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Brain–computer Interface
A brain–computer interface (BCI), sometimes called a brain–machine interface (BMI) or smartbrain, is a direct communication pathway between the brain, brain's electrical activity and an external device, most commonly a computer or robotic limb. BCIs are often directed at researching, Brain mapping, mapping, assisting, Augmented cognition, augmenting, or repairing human Cognitive skill, cognitive or Sensory-motor coupling, sensory-motor functions. Implementations of BCIs range from non-invasive (Electroencephalography, EEG, Magnetoencephalography, MEG, Electrooculography, EOG, Magnetic resonance imaging, MRI) and partially invasive (Electrocorticography, ECoG and endovascular) to invasive (microelectrode array), based on how close electrodes get to brain tissue.Michael L Martini, BA, Eric Karl Oermann, MD, Nicholas L Opie, PhD, Fedor Panov, MD, Thomas Oxley, MD, PhD, Kurt Yaeger, MD, Sensor Modalities for Brain-Computer Interface Technology: A Comprehensive Literature Review, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanometer
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. A galvanometer works by deflecting a pointer in response to an electric current flowing through a coil in a constant magnetic field. Galvanometers can be thought of as a kind of actuator. Galvanometers came from the observation, first noted by Hans Christian Ørsted in 1820, that a magnetic compass's needle deflects when near a wire having electric current. They were the first instruments used to detect and measure small amounts of current. André-Marie Ampère, who gave mathematical expression to Ørsted's discovery, named the instrument after the Italian electricity researcher Luigi Galvani, who in 1791 discovered the principle of the frog galvanoscope – that electric current would make the legs of a dead frog jerk. Galvanometers have bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siemens
Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', ''Energy'', ''Healthcare'' (Siemens Healthineers), and ''Infrastructure & Cities'', which represent the main activities of the corporation. The corporation is a prominent maker of medical diagnostics equipment and its medical health-care division, which generates about 12 percent of the corporation's total sales, is its second-most profitable unit, after the industrial automation division. In this area, it is regarded as a pioneer and the company with the highest revenue in the world. The corporation is a component of the Euro Stoxx 50 stock market index. Siemens and its subsidiaries employ approximately 303,000 people worldwide and reported global revenue of around €62 billion in 2021 according to its earnings release. History 1847 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lippmann Electrometer
A Lippmann electrometer is a device for detecting small rushes of electric current and was invented by Gabriel Lippmann in 1873.Fritz Scholz''Electroanalytical Methods: Guide to Experiments and Applications'' 2nd ed., Springer, 2010. The device consists of a tube which is thick on one end and very thin on the other. The thin end is designed to act as a capillary tube. The tube is half-filled with mercury with a small amount of dilute sulfuric acid above the mercury in the capillary tube. Metal wires are connected at the thick end into the mercury and at the thin end into the sulfuric acid. When the pulse of electricity arrives it changes the surface tension of the mercury and allows it to leap up a short distance in the capillary tube. This device was used in the first practical ECG Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Wave
Alpha waves, or the alpha rhythm, are neural oscillations in the frequency range of 8–12 Hz likely originating from the synchronous and coherent (in phase or constructive) electrical activity of thalamic pacemaker cells in humans. Historically, they are also called "Berger's waves" after Hans Berger, who first described them when he invented the EEG in 1924. Alpha waves are one type of brain waves detected by electrophysiological and closely related methods, such as by electroencephalography (EEG) or magnetoencephalography (MEG), and can be quantified using quantitative electroencephalography (qEEG). They can be predominantly recorded from the occipital lobes during wakeful relaxation with closed eyes and were the earliest brain rhythm recorded in humans. Alpha waves are reduced with open eyes and sleep, while they are enhanced during drowsiness. Historically, they were thought to represent the activity of the visual cortex in an idle state. More recent papers have argued t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Oscillation
Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macrosco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroencephalography
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. It is typically non-invasive, with the EEG electrodes placed along the scalp (commonly called "scalp EEG") using the International 10-20 system, or variations of it. Electrocorticography, involving surgical placement of electrodes, is sometimes called " intracranial EEG". Clinical interpretation of EEG recordings is most often performed by visual inspection of the tracing or quantitative EEG analysis. Voltage fluctuations measured by the EEG bioamplifier and electrodes allow the evaluation of normal brain activity. As the electrical activity monitored by EEG originates in neurons in the underlying brain tissue, the recordings made by the electrodes on the surface of the scalp vary in accordance with their orientation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Berger
Hans Berger (21 May 1873 – 1 June 1941) was a German psychiatrist. He is best known as the inventor of electroencephalography (EEG) in 1924, which is a method used for recording the electrical activity of the brain, commonly described in terms of brainwaves, and as the discoverer of the alpha wave rhythm which is a type of brainwave. Alpha waves have been eponymously referred to as the "Berger wave." Biography Berger was born in Neuses (now part of Coburg), Saxe-Coburg and Gotha, Germany. After attending Casimirianum, where he gained his abitur in 1892, Berger enrolled as a mathematics student at the Friedrich Schiller University of Jena with the intention of becoming an astronomer. After one semester, he abandoned his studies and enlisted for a year of service in the cavalry. During a training exercise, his horse suddenly reared, and he landed in the path of a horse-drawn cannon. The driver of the artillery battery halted the horses in time, leaving the young Berger shak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamocortical Dysrhythmia
Thalamocortical dysrhythmia (TCD) is a theoretical framework in which neuroscientists try to explain the positive and negative symptoms induced by neuropsychiatric disorders like Parkinson's Disease, neurogenic pain, tinnitus, visual snow syndrome, schizophrenia, obsessive–compulsive disorder, depressive disorder and epilepsy. In TCD, normal thalamocortical resonance is disrupted by changes in the behaviour of neurons in the thalamus. TCD can be treated with neurosurgical methods like the central lateral thalamotomy, which due to its invasiveness is only used on patients that have proven resistant to conventional therapies. Background At the base of the theory lies diminished excitatory or increased inhibitory input at the thalamic level. This leads to a switch of the thalamocortical neurons from tonic to burst firing and subsequently entrains thalamic and cortical areas with pathological oscillations at around 5 Hz. Evidence Evidence for TCD comes from Magnetoencephalogr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mental State
A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definition of the term. According to '' epistemic approaches'', the essential mark of mental states is that their subject has privileged epistemic access while others can only infer their existence from outward signs. '' Consciousness-based approaches'' hold that all mental states are either conscious themselves or stand in the right relation to conscious states. '' Intentionality-based approaches'', on the other hand, see the power of minds to refer to objects and represent the world as the mark of the mental. According to '' functionalist approaches'', mental states are defined in terms of their role in the causal network independent of their intrinsic properties. Some philosophers deny all the aforementioned approaches by holding that the term " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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