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Lateralized Readiness Potential
In neuroscience, the lateralized readiness potential (LRP) is an event-related brain potential, or increase in electrical activity at the surface of the brain, that is thought to reflect the preparation of motor activity on a certain side of the body; in other words, it is a spike in the electrical activity of the brain that happens when a person gets ready to move one arm, leg, or foot. It is a special form of bereitschaftspotential (a general pre-motor potential). LRPs are recorded using electroencephalography (EEG) and have numerous applications in cognitive neuroscience. History Kornhuber and Deecke's discovery of the Bereitschaftspotential (German for readiness potential) led to research on the now extensively used LRP, which has often been investigated in the context of the mental chronometry paradigm.Coles, M. G. H., 1988. Modern Mind-brain Reading: Psychophysiology, Physiology, and Cognition. 26, 251–269. In the basic chronometric paradigm, the subject experiences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developmental biology, cytology, psychology, physics, computer science, chemistry, medicine, statistics, and mathematical modeling to understand the fundamental and emergent properties of neurons, glia and neural circuits. The understanding of the biological basis of learning, memory