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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Outline of brain mapping | 2/3 | https://en.wikipedia.org/wiki/Outline_of_brain_mapping | reference | science, encyclopedia | 2026-05-05T04:29:51.311848+00:00 | kb-cron |
=== General === Most imaging work to date on individual neurons has been conducted outside the brain, typically on large neurons, and has been most frequently destructive. New techniques are however rapidly emerging. Search on "Single neuron imaging" and see related topics: Biological neuron model, Single-unit recording, Neural oscillation, Computational neuroscience. dMRI (above) is also promising in non-destructive imaging of single neurons inside the brain. History of neuroimaging (redirects from Brain scanner) Neuroimaging (redirects from Brain function map) Connectomics – mapping technique showing neural connections in a nervous system.
=== Specific systems === Cortical stimulation mapping Diffusion MRI (dMRI) – includes diffusion tensor imaging (DTI) and diffusion functional MRI (DfMRI). dMRI is a recent breakthrough in brain mapping allowing the visualization of cross connections between different anatomical parts of the brain. It allows noninvasive imaging of white matter fiber structure and in addition to mapping can be useful in clinical observations of abnormalities, including damage from stroke. Electroencephalography (EEG) – uses electrodes on the scalp and other techniques to detect the electrical flow of currents. Electrocorticography – intracranial EEG, the practice of using electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. Electrophysiological techniques for clinical diagnosis Functional magnetic resonance imaging (fMRI) Medical image computing (brain research of leads medical and surgical uses of mapping technology) Neurostimulation (in research stimulation is frequently used in conjunction with imaging) Positron emission tomography (PET) – a nuclear medical imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Three-dimensional images of tracer concentration within the body are then constructed by computer analysis. In modern scanners, three dimensional imaging is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session, in the same machine.
=== Imaging and recording componentry ===
==== Electrochemical ==== Haemodynamic response – the rapid delivery of blood to active neuronal tissues. Blood Oxygenation Level Dependent signal (BOLD), corresponds to the concentration of deoxyhemoglobin. The BOLD effect is based on the fact that when neuronal activity is increased in one part of the brain, there is also an increased amount of cerebral blood flow to that area. Functional magnetic resonance imaging is enabled by the detection of the BOLD signal. Event-related functional magnetic resonance imaging can be used to detect changes in the Blood Oxygen Level Dependent (BOLD) hemodynamic response to neural activity in response to certain events.
==== Electrical ==== Event-related potential – positive and negative 10μ to 100μ Volts (μ is millionths) responses, measured via noninvasive electrodes attached to the scalp, that are the reliable and repeatable results of a certain specific sensory, cognitive, or motor event. These are also called a stereotyped electrophysiological response to a stimulus. They are called somatosensory evoked potentials when they are elicited by sensory (vs. cognitive or motor) event stimuli. The voltage swing sequences are recorded and broken down by positive and negative, and by how long after the stimulus they are observed. For example, [N100] is a negative swing observed between 80 and 120 milliseconds (100 being the midpoint) after the onset of the stimulus. Alternatively, the voltage swings are labeled based on their order, N1 being the first negative swing observed, N2 the second negative swing, etc. See: N100 (neuroscience), N200 (neuroscience), P300 (neuroscience), N400 (neuroscience), P600 (neuroscience). The first negative and positive swings (see Visual N1, C1 and P1 (neuroscience)) in response to visual stimulation are of particular interest in studying sensitivity and selectiveness of attention.
==== Electromagnetic ==== Magnetoencephalography – a technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers In research, MEG's primary use is the measurement of time courses of activity. MEG can resolve events with a precision of 10 milliseconds or faster, while functional MRI (fMRI), which depends on changes in blood flow, can at best resolve events with a precision of several hundred milliseconds. MEG also accurately pinpoints sources in primary auditory, somatosensory and motor areas. For creating functional maps of human cortex during more complex cognitive tasks, MEG is most often combined with fMRI, as the methods complement each other. Neuronal (MEG) and hemodynamic (fMRI) data do not necessarily agree, in spite of the tight relationship between local field potentials (LFP) and blood oxygenation level dependent (BOLD) signals
==== Radiological ==== Positron-emitting radionuclide (tracer). See Positron emission tomography Altanserin – a compound that binds to a serotonin receptor. When labeled with the isotope fluorine-18 it is used as a radioligand in positron emission tomography (PET) studies of the brain.
==== Visual processing and image enhancement ==== Scientific visualization – an interdisciplinary branch of science primarily concerned with the visualization of three-dimensional phenomena (including medical, biological, and others), where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps with a dynamic (time) component. It is considered a branch of computer science that is a subset of computer graphics. Brain mapping is a leading beneficiary of advances in scientific visualization. Blob detection – an area in computer vision, A blob is a region of a digital image in which some properties (such as brightness or color, compared to areas surrounding those regions) are constant or vary within a prescribed range of values; all the points in a blob can be considered in some sense to be similar to each other