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A SHORT GLOSSARY OF TERMS CLINICAL ENCEPHALOGRAPHY
Activation is the manifestation of activity of the functional system aimed at maintaining a certain state of the brain.
Activating tonic is a manifestation of the activities of an activating functional systems aimed at maintaining a certain level of wakefulness. In EEG is reflected in the ability to hold a certain frequency-amplitude pattern, characterizing the level of a certain state of the brain.
Activation of phasic - manifestation of activity of functional systems aimed at providing an orienting response. In EEG is reflected in the reaction of awakening.
Activity - bioelectric potentials of the brain, reflected in a sequence of waves of any frequency and amplitude. Isolated spontaneous activity, sleep activity, background activity and epileptic activity, etc. In the narrow sense of the words is opposed to the term "rhythm" (see ).
Activity of sleep - bioelectricity the spontaneous activity recorded during sleep.
Alpha-activity - bioelectric component, representing the potential oscillations with a frequency of 8 to 13 Hz with different oscillation periods, distributed in a random order.
Alpha wave - a single oscillation of the potential difference in length 75-130 MS, having a form approaching a sine wave.
Alpha-frequency band oscillations of the potential that lies in the range from 8 to 13 Hz.
Alpha rhythm is one of the main brain rhythms, which is a rhythmic oscillation of potential with a constant frequency lying in the range of 8 to 13 Hz.
The wave amplitude - the magnitude of the potential oscillations peak-to-peak; measured in microvolt values.
Aperiodic way (activity) - the electrical activity consisting of wave components with different periods and are randomly distributed.
The artifact signal due to an extracerebral source, observed at EEG; distinguish physical and biological causes of artifacts.
Asymmetry - lack of symmetry, similarity, relevance, uniformity of the potential in the corresponding structures of the two hemispheres of the brain or convexital surface (see ).
Async - the simultaneous emergence of phenomena of the EEG in different structures of the brain or its convexital surface.
The basal surface of the brain surface of the brain adjacent to the skull base.
Beta-activity - bioelectric component, representing the potential oscillations with a frequency from 13 to 35 Hz with different oscillation periods, distributed in a random order.
Beta wave - a single oscillation of the potential difference of duration from 35 to 75 MS.
Beta frequency range oscillations of the potential that lies in the range from 13 to 35 Hz.
Beta-rhythm is one of the main brain rhythms, which is a rhythmic oscillation of potential with a constant frequency lying in the range from 13 to 35 Hz. For reasons of clinical-physiological nature secrete beta-low frequency, or the beta-1 rhythm (from 13 to 25 Hz); and beta-high frequency, or the beta-2 rhythm (from 25 to 35 Hz).
Bilateral (rhythm) - bioelectric phenomenon, expressed symmetrically in the temporal, lateral parietal and occipital departments convexital surface of the brain; if corticotherapie or subcategory - in symmetric divisions of both hemispheres.
Bioelectric silence is the absence of the bioelectric processes in the brain tissue in consequence of the death of the brain.
Bipolar allotment check from two electrodes, each of which is located above the projection of the medulla.
Spindle-shaped image (rhythm) - amplitude modulation any rate, having the form of a number of consecutive spindles.
Spindles sleep spindle - shaped flash bioelectrical activity that occur during sleep with a frequency of about 14-16 Hz.
The vertex potential is a complex of waves of different periods, maximally expressed in makuleke region (vertex); is the consequence of irritation of any sensory modality.
Anxiety - sensitivity of tissues or cells to the effects, leading to transition from a state of physiological rest is in an active state. Measure of excitability is the threshold effect: the lower the threshold of stimulation, the higher the anxiety.
Wave - any single fluctuation of the potential of any period, amplitude and shape.
Flash (activity rhythm) - appearance on the background of a dominant rhythm (activity) of any other frequency components, amplitude not exceeding the background.
Caused by activity - bioelectric reaction of the brain in response to external stimuli.
Caused by the potential wave or group of waves in a complex (see ) statistical validity in response to sensory irritation of any modality.
High-frequency activity - the activity, the frequency of which exceeds the alpha range.
High-frequency low-amplitude asynchronous activity of low-amplitude high-frequency polyrhythmic recording of bioelectric activity frequency greater than 35 Hz, an amplitude of 2-5 mV.
Gamma-activity - bioelectric component, representing the potential oscillations with a frequency lying in the band above 35 Hz with different oscillation periods, distributed in a random order.
