizations and project managers to encourage teamwork. Many of these teams will be cross-functional teams that can draw on a multitude of talents and knowledge. To develop high-performing cross-functional teams, managers must understand motivations, functional loyalties, and the different backgrounds of the individual team members. To develop a better understanding of these issues, managers can learn from experience and from literature on teams and teaming concepts. When studying the literature to learn about cross-functional teaming, managers will find many good theoretical concepts, but when put into practice, these concepts have varying effects. This issue of varying effectiveness is what drives the research for this paper. The teaming concepts were studied to confirm or modify current understanding. The literature was compared with a {open_quotes}ground truth{close_quotes}, a survey of the reality of teaming practices, to examine the teaming concepts that the literature finds to be critical to the success of teams. These results are compared to existing teams to determine if such techniques apply in real-world cases.

Miller, M.A.

1996-08-01

326

NIRS Trajectories in Oxy-Deoxy Hb Plane and the Trajectory Map to Understand Brain Activities Related to Human Interface  

Microsoft Academic Search

NIRS trajectory method is proposed to understand brain activities engaged in mobile device operation. The trajectory is the\\u000a plot of oxy- and deoxy- Hb (hemoglobin concentration) data to the Oxy-Deoxy Hb plane. Three basic trajectories and some complex\\u000a trajectories are explained. Total brain activities are represented by a set of NIRS trajectories derived from NIRS channels\\u000a located on the head

Hiroshi Tamura; Masako Omori; Masami Choui

2007-01-01

327

Understanding Alterations During Human Brain Development with Molecular Imaging: Role in Determining Serotonin and GABA Mechanisms in Autism  

Microsoft Academic Search

\\u000a The purpose of this chapter is to present an approach to the understanding of chemical differences in the brains of children\\u000a with autism and to use to information to design new treatments for autism. The approach is to utilize information about how\\u000a the processes in the developing brain of an autistic child differs from those in typically developing children discovered

Diane C. Chugani

328

MRI Contrast Agents for Functional Molecular Imaging of Brain Activity  

PubMed Central

Summary Functional imaging with MRI contrast agents is an emerging experimental approach that can combine the specificity of cellular neural recording techniques with noninvasive whole-brain coverage. A variety of contrast agents sensitive to aspects of brain activity have recently been introduced. These include new probes for calcium and other metal ions that offer high sensitivity and membrane permeability, as well as imaging agents for high resolution pH and metabolic mapping in living animals. Genetically-encoded MRI contrast agents have also been described. Several of the new probes have been validated in the brain; in vivo use of other agents remains a challenge. This review outlines advantages and disadvantages of specific molecular imaging approaches and discusses current or potential applications in neurobiology.

Jasanoff, Alan

2009-01-01

329

Scientific Understanding of Non-Chromated Corrosion Inhibitors Function.  

National Technical Information Service (NTIS)

This project generated understanding of the mechanisms of non- chromate corrosion inhibiting coating systems by studying cross-cutting issues and leading chromate-free chemicals and systems. In Task 1, Trivalent Chromium Process coatings were found to rel...

G. Swain G. S. Frankel M. Jaworowski R. G. Buchheit

2013-01-01

330

Quantification of functional alterations after in vitro traumatic brain injury.  

PubMed

Traumatic brain injury (TBI) is caused by mechanical forces, producing tissue deformation at the moment of injury. Complex cellular, neurochemical and metabolic alterations are initiated by the deformation and result in delayed cell death and dysfunction. Using an in vitro model of TBI based on organotypic brain slice cultures, we have quantitatively studied the relationship between tissue deformation and functional outcome. Specifically, we studied the effects of low levels of tissue deformation on the functional outcomes as measured by electrophysiology recordings. In response to 5% and 10% biaxial Lagrangian strain, the maximal evoked response and the excitability of neural networks were found to be decreased. Additionally, the different anatomic subregions of the hippocampus displayed different levels of impairment to the injuries. These results suggest that the network function was affected by low levels of applied strain which induced minimal cell death in previous studies. PMID:19963487

Yu, Zhe; Elkin, Benjamin S; Morrison, Barclay

2009-01-01

331

Personality Is Reflected in the Brain's Intrinsic Functional Architecture  

PubMed Central

Personality describes persistent human behavioral responses to broad classes of environmental stimuli. Investigating how personality traits are reflected in the brain's functional architecture is challenging, in part due to the difficulty of designing appropriate task probes. Resting-state functional connectivity (RSFC) can detect intrinsic activation patterns without relying on any specific task. Here we use RSFC to investigate the neural correlates of the five-factor personality domains. Based on seed regions placed within two cognitive and affective ‘hubs’ in the brain—the anterior cingulate and precuneus—each domain of personality predicted RSFC with a unique pattern of brain regions. These patterns corresponded with functional subdivisions responsible for cognitive and affective processing such as motivation, empathy and future-oriented thinking. Neuroticism and Extraversion, the two most widely studied of the five constructs, predicted connectivity between seed regions and the dorsomedial prefrontal cortex and lateral paralimbic regions, respectively. These areas are associated with emotional regulation, self-evaluation and reward, consistent with the trait qualities. Personality traits were mostly associated with functional connections that were inconsistently present across participants. This suggests that although a fundamental, core functional architecture is preserved across individuals, variable connections outside of that core encompass the inter-individual differences in personality that motivate diverse responses.

Adelstein, Jonathan S.; Shehzad, Zarrar; Mennes, Maarten; DeYoung, Colin G.; Zuo, Xi-Nian; Kelly, Clare; Margulies, Daniel S.; Bloomfield, Aaron; Gray, Jeremy R.; Castellanos, F. Xavier; Milham, Michael P.

2011-01-01

332

The effect of criticism on functional brain connectivity and associations with neuroticism.  

PubMed

Neuroticism is a robust personality trait that constitutes a risk factor for psychopathology, especially anxiety disorders and depression. High neurotic individuals tend to be more self-critical and are overly sensitive to criticism by others. Hence, we used a novel resting-state paradigm to investigate the effect of criticism on functional brain connectivity and associations with neuroticism. Forty-eight participants completed the NEO Personality Inventory Revised (NEO-PI-R) to assess neuroticism. Next, we recorded resting state functional magnetic resonance imaging (rsfMRI) during two sessions. We manipulated the second session before scanning by presenting three standardized critical remarks through headphones, in which the subject was urged to please lie still in the scanner. A seed-based functional connectivity method and subsequent clustering were used to analyse the resting state data. Based on the reviewed literature related to criticism, we selected brain regions associated with self-reflective processing and stress-regulation as regions of interest. The findings showed enhanced functional connectivity between the clustered seed regions and brain areas involved in emotion processing and social cognition during the processing of criticism. Concurrently, functional connectivity was reduced between these clusters and brain structures related to the default mode network and higher-order cognitive control. Furthermore, individuals scoring higher on neuroticism showed altered functional connectivity between the clustered seed regions and brain areas involved in the appraisal, expression and regulation of negative emotions. These results may suggest that the criticized person is attempting to understand the beliefs, perceptions and feelings of the critic in order to facilitate flexible and adaptive social behavior. Furthermore, multiple aspects of emotion processing were found to be affected in individuals scoring higher on neuroticism during the processing of criticism, which may increase their sensitivity to negative social-evaluation. PMID:23922755

Servaas, Michelle Nadine; Riese, Harriëtte; Renken, Remco Jan; Marsman, Jan-Bernard Cornelis; Lambregs, Johan; Ormel, Johan; Aleman, André

2013-07-26

333

Neuroergonomics - Analyzing Brain Function to Enhance Human Performance in Complex Systems.  

National Technical Information Service (NTIS)

Why Neuroergonomics. To design effective human-machine systems, we must (1) Understand mind in relation to work and technology -- ergonomics (2) Mind cannot be understood without studying the brain -- neuroscience (3) Hence study brain and mind in complex...

R. Parasuraman

2008-01-01

334

Neuropsychological Evidence for the Role of Graphical and Algebraic Representations in Understanding Function  

Microsoft Academic Search

There are difficulties accessing students' thinking about mathematical concepts, although methods such as task observation and interviews provide some useful information. In recent years it has become possible to use functional magnetic resonance imaging (fMRI) techniques to access brain activity while students are thinking about mathematics. In this study we have used this technique to examine brain activity while students

Michael O. J. Thomas; Anna J. Wilson; Michael C. Corballis; Vanessa K. Lim

335

Understanding and Assessing the Motivations of Volunteers: A Functional Approach  

Microsoft Academic Search

The authors applied functionalist theory to the question of the motivations underlying volunteerism, hypothesized 6 functions potentially served by volunteerism, and designed an instrument to assess these functions (Volunteer Functions Inventory; VFI). Exploratory and confirmatory factor analyses on diverse samples yielded factor solutions consistent with functionalist theorizing; each VFI motivation, loaded on a single factor, possessed substantial internal consistency and

E. Gil Clary; Mark Snyder; Robert D. Ridge; John Copeland; Arthur A. Stukas; Julie Haugen; Peter Miene

1998-01-01

336

Recent advances in the understanding of egg white protein functionality  

Microsoft Academic Search

Hen egg white proteins have been extensively utilized as ingredients in food processing because of their unique functional properties, such as gelling and foaming. This review article describes the molecular basis for the development of these functional properties during processing, as well as studies of the development of new methods for improving the functional properties of egg white proteins. The

Yoshinori Mine

1995-01-01

337

Effect of brain shift on the creation of functional atlases for deep brain stimulation surgery  

PubMed Central

Purpose In the recent past many groups have tried to build functional atlases of the deep brain using intra-operatively acquired information such as stimulation responses or micro-electrode recordings. An underlying assumption in building such atlases is that anatomical structures do not move between pre-operative imaging and intra-operative recording. In this study, we present evidences that this assumption is not valid. We quantify the effect of brain shift between pre-operative imaging and intra-operative recording on the creation of functional atlases using intra-operative somatotopy recordings and stimulation response data. Methods A total of 73 somatotopy points from 24 bilateral subthalamic nucleus (STN) implantations and 52 eye deviation stimulation response points from 17 bilateral STN implantations were used. These points were spatially normalized on a magnetic resonance imaging (MRI) atlas using a fully automatic non-rigid registration algorithm. Each implantation was categorized as having low, medium or large brain shift based on the amount of pneumocephalus visible on post-operative CT. The locations of somatotopy clusters and stimulation maps were analyzed for each category. Results The centroid of the large brain shift cluster of the somatotopy data (posterior, lateral, inferior: 3.06, 11.27, 5.36 mm) was found posterior, medial and inferior to that of the medium cluster (2.90, 13.57, 4.53 mm) which was posterior, medial and inferior to that of the low shift cluster (1.94, 13.92, 3.20 mm). The coordinates are referenced with respect to the mid-commissural point. Euclidean distances between the centroids were 1.68, 2.44 and 3.59 mm, respectively for low-medium, medium-large and low-large shift clusters. We found similar trends for the positions of the stimulation maps. The Euclidian distance between the highest probability locations on the low and medium-large shift maps was 4.06 mm. Conclusion The effect of brain shift in deep brain stimulation (DBS) surgery has been demonstrated using intra-operative somatotopy recordings as well as stimulation response data. The results not only indicate that considerable brain shift happens before micro-electrode recordings in DBS but also that brain shift affects the creation of accurate functional atlases. Therefore, care must be taken when building and using such atlases of intra-operative data and also when using intra-operative data to validate anatomical atlases.

