Download or read book Effect of Age on the Functional Connectivity of Brain Regions Involved in Olfaction written by Rose Calhoun Haney and published by . This book was released on 2005 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study investigated the functional interactions among brains regions typically involved in olfactory processing with the application of structural equation modeling (SEM) to functional magnetic resonance (fMRI) imaging data. fMRI data was obtained during an odor detection task from ten healthy young and ten healthy elderly gender matched participants. Interregional correlations from fMRI signal data were used to calculate path coefficients and were then compared between groups using a stacked model approach. Results demonstrated that the left hemisphere functional networks differed between age groups. Comparison of path coefficients showed stronger interactions in the young occurring between piriform-amydala, piriform-entorhinal, and amydala-hippocampal connections. Interestingly, a stronger functional interaction between the piriform-orbital frontal connection was observed in the elderly network. In contrast to the left hemisphere, right hemisphere networks did not differ between age groups. These findings revealed age-related changes in functional connectivity among brain regions involved in odor detection, as well as contributed to a growing body of literature suggesting possible compensatory mechanisms occurring in the aging brain. The present study also applied SEM to fMRI data and compared functional networks between ten young and ten elderly gender matched participants during an olfactory recognition memory task. Age-related differences were observed in the left hemisphere functional network with stronger interactions occurring between the amygdala-hippocampal and amygdala-parahippocampal connections. Functional networks in the right hemisphere differed between age groups, with stronger interactions for the young occurring between the piriform-amygdala, piriform-entorhinal, and hippocampal-parahippocampal connections. Additionally, the elderly functional networks for both left and right hemispheres had a reduced number of significant functional pathways associated with the olfactory recognition memory task. This reduction in number of significant functional pathways corresponded with a significantly poorer performance by elderly on recognition accuracy. These findings suggest age-related changes in functional connectivity among brain regions involved in olfactory recognition memory, and support prior olfactory recognition memory research that suggests that the interaction between left and right hemispheres allows for optimal performance for more complex olfactory processing.

Download or read book The Neurobiology of Olfaction written by Anna Menini and published by CRC Press. This book was released on 2009-11-24 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Overview of Advances in OlfactionThe common belief is that human smell perception is much reduced compared with other mammals, so that whatever abilities are uncovered and investigated in animal research would have little significance for humans. However, new evidence from a variety of sources indicates this traditional view is likely

Download or read book Brain Networks in Aging Reorganization and Modulation by Interventions written by Junfeng Sun and published by Frontiers Media SA. This book was released on 2018-02-22 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Old adults undertake multiple reduced cognitive abilities in aging, which are accompanied with specific brain reorganization in forms of regional brain activity and brain tissues, inter-region connectivity, and topology of whole brain networks in both function and structure. The plasticity changes of brain activities in old adults are explained by the mechanisms of compensation and dedifferentiation. For example, older adults have been observed to have greater, usually bilateral, prefrontal activities during memory tasks compared to the typical unilateral prefrontal activities in younger adults, which was explained as a compensation for the reduced brain activities in visual processing cortices. Dedifferentiation is another mechanism to explain that old adults are with much less selective and less distinct activity in task-relevant brain regions compared with younger adults. A larger number of studies have examined the plasticity changes of brain from the perspective of regional brain activities. However, studies on only regional brain activities cannot fully elucidate the neural mechanisms of reduced cognitive abilities in aging, as multiple regions are integrated together to achieve advanced cognitive function in human brain. In recent years, brain connectivity/network, which targets how brain regions are integrated, have drawn increasing attention in neuroscience with the development of neuroimaging techniques and graph theoretical analysis. Connectivity quantifies functional association or neural fibers between two regions that may be spatially far separated, and graph theoretical analysis of brain network examines the complex interactions among multiple regions from the perspective of topology. Studies showed that compared to younger adults, older adults had altered strength of task-relevant functional connectivity between specific brain regions in cognitive tasks, and the alternation of connectivity are correlated to behavior performance. For example, older adults had weaker functional connectivity between the premotor cortex and a region in the left dorsolateral prefrontal cortex in a working memory task. Interventions like cognitive training and neuro-modulation (e.g., transcranial magnetic stimulation) have been shown to be promising in regaining or retaining the decreasing cognitive abilities in aging. However, only few neuroimaging studies have examined the influence of interventions to old adult’s brain activity, connectivity, and cognitive performance. This Research Topic calls for contributions on brain network of subjects in normal aging or with age-related diseases like mild cognitive impairment and Alzheimer’s disease. The studies are expected to be based on neuroimaging techniques including but not limited to functional magnetic resonance imaging, Electroencephalography, and diffusion tensor imaging, and contributions on the influence of interventions to brain networks in aging are highly encouraged. All these studies would enrich our understanding of neural mechanisms underlying aging, and offer new insights for developing possible interventions to retain cognitive abilities in aging subjects.