Gamma wave - a single oscillation of the potential difference of duration from 35 to 20 MS.
Gamma frequency range oscillations of the potential that lies in the range from 35 to 50 Hz.
Gamma rhythm is one of the main brain rhythms (see ), which is a rhythmic oscillation of potential with a constant frequency lying in the range above 35 Hz.
Harmonics - occurrence of rhythms is a multiple of the frequency of the light flashes and is higher than the original 2-3 times.
Generalization (generalized change of activity) - the appearance of changes in bioelectrical activity across all brain regions simultaneously.
Hertz - unit of frequency of sinusoidal oscillations, expressed in cycles per second (colab./s); applies only to a stationary process (see ).
Hyperventilation is regular deep breathing for a few (usually three) minutes.
Depth EEG recording of brain activity obtained through electrodes immersed inside the brain during neurosurgical operations or by implantation. In cases when immersion of the electrode is controlled stereotaxically measurements, recording bioelectrical activity is called stereotactic depth EEG.
Depth electrode - electrode immersed in the depths of the brain.
Two-phase wave - a single oscillation, the extremes of which exceed neighboring components on both sides.
Delta-activity - bioelectric component, representing the potential oscillations with a frequency of 0, 3 and 4 Hz with different oscillation periods, distributed in a random order.
Delta wave - a single oscillation of the potential difference longer than 250 MS, having a form approaching a sine wave.
The Delta-frequency range oscillations of the potential that lies in the range from 0, 3 to 4 Hz.
Depression (rhythm) is an abrupt decrease in the amplitude, depression or complete disappearance of the amplitude of the dominant rhythm.
Desynchronization - the disappearance of the regular rhythm of the EEG spectrum and replace it with low-amplitude aperiodic high-frequency activity.
The range (band) of frequencies, plot the frequency spectrum, limited frequency defined by the framework.
Diffuse changes in the activity - unsynchronized changes of bioelectric activity, which is observed in all regions of the brain.
The dominant rhythm (activity) rhythm or activity, the prevailing index or amplitude over the measured segment of the EEG recordings.
E-wave, a slow negative wave that appears while waiting for the irritating stimulus after the filing of the preliminary signal.
Needle electrode - electrode in the form of needles, injected into a particular tissue.
Isoelectricity line or tape electroencephalograph or on the screen of the oscilloscope in the absence of a potential difference at the output of the final stage amplifier. Points on isoelectric lines, dedicated electronic circuits can be used in various techniques of EEG analysis.
The index of rhythm, the time of presence of a particular rhythm (activity) in relation to the time of registration of EEG, expressed as a percentage.
Calibration - flow talonrakennus signal to the amplifier input for further comparison with the recorded EEG.
Channel electroencephalograph –electronic circuit for amplification and registration of the potential difference occurring between a pair of recording electrodes; EEG modern have 8, 13, 16, 20 channels.
Complex activity consisting of two or more components of a particular form, different from the main rhythm, and retains its structure when repeated.
K-complex - the appearance of multiple slow waves with increasing period, passing in a flash of low-frequency beta-rhythm.
A complex of multiple spikes is a sequence of two or more spikes (see ).
Slow wave is a sequence of two or more spikes, and one or two slow waves.
Complex slow spike–wave complex, consisting of spike and slow Delta waves.
The complex spike-wave complex, consisting of spike (cm) and slow wave. And multiple, and single spikes can be in front of slow waves, on top of slow waves and slow waves after; depending on this they are called spike-wave, helmet-shaped wave, wave spike.
Component (component) EEG - any component of the EEG: the wave complex, rhythm, activity, etc.
Convexital surface of the brain surface of the brain adjacent to the frontal, parietal, temporal and occipital bones of the skull.
Cortical electrode - electrode placed directly on the surface of the brain or immersed in the cortex.
Time constant - the time constant of the amplifier.
Lability - the ability of tissue to perform a certain number of individual completed cycles of excitation per second.
Local changes in activity, changes in the bioelectric activity localized in a strictly limited area.
Slow activity - activity that lies in the band of theta and Delta frequencies.
Slow spike - a single oscillation of the potential duration of 80 to 120 MS.
Interelectrode distance - the distance between a pair of recording electrodes connected to the amplifier input. The small interelectrode distance - the distance between two neighboring electrodes corresponding to 20% of the total length of the line drawn according to the "ten-twenty" Jasper. Large interelectrode distance-the distance between two neighboring electrodes, constituting 50% of the total length of the line drawn under the "ten-twenty" Jasper.