Pallavaram, Srivatsan; Remple, Michael S.; Neimat, Joseph S.; Kao, Chris; Konrad, Peter E.; D'Haese, Pierre-Francois

2011-01-01

338

Analysis of functional neuronal connectivity in the Drosophila brain  

PubMed Central

Drosophila melanogaster is a valuable model system for the neural basis of complex behavior, but an inability to routinely interrogate physiologic connections within central neural networks of the fly brain remains a fundamental barrier to progress in the field. To address this problem, we have introduced a simple method of measuring functional connectivity based on the independent expression of the mammalian P2X2 purinoreceptor and genetically encoded Ca2+ and cAMP sensors within separate genetically defined subsets of neurons in the adult brain. We show that such independent expression is capable of specifically rendering defined sets of neurons excitable by pulses of bath-applied ATP in a manner compatible with high-resolution Ca2+ and cAMP imaging in putative follower neurons. Furthermore, we establish that this approach is sufficiently sensitive for the detection of excitatory and modulatory connections deep within larval and adult brains. This technically facile approach can now be used in wild-type and mutant genetic backgrounds to address functional connectivity within neuronal networks governing a wide range of complex behaviors in the fly. Furthermore, the effectiveness of this approach in the fly brain suggests that similar methods using appropriate heterologous receptors might be adopted for other widely used model systems.

Yao, Zepeng; Macara, Ann Marie; Lelito, Katherine R.; Minosyan, Tamara Y.

2012-01-01

339

Analysis of functional neuronal connectivity in the Drosophila brain.  

PubMed

Drosophila melanogaster is a valuable model system for the neural basis of complex behavior, but an inability to routinely interrogate physiologic connections within central neural networks of the fly brain remains a fundamental barrier to progress in the field. To address this problem, we have introduced a simple method of measuring functional connectivity based on the independent expression of the mammalian P2X2 purinoreceptor and genetically encoded Ca(2+) and cAMP sensors within separate genetically defined subsets of neurons in the adult brain. We show that such independent expression is capable of specifically rendering defined sets of neurons excitable by pulses of bath-applied ATP in a manner compatible with high-resolution Ca(2+) and cAMP imaging in putative follower neurons. Furthermore, we establish that this approach is sufficiently sensitive for the detection of excitatory and modulatory connections deep within larval and adult brains. This technically facile approach can now be used in wild-type and mutant genetic backgrounds to address functional connectivity within neuronal networks governing a wide range of complex behaviors in the fly. Furthermore, the effectiveness of this approach in the fly brain suggests that similar methods using appropriate heterologous receptors might be adopted for other widely used model systems. PMID:22539819

Yao, Zepeng; Macara, Ann Marie; Lelito, Katherine R; Minosyan, Tamara Y; Shafer, Orie T

2012-04-25

340

Transient crossed aphasia evidenced by functional brain imagery.  

PubMed

Crossed aphasia refers to language deficits induced by unilateral right hemisphere injuries in right-handed people who had no previous history of brain damage. One of the intriguing questions concerning crossed aphasia is the atypical language representation in the brain. In this respect, fMRI is a valuable tool for understanding the neural basis of crossed aphasia. Here, we used neuropsychological and fMRI language tasks in a right-handed subject who presented a crossed aphasia due to a right frontal meningioma. fMRI maps from two language tasks showed bilateral patterns of activation. In the light of previous studies reporting much frequent bilateral than exclusive right hemisphere representations, we hypothesise that some crossed aphasia cases could occur in subjects with bilateral language representation. PMID:15073515

Khateb, Asaid; Martory, Marie-Dominique; Annoni, Jean-Marie; Lazeyras, François; de Tribolet, Nicolas; Pegna, Alan J; Mayer, Eugène; Michel, Christoph M; Seghier, Mohamed L

2004-04-01

341

Multiscale topological properties of functional brain networks during motor imagery after stroke.  

PubMed

In recent years, network analyses have been used to evaluate brain reorganization following stroke. However, many studies have often focused on single topological scales, leading to an incomplete model of how focal brain lesions affect multiple network properties simultaneously and how changes on smaller scales influence those on larger scales. In an EEG-based experiment on the performance of hand motor imagery (MI) in 20 patients with unilateral stroke, we observed that the anatomic lesion affects the functional brain network on multiple levels. In the beta (13-30Hz) frequency band, the MI of the affected hand (Ahand) elicited a significantly lower smallworldness and local efficiency (Eloc) versus the unaffected hand (Uhand). Notably, the abnormal reduction in Eloc significantly depended on the increase in interhemispheric connectivity, which was in turn determined primarily by the rise of regional connectivity in the parieto-occipital sites of the affected hemisphere. Further, in contrast to the Uhand MI, in which significantly high connectivity was observed for the contralateral sensorimotor regions of the unaffected hemisphere, the regions with increased connectivity during the Ahand MI lay in the frontal and parietal regions of the contralaterally affected hemisphere. Finally, the overall sensorimotor function of our patients, as measured by Fugl-Meyer Assessment (FMA) index, was significantly predicted by the connectivity of their affected hemisphere. These results improve on our understanding of stroke-induced alterations in functional brain networks. PMID:23791916

De Vico Fallani, Fabrizio; Pichiorri, Floriana; Morone, Giovanni; Molinari, Marco; Babiloni, Fabio; Cincotti, Febo; Mattia, Donatella

2013-06-19

342

Revealing Topological Organization of Human Brain Functional Networks with Resting-State Functional near Infrared Spectroscopy  

PubMed Central

Background The human brain is a highly complex system that can be represented as a structurally interconnected and functionally synchronized network, which assures both the segregation and integration of information processing. Recent studies have demonstrated that a variety of neuroimaging and neurophysiological techniques such as functional magnetic resonance imaging (MRI), diffusion MRI and electroencephalography/magnetoencephalography can be employed to explore the topological organization of human brain networks. However, little is known about whether functional near infrared spectroscopy (fNIRS), a relatively new optical imaging technology, can be used to map functional connectome of the human brain and reveal meaningful and reproducible topological characteristics. Results We utilized resting-state fNIRS (R-fNIRS) to investigate the topological organization of human brain functional networks in 15 healthy adults. Brain networks were constructed by thresholding the temporal correlation matrices of 46 channels and analyzed using graph-theory approaches. We found that the functional brain network derived from R-fNIRS data had efficient small-world properties, significant hierarchical modular structure and highly connected hubs. These results were highly reproducible both across participants and over time and were consistent with previous findings based on other functional imaging techniques. Conclusions Our results confirmed the feasibility and validity of using graph-theory approaches in conjunction with optical imaging techniques to explore the topological organization of human brain networks. These results may expand a methodological framework for utilizing fNIRS to study functional network changes that occur in association with development, aging and neurological and psychiatric disorders.

Zhao, Tengda; Shu, Ni; He, Yong

2012-01-01

343

Executive functioning and adaptive living skills after acquired brain injury.  

PubMed

Executive dysfunction is common following brain injury, with impairments involving attention, social pragmatics, higher-order thinking, judgment, and reasoning. Executive function impairments may have a direct impact on an individual's ability to return to instrumental activities of daily living (IADL), including employment, money management, driving, and maintaining a residence. Research has shown that neuropsychological executive function measures may be able to predict daily-living skills. There is limited research evaluating the relationship between executive functions and IADLs in adults with acquired brain injuries (ABI), with none investigating levels of proficiency as related to specific test scores. We hypothesize that neuropsychological executive function measures will have significant and moderate-to-strong correlations with participant-rated proficiency on functional tasks as measured by the Mayo-Portland Adaptability Inventory. Results support that IQ and some of the executive function measures (Processing Speed, Working Memory, and Trail-Making Test-Part B) correlated significantly and strongly and explained unique variance in all IADLs in this study. Data suggest that individuals with ABI who performed in the higher end of the low-average range or higher on measures of executive functioning tend to require little or no assistance to be independent with transportation, money management, living without support, and employment. Results also suggest that individuals with less executive dysfunction are likely to have greater overall community participation. PMID:23373638

Perna, Robert; Loughan, Ashlee R; Talka, Kristin

2012-07-31

344

Developmental changes in brain activation and functional connectivity during response inhibition in the early childhood brain.  

PubMed

Response inhibition is an attention function which develops relatively early during childhood. Behavioral data suggest that by the age of 3, children master the basic task requirements for the assessment of response inhibition but performance improves substantially until the age of 7. The neuronal mechanisms underlying these developmental processes, however, are not well understood. In this study, we examined brain activation patterns and behavioral performance of children aged between 4 and 6years compared to adults by applying a go/no-go paradigm during near-infrared spectroscopy (NIRS) brain imaging. We furthermore applied task-independent functional connectivity measures to the imaging data to identify maturation of intrinsic neural functional networks. We found a significant group×condition related interaction in terms of inhibition-related reduced right fronto-parietal activation in children compared to adults. In contrast, motor-related activation did not differ between age groups. Functional connectivity analysis revealed that in the children's group, short-range coherence within frontal areas was stronger, and long-range coherence between frontal and parietal areas was weaker, compared to adults. Our findings show that in children aged from 4 to 6years fronto-parietal brain maturation plays a crucial part in the cognitive development of response inhibition. PMID:23265620

Mehnert, Jan; Akhrif, Atae; Telkemeyer, Silke; Rossi, Sonja; Schmitz, Christoph H; Steinbrink, Jens; Wartenburger, Isabell; Obrig, Hellmuth; Neufang, Susanne

2012-12-21

345

Alteration and Reorganization of Functional Networks: A New Perspective in Brain Injury Study  

PubMed Central

Plasticity is the mechanism underlying the brain’s potential capability to compensate injury. Recently several studies have shown how functional connections among the brain areas are severely altered by brain injury and plasticity leading to a reorganization of the networks. This new approach studies the impact of brain injury by means of alteration of functional interactions. The concept of functional connectivity refers to the statistical interdependencies between physiological time series simultaneously recorded in various areas of the brain and it could be an essential tool for brain functional studies, being its deviation from healthy reference an indicator for damage. In this article, we review studies investigating functional connectivity changes after brain injury and subsequent recovery, providing an accessible introduction to common mathematical methods to infer functional connectivity, exploring their capabilities, future perspectives, and clinical uses in brain injury studies.

Castellanos, Nazareth P.; Bajo, Ricardo; Cuesta, Pablo; Villacorta-Atienza, Jose Antonio; Paul, Nuria; Garcia-Prieto, Juan; del-Pozo, Francisco; Maestu, Fernando

2011-01-01

346

A biomedical information system for neuroimaging and brain function  

NASA Astrophysics Data System (ADS)

In order to solve the database interoperability and neuroscientific information integration, we have built an internet-accessible Biomedical Information System (BMIS) for neuroimaging and brain function research. BMIS is a multi-purpose academic periodical full-text literature platform; it safeguards the literature involving Neuroscience, Biomedical Photonics, Medical Imaging, Bioinformatics and so on, and can carry on the input, retrieval and maintenance of the literature data. Based on the cluster system of TS10000 and new data processing technologies, the establishment of this integrated, individualized and extensible system will provide the massive data set needed for knowledge discovery and will serve as a foundation for future hypothesis-driven experiments, which begin with a special problem of substantial scientific interest about neuroimaging and brain function.

You, Jun; Zhang, Jie; Luo, Qingming

2007-05-01

347

Patching the glia reveals the functional organisation of the brain.  

PubMed

The neuroglia was initially conceived by Rudolf Virchow as a non-cellular connective tissue holding neurones together. In 1894, Carl Ludwig Schleich proposed a hypothesis of fully integrated and interconnected neuronal-glial circuits as a substrate for brain function. This hypothesis received direct experimental support only hundred years later, after several physiological techniques, and most notably the patch-clamp method, were applied to glial cells. These experiments have demonstrated the existence of active and bi-directional neuronal-glial communications, integrating neuronal networks and glial syncytium into one functional circuit. The data accumulated during last 15 years prompt rethinking of the neuronal doctrine towards more inclusive concept, which regards both neurones and glia as equally responsible for information processing in the brain. PMID:16775706

Verkhratsky, Alexei

2006-06-15

348

Towards a Functional Understanding of Protein N-Terminal Acetylation  

Microsoft Academic Search

Protein N-terminal acetylation is a major modification of eukaryotic proteins. Its functional implications include regulation of protein–protein interactions and targeting to membranes, as demonstrated by studies of a handful of proteins. Fifty years after its discovery, a potential general function of the N-terminal acetyl group carried by thousands of unique proteins remains enigmatic. However, recent functional data suggest roles for

Thomas Arnesen

2011-01-01

349

Understanding and Reducing Errors in Density Functional Calculations  

NASA Astrophysics Data System (ADS)

We decompose the energy error of any variational density functional theory calculation into a contribution due to the approximate functional and that due to the approximate density. Typically, the functional error dominates, but in many interesting situations the density-driven error dominates. Examples range from calculations of electron affinities to preferred geometries of ions and radicals in solution. In these abnormal cases, the error in density functional theory can be greatly reduced by using a more accurate density. A small orbital gap often indicates a substantial density-driven error.