Download or read book Neuromorphic Olfaction written by Krishna C. Persaud and published by CRC Press. This book was released on 2016-04-19 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many advances have been made in the last decade in the understanding of the computational principles underlying olfactory system functioning. Neuromorphic Olfaction is a collaboration among European researchers who, through NEUROCHEM (Fp7-Grant Agreement Number 216916)-a challenging and innovative European-funded project-introduce novel computing p

Download or read book The Neurology of Olfaction written by Christopher H. Hawkes and published by Cambridge University Press. This book was released on 2009-02-12 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Written by two experts in the field, this book provides information useful to physicians for assessing and managing chemosensory disorders - with appropriate case-histories - and summarizes the current scientific knowledge of human olfaction. It will be of particular interest to neurologists, otolaryngologists, psychologists, psychiatrists, and neuroscientists."--BOOK JACKET.

Download or read book Discovering the Brain written by National Academy of Sciences and published by National Academies Press. This book was released on 1992-01-01 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brain ... There is no other part of the human anatomy that is so intriguing. How does it develop and function and why does it sometimes, tragically, degenerate? The answers are complex. In Discovering the Brain, science writer Sandra Ackerman cuts through the complexity to bring this vital topic to the public. The 1990s were declared the "Decade of the Brain" by former President Bush, and the neuroscience community responded with a host of new investigations and conferences. Discovering the Brain is based on the Institute of Medicine conference, Decade of the Brain: Frontiers in Neuroscience and Brain Research. Discovering the Brain is a "field guide" to the brainâ€"an easy-to-read discussion of the brain's physical structure and where functions such as language and music appreciation lie. Ackerman examines: How electrical and chemical signals are conveyed in the brain. The mechanisms by which we see, hear, think, and pay attentionâ€"and how a "gut feeling" actually originates in the brain. Learning and memory retention, including parallels to computer memory and what they might tell us about our own mental capacity. Development of the brain throughout the life span, with a look at the aging brain. Ackerman provides an enlightening chapter on the connection between the brain's physical condition and various mental disorders and notes what progress can realistically be made toward the prevention and treatment of stroke and other ailments. Finally, she explores the potential for major advances during the "Decade of the Brain," with a look at medical imaging techniquesâ€"what various technologies can and cannot tell usâ€"and how the public and private sectors can contribute to continued advances in neuroscience. This highly readable volume will provide the public and policymakersâ€"and many scientists as wellâ€"with a helpful guide to understanding the many discoveries that are sure to be announced throughout the "Decade of the Brain."