The interelectrode resistance is the resistance between a pair of electrodes in kilomax measured when using DC.
Inverse phase - to facilitate the finding of pathological use abstraction "chain"; is that when there are multiple pairs of electrodes for the discharge are made in such a way that the second electrode of this pair is included as the first electrode in the other pair, and the second electrode in the second pair is for the third electrode, which will be the first electrode in the third pair, etc.; the existence of such a specific activity in two channels (one in phase and another out of phase) in the absence of it in all others immediately allows you to set the point at which it is localized.
Monopolar abstraction - abstraction at which one of the electrodes on the projection of brain tissue, and the second on an indifferent point.
Monofaznae wave - a single oscillation extremum which exceeds neighboring components in the same direction.
Mu rhythm - rhythmic potential oscillations in the 7-11 Hz band with a large difference in half-cycles (synonyms: arcuate rhythm, scalloping rhythm rhythmically following the spikes of positive polarity).
The imposition of a (assimilation) - see Reaction of mastering rhythm.
Hazofakelne electrode - see Basal electrode.
Irregular is a term applied to the components of the electroencephalogram manifested intermittent during the recording.
Low-amplitude electroencephalogram EEG in which the potential difference when a bipolar lead with small inter-electrode distances does not exceed 10 mV.
Single-phase wave - see wave monophasic.
Estimated reaction - active response to unexpected change in the usual situation, the behavioral response to novelty. The estimated response consists of a behavioral, electroencephalographic vegetativnoi component that is recorded on EEG in the form of depression of the dominant rhythm. The most commonly used stimulus to study an orienting response is a single flash light standard photostim.
The basic rhythms of the brain - the Delta rhythm, theta rhythm, alpha rhythm, low-frequency beta rhythm (beta-1-rhythm), high-frequency beta-rhythm (beta-2 rhythm), the gamma rhythm.
Abstraction - a method of switching electrodes, which conduct registration of biopotentials of the brain. Distinguish derivations: bipolar, monopolar, referential, Sterno-spinal averaged.
Abstraction bipolar - registration of bioelectrical processes of the brain in conditions when the amplifier input is supplied, the potential difference between two active electrodes (see Electrode, active).
Abstraction monopolar – registration of bioelectrical processes of the brain in conditions when the amplifier input is supplied, the potential difference between the active and indifferent (see common Electrode) electrodes.
Abstraction reference – registration of bioelectrical processes of the brain in conditions when the difference of potentials at several points of the brain are registered in respect of one region.
Abstraction Sterno-spinal - registration of bioelectrical processes of the brain in conditions when the potential difference is recorded between the active electrode and the electrode Sterno-spinal.
The diversion averaged - registration of bioelectrical processes of the brain in conditions when the potential difference is recorded between the active electrode (active electrode) and the average electrode.
The diversion of basal - registration of bioelectrical processes of the brain in conditions when the potential difference is recorded between the active electrode and the electrode basal.
Nasopharyngeal abstraction, see Abstraction basal.
The focus of pathological activity Focus of pathological activity.
Paroxysm is the appearance on the background of the dominant rhythm (activity) of different frequency components with the amplitude exceeding background activity.
A pattern is a logical distribution of the different components of the EEG across convexital surface as inherent in the individual manifestations of the EEG of the subject, and characterizing certain features of the functional state of the brain of a healthy person and in various pathological conditions.
Period - the duration of one oscillation of the potential.
Rush - a single oscillation of potential with a duration of 30 to 60 MS.
Flat EEG, see low-amplitude EEG.
Polymorphic slow activity - activity frequency up to 8 Hz, consisting of raznooobraznyh irregular fluctuations of different period without the dominance of any rhythm.
Polygraphic recording - simultaneous recording of several physiological processes such as EEG, rheoencephalogram REG, ECG, respirogram, oculogram, blood pressure, etc.
Polyrhythm (polyrhythmic activity) - simultaneous occurrence of EEG several major relatively close in amplitude of brain rhythms, nakladyvaya each other in a random order.
Time constant is a characteristic of the channel electroencephalograph, which defines the channel bandwidth for low frequencies is measured relative to its initial shear in response to application of a potential difference DC to the input of the amplifier; the bigger the time constant, the slower the frequency of the transmit amplifier.