Kim, Min-Cheol; Sim, Eunji; Burke, Kieron

2013-08-01

350

Neuroimaging Studies of Normal Brain Development and Their Relevance for Understanding Childhood Neuropsychiatric Disorders  

Microsoft Academic Search

ObjectiveTo review the maturational events that occur during prenatal and postnatal brain development and to present neuroimaging findings from studies of healthy individuals that identify the trajectories of normal brain development.

Rachel Marsh; Andrew J. Gerber; Bradley S. Peterson

2008-01-01

351

A biomedical information system for neuroimaging and brain function  

Microsoft Academic Search

In order to solve the database interoperability and neuroscientific information integration, we have built an internet-accessible Biomedical Information System (BMIS) for neuroimaging and brain function research. BMIS is a multi-purpose academic periodical full-text literature platform; it safeguards the literature involving Neuroscience, Biomedical Photonics, Medical Imaging, Bioinformatics and so on, and can carry on the input, retrieval and maintenance of the

Jun You; Jie Zhang; Qingming Luo

2007-01-01

352

Automated Talairach Atlas labels for functional brain mapping  

Microsoft Academic Search

An automated coordinate-based system to retrieve brain labels from the 1988 Talairach Atlas, called the Talairach Daemon (TD), was previously introduced (Lancaster et al., 1997). In the present study, the TD system and its 3-D database of labels for the 1988 Talairach atlas were tested for labeling of functional activation foci. TD system labels were compared with author-designated labels of

Jack L. Lancaster; Marty G. Woldorff; Lawrence M. Parsons; Mario Liotti; Catarina S. Freitas; Lacy Rainey; Peter V. Kochunov; Dan Nickerson; Shawn A. Mikiten; Peter T. Fox

2000-01-01

353

Exploiting Temporal Information in Functional Magnetic Resonance Imaging Brain Data  

Microsoft Academic Search

Functional Magnetic Resonance Imaging(fMRI) has enabled scientists to look into the active human brain, leading to a flood of new data, thus encouraging the development of new data analysis methods. In this paper, we contribute a comprehensive framework for spatial and tem- poral exploration of fMRI data, and apply it to a challenging case study: separating drug addicted subjects from

Lei Zhang; Dimitris Samaras; Dardo Tomasi; Nelly Alia-klein; Lisa Cottone; Andreana Leskovjan; Nora D. Volkow; Rita Goldstein

2005-01-01

354

Normalizing hematocrit in dialysis patients improves brain function  

Microsoft Academic Search

Recombinant human erythropoietin (rHuEPO) treatment has been shown to improve brain and cognitive function in anemic dialysis patients. Significant debate continues, however, regarding the appropriate target hematocrit (Hct) that will lead to the greatest benefits while considering possible side effects and costs of rHuEPO. Current practice results in an Hct averaging only 31% to 32% in dialysis patients, a level

Janiece L. Pickett; David C. Theberge; Warren S. Brown; Suzanne U. Schweitzer; Allen R. Nissenson

1999-01-01

355

Patching the glia reveals the functional organisation of the brain  

Microsoft Academic Search

The neuroglia was initially conceived by Rudolf Virchow as a non-cellular connective tissue holding neurones together. In\\u000a 1894, Carl Ludwig Schleich proposed a hypothesis of fully integrated and interconnected neuronal-glial circuits as a substrate\\u000a for brain function. This hypothesis received direct experimental support only hundred years later, after several physiological\\u000a techniques, and most notably the patch-clamp method, were applied to

Alexei Verkhratsky

2006-01-01

356

Understanding Complex Natural Systems by Articulating Structure-Behavior-Function Models  

ERIC Educational Resources Information Center

|Artificial intelligence research on creative design has led to Structure-Behavior-Function (SBF) models that emphasize functions as abstractions for organizing understanding of physical systems. Empirical studies on understanding complex systems suggest that novice understanding is shallow, typically focusing on their visible structures and…

Vattam, Swaroop S.; Goel, Ashok K.; Rugaber, Spencer; Hmelo-Silver, Cindy E.; Jordan, Rebecca; Gray, Steven; Sinha, Suparna

2011-01-01

357

Using Proton Magnetic Resonance Imaging and Spectroscopy to Understand Brain "Activation"  

ERIC Educational Resources Information Center

Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain "activation" studies. These perturbations usually continue throughout the period of the…

Baslow, Morris H.; Guilfoyle, David N.

2007-01-01

358

Using proton magnetic resonance imaging and spectroscopy to understand brain “activation”  

Microsoft Academic Search

Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain “activation” studies. These perturbations usually continue throughout the period of the stimulating event, and then subside when the event is terminated. In this

Morris H. Baslow; David N. Guilfoyle

2007-01-01

359

Using Proton Magnetic Resonance Imaging and Spectroscopy to Understand Brain "Activation"  

ERIC Educational Resources Information Center

|Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain "activation" studies. These perturbations usually continue throughout the period of the…

Baslow, Morris H.; Guilfoyle, David N.

2007-01-01

360

Structural and functional neuroimaging studies of the suicidal brain.  

PubMed

Suicidality is a major challenge for today's health care. Evidence suggests that there are differences in cognitive functioning of suicidal patients but the knowledge about the underlying neurobiology is limited. Brain imaging offers the advantage of a non-invasive in vivo direct estimation of detailed brain structure, regional brain functioning and estimation of molecular processes in the brain. We have reviewed the literature on neuroimaging studies of the suicidal brain. This article contains studies on structural imaging such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) and functional imaging, consisting of Positron Emission Tomography (PET), Single Photon Emission Tomography (SPECT) and functional MRI (fMRI). We classified the results of the different imaging modalities in structural and functional imaging. Within our research, we found no significant differences in the suicidal brain demonstrated by Computed Tomography. Magnetic Resonance Imaging studies in subjects with a history of suicide attempt on the other hand deliver differing results, mostly pointing at a higher prevalence of white (especially deep white matter and periventricular) and grey matter hyperintensities in the frontal, temporal and/or parietal lobe and decreased volumes in the frontal and temporal lobe. There seems to be a trend towards findings of reduced grey matter volume in the frontal lobe. Overall, there is no consensus of opinion on structural imaging of the suicidal brain. Research on functional imaging is further divided into studies in resting state, studies in activation conditions and studies on brain neurotransmitters, transporters and receptors. A common finding in functional neuroimaging in resting conditions is a decreased perfusion in the prefrontal cortex of suicidal patients. During cognitive activation, perfusion deficits in the prefrontal cortex have been observed. After fenfluramine challenge, the prefrontal cortex metabolism seems to be inversely correlated to the lethality of previous suicide attempt. The few studies that examined the serotonin transporter in suicide found no significant differences in binding potential. In suicide attempters there seems to be a negative correlation between impulsivity and SERT binding. Our group found a reduced 5-HT(2A) binding in the frontal cortex in patients with a recent suicide attempt. The binding index was significantly lower in the deliberate self injury patients compared to the deliberate self poisoning patients. The few authors that examined DAT binding in suicide found no significant DAT differences between patients and controls. However they demonstrated significant negative correlations between DAT binding potential and mental energy among suicide attempters, but not in healthy control subjects. We did not find studies measuring the binding potential of the noradrenalin or gamma amino butyric acid transporter or receptor in suicidal subjects. Several reports have suggested abnormalities of GABA neurotransmission in depression. During our literature search, we have focused on neuroimaging studies in suicidal populations, but in the absence of evidence in the literature on this group or when further collateral evidence is appropriate, this overview expands to results in impulsive aggressive or in depressed subjects. PMID:21216267

Desmyter, S; van Heeringen, C; Audenaert, K

2011-01-06

361

How Should Educational Neuroscience Conceptualise the Relation between Cognition and Brain Function? Mathematical Reasoning as a Network Process  

ERIC Educational Resources Information Center

|Background: There is increasing interest in applying neuroscience findings to topics in education. Purpose: This application requires a proper conceptualization of the relation between cognition and brain function. This paper considers two such conceptualizations. The area focus understands each cognitive competency as the product of one (and…

Varma, Sashank; Schwartz, Daniel L.

2008-01-01

362

General Constraints on the Architectures of Functionally Complex Learning Systems: Implications for Understanding Human Memory  

Microsoft Academic Search

The human brain is a functionally complex system. It can be demonstrated both on theoretical grounds and from design experience with functionally complex electronic systems that practical considerations such as the needs to limit information recording and processing resources and to be able to make functional changes without excessive undesirable side effects place severe constraints on how information is stored

L. Andrew Coward

363

Understanding of basic mechanisms of ?-cell function and survival  

Microsoft Academic Search

Type 1 and type 2 diabetes are both diseases of insulin insufficiency, although they develop by distinct pathways. The recent\\u000a surge in the incidence of type 2 diabetes and the chronic ailments confronted by patients with either form of the disease\\u000a highlight the need for better understanding of ?-cell biology. In this review, we present recent work focused on this

Christopher B. Newgard; Hans E. Hohmeier; Danhong Lu; Mette Valentin Jensen; Veronique V. Tran; Guoxun Chen; Shawn Burgess; A. Dean Sherry

2004-01-01

364

Decreased brain reward function during nicotine withdrawal in C57BL6 mice: Evidence from intracranial self-stimulation (ICSS) studies  

Microsoft Academic Search

Deficits in brain reward function during nicotine withdrawal may serve as an important substrate for negative reinforcement that contributes to the persistence of the tobacco habit in human smokers. The ability to assess withdrawal-associated reward deficits in genetically modified mice may facilitate understanding of the neurobiological mechanisms of nicotine dependence. Here, we assessed the effects of nicotine withdrawal on brain

Paul M. Johnson; Jonathan A. Hollander; Paul J. Kenny

2008-01-01

365

Brain potential and functional MRI evidence for how to handle two languages with one brain  

Microsoft Academic Search

Bilingual individuals need effective mechanisms to prevent interference from one language while processing material in the other. Here we show, using event-related brain potentials and functional magnetic resonance imaging (fMRI), that words from the non-target language are rejected at an early stage before semantic analysis in bilinguals. Bilingual Spanish\\/Catalan and monolingual Spanish subjects were instructed to press a button when

Antoni Rodriguez-Fornells; Michael Rotte; Hans-Jochen Heinze; Tömme Nösselt; Thomas F. Münte

2002-01-01

366

Early functional brain development in autism and the promise of sleep fMRI  

Microsoft Academic Search

Functional magnetic resonance imaging (fMRI) is a powerful tool for examining brain function but has yet to be systematically applied to the study of brain development in autism. Recently, however, scientists have begun to apply fMRI during natural sleep as a mechanism to study function in the developing brain. When considering the study of autism, this method opens considerable doors

Karen Pierce

2011-01-01

367

Changes in regional brain perfusion during functional brain activation: comparison of [(64)Cu]-PTSM with [(14)C]-Iodoantipyrine.  