Download or read book Investigation of an Innate Olfactory visual Functional Connection in the Human Brain Using FMRI written by Brittany Martinez and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We are constantly bombarded with stimuli from multiple sensory sources in the environment of our natural world. The innate behavioral responses to the environment, therefore, are based on our brains ability to integrate distinct and complex sensory information into a comprehensive and understandable percept (1). Therefore, multisensory integration is a phenomenon that involves combining multimodal sensory information from a target stimulus into a coherent signal. Despite substantial knowledge of the fundamental processes involved in multisensory integration, there is still much to be learned because majority of studies have focused on one sensory modality at a time (2). One particular aspect that is largely overlooked is the interplay between the visual and olfactory systems (3). Despite olfaction being a vestigial sense, landmark studies have consistently demonstrated, strong behavioral and physiological responses to olfactory stimuli even at levels below conscious perception, (4-7).Behavioral, anatomical, and neurofunctional evidence exists supporting the likelihood of an innate olfactory-visual functional connection in the human brain (8-43). Furthermore, pioneering research on the topic of olfactory-visual interactions has utilized fMRI to delineate the neural networks underlying the interplay between these two sensory systems (44-55). However, many of these studies employed fMRI paradigms to better understand the influence of visual information over olfactory processing. This dissertation aimed to utilize olfactory-visual association fMRI paradigms to better elucidate the reciprocal relationship between the olfactory and visual systems in the human brain. The overall goal was to develop a more comprehensive model of the neural networks underlying the human olfactory function.Olfaction is the most studied chemosensory system, however, the functioning of this network is still not well understood because of its complicated neuroanatomical organization (56). This dissertation, therefore, sought to elucidate several unknown aspects of the functional connection between the olfactory and visual systems by testing several hypotheses about this innate connection. First, Chapter 2 of this dissertation focused on investigating the role of congruence during the formation of olfactory-visual associations. It was hypothesized that olfactory-visual associations could be rapidly formed by a neutral, non-lexical abstract visual symbols, as evidenced by significant olfactory system activation during testing conditions consisting of presenting a visual cue that was previously paired with an odor compared to an unpaired visual cue. It was also hypothesized that a lexical, semantically congruent visual cue, would produce greater olfactory-visual activation during both the acquisition and testing phases compared to a lexical, semantically incongruent visual cue or a neutral, non-lexical symbol. The results reinforced that rapid olfactory-visual associations could be formed by neutral, non-lexical visual cues, via modulation of visual activation by visual information. This indicated that olfactory-visual associations could be formed innately, in a reflexively manner to facilitate the odor naming process. Furthermore, lexical, semantically congruent, multisensory visual cues were found to elicit patterns of greater visual and language-related activation, mostly likely subserving an olfactory-visual-lexical integrative process that may be responsible for odor identification and naming in the human brain (57-59).Chapter 3 of this dissertation tested the hypothesis that an odor-attention task, involving higher-order cognitive decision-making and attentional processes to an olfactory stimulus, will elicit significantly stronger olfactory-visual associative neural activation compared to less complex visual-attention task that requires only detection of a visual stimulus. The findings here indicated that rapid olfactory-visual associations may be formed via modulation of the visual system by olfactory information, regardless of the task context. This suggests a unique, intrinsic mechanism between the olfactory and visual systems that provides odors an avenue to influence visual processing of stimuli, regardless of which sensory cue is selectively attended to. Chapter 4 of this dissertation consisted of an investigation of the effect of age on neural activity in response to an olfactory-visual association paradigm in an older, cognitively normal participant cohort. Based on previous findings, it was hypothesized that a significant age-related decline would be observed in neural activity in response to this paradigm and that male subjects would display significantly greater deficits on olfactory-visual associative activation compared to female subjects. The results highlighted a significant effect of normal aging on the olfactory-visual functional connection and differential patterns of decline were observed in men and women, with women appearing to be more resilient to this effect.In summary, this dissertation made significant strides in elucidating several unknown aspects of this under-researched piece of brain function. Overall, the results support the existence of an innate olfactory-visual functional connection, in that rapid olfactory-visual associations can be formed using non-lexical, neutral symbols, but that a lexical, semantically congruent visual cue Smell appears to elicit stronger associations between olfactory and visual stimuli, leading to increased activation in visual brain regions. Furthermore, higher order cognitive tasks also appear to influence this effect by increasing activation in visual and olfactory regions, thus likely enhancing the strength of the olfactory-visual association. Finally, it was also observed that there is a significant, negative effect of age of the innate functional connection between the olfactory and visual systems and that women may be more resilient to this effect due to improved connectivity between olfactory structures. Taken together, these findings not only provide evidence of an innate olfactory-visual functional connection, but also offer valuable insight into modulating factors of this connection.

