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NeuroImage Aug 2012The rapid development of fMRI was paralleled early on by the adaptation of MR spectroscopic imaging (MRSI) methods to quantify water relaxation changes during brain... (Review)
Review
The rapid development of fMRI was paralleled early on by the adaptation of MR spectroscopic imaging (MRSI) methods to quantify water relaxation changes during brain activation. This review describes the evolution of multi-echo acquisition from high-speed MRSI to multi-echo EPI and beyond. It highlights milestones in the development of multi-echo acquisition methods, such as the discovery of considerable gains in fMRI sensitivity when combining echo images, advances in quantification of the BOLD effect using analytical biophysical modeling and interleaved multi-region shimming. The review conveys the insight gained from combining fMRI and MRSI methods and concludes with recent trends in ultra-fast fMRI, which will significantly increase temporal resolution of multi-echo acquisition.
Topics: Brain; Brain Mapping; History, 20th Century; History, 21st Century; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy
PubMed: 22056458
DOI: 10.1016/j.neuroimage.2011.10.057 -
ACS Nano Mar 2013Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general... (Review)
Review
Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the activities of one neuron or a few neurons at a time. Neurochemical approaches focus on single neurotransmitters. Yet, there is an increasing realization that neural circuits operate at emergent levels, where the interactions between hundreds or thousands of neurons, utilizing multiple chemical transmitters, generate functional states. Brains function at the nanoscale, so tools to study brains must ultimately operate at this scale, as well. Nanoscience and nanotechnology are poised to provide a rich toolkit of novel methods to explore brain function by enabling simultaneous measurement and manipulation of activity of thousands or even millions of neurons. We and others refer to this goal as the Brain Activity Mapping Project. In this Nano Focus, we discuss how recent developments in nanoscale analysis tools and in the design and synthesis of nanomaterials have generated optical, electrical, and chemical methods that can readily be adapted for use in neuroscience. These approaches represent exciting areas of technical development and research. Moreover, unique opportunities exist for nanoscientists, nanotechnologists, and other physical scientists and engineers to contribute to tackling the challenging problems involved in understanding the fundamentals of brain function.
Topics: Animals; Brain Mapping; Humans; Models, Neurological; Nanomedicine; Nanoparticles; Nanotechnology; Nervous System Physiological Phenomena
PubMed: 23514423
DOI: 10.1021/nn4012847 -
Current Opinion in Neurology Aug 2009This article reviews recent developments in the field of amyloid imaging using PET, specifically the ability to quantify the amount and distribution of brain... (Review)
Review
PURPOSE OF REVIEW
This article reviews recent developments in the field of amyloid imaging using PET, specifically the ability to quantify the amount and distribution of brain beta-amyloid, the protein that occupies a central position in leading theories of the pathogenesis of Alzheimer's disease.
RECENT FINDINGS
Several imaging-disorder correlations place the technique itself on a stronger footing by showing good agreement between in-vivo and histological measures of beta-amyloid deposition. Correlations between beta-amyloid and other measures of dementia - cognition, brain atrophy, and glucose metabolism - appear to support a view that beta-amyloid triggers a host of downstream alterations that are closely related to dementia severity and progression. However, associations between PET measures of beta-amyloid and cognition are generally fairly weak. The implications for clinical use are still uncertain. It seems likely that amyloid imaging will be useful for differentiating dementias associated with beta-amyloid from those that are not, but the utility of this approach will depend on the availability of effective beta-amyloid-directed treatments. Similarly, amyloid imaging offers the potential for predicting which nondemented individuals will eventually develop Alzheimer's disease, although here again the measurement of downstream beta-amyloid effects may be important.
SUMMARY
The ability to quantify the onset and progression of beta-amyloid disorder in the brain offers the potential for investigating a host of questions concerning individual and neural vulnerability and the amyloid hypothesis of Alzheimer's disease itself. These findings will have important basic and clinical implications.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Brain; Brain Mapping; Humans; Positron-Emission Tomography
PubMed: 19478666
DOI: 10.1097/WCO.0b013e32832d93c7 -
Neuron Jul 2018Human neuroimaging research has transitioned from mapping local effects to developing predictive models of mental events that integrate information distributed across... (Review)
Review
Human neuroimaging research has transitioned from mapping local effects to developing predictive models of mental events that integrate information distributed across multiple brain systems. Here we review work demonstrating how multivariate predictive models have been utilized to provide quantitative, falsifiable predictions; establish mappings between brain and mind with larger effects than traditional approaches; and help explain how the brain represents mental constructs and processes. Although there is increasing progress toward the first two of these goals, models are only beginning to address the latter objective. By explicitly identifying gaps in knowledge, research programs can move deliberately and programmatically toward the goal of identifying brain representations underlying mental states and processes.
Topics: Brain; Brain Mapping; Humans; Neuroimaging; Neurons
PubMed: 30048614
DOI: 10.1016/j.neuron.2018.06.009 -
Neuron Dec 2015Brodmann has pioneered structural brain mapping. He considered functional and pathological criteria for defining cortical areas in addition to cytoarchitecture. Starting... (Review)
Review
Brodmann has pioneered structural brain mapping. He considered functional and pathological criteria for defining cortical areas in addition to cytoarchitecture. Starting from this idea of structural-functional relationships at the level of cortical areas, we will argue that the cortical architecture is more heterogeneous than Brodmann's map suggests. A triple-scale concept is proposed that includes repetitive modular-like structures and micro- and meso-maps. Criteria for defining a cortical area will be discussed, considering novel preparations, imaging and optical methods, 2D and 3D quantitative architectonics, as well as high-performance computing including analyses of big data. These new approaches contribute to an understanding of the brain on multiple levels and challenge the traditional, mosaic-like segregation of the cerebral cortex.