PubMed

A dilemma in behavioral brain mapping is that conventional techniques immobilize the subject, extinguishing all but the simplest behaviors. This is avoided if brain activation is imaged after completion of the behavior and tissue capture of the tracer. A single-pass flow tracer proposed for positron emission tomography (PET) is a radiolabeled copper(II) complex of pyruvaldehyde bis(N(4)-methylthiosemicarbazone), [Cu(64)]-PTSM. [Cu(64)]-PTSM reaches steady-state cerebral distribution more rapidly than the metabolic tracer [(18)F]-fluorodeoxyglucose, allowing imaging with substantially greater temporal resolution. Using dual-label autoradiography, this study compares the relative regional cerebral blood flow tracer distribution (CBF-TR) of [(64)Cu]-PTSM to that of the classic perfusion tracer [(14)C]-iodoantipyrine in a rat model during treadmill walking. Rats were exposed to continuous walking on a treadmill and compared to quiescent controls. [(64)Cu]-PTSM was bolus injected (iv) after 1 min, followed by a 5-minute uptake and subsequent bolus injection of [(14)C]-iodoantipyrine. CBF-TR was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping, as well as by region-of-interest analysis. A high homology was found between the [(64)Cu]-PTSM and [(14)C]-iodoantipyrine patterns of cerebral activation in cortical and subcortical regions. For white matter, however, [(64)Cu]-PTSM showed lower perfusion than [(14)Cu]-iodoantipyrine. [(64)Cu]-PTSM is a useful tracer for functional brain mapping in freely-moving subjects. Its application in conjunction with PET promises to increase our understanding of the neural circuitry of behaviors dependent on locomotion. PMID:18687316

Holschneider, D P; Yang, J; Sadler, T R; Galifianakis, N B; Bozorgzadeh, M H; Bading, J R; Conti, P S; Maarek, J-M I

2008-07-19

368

Changes in Regional Brain Perfusion During Functional Brain Activation: Comparison of [64Cu]-PTSM with [14C]-Iodoantipyrine  

PubMed Central

A dilemma in behavioral brain mapping is that conventional techniques immobilize the subject, extinguishing all but the simplest behaviors. This is avoided if brain activation is imaged after completion of the behavior and tissue capture of the tracer. A single-pass flow tracer proposed for positron emission tomography (PET) is a radiolabeled copper(II) complex of pyruvaldehyde bis(N4-methylthiosemicarbazone), [Cu64]-PTSM. [Cu64]-PTSM reaches steady-state cerebral distribution more rapidly than the metabolic tracer [18F]-fluorodeoxyglucose, allowing imaging with substantially greater temporal resolution. Using dual-label autoradiography, this study compares the relative regional cerebral blood flow tracer distribution (CBF-TR) of [64Cu]-PTSM to that of the classic perfusion tracer [14C]-iodoantipyrine in a rat model during treadmill walking. Rats were exposed to continuous walking on a treadmill and compared to quiescent controls. [64Cu]-PTSM was bolus injected (iv) after 1 minute, followed by a 5 minute uptake and subsequent bolus injection of [14C]-iodoantipyrine. CBF-TR was quantified by autoradiography and analyzed in the three-dimensionally reconstructed brain by statistical parametric mapping, as well as by region-of-interest analysis. A high homology was found between the [64Cu]-PTSM and [14C]-iodoantipyrine patterns of cerebral activation in cortical and subcortical regions. For white matter, however, [64Cu]-PTSM showed lower perfusion than [14Cu]-iodoantipyrine. [64Cu]-PTSM is a useful tracer for functional brain mapping in freely-moving subjects. Its application in conjunction with PET promises to increase our understanding of the neural circuitry of behaviors dependent on locomotion.

Holschneider, DP; Yang, J; Sadler, TR; Galifianakis, NB; Bozorgzadeh, MH; Bading, JR; Conti, PS; Maarek, J-M I

2008-01-01

369

Problems in understanding the organization, structure and function of chromosomes.  

National Technical Information Service (NTIS)

Despite intensive investigation of mammalian chromosomes, we are still largely ignorant of the basic rules that govern their organization, structure, and functions. This situation results from the current limitations in available technologies to elucidate...

E. M. Bradbury

1990-01-01

370

Understanding skin care and skin barrier function in infants.  

PubMed

Skin care practices involving the application of products to the skin are common. This article focuses on these aspects of infant skin care, the importance of skin barrier function and how the use of products and therapies applied to the skin can affect skin?barrier function. It also challenges current practice and tradition, and highlights the evolving body of research into practice and tradition. PMID:24021151

Lawton, Sandra

2013-09-01

371

Yeast sphingolipids: Recent developments in understanding biosynthesis, regulation, and function  

Microsoft Academic Search

Sphingolipids function as required membrane components of virtually all eukaryotic cells. Data indicate that members of the sphingolipid family of lipids, including sphingoid bases, sphingoid base phosphates, ceramides, and complex sphingolipids, serve vital functions in cell biology by both direct mechanisms (e.g., binding to G-protein coupled receptors to transduce an extracellular signal) and indirect mechanisms (e.g., facilitating correct intracellular protein

L. Ashley Cowart; Lina M. Obeid

2007-01-01

372

Altered functional brain networks in Prader-Willi syndrome  

PubMed Central

Prader–Willi syndrome (PWS) is a genetic imprinting disorder characterized mainly by hyperphagia and early childhood obesity. Previous functional neuroimaging studies used visual stimuli to examine abnormal activities in the eating-related neural circuitry of patients with PWS. It was found that patients with PWS exhibited both excessive hunger and hyperphagia consistently, even in situations without any food stimulation. In the present study, we employed resting-state functional MRI techniques to investigate abnormal brain networks related to eating disorders in children with PWS. First, we applied amplitude of low-frequency fluctuation analysis to define the regions of interest that showed significant alterations in resting-state brain activity levels in patients compared with their sibling control group. We then applied a functional connectivity (FC) analysis to these regions of interest in order to characterize interactions among the brain regions. Our results demonstrated that patients with PWS showed decreased FC strength in the medial prefrontal cortex (MPFC)/inferior parietal lobe (IPL), MPFC/precuneus, IPL/precuneus and IPL/hippocampus in the default mode network; decreased FC strength in the pre-/postcentral gyri and dorsolateral prefrontal cortex (DLPFC)/orbitofrontal cortex (OFC) in the motor sensory network and prefrontal cortex network, respectively; and increased FC strength in the anterior cingulate cortex/insula, ventrolateral prefrontal cortex (VLPFC)/OFC and DLPFC/VLPFC in the core network and prefrontal cortex network, respectively. These findings indicate that there are FC alterations among the brain regions implicated in eating as well as rewarding, even during the resting state, which may provide further evidence supporting the use of PWS as a model to study obesity and to provide information on potential neural targets for the medical treatment of overeating.

Zhang, Yi; Zhao, Heng; Qiu, Siyou; Tian, Jie; Wen, Xiaotong; Miller, Jennifer L.; von Deneen, Karen M.; Zhou, Zhenyu; Gold, Mark S.; Liu, Yijun

2013-01-01

373

Multifaceted Genomic Risk for Brain Function in Schizophrenia  

PubMed Central

Recently, deriving candidate endophenotypes from brain imaging data has become a valuable approach to study genetic influences on schizophrenia (SZ), whose pathophysiology remains unclear. In this work we utilized a multivariate approach, parallel independent component analysis, to identify genomic risk components associated with brain function abnormalities in SZ. 5157 candidate single nucleotide polymorphisms (SNPs) were derived from genome-wide array based on their possible connections with SZ and further investigated for their associations with brain activations captured with functional magnetic resonance imaging (fMRI) during a sensorimotor task. Using data from 92 SZ patients and 116 healthy controls, we detected a significant correlation (r= 0.29; p= 2.41×10?5) between one fMRI component and one SNP component, both of which significantly differentiated patients from controls. The fMRI component mainly consisted of precentral and postcentral gyri, the major activated regions in the motor task. On average, higher activation in these regions was observed in participants with higher loadings of the linked SNP component, predominantly contributed to by 253 SNPs. 138 identified SNPs were from known coding regions of 100 unique genes. 31 identified SNPs did not differ between groups, but moderately correlated with some other group-discriminating SNPs, indicating interactions among alleles contributing towards elevated SZ susceptibility. The genes associated with the identified SNPs participated in four neurotransmitter pathways: GABA receptor signaling, dopamine receptor signaling, neuregulin signaling and glutamate receptor signaling. In summary, our work provides further evidence for the complexity of genomic risk to the functional brain abnormality in SZ and suggests a pathological role of interactions between SNPs, genes and multiple neurotransmitter pathways.

Chen, Jiayu; Calhoun, Vince D.; Pearlson, Godfrey D.; Ehrlich, Stefan; Turner, Jessica A.; Ho, Beng-Choon; Wassink, Thomas H.; Michael, Andrew M; Liu, Jingyu

2012-01-01

374

Altered functional brain networks in Prader-Willi syndrome.  

PubMed

Prader-Willi syndrome (PWS) is a genetic imprinting disorder characterized mainly by hyperphagia and early childhood obesity. Previous functional neuroimaging studies used visual stimuli to examine abnormal activities in the eating-related neural circuitry of patients with PWS. It was found that patients with PWS exhibited both excessive hunger and hyperphagia consistently, even in situations without any food stimulation. In the present study, we employed resting-state functional MRI techniques to investigate abnormal brain networks related to eating disorders in children with PWS. First, we applied amplitude of low-frequency fluctuation analysis to define the regions of interest that showed significant alterations in resting-state brain activity levels in patients compared with their sibling control group. We then applied a functional connectivity (FC) analysis to these regions of interest in order to characterize interactions among the brain regions. Our results demonstrated that patients with PWS showed decreased FC strength in the medial prefrontal cortex (MPFC)/inferior parietal lobe (IPL), MPFC/precuneus, IPL/precuneus and IPL/hippocampus in the default mode network; decreased FC strength in the pre-/postcentral gyri and dorsolateral prefrontal cortex (DLPFC)/orbitofrontal cortex (OFC) in the motor sensory network and prefrontal cortex network, respectively; and increased FC strength in the anterior cingulate cortex/insula, ventrolateral prefrontal cortex (VLPFC)/OFC and DLPFC/VLPFC in the core network and prefrontal cortex network, respectively. These findings indicate that there are FC alterations among the brain regions implicated in eating as well as rewarding, even during the resting state, which may provide further evidence supporting the use of PWS as a model to study obesity and to provide information on potential neural targets for the medical treatment of overeating. PMID:23335390

Zhang, Yi; Zhao, Heng; Qiu, Siyou; Tian, Jie; Wen, Xiaotong; Miller, Jennifer L; von Deneen, Karen M; Zhou, Zhenyu; Gold, Mark S; Liu, Yijun

2013-01-21

375

Updates and Future Horizons on the Understanding, Diagnosis, and Treatment of Sturge-Weber Syndrome Brain Involvement  

ERIC Educational Resources Information Center

|Aim: To review recent developments in the understanding, diagnosis, and treatment of Sturge-Weber syndrome (SWS). Method: Members of the Brain Vascular Malformation Consortium Sturge-Weber Syndrome National Workgroup contributed their expertise to review the literature and present promising directions for research. Results: The increasing number…

Lo, Warren; Marchuk, Douglas A.; Ball, Karen L.; Juhasz, Csaba; Jordan, Lori C.; Ewen, Joshua B.; Comi, Anne

2012-01-01

376

Updates and Future Horizons on the Understanding, Diagnosis, and Treatment of Sturge-Weber Syndrome Brain Involvement  

ERIC Educational Resources Information Center

Aim: To review recent developments in the understanding, diagnosis, and treatment of Sturge-Weber syndrome (SWS). Method: Members of the Brain Vascular Malformation Consortium Sturge-Weber Syndrome National Workgroup contributed their expertise to review the literature and present promising directions for research. Results: The increasing number…

Lo, Warren; Marchuk, Douglas A.; Ball, Karen L.; Juhasz, Csaba; Jordan, Lori C.; Ewen, Joshua B.; Comi, Anne

2012-01-01

377

Synchronization-based approach for detecting functional activation of brain.  