Download or read book Micro Meso and Macro Connectomics of the Brain written by Henry Kennedy and published by Springer. This book was released on 2016-03-10 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has brought together leading investigators who work in the new arena of brain connectomics. This includes ‘macro-connectome’ efforts to comprehensively chart long-distance pathways and functional networks; ‘micro-connectome’ efforts to identify every neuron, axon, dendrite, synapse, and glial process within restricted brain regions; and ‘meso-connectome’ efforts to systematically map both local and long-distance connections using anatomical tracers. This book highlights cutting-edge methods that can accelerate progress in elucidating static ‘hard-wired’ circuits of the brain as well as dynamic interactions that are vital for brain function. The power of connectomic approaches in characterizing abnormal circuits in the many brain disorders that afflict humankind is considered. Experts in computational neuroscience and network theory provide perspectives needed for synthesizing across different scales in space and time. Altogether, this book provides an integrated view of the challenges and opportunities in deciphering brain circuits in health and disease.

Download or read book Smell and Taste Disorders written by Christopher H. Hawkes and published by Cambridge University Press. This book was released on 2018-01-25 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a comprehensive and unique text that details the latest research on smell and taste disorders for use by clinicians and scientists.

Download or read book Statistical Signal Processing for Neuroscience and Neurotechnology written by Karim G. Oweiss and published by Academic Press. This book was released on 2010-09-22 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a uniquely comprehensive reference that summarizes the state of the art of signal processing theory and techniques for solving emerging problems in neuroscience, and which clearly presents new theory, algorithms, software and hardware tools that are specifically tailored to the nature of the neurobiological environment. It gives a broad overview of the basic principles, theories and methods in statistical signal processing for basic and applied neuroscience problems.Written by experts in the field, the book is an ideal reference for researchers working in the field of neural engineering, neural interface, computational neuroscience, neuroinformatics, neuropsychology and neural physiology. By giving a broad overview of the basic principles, theories and methods, it is also an ideal introduction to statistical signal processing in neuroscience. A comprehensive overview of the specific problems in neuroscience that require application of existing and development of new theory, techniques, and technology by the signal processing community Contains state-of-the-art signal processing, information theory, and machine learning algorithms and techniques for neuroscience research Presents quantitative and information-driven science that has been, or can be, applied to basic and translational neuroscience problems

Download or read book The Physics of the Mind and Brain Disorders written by Ioan Opris and published by Springer. This book was released on 2017-12-01 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers recent advances in the understanding of brain structure, function and disorders based on the fundamental principles of physics. It covers a broad range of physical phenomena occurring in the brain circuits for perception, cognition, emotion and action, representing the building blocks of the mind. It provides novel insights into the devastating brain disorders of the mind such as schizophrenia, dementia, autism, aging or addictions, as well as into the new devices for brain repair. The book is aimed at basic researchers in the fields of neuroscience, physics, biophysics and clinicians in the fields of neurology, neurosurgery, psychology, psychiatry.

Download or read book The Brain and Behavior written by David L. Clark and published by Cambridge University Press. This book was released on 2005-09-08 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: New edition building on the success of previous one. Retains core aim of providing an accessible introduction to behavioral neuroanatomy.

Download or read book Atlas of the Human Brain written by Juergen K Mai and published by Academic Press. This book was released on 2008 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accompanying DVD-ROM contains ... "the atlas in electronic format, but also a 3-D visualization software that allows easy browsing of the images, and a feature to allow direct retrieval of brain areas using coordinates obtained in magnetic resonance imaging."--P. [4] of cover.

Download or read book The Cambridge Handbook of Cognitive Aging written by Ayanna K. Thomas and published by Cambridge University Press. This book was released on 2020-05-28 with total page 1019 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decades of research have demonstrated that normal aging is accompanied by cognitive change. Much of this change has been conceptualized as a decline in function. However, age-related changes are not universal, and decrements in older adult performance may be moderated by experience, genetics, and environmental factors. Cognitive aging research to date has also largely emphasized biological changes in the brain, with less evaluation of the range of external contributors to behavioral manifestations of age-related decrements in performance. This handbook provides a comprehensive overview of cutting-edge cognitive aging research through the lens of a life course perspective that takes into account both behavioral and neural changes. Focusing on the fundamental principles that characterize a life course approach - genetics, early life experiences, motivation, emotion, social contexts, and lifestyle interventions - this handbook is an essential resource for researchers in cognition, aging, and gerontology.