The potential is a generalized characteristic that determines the interaction of charges in the studied region of the brain, with the charge imposed on the area of the electrode (determined by the energy of the electric field calculated on a single charge). In quantitative terms corresponds to the voltage between the electrode and the ground (zero potential).
Process-phase - two or more oscillatory processes, one in relation to the other synchronously in time.
Process antiphase to two of the oscillatory process, out of phase (see) 180 degrees.
Category after action (trace level) - a set of waves or a flash of rhythmic fluctuations in potential, following the response to afferent irritation or response to direct stimulation to any of the structures of the brain.
Reactivity - the ability of a tissue or organ to respond to stimulation of any kind of response inherent only in living tissue. In electroencephalography, the term "reagent ity" understand the quantitative characteristic of the bioelectrical brain potentials in response to physiological or physical impact.
Regularity is a term used to describe the constancy of the period or the form of waves or wave complexes over a sufficiently long period of time.
Reaction involving - in the classical form obtained on animals in the form of low frequency response in the rhythm of nonspecific irritation of the thalamus observed in front of them the brain; in humans, see similar manifestations in rhythmic photostimulation in the form of assimilation of the rhythm only in frontal brain regions from 4 to 8 Hz.
The reaction of mastering rhythm - the emergence of bioelectrical brain activity rhythmic components corresponding to the frequency of a rhythmic stimulus (usually a light).
Rhythm - electrical activity having a constant period of oscillation.
Rhythmic photic stimulation (RFU) - functional load intermittent light of different frequency of light flashings when used as a light source lamp with the duration of the light flash no more than 50 MS (gas discharge flash lamp).
Romanticheski rhythm gusto from the allocated band of the alpha rhythm according to the following criteria: localized in Tsentralno-temporal regions of the brain with inhibited motor activity, has no diagnostic value.
Infraslow fluctuations - changes in brain potentials with period of 3 or more.
Selector - a device that allows of the many established during the mouth on the head of the electrodes to pick up some parui connect it to a specific channel electroencephalograph.
Sigma-rhythm alpha-like high-amplitude vari ant of low-frequency beta rhythm, (16 Hz); it is often observed out as a result of pharmacological action of Barberton, with the defeat of diencephalic structures of the brain, during sleep it. D.
Synchronization - organization of the physico-chemical processes of the brain, contributing to regularity (see )its bioelectric activity.
System "ten-twenty" (10-20) - the standard system installation (placement) of electrodes on the surface, which is recommended by the International Federation of electroencephalography and clinical neurophysiology. The location of the electrodes is determined as follows: the line connecting the nose and the occiput, is divided into 10 segments, each of which corresponds to 10% of the total HN length of line drawn at the convexital surface. The first and last electrodes applied at a distance corresponding to 10% of the total length of the line from adjacent anatomical structures. From the first electrode at a distance corresponding to 20% of the total length of the line overlaps the other electrode and Thus, through the nose-the back of the head (the median line, or the vertex line) is applied 5 electrodes. On the line of the outer ear canal mikulecky electrode (Central line)in the same condition is applied to two electrodes on each hemisphere. Lines, parallel median (vertex) and passing through the electrodes, superimposed on the Central line are called parasagittal and temporal (right and left). While parasagittal line 5 is applied to the electrodes, and the temporal - 3 electrode. Only in this case convexital surface 21 is applied to the electrode. Often use a variant in which two electrodes with the vertex line is transferred to the temporal region, i.e. condense the temporal line. When the location of electrodes on the system "10-20" projection eponymous electrodes always fall on the corresponding anatomical region of the brain.
Scalpula EEG, see Electroencephalogram.
Spontaneous activity of the biological activity of the brain, due to its operation in the various States (active wakefulness, passive wakefulness, dream, etc.).
Sleep stage - specific phase of sleep, which has functional value and is characterized by a certain spectral composition of brain activity and other manifestations.
Stationary process - a process by which the probabilistic characteristics do not change over time, Etc
Standard electrode placement, see the System "10-20".
Stereotactic depth EEG recording of the electrical activity of the cortex or subcortical structures of the brain taken from electrodes immersed inside the medulla with the help of a stereotaxic apparatus.
Sub-harmonics, which is a transformation of rhythms in the direction of low frequencies that are multiples of the frequency of the light flashes.
Theta-activity - bioelectric component, representing the potential oscillations with a frequency of 8 Hz AR4 with different oscillation periods, distributed in a random order.