PubMed

In this paper, we investigate a synchronization-based, data-driven clustering approach for the analysis of functional magnetic resonance imaging (fMRI) data, and specifically for detecting functional activation from fMRI data. We first define a new measure of similarity between all pairs of data points (i.e., time series of voxels) integrating both complete phase synchronization and amplitude correlation. These pairwise similarities are taken as the coupling between a set of Kuramoto oscillators, which in turn evolve according to a nearest-neighbor rule. As the network evolves, similar data points naturally synchronize with each other, and distinct clusters will emerge. The clustering behavior of the interaction network of the coupled oscillators, therefore, mirrors the clustering property of the original multiple time series. The clustered regions whose cross-correlation coefficients are much greater than other regions are considered as the functionally activated brain regions. The analysis of fMRI data in auditory and visual areas shows that the recognized brain functional activations are in complete correspondence with those from the general linear model of statistical parametric mapping, but with a significantly lower time complexity. We further compare our results with those from traditional K-means approach, and find that our new clustering approach can distinguish between different response patterns more accurately and efficiently than the K-means approach, and therefore more suitable in detecting functional activation from event-related experimental fMRI data. PMID:23020467

Hong, Lei; Cai, Shi-Min; Zhang, Jie; Zhuo, Zhao; Fu, Zhong-Qian; Zhou, Pei-Ling

2012-09-01

378

Synchronization-based approach for detecting functional activation of brain  

NASA Astrophysics Data System (ADS)

In this paper, we investigate a synchronization-based, data-driven clustering approach for the analysis of functional magnetic resonance imaging (fMRI) data, and specifically for detecting functional activation from fMRI data. We first define a new measure of similarity between all pairs of data points (i.e., time series of voxels) integrating both complete phase synchronization and amplitude correlation. These pairwise similarities are taken as the coupling between a set of Kuramoto oscillators, which in turn evolve according to a nearest-neighbor rule. As the network evolves, similar data points naturally synchronize with each other, and distinct clusters will emerge. The clustering behavior of the interaction network of the coupled oscillators, therefore, mirrors the clustering property of the original multiple time series. The clustered regions whose cross-correlation coefficients are much greater than other regions are considered as the functionally activated brain regions. The analysis of fMRI data in auditory and visual areas shows that the recognized brain functional activations are in complete correspondence with those from the general linear model of statistical parametric mapping, but with a significantly lower time complexity. We further compare our results with those from traditional K-means approach, and find that our new clustering approach can distinguish between different response patterns more accurately and efficiently than the K-means approach, and therefore more suitable in detecting functional activation from event-related experimental fMRI data.

Hong, Lei; Cai, Shi-Min; Zhang, Jie; Zhuo, Zhao; Fu, Zhong-Qian; Zhou, Pei-Ling

2012-09-01

379

High-resolution BOLD venographic imaging: a window into brain function.  

PubMed

This paper reviews the recent development of a new high-resolution magnetic resonance imaging approach to visualizing small veins in the human brain with diameters in the sub-millimeter range, which is smaller than a voxel. It briefly introduces the physical background of the underlying bulk magnetic susceptibility effects, on which this approach is based, and it demonstrates the successful application of the method for imaging different intracranial lesions, like venous anomalies, arteriovenous malformations and brain tumors. The susceptibility difference between venous blood and the surrounding tissue is used to generate contrast. Using this method it is possible to visualize draining veins in lesions better than conventional magnetic resonance imaging methods, which often require application of a contrast medium or even conventional catheter angiography. Limitations of the method are discussed. The ability to highlight deoxygenated blood with high spatial resolution yields important vascular parameters which may be helpful for improved modeling of MR signal changes during functional brain activation, it may lead to a better understanding of brain function in diseased states, or it may even offer the possibility of differentiating benign from malignant tumors non-invasively. PMID:11746938

Reichenbach, J R; Haacke, E M

380

Understanding trends in functional limitations among older Americans.  

PubMed Central

OBJECTIVES: This report documents trends in functional limitations among older Americans from 1984 to 1993 and investigates reasons for such trends. METHODS: We applied logistic regression to data for noninstitutionalized Americans aged 50 years and older from the Survey of Income and Program Participation. We focused on 4 functional limitation measures unlikely to be affected by changes in role expectations and living environments: reported difficulty seeing words in a newspaper, lifting and carrying 10 pounds, climbing a flight of stairs, and walking a quarter of a mile. RESULTS: We found large declines in the crude prevalence of functional limitations, especially for those 80 years and older. Generally, changes in population composition explained only a small portion of the downward trends. Once changes in population composition and mobility-related device use were considered for difficulty walking, significant improvements in functioning remained for the 65- to 79-year-old group. CONCLUSIONS: Changes in population composition, device use, survey design, role expectations, and living environments do not appear to account completely for improvements in functioning. We infer that changes in under-lying physiological capability--whether real or perceived--likely underlie such trends.

Freedman, V A; Martin, L G

1998-01-01

381

Brain function differences in language processing in children and adults with autism.  

PubMed

Comparison of brain function between children and adults with autism provides an understanding of the effects of the disorder and associated maturational differences on language processing. Functional imaging (functional magnetic resonance imaging) was used to examine brain activation and cortical synchronization during the processing of literal and ironic texts in 15 children with autism, 14 children with typical development, 13 adults with autism, and 12 adult controls. Both the children and adults with autism had lower functional connectivity (synchronization of brain activity among activated areas) than their age and ability comparison group in the left hemisphere language network during irony processing, and neither autism group had an increase in functional connectivity in response to increased task demands. Activation differences for the literal and irony conditions occurred in key language-processing regions (left middle temporal, left pars triangularis, left pars opercularis, left medial frontal, and right middle temporal). The children and adults with autism differed from each other in the use of some brain regions during the irony task, with the adults with autism having activation levels similar to those of the control groups. Overall, the children and adults with autism differed from the adult and child controls in (a) the degree of network coordination, (b) the distribution of the workload among member nodes, and (3) the dynamic recruitment of regions in response to text content. Moreover, the differences between the two autism age groups may be indicative of positive changes in the neural function related to language processing associated with maturation and/or educational experience. Autism Res 2013, ??: ??-??. © 2013 International Society for Autism Research, Wiley Periodicals, Inc. PMID:23495230

Williams, Diane L; Cherkassky, Vladimir L; Mason, Robert A; Keller, Timothy A; Minshew, Nancy J; Just, Marcel Adam

2013-03-14

382

Socioeconomic status and functional brain development - associations in early infancy.  

PubMed

Socioeconomic status (SES) impacts on both structural and functional brain development in childhood, but how early its effects can be demonstrated is unknown. In this study we measured resting baseline EEG activity in the gamma frequency range in awake 6-9-month-olds from areas of East London with high socioeconomic deprivation. Between-subject comparisons of infants from low- and high-income families revealed significantly lower frontal gamma power in infants from low-income homes. Similar power differences were found when comparing infants according to maternal occupation, with lower occupational status groups yielding lower power. Infant sleep, maternal education, length of gestation, and birth weight, as well as smoke exposure and bilingualism, did not explain these differences. Our results show that the effects of socioeconomic disparities on brain activity can already be detected in early infancy, potentially pointing to very early risk for language and attention difficulties. This is the first study to reveal region-selective differences in functional brain development associated with early infancy in low-income families. PMID:24033573

Tomalski, Przemyslaw; Moore, Derek G; Ribeiro, Helena; Axelsson, Emma L; Murphy, Elizabeth; Karmiloff-Smith, Annette; Johnson, Mark H; Kushnerenko, Elena

2013-08-07

383

Heritability of human brain functioning as assessed by electroencephalography.  

PubMed Central

To study the genetic and environmental contributions to individual differences in CNS functioning, the electroencephalogram (EEG) was measured in 213 twin pairs age 16 years. EEG was measured in 91 MZ and 122 DZ twins. To quantify sex differences in the genetic architecture, EEG was measured in female and male same-sex twins and in opposite-sex twins. EEG was recorded on 14 scalp positions during quiet resting with eyes closed. Spectral powers were calculated for four frequency bands: delta, theta, alpha, and beta. Twin correlations pointed toward high genetic influences for all these powers and scalp locations. Model fitting confirmed these findings; the largest part of the variance of the EEG is explained by additive genetic factors. The averaged heritabilites for the delta, theta, alpha and beta frequencies was 76%, 89%, 89%, and 86%, respectively. Multivariate analyses suggested that the same genes for EEG alpha rhythm were expressed in different brain areas in the left and right hemisphere. This study shows that brain functioning, as indexed by rhythmic brain-electrical activity, is one of the most heritable characteristics in humans.

van Beijsterveldt, C. E.; Molenaar, P. C.; de Geus, E. J.; Boomsma, D. I.

1996-01-01

384

Crayfish brain-protocerebrum and retina show serotonergic functional relationship.  

PubMed

The results from various studies have indicated possible functional relationships between crayfish electroretinogram (ERG) rhythmic amplitude changes and the serotonergic pathways projecting from the central brain through the optic neuropils to the eye, but to date, this functional interaction has not been proven. Here, in a set of experiments using an isolated eyestalk-brain preparation, we investigated whether there is a circadian input from the brain to retina that regulates this rhythm. We sought to determine whether the protocerebral bridge (PB) stimulation affects the ERG amplitude in accordance with the zeitgeber time (ZT) and whether 5-HT modulates the associate input. Our results showed that photic stimulation of retina produced changes in both the amplitude and the frequency of spontaneous electrical activity in the protocerebral neuropils. In addition, electrical stimulation of the medial protocerebrum, particularly the PB, produced statistically significant changes in the ERG that depended on both the time of day and the level of serotonin. This suggests that pathways between retina and PB seem to be serotonergic. PMID:21911207

Valdés-Fuentes, Marlen; Prieto-Sagredo, Julio; Fanjul-Moles, María Luisa

2011-08-19

385

Modularity and Self-Organized Functional Architectures in the Brain  

NASA Astrophysics Data System (ADS)

It is generally believed that cognition involves the self-organization of coherent dy- namic functional networks across several brain regions in response to incoming stimulus and internal modulation. These context-dependent networks arise continually from the spatiotemporally multi-scale structural substrate of the brain configured by evolution, development and previous experience, persisting for 100-200 ms and generating re- sponses such as imagery, recall and motor action. In the current paper, we show that a system of interacting modular attractor networks can use a selective mechanism for assembling functional networks from the modular substrate. We use the approach to develop a model of idea-generation in the brain. Ideas are modeled as combinations of concepts organized in a recurrent network that reflects previous associations between them. The dynamics of this network, resulting in the transient co-activation of concept groups, is seen as a search through the space of ideas, and attractor dynamics is used to "shape" this search. The process is required to encompass both rapid retrieval of old ideas in familiar contexts and efficient search for novel ones in unfamiliar situations (or during brainstorming). The inclusion of an adaptive modulatory mechanism allows the network to balance the competing requirements of exploiting previous learning and exploring new possibilities as needed in different contexts.

Iyer, Laxmi; Minai, Ali A.; Doboli, Simona; Brown, Vincent R.

386

Roles of Brain Angiotensin II in Cognitive Function and Dementia  

PubMed Central

The brain renin-angiotensin system (RAS) has been highlighted as having a pathological role in stroke, dementia, and neurodegenerative disease. Particularly, in dementia, epidemiological studies indicate a preventive effect of RAS blockade on cognitive impairment in Alzheimer disease (AD). Moreover, basic experiments suggest a role of brain angiotensin II in neural injury, neuroinflammation, and cognitive function and that RAS blockade attenuates cognitive impairment in rodent dementia models of AD. Therefore, RAS regulation is expected to have therapeutic potential for AD. Here, we discuss the role of angiotensin II in cognitive impairment and AD. Angiotensin II binds to the type 2 receptor (AT2) and works mainly by binding with the type 1 receptor (AT1). AT2 receptor signaling plays a role in protection against multiple-organ damage. A direct AT2 receptor agonist is now available and is expected to reduce inflammation and oxidative stress and enhance cell differentiation. We and other groups reported that AT2 receptor activation enhances neuronal differentiation and neurite outgrowth in the brain. Here, we also review the effect of the AT2 receptor on cognitive function. RAS modulation may be a new therapeutic option for dementia including AD in the future.