Download or read book Methods in Chemosensory Research written by Sidney A. Simon and published by CRC Press. This book was released on 2001-09-26 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods in Chemosensory Research describes new molecular, electrophysiological, engineering, genetic, behavioral, psychophysical, and imaging techniques that have recently been adapted to investigate the basic neuronal mechanisms underlying chemoreception. Written by leaders in the field of neuronal chemoreception specializing in olfaction, gustation, baroreception, and chemical irritation caused by environmental pollutants, this unique book combines novel methods to investigate all aspects of taste and olfaction. These methods range from the molecular level to the investigation of individual cell taste and olfactory epithelia.

Download or read book The Human Nervous System written by George Paxinos and published by Academic Press. This book was released on 2012-12-02 with total page 1211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Human Nervous System is a definitive account of human neuroanatomy, with a comprehensive coverage of the brain, spinal cord, and peripheral nervous system. The cytoarchitecture, chemoarchitecture, connectivity, and major functions of neuronal structures are examined by acknowledged authorities in the field, such as: Alheid, Amaral, Armstrong, Beitz, Burke, de Olmos, Difiglia, Garey, Gerrits, Gibbins, Holstege, Kaas, Martin, McKinley, Norgren, Ohye, Paxinos, Pearson, Pioro, Price, Saper, Sasaki, Schoenen, Tadork, Voogd, Webster, Zilles, and their associates. Large, clearly designed 8-1/2" x 11" format 35 information-packed chapters 500 photomicrographs and diagrams 6,200 bibliographic entries Table of contents for every chapter Exceptionally cross-referenced Detailed subject index Substantial original research work Mini atlases of some brain regions

Download or read book Handbook of functional connectivity Magnetic Resonance Imaging methods in CONN written by Alfonso Nieto-Castanon and published by Hilbert Press. This book was released on 2020-01-31 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook describes methods for processing and analyzing functional connectivity Magnetic Resonance Imaging (fcMRI) data using the CONN toolbox, a popular freely-available functional connectivity analysis software. Content description [excerpt from introduction] The first section (fMRI minimal preprocessing pipeline) describes standard and advanced preprocessing steps in fcMRI. These steps are aimed at correcting or minimizing the influence of well-known factors affecting the quality of functional and anatomical MRI data, including effects arising from subject motion within the scanner, temporal and spatial image distortions due to the sequential nature of the scanning acquisition protocol, and inhomogeneities in the scanner magnetic field, as well as anatomical differences among subjects. Even after these conventional preprocessing steps, the measured blood-oxygen-level-dependent (BOLD) signal often still contains a considerable amount of noise from a combination of physiological effects, outliers, and residual subject-motion factors. If unaccounted for, these factors would introduce very strong and noticeable biases in all functional connectivity measures. The second section (fMRI denoising pipeline) describes standard and advanced denoising procedures in CONN that are used to characterize and remove the effect of these residual non-neural noise sources. Functional connectivity Magnetic Resonance Imaging studies attempt to quantify the level of functional integration across different brain areas. The third section (functional connectivity measures) describes a representative set of functional connectivity measures available in CONN, each focusing on different indicators of functional integration, including seed-based connectivity measures, ROI-to-ROI measures, graph theoretical approaches, network-based measures, and dynamic connectivity measures. Second-level analyses allow researchers to make inferences about properties of groups or populations, by generalizing from the observations of only a subset of subjects in a study. The fourth section (General Linear Model) describes the mathematics behind the General Linear Model (GLM), the approach used in CONN for all second-level analyses of functional connectivity measures. The description includes GLM model definition, parameter estimation, and hypothesis testing framework, as well as several practical examples and general guidelines aimed at helping researchers use this method to answer their specific research questions. The last section (cluster-level inferences) details several approaches implemented in CONN that allow researchers to make meaningful inferences from their second-level analysis results while providing appropriate family-wise error control (FWEC), whether in the context of voxel-based measures, such as when studying properties of seed-based maps across multiple subjects, or in the context of ROI-to-ROI measures, such as when studying properties of ROI-to-ROI connectivity matrices across multiple subjects.