Theta wave - a single oscillation of the potential difference duration 130-250 MS, having a form approaching a sine wave.
Theta-frequency range of the fluctuating potential, lying from 4 to 8 Hz.
Theta rhythm is one of the main brain rhythms (see ), which is a rhythmic oscillation of potential with a constant frequency lying within the OT4 to 8 Hz.
Trigger stimulation - stimulation in the rhythm of oscillations of the potential of the brain. Control the rhythm of irritation through feedback by applying it to fluctuations of potential and turning them into a control signal for the corresponding stimulator. The most common trigger is the method of photostimulation.
Toporama - picture of the spatial distribution of biopotentials, such as the cerebral cortex.
Triangulation - bipolar lead electrodes, arranged in a triangle on the convexital surface.
Phase - the most important characteristic of the oscillatory process, which determines the angle corresponding to the time elapsed from any arbitrarily selected time (if the period of oscillation, corresponding to 360 degrees).
Focus patologicheskoi activity projection area of the brain convexital on the surface, which is most clearly expressed specific pathological forms of the potentials.
Background activity - bioelectric activity of the brain in a state of passive wakefulness, i.e. the state, against which the EEG is usually carried out the study for clinical purposes.
Photobiologically response - the response to rhythmic photic stimulation, characterized by muscle contractions in the rhythm of stimulation.
Testimonial - effects on the test sound stimulus; used as functional load.
Light - exposure of the test light stimulus; used as a functional on the load.
The functional load of any impact on the body to identify the features of responses on which to assess the functional state of the reacting system.
Frequency - number of oscillations in 1 s (Hz Caleb./C).
Helmet wave - see spike-wave.
Electrical activity of the brain - all kinds of bioelectrical processes generated by different elements of the brain tissue.
Electrocorticogram (ECOG) recording bioelectric processes in the conditions of direct discharge from the exposed surface of the brain or with electrodes immersed inside the bark.
Electrocorticogram (Ascog) - recording of bioelectrical processes with electrodes, loaded on into the depths of the brain.
Electrocerebral (Ezbg) - recording of electrical processes in the cerebellum.
Electroencephalogram (EEG) - recording of bioelectrical processes of the brain, taken through electrodes placed not directly on brain tissue, but separated from her bone and skin.
Electroencephalography is a branch of physiology that studies the electrical processes.
The electrode is active - electrode is located directly above the brain structures or embedded in the brain.
Electrode, indifferent electrode, which has no direct contact with the brain or located in an area where there is no brain activity.
The working electrode is the active electrode used to record the potential difference, combined with the indifferent electrode.
The electrode basal electrode inserted through the nasal passage and is located on the hard palate; the abduction from the basal region.
The nasopharyngeal electrode: see Electrode of the basal.
The electrode Sterno-spinally point on the movable arm of the potentiometer (used for eliminating electrocardiographic signal), on the stationary shoulders which serves activity with electrodes mounted on the spinous process of the seventh cervical vertebra and on the right sternoclavicular joint.
The common electrode is any electrode, on which is recorded the bioelectric processes with multiple active electrodes.
Reference electrode: see Electrode in common.
Spheroidally electrode - needle or wire electrode inserted through the soft tissue of the face nizhnesulsky arc; the electrode tip is located within the base of the skull in the region of the oval window.
The electrode - averaged artificial point in the circuit switching of the electrodes, which through сопротивление0, 5-2 Mω is connected with all active electrodes on the convexital surface of the brain imposed on the scheme"10-20"Jasper and is used as a common electrode to all other electrodes.
Epileptic activity - brain activity characteristic of the discharge of an epileptic focus and which is the criterion of its existence regardless of the clinical manifestations of epilepsy. The indicators of the presence of the epileptic focus include complexes paroxysms of spike wave paroxysms of theta waves, paroxysms Delta waves, single or multiple spikes, slow spikes, etc.
Era analysis is a time arbitrarily selected to analyze a portion of the electroencephalogram. In clinical electroencephalography epoch analysis is often 10 seconds.
Sincerely, S. V.<
EEG
Just the same arhinuzhnaya information for the user MM (particularly about average electrode) 
moreover, ALL you need to have Ust on the forum in the relevant sections. Here... 
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Сергей Владимирович
- Posts:30
- Joined:Tue Mar 20, 2007 5:39
Books on EEG can be downloaded here: http://forum.neuroscience.ru/archive/in ... -1427.html