Topics: Atlases as Topic; Brain; Brain Mapping; Humans; Nerve Net
PubMed: 26687219
DOI: 10.1016/j.neuron.2015.12.001 -
The Neuroscientist : a Review Journal... Apr 2020Functional magnetic resonance imaging has proved to be a powerful tool to characterize spatiotemporal patterns of human brain activity. Analysis methods broadly fall... (Review)
Review
Functional magnetic resonance imaging has proved to be a powerful tool to characterize spatiotemporal patterns of human brain activity. Analysis methods broadly fall into two camps: those summarizing properties of a region and those measuring interactions among regions. Here we pose an unappreciated question in the field: What are the strengths and limitations of each approach to study fundamental neural processes? We explore the relative utility of region- and connection-based measures in the context of three topics of interest: neurobiological relevance, brain-behavior relationships, and individual differences in brain organization. In each section, we offer illustrative examples. We hope that this discussion offers a novel and useful framework to support efforts to better understand the macroscale functional organization of the brain and how it relates to behavior.
Topics: Brain; Brain Mapping; Connectome; Humans; Magnetic Resonance Imaging; Nerve Net; Neural Pathways
PubMed: 31304866
DOI: 10.1177/1073858419860115 -
Nature Neuroscience Jun 2012As the racial composition of the population changes, intergroup interactions are increasingly common. To understand how we perceive and categorize race and the attitudes... (Review)
Review
As the racial composition of the population changes, intergroup interactions are increasingly common. To understand how we perceive and categorize race and the attitudes that flow from it, scientists have used brain imaging techniques to examine how social categories of race and ethnicity are processed, evaluated and incorporated in decision-making. We review these findings, focusing on black and white race categories. A network of interacting brain regions is important in the unintentional, implicit expression of racial attitudes and its control. On the basis of the overlap in the neural circuitry of race, emotion and decision-making, we speculate as to how this emerging research might inform how we recognize and respond to variations in race and its influence on unintended race-based attitudes and decisions.
Topics: Black or African American; Attitude; Brain Mapping; Humans; Neurosciences; United States; White People
PubMed: 22735516
DOI: 10.1038/nn.3136 -
Trends in Neurosciences Dec 2021The internal organization of hippocampal formation has been studied for more than a century. Although early accounts emphasized its subfields along the medial-lateral... (Review)
Review
The internal organization of hippocampal formation has been studied for more than a century. Although early accounts emphasized its subfields along the medial-lateral axis, findings in recent decades have highlighted also the anterior-to-posterior (i.e., longitudinal) axis as a key contributor to this brain region's functional organization. Hence, understanding of hippocampal function likely demands characterizing both medial-to-lateral and anterior-to-posterior axes, an approach that has been concretized by recent advances in in vivo parcellation and gradient mapping techniques. Following a short historical overview, we review the evidence provided by these approaches in brain-mapping studies, as well as the perspectives they open for addressing the behavioral relevance of the interacting organizational axes in healthy and clinical populations.
Topics: Brain; Brain Mapping; Hippocampus; Humans; Magnetic Resonance Imaging; Neural Pathways
PubMed: 34756460
DOI: 10.1016/j.tins.2021.10.003 -
Sensors (Basel, Switzerland) Nov 2023Electroencephalography (EEG) is a widely recognised non-invasive method for capturing brain electrophysiological activity [...].
Electroencephalography (EEG) is a widely recognised non-invasive method for capturing brain electrophysiological activity [...].
Topics: Brain; Brain Mapping; Electroencephalography; Signal Processing, Computer-Assisted; Electrophysiological Phenomena
PubMed: 38005444
DOI: 10.3390/s23229056 -
International Journal of... Jan 2014The primary function of the human brain is arguably to optimize the results of our motor actions in an ever-changing environment. Our cognitive processes and supporting... (Review)
Review
The primary function of the human brain is arguably to optimize the results of our motor actions in an ever-changing environment. Our cognitive processes and supporting brain dynamics are inherently coupled both to our environment and to our physical structure and actions. To investigate human cognition in its most natural forms demands imaging of brain activity while participants perform naturally motivated actions and interactions within a full three-dimensional environment. Transient, distributed brain activity patterns supporting spontaneous motor actions, performed in pursuit of naturally motivated goals, may involve any or all parts of cortex and must be precisely timed at a speed faster than the speed of thought and action. Hemodynamic imaging methods give information about brain dynamics on a much slower scale, and established techniques for imaging brain dynamics in all modalities forbid participants from making natural extensive movements so as to avoid intractable movement-related artifacts. To overcome these limitations, we are developing mobile brain/body imaging (MoBI) approaches to study natural human cognition. By synchronizing lightweight, high-density electroencephalographic (EEG) recording with recordings of participant sensory experience, body and eye movements, and other physiological measures, we can apply advanced data analysis techniques to the recorded signal ensemble. This MoBI approach enables the study of human brain dynamics accompanying active human cognition in its most natural forms. Results from our studies have provided new insights into the brain dynamics supporting natural cognition and can extend theories of human cognition and its evolutionary function - to optimize the results of our behavior to meet ever-changing goals, challenges, and opportunities.
Topics: Brain; Brain Mapping; Cognition; Humans; Mobile Applications; Movement; Neuroimaging
PubMed: 24076470
DOI: 10.1016/j.ijpsycho.2013.09.003