Mogi, Masaki; Iwanami, Jun; Horiuchi, Masatsugu

2012-01-01

387

Students' Understanding of the General Notion of a Function of Two Variables  

ERIC Educational Resources Information Center

In this study we analyze students' understanding of two-variable function; in particular we consider their understanding of domain, possible arbitrary nature of function assignment, uniqueness of function image, and range. We use APOS theory and semiotic representation theory as a theoretical framework to analyze data obtained from interviews with…

Martinez-Planell, Rafael; Trigueros Gaisman, Maria

2012-01-01

388

Reorganization of Functional Connectivity as a Correlate of Cognitive Recovery in Acquired Brain Injury  

ERIC Educational Resources Information Center

|Cognitive processes require a functional interaction between specialized multiple, local and remote brain regions. Although these interactions can be strongly altered by an acquired brain injury, brain plasticity allows network reorganization to be principally responsible for recovery. The present work evaluates the impact of brain injury on…

Castellanos, Nazareth P.; Paul, Nuria; Ordonez, Victoria E.; Demuynck, Olivier; Bajo, Ricardo; Campo, Pablo; Bilbao, Alvaro; Ortiz, Tomas; del-Pozo, Francisco; Maestu, Fernando

2010-01-01

389

Alteration and reorganization of functional networks: a new perspective in brain injury study.  

PubMed

Plasticity is the mechanism underlying the brain's potential capability to compensate injury. Recently several studies have shown how functional connections among the brain areas are severely altered by brain injury and plasticity leading to a reorganization of the networks. This new approach studies the impact of brain injury by means of alteration of functional interactions. The concept of functional connectivity refers to the statistical interdependencies between physiological time series simultaneously recorded in various areas of the brain and it could be an essential tool for brain functional studies, being its deviation from healthy reference an indicator for damage. In this article, we review studies investigating functional connectivity changes after brain injury and subsequent recovery, providing an accessible introduction to common mathematical methods to infer functional connectivity, exploring their capabilities, future perspectives, and clinical uses in brain injury studies. PMID:21960965

Castellanos, Nazareth P; Bajo, Ricardo; Cuesta, Pablo; Villacorta-Atienza, José Antonio; Paúl, Nuria; Garcia-Prieto, Juan; Del-Pozo, Francisco; Maestú, Fernando

2011-09-21

390

Understanding the Transformation of the IT Function in Organizations  

Microsoft Academic Search

Many IT researchers have tried to describe the IT function and to explain its transformation over time. Nevertheless, we observed that existing characterizations are often based on a single dimension, attached to historical periods or built into a normative discourse that calls for an ideal profile. We do not subscribe to these premises, seeing that there might be a series

Manon G. Guillemette; Guy Pare

2005-01-01

391

Weightlessness - a model to understand how gravity modulates cardiovascular function  

Microsoft Academic Search

Gravity stresses the cardiovascular system in humans by decreasing the blood supply to the heart. As a consequence of this, reflexes are constantly activated to increase heart rate, constrict the blood vessels and diminish the renal output of fluid. To explore how gravity modulates cardiovascular function, longterm weightlessness in space is a useful tool. Therefore, we have participated in space

Peter Norsk

392

High School Students' Understanding of the Function Concept  

ERIC Educational Resources Information Center

|This paper is a study of part of the Algebra Project's program for underrepresented high school students from the lowest quartile of academic achievement, social and economic status. The study focuses on students' learning the concept of function. The curriculum and pedagogy are part of an innovative, experimental approach designed and…

Dubinsky, Ed; Wilson, Robin T.

2013-01-01

393

Understanding function and other outcomes in cerebral palsy  

PubMed Central

Synopsis Describing the status of children with CP and quantifying change in their status are two central challenges to research and clinical management of CP. The science of assessing and reporting status is outcome measurement and it is rapidly developing in the arena of CP. Due to the large number of domains to measure, the variability of CP manifestations, and a limited number of ‘gold standard’ evaluations, creating an accurate, comprehensive, responsive, and broadly applicable measurement strategy is a serious endeavor. Currently, a range of outcome measures are available to address CP issues across the spectrum of disability. The use of these measures, and others yet to be developed, will provide researchers and clinicians the best means to understand CP and the effects of treatments.

Adams, Jilda Vargus

2009-01-01

394

STRENGTHENED FUNCTIONAL CONNECTIVITY IN THE BRAIN DURING MUSCLE FATIGUE  

PubMed Central

Fatigue caused by sustaining submaximal-intensity muscle contraction(s) involves increased activation in the brain such as primary motor cortex (M1), primary sensory cortex (S1), Premotor and supplementary motor area (PM&SMA) and prefrontal cortex (PFC). The synchronized increases in activation level in these cortical areas suggest fatigue-related strengthening of functional coupling within the motor control network. In the present study, this hypothesis was tested using the cross-correlation based functional connectivity (FC) analysis method. Ten subjects performed a 20-minute intermittent (3.5s ON/6.5s OFF, 120 trials total) handgrip task using the right hand at 50% maximal voluntary contraction (MVC) force level while their brain was scanned by a 3T Siemens Trio scanner using echo planar imaging (EPI) sequence. A representative signal time course of the left M1 was extracted by averaging the time course data of a 2-mm cluster of neighboring voxels of local maximal activation foci, which was identified by a general linear model. Two FC activation maps were created for each subject by cross-correlating the time course data of the minimal (the first 10 trials) and significant (the last 10 trials) fatigue stages across all the voxels in the brain to the corresponding representative time course. Histogram and quantile regression analysis were used to compare the FC between the minimal and significant fatigue stages and the results showed a significant increase in FC among multiple cortical regions, including right M1 and bilateral PM&SMA, S1 and PFC. This strengthened FC indicates that when muscle fatigue worsens, many brain regions increase their coupling with the left M1, the primary motor output control center for the right handgrip, to compensate for diminished force generating capability of the muscle in a coordinated fashion by enhancing the descending command for greater muscle recruitment to maintain the same force.

Jiang, Zhiguo; Wang, Xiao-Feng; Kisiel-Sajewicz, Katarzyna; Yan, Jin H; Yue, Guang H

2012-01-01

395

Extracting MRS discriminant functional features of brain tumors.  

PubMed

The current challenge in automatic brain tumor classification based on MRS is the improvement of the robustness of the classification models that explicitly account for the probable breach of the independent and identically distributed conditions in the MRS data points. To contribute to this purpose, a new algorithm for the extraction of discriminant MRS features of brain tumors based on a functional approach is presented. Functional data analysis based on region segmentation (RSFDA) is based on the functional data analysis formalism using nonuniformly distributed B splines according to spectral regions that are highly correlated. An exhaustive characterization of the method is presented in this work using controlled and real scenarios. The performance of RSFDA was compared with other widely used feature extraction methods. In all simulated conditions, RSFDA was proven to be stable with respect to the number of variables selected and with respect to the classification performance against noise and baseline artifacts. Furthermore, with real multicenter datasets classification, RSFDA and peak integration (PI) obtained better performance than the other feature extraction methods used for comparison. Other advantages of the method proposed are its usefulness in selecting the optimal number of features for classification and its simplified functional representation of the spectra, which contributes to highlight the discriminative regions of the MR spectrum for each classification task. PMID:23239454

Fuster-Garcia, Elies; Tortajada, Salvador; Vicente, Javier; Robles, Montserrat; García-Gómez, Juan M

2012-12-12

396

Asymmetry brain function in auditory cortex: A functional near-infrared spectroscopy study.  

PubMed

Functional near-infrared spectroscopy (fNIRS) can measure the change of hemodynamic response, it enables to determine the concentration changes of oxy-hemoglobin and deoxy-hemoglobin. The aim in this paper is to investigate the forms of lateralization or asymmetry brain function in auditory cortex using fNIRS. This technique shows good promise for assessment of asymmetry functions in the auditory cortex. PMID:24110054

Santosa, Hendrik; Hong, Keum-Shik

2013-07-01

397

Understanding the development and function of T follicular helper cells  

Microsoft Academic Search

A fundamental function of T helper (Th) cells is to regulate B-cell proliferation and immunoglobulin class switching, especially in the germinal centers. Th1 and Th2 lineages of CD4+ T cells have long been considered to play an essential role in helping B cells by promoting the production immunoglobulin G2a (IgG2a) and IgG1\\/IgE, respectively. Recently, it has become clear that a

Roza I Nurieva; Yeonseok Chung

2010-01-01

398

Current understanding of Th2 cell differentiation and function.  

PubMed

Helper T cell (Th) has been identified as a critical immune cell for regulating immune response since 1980s. The type 2 helper Tcell (Th2), characterized by the production of interleukin-4 (IL-4), IL-5 and IL-13, plays a critical role in immune response against helminths invading cutaneous or mucosal sites. It also has a functional role in the pathophysiology of allergic diseases such as asthma and allergic diarrhea. Currently, most studies have shed light on Th2 cell function and behavior in specific diseases, such as asthma and helminthes inflammation, but not on Th2 cell itself and its differentiation. Based on different cytokines and specific behavior in recent research, Th2 cell is also regarded as new subtypes of T cell, such as IL-9 secreting T cell (Th9) and CXCR5(+) T follicular helper cells. Here, we will discuss the latest view of Th2 cell towards their function and the involvement of Th2 cell in diseases. PMID:21904976

Li, Zhenhu; Zhang, Yuan; Sun, Bing

2011-09-09

399

Using computational models to relate structural and functional brain connectivity  

PubMed Central

Modern imaging methods allow a non-invasive assessment of both structural and functional brain connectivity. This has lead to the identification of disease-related alterations affecting functional connectivity. The mechanism of how such alterations in functional connectivity arise in a structured network of interacting neural populations is as yet poorly understood. Here we use a modeling approach to explore the way in which this can arise and to highlight the important role that local population dynamics can have in shaping emergent spatial functional connectivity patterns. The local dynamics for a neural population is taken to be of the Wilson–Cowan type, whilst the structural connectivity patterns used, describing long-range anatomical connections, cover both realistic scenarios (from the CoComac database) and idealized ones that allow for more detailed theoretical study. We have calculated graph–theoretic measures of functional network topology from numerical simulations of model networks. The effect of the form of local dynamics on the observed network state is quantified by examining the correlation between structural and functional connectivity. We document a profound and systematic dependence of the simulated functional connectivity patterns on the parameters controlling the dynamics. Importantly, we show that a weakly coupled oscillator theory explaining these correlations and their variation across parameter space can be developed. This theoretical development provides a novel way to characterize the mechanisms for the breakdown of functional connectivity in diseases through changes in local dynamics.

Hlinka, Jaroslav; Coombes, Stephen

2012-01-01

400

Detecting brain state changes via fiber-centered functional connectivity analysis.  

PubMed

Diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) have been widely used to study structural and functional brain connectivity in recent years. A common assumption used in many previous functional brain connectivity studies is the temporal stationarity. However, accumulating literature evidence has suggested that functional brain connectivity is under temporal dynamic changes in different time scales. In this paper, a novel and intuitive approach is proposed to model and detect dynamic changes of functional brain states based on multimodal fMRI/DTI data. The basic idea is that functional connectivity patterns of all fiber-connected cortical voxels are concatenated into a descriptive functional feature vector to represent the brain's state, and the temporal change points of brain states are decided by detecting the abrupt changes of the functional vector patterns via the sliding window approach. Our extensive experimental results have shown that meaningful brain state change points can be detected in task-based fMRI/DTI, resting state fMRI/DTI, and natural stimulus fMRI/DTI data sets. Particularly, the detected change points of functional brain states in task-based fMRI corresponded well to the external stimulus paradigm administered to the participating subjects, thus partially validating the proposed brain state change detection approach. The work in this paper provides novel perspective on the dynamic behaviors of functional brain connectivity and offers a starting point for future elucidation of the complex patterns of functional brain interactions and dynamics. PMID:22941508

Li, Xiang; Lim, Chulwoo; Li, Kaiming; Guo, Lei; Liu, Tianming

2013-04-01

401

The Neurobiology of Adolescence: Changes in brain architecture, functional dynamics, and behavioral tendencies  

PubMed Central

Adolescence is a period of increased behavioral and psychiatric vulnerabilities. It is also a time of dramatic structural and functional neurodevelopment. In recent years studies have examined the precise nature of these brain and behavioral changes, and several hypotheses link them together. In this review we discuss this research and recent electrophysiological data from behaving rats that demonstrate reduced neuronal coordination and processing efficiency in adolescents. A more comprehensive understanding of these processes will further our knowledge of adolescent behavioral vulnerabilities and the pathophysiology of mental illnesses that manifest during this period.

Sturman, David A.; Moghaddam, Bita

2011-01-01

402

Steroid hormones and brain development: some guidelines for understanding actions of pseudohormones and other toxic agents  

Microsoft Academic Search

Gonadal, adrenal, and thyroid hormones affect the brain directly, and the sensitivity to hormones begins in embryonic life with the appearance of hormone receptor sites in discrete populations of neurons. Because the secretion of hormones is also under control by its neural and pituitary targets, the brain-endocrine axis during development is in a delicately balanced state that can be upset

McEwen

1987-01-01

403

An integrated biopsychosocial approach to understanding awareness deficits in Alzheimer's disease and brain injury  

Microsoft Academic Search

Considerable emphasis has been placed upon cognitive neuropsychological explanations of awareness disorders in brain injury and Alzheimer's disease (AD), with relatively few models acknowledging the role of psychosocial factors. The present paper explores clinical presentations of unawareness in brain injury and AD, reviews the evidence for the influence of psychosocial factors alongside neuropsychological changes, and considers a number of key

Tamara Ownsworth; Linda Clare; Robin Morris

2006-01-01

404

The Brain and Consciousness: Sources of Information for Understanding Adult Learning.  

ERIC Educational Resources Information Center

|Reviews current knowledge of the brain in the areas of neurobiology, aging, and consciousness as conceived by different cultures. Derives learning principles that take into account the brain's plasticity, ability to respond to learning throughout life, and the involvement of emotional and sensory experience. (Contains 27 references.) (SK)|

Hill, Lilian H.

2001-01-01

405

The Retinal Wholemount Technique: A Window to Understanding the Brain and Behaviour  

Microsoft Academic Search

The accessibility of the vertebrate retina has provided the opportunity to assess various parameters of the visual abilities of a range of species. This thin but complex extension of the brain achieves a large proportion of the necessary visual processing of an optical image before information is delivered to the brain as neural impulses. Studies of the retina as a

Jeremy F. P. Ullmann; Bret A. Moore; Shelby E. Temple; Esteban Fernández-Juricic; Shaun P. Collin

2012-01-01

406

II. Temporal patterns of longitudinal change in aging brain function.  

PubMed

Time-dependent changes in brain activity were assessed in a group of older adults who maintained good physical and cognitive health at years 1, 3, 5, 7, and 9 of the Baltimore Longitudinal Study of Aging neuroimaging study. Each year, these participants underwent PET scans during rest and delayed verbal and figural recognition memory conditions. While memory performance remained stable over the 8 years, both generalized and modality-specific patterns of time-dependent changes in regional cerebral blood flow (rCBF) were found. Many brain regions showed steady, progressive changes in rCBF over the 8 years while others maintained rCBF for a number of years before showing incremental declines or increases in activity. These temporal patterns of change were observed in many regions of the brain, particularly in the frontal and temporal lobes, suggesting that there are distinctive patterns of age-related functional decline and compensatory activity over time. The precise patterns of regional involvement and the temporal dynamics of rCBF change within specific regions vary based on cognitive processing demands. PMID:17178430

Beason-Held, L L; Kraut, M A; Resnick, S M

2006-12-18

407

Functional Connectivity Targeting for Deep Brain Stimulation in Essential Tremor  

PubMed Central

Background and Purpose Deep brain stimulation of the thalamus has become a valuable treatment for medication-refractory essential tremor, but current targeting provides for only a limited ability to account for individual anatomic variability. We examined whether functional connectivity measurements between the motor cortex, superior cerebellum, and thalamus would allow discrimination of precise targets useful for image guidance of neurostimulator placement. Materials and Methods Resting BOLD images (8 minutes) were obtained in 58 healthy adolescent and adult volunteers. ROI’s were identified from an anatomic atlas and a finger movement task in each subject in the primary motor cortex and motor activation region of bilateral superior cerebellum. Correlation was measured in the time series of each thalamic voxel with the 4 seeds. An analogous procedure was performed on a single subject imaged for 10 hours to constrain time needed for single subject optimization of thalamic targets. Results Mean connectivity images from 58 subjects showed precisely localized targets within the expected location of the ventral intermediate nucleus of the thalamus, within a single voxel of currently used deep brain stimulation anatomic targets. These targets could be mapped with single voxel accuracy in a single subject with 3 hours of imaging time, although targets were reproduced in different locations for the individual than for the group averages. Conclusion Interindividual variability likely exists in optimal placement for thalamic deep brain stimulation targeting of the cerebellar thalamus for essential tremor. Individualized thalamic targets can be precisely estimated for image guidance with sufficient imaging time.

Anderson, Jeffrey S.; Dhatt, Harpreet S.; Ferguson, Michael A.; Lopez-Larson, Melissa; Schrock, Lauren E.; House, Paul A.; Yurgelun-Todd, Deborah

2011-01-01

408

Operating characteristics of executive functioning tests following traumatic brain injury.  

PubMed

The primary purposes of this study were to determine if controls, and mild and moderate/severe traumatic brain injury (TBI) patients performed differently on a battery of executive functioning (EF) tests, and to identify the operating characteristics of EF tests in this population. Participants consisted of 46 brain-injured individuals and 24 healthy controls. All participants completed an extensive battery of EF tests. Results showed that mild TBI participants performed worse than controls on the Trail Making Test Part B, and that moderate/severe TBI participants consistently performed worse than either group on a variety of EF measures. Tests of EF exhibited a wide range of operating characteristics, suggesting that some EF tests are better than others in identifying TBI-related neurocognitive impairment. Predictive values were better for individuals with moderate/severe TBI than mild TBI. Overall, the Digit Span Backward Test showed the best positive predictive power in differentiating TBI. Our results provide useful data that may guide test selection in evaluating EF in patients with traumatic brain injury. PMID:21069617

Demery, Jason A; Larson, Michael J; Dixit, Neha K; Bauer, Russell M; Perlstein, William M

2010-11-01

409

Operating Characteristics of Executive Functioning Tests Following Traumatic Brain Injury  

PubMed Central

The primary purposes of this study were to determine if controls, mild, and moderate/severe traumatic brain injury (TBI) patients performed differently on a battery of executive functioning (EF) tests, and to identify the operating characteristics of EF tests in this population. Participants consisted of 46 brain injured individuals and 24 healthy controls. All participants completed an extensive battery of EF tests. Results showed that mild TBI participants performed worse than controls on the Trail Making Test Part B, and that moderate/severe TBI participants consistently performed worse than either group on a variety of EF measures. Tests of EF exhibited a wide range of operating characteristics, suggesting that some EF tests are better than others in identifying TBI-related neurocognitive impairment. Predictive values were better for individuals with moderate/severe TBI than mild TBI. Overall, the Digit Span Backward Test showed the best positive predictive power in differentiating TBI. Our results provide useful data that may guide test selection in evaluating EF in patients with traumatic brain injury.

Demery, Jason A.; Larson, Michael J.; Dixit, Neha K.; Bauerand, Russell M.; Perlstein, William M.

2010-01-01

410

Regional cortical volume and cognitive functioning following traumatic brain injury.  

PubMed

There has been limited examination of the effect of brain pathology on subsequent function. The current study examined the relationships between regional variation in grey matter volume, age and cognitive impairment using a semi-automated image analysis tool. This study included 69 individuals with mild-to-severe TBI, 41 of whom also completed neuropsychological tests of attention, working memory, processing speed, memory and executive functions. A widespread reduction in grey matter volume was associated with increasing age. Regional volumes that were affected also related to the severity of injury, whereby the most severe TBI participants displayed the most significant pathology. Poorer retention of newly learned material was associated with reduced cortical volume in frontal, parietal, and occipital brain regions. In addition, poorer working memory and executive control performance was found for individuals with lower cortical volume in temporal, parietal, and occipital regions. These findings are largely in line with previous literature, which suggests that frontal, temporal, and parietal regions are integral for the encoding of memories into long-term storage, memory retrieval, and working memory. The present study suggests that automated image analysis methods may be used to explore the relationships between regional variation in grey matter volume and cognitive function following TBI. PMID:23872098

Spitz, Gershon; Bigler, Erin D; Abildskov, Tracy; Maller, Jerome J; O'Sullivan, Richard; Ponsford, Jennie L

2013-07-18

411

Delta opioid receptors in brain function and diseases.  

PubMed

Evidence that the delta opioid receptor (DOR) is an attractive target for the treatment of brain disorders has strengthened in recent years. This receptor is broadly expressed in the brain, binds endogenous opioid peptides, and shows as functional profile highly distinct from those of mu and kappa opioid receptors. Our knowledge of DOR function has enormously progressed from in vivo studies using pharmacological tools and genetic approaches. The important role of this receptor in reducing chronic pain has been extensively overviewed; therefore this review focuses on facets of delta receptor activity relevant to psychiatric and other neurological disorders. Beneficial effects of DOR agonists are now well established in the context of emotional responses and mood disorders. DOR activation also regulates drug reward, inhibitory controls and learning processes, but whether delta compounds may represent useful drugs in the treatment of drug abuse remains open. Epileptogenic and locomotor-stimulating effects of delta agonists appear drug-dependent, and the possibility of biased agonism at DOR for these effects is worthwhile further investigations to increase benefit/risk ratio of delta therapies. Neuroprotective effects of DOR activity represent a forthcoming research area. Future developments in DOR research will benefit from in-depth investigations of DOR function at cellular and circuit levels. PMID:23764370

Chu Sin Chung, Paul; Kieffer, Brigitte L

2013-06-10

412

Effects of alcohol intake on brain structure and function in non-alcohol-dependent drinkers  

Microsoft Academic Search

About 85% of the adult population in the Netherlands regularly drinks alcohol. Chronic excessive alcohol intake in alcohol-dependent individuals is known to have damaging effects on brain structure and function. Relatives of alcohol-dependent individuals display differences in brain function that are similar to those found in alcoholics, even if they have never been drinking alcohol. This suggests that brain damage

Eveline Astrid de Bruin

2005-01-01

413

Preinjury emotional and family functioning in caregivers of persons with traumatic brain injury  

Microsoft Academic Search

Sander AM, Sherer M, Malec JF, High WM Jr, Thompson RN, Moessner AM, Josey J. Preinjury emotional and family functioning in caregivers of persons with traumatic brain injury. 2003;84:197-203. Objective: To characterize the preinjury family functioning, emotional distress, and social support of caregivers of persons with traumatic brain injury (TBI). Design: Inception cohort. Setting: Three Traumatic Brain Injury Model Systems

Angelle M. Sander; Mark Sherer; James F. Malec; Walter M. High; Risa Nakase Thompson; Anne M. Moessner; Jennifer Josey

2003-01-01

414

Some Problems for Representations of Brain Organization Based on Activation in Functional Imaging  

ERIC Educational Resources Information Center

Functional brain imaging has overshadowed traditional lesion studies in becoming the dominant approach to the study of brain-behavior relationships. The proponents of functional imaging studies frequently argue that this approach provides an advantage over lesion studies by observing normal brain activity in vivo without the disruptive effects of…

Sidtis, John J.

2007-01-01

415

Acute Toluene Exposure and Rat Visual Function in Proportion to Momentary Brain Concentration  

Microsoft Academic Search

Acute exposure to toluene was assessed in two experiments to determine the relationship between brain toluene concentration and changes in neurophysiological function. The concentration of toluene in brain tissue at the time of assessment was estimated using a physiologically based pharmacokinetic model. Brain neurophysiological function was measured using pattern-elicited visual evoked potentials (VEP) recorded from electrodes located over visual cortex

William K. Boyes; Mark Bercegeay; Quentin Todd Krantz; Elaina M. Kenyon; Ambuja S. Bale; Timothy J. Shafer; Philip J. Bushnell; Vernon A. Benignus

2007-01-01

416

Surface reconstruction from volume data used for creating an adaptable functional brain atlas  

Microsoft Academic Search

Functions for creating adaptable atlas structures from volume data have now been included in the Karolinska Computerized Brain Atlas (CBA) software system. The main objective is to allow the user to create functional structures based on data from brain activation studies with positron emission tomography (PET). The new structures will be related to the anatomy of the CBA database brain.

Lennart Thurfjell; Christian Bohm; Ewert Bengtsson

1994-01-01

417

Individual differences in general intelligence correlate with brain function during nonreasoning tasks  

Microsoft Academic Search

Brain imaging can help identify the functional neuroanatomy of general intelligence (i.e., “g”) and indicate how brain areas salient to g relate to information processing. An important question is whether individual differences in g among subjects are related to brain function even when nonreasoning tasks are studied. If so, this would imply that individuals with high g scores may process

Richard J. Haier; Nathan S. White; Michael T. Alkire

2003-01-01

418

Electroencephalographic Power and Coherence Analyses Suggest Altered Brain Function in Abstinent Male Heroin-Dependent Patients  

Microsoft Academic Search

Previous studies have shown that drug abuse is associated with altered brain function. However, studies of heroin abuse-related brain dysfunctions are scarce. Electroencephalographic (EEG) power and coherence analyses are two important tools for examining the effects of drugs on brain function. In the present study, we compared EEG power and coherence measures of 18 abstinent heroin-dependent subjects with those of

Ingmar H. A. Franken; Cornelis J. Stam; Vincent M. Hendriks; Wim van den Brink

2004-01-01

419

Brain Structure and Executive Functions in Children with Cerebral Palsy: A Systematic Review  

ERIC Educational Resources Information Center

|This systematic review aimed to establish the current knowledge about brain structure and executive function (EF) in children with cerebral palsy (CP). Five databases were searched (up till July 2012). Six articles met the inclusion criteria, all included structural brain imaging though no functional brain imaging. Study quality was assessed…

Weierink, Lonneke; Vermeulen, R. Jeroen; Boyd, Roslyn N.

2013-01-01

420

Deciphering the functions and regulation of brain-enriched A-to-I RNA editing.  

PubMed

Adenosine-to-inosine (A-to-I) RNA editing, in which genomically encoded adenosine is changed to inosine in RNA, is catalyzed by adenosine deaminase acting on RNA (ADAR). This fine-tuning mechanism is critical during normal development and diseases, particularly in relation to brain functions. A-to-I RNA editing has also been hypothesized to be a driving force in human brain evolution. A large number of RNA editing sites have recently been identified, mostly as a result of the development of deep sequencing and bioinformatic analyses. Deciphering the functional consequences of RNA editing events is challenging, but emerging genome engineering approaches may expedite new discoveries. To understand how RNA editing is dynamically regulated, it is imperative to construct a spatiotemporal atlas at the species, tissue and cell levels. Future studies will need to identify the cis and trans regulatory factors that drive the selectivity and frequency of RNA editing. We anticipate that recent technological advancements will aid researchers in acquiring a much deeper understanding of the functions and regulation of RNA editing. PMID:24165678

Li, Jin Billy; Church, George M

2013-10-28

421

Towards understanding the biological function of hopanoids (Invited)  

NASA Astrophysics Data System (ADS)

Rhodopseudomonas palustris TIE-1 expresses bacterial hopanoid lipids that are structurally similar and evolutionarily related to eukaryotic sterols. The genome of R. palustris TIE-1 contains two copies of the hpnN gene (hpnN1 and hpnN2) that are orthologs of genes encoding eukaryotic sterol and lipid transporters. Hopanoid localization to the outer membrane was found to be dependent upon hpnN1. Since the cell cycle of R. palustris TIE-1 is obligately bimodal with each cell division resulting in the generation of one mother and one swarmer cell, evidence was obtained that hopanoids where specifically localized to the outer membrane of mother cells. The sequestration of hopanoids to the mother cells was also disrupted by the deletion of the hpnN1 gene. Mutants lacking the hopanoid transporters were able to grow normally at 30 °C but showed decreased growth at 38 °C. The hopanoid transporter mutant formed cellular filaments when grown at elevated temperature. Because sedimentary steranes and hopanes comprise some of the earliest evidence for the emergence of distinct bacteria and eukaryotic phyla, a better appreciation of the function of hopanoids will improve our ability to interpret the evolution of life on Earth.

Doughty, D. M.; Hunter, R.; Summons, R. E.; Newman, D. K.

2010-12-01

422

Functional outcomes in schizophrenia: understanding the competence-performance discrepancy.  

PubMed

A problem in the study and treatment of functional disability in schizophrenia is that factors other than competence (what one can do) can limit real-world performance (what one does). We examined predictors of the competence-performance discrepancy in both adaptive and interpersonal domains. Patients with schizophrenia (N = 96) were evaluated at baseline of a clinical treatment study. Discrepancy scores were created by considering each subject's competence relative to their real-world performance in interpersonal and adaptive behaviour domains. Logistic regression analyses revealed that for the interpersonal competence-performance discrepancy, living in a group home, better neurocognition, more time spent in the hospital since a first episode of psychosis, and a longer first hospitalization predicted a greater discrepancy between interpersonal competence and performance measures. For adaptive behaviour, shorter time since most recent hospitalization, more depressive symptoms, greater number of months of first hospitalization, older age at baseline, younger age at first hospitalization, and more time spent in the hospital since a first episode of psychosis predicted a greater adaptive competence-performance discrepancy. A different pattern of demographic and clinical features may limit the extent to which patients are deploying interpersonal versus adaptive skills in everyday life. PMID:21944429

Gupta, Maya; Bassett, Emma; Iftene, Felicia; Bowie, Christopher R

2011-09-22

423

Understanding global patterns of mammalian functional and phylogenetic diversity.  

PubMed

Documenting and exploring the patterns of diversity of life on Earth has always been a central theme in biology. Species richness despite being the most commonly used measure of diversity in macroecological studies suffers from not considering the evolutionary and ecological differences among species. Phylogenetic diversity (PD) and functional diversity (FD) have been proposed as alternative measures to overcome this limitation. Although species richness, PD and FD are closely related, their relationships have never been investigated on a global scale. Comparing PD and FD with species richness corroborated the general assumptions of surrogacy of the different diversity measures. However, the analysis of the residual variance suggested that the mismatches between the diversity measures are influenced by environmental conditions. PD increased relative to species richness with increasing mean annual temperature, whereas FD decreased with decreasing seasonality relative to PD. We also show that the tropical areas are characterized by a FD deficit, a phenomenon, that suggests that in tropical areas more species can be packed into the ecological space. We discuss potential mechanisms that could have resulted in the gradient of spatial mismatch observed in the different biodiversity measures and draw parallels to local scale studies. We conclude that the use of multiple diversity measures on a global scale can help to elucidate the relative importance of historical and ecological processes shaping the present gradients in mammalian diversity. PMID:21807734

Safi, Kamran; Cianciaruso, Marcus V; Loyola, Rafael D; Brito, Daniel; Armour-Marshall, Katrina; Diniz-Filho, José Alexandre F

2011-09-12

424

Brain basis of early parent-infant interactions: psychology, physiology, and in vivo functional neuroimaging studies.  

PubMed

Parenting behavior critically shapes human infants' current and future behavior. The parent-infant relationship provides infants with their first social experiences, forming templates of what they can expect from others and how to best meet others' expectations. In this review, we focus on the neurobiology of parenting behavior, including our own functional magnetic resonance imaging (fMRI) brain imaging experiments of parents. We begin with a discussion of background, perspectives and caveats for considering the neurobiology of parent-infant relationships. Then, we discuss aspects of the psychology of parenting that are significantly motivating some of the more basic neuroscience research. Following that, we discuss some of the neurohormones that are important for the regulation of social bonding, and the dysregulation of parenting with cocaine abuse. Then, we review the brain circuitry underlying parenting, proceeding from relevant rodent and nonhuman primate research to human work. Finally, we focus on a study-by-study review of functional neuroimaging studies in humans. Taken together, this research suggests that networks of highly conserved hypothalamic-midbrain-limbic-paralimbic-cortical circuits act in concert to support aspects of parent response to infants, including the emotion, attention, motivation, empathy, decision-making and other thinking that are required to navigate the complexities of parenting. Specifically, infant stimuli activate basal forebrain regions, which regulate brain circuits that handle specific nurturing and caregiving responses and activate the brain's more general circuitry for handling emotions, motivation, attention, and empathy--all of which are crucial for effective parenting. We argue that an integrated understanding of the brain basis of parenting has profound implications for mental health. PMID:17355399

Swain, James E; Lorberbaum, Jeffrey P; Kose, Samet; Strathearn, Lane

425

Roles for oestrogen receptor ? in adult brain function.  

PubMed

Oestradiol exerts a profound influence upon multiple brain circuits. For the most part, these effects are mediated by oestrogen receptor (ER)?. We review here the roles of ER?, the other ER isoform, in mediating rodent oestradiol-regulated anxiety, aggressive and sexual behaviours, the control of gonadotrophin secretion, and adult neurogenesis. Evidence exists for: (i) ER? located in the paraventricular nucleus underpinning the suppressive influence of oestradiol on the stress axis and anxiety-like behaviour; (ii) ER? expressed in gonadotrophin-releasing hormone neurones contributing to oestrogen negative-feedback control of gonadotrophin secretion; (iii) ER? controlling the offset of lordosis behaviour; (iv) ER? suppressing aggressive behaviour in males; (v) ER? modulating responses to social stimuli; and (vi) ER? in controlling adult neurogenesis. This review highlights two major themes; first, ER? and ER? are usually tightly inter-related in the oestradiol-dependent control of a particular brain function. For example, even though oestradiol feedback to control reproduction occurs principally through ER?-dependent mechanisms, modulatory roles for ER? also exist. Second, the roles of ER? and ER? within a particular neural network may be synergistic or antagonistic. Examples of the latter include the role of ER? to enhance, and ER? to suppress, anxiety-like and aggressive behaviours. Splice variants such as ER?2, acting as dominant negative receptors, are of further particular interest because their expression levels may reflect preceeding oestradiol exposure of relevance to oestradiol replacement therapy. Together, this review highlights the predominant modulatory, but nonetheless important, roles of ER? in mediating the many effects of oestradiol upon adult brain function. PMID:21851428

Handa, R J; Ogawa, S; Wang, J M; Herbison, A E

2012-01-01

426

Understanding the role of nutrition in the brain and behavioral development of toddlers and preschool children: identifying and addressing methodological barriers.  

PubMed

The preschool years (i.e. 1-5 years of age) is a time of rapid and dramatic postnatal brain development (i.e. neural plasticity), and of fundamental acquisition of cognitive development (i.e. working memory, attention and inhibitory control). Also, it is a time of transition from a direct maternal mediation/selection of diet-based nutrition to food selection that is more based on self-selection and self-gratification. However, there have been fewer published studies in preschool children than in infants or school-aged children that examined the role of nutrition in brain/mental development (125 studies versus 232 and 303 studies, respectively during the last 28 years). This may arise because of age-related variability, in terms of individual differences in temperament, linguistic ability, and patterns of neural activity that may affect assessment of neural and cognitive development in pre-school children. In this review, we suggest several approaches for assessing brain function in children that can be refined. It would be desirable if the discipline developed some common elements to be included in future studies of diet and brain function, with the idea that they would complement more targeted measures based on time of exposure and understanding of data from animal models. Underlining this approach is the concept of 'window of sensitivity' during which nutrients may affect postnatal neural development: investigators and expert panels need to look specifically for region-specific changes and do so with understanding of the likely time window during which the nutrient was, or was not available. PMID:19761650

Rosales, Francisco J; Reznick, J Steven; Zeisel, Steven H

2009-10-01

427

The central adaptation syndrome: Psychosocial stress as a trigger for adaptive modifications of brain structure and brain function  

Microsoft Academic Search

This review makes an attempt to combine data from biological and psychosocial stress literature and to suggest an alternative interpretation of the relationship between stress and disease. It rearranges the presently available knowledge on the short- and long-term effects of stress on many different aspects of brain structure and brain function in the form of a new conceptualization of the

Gerald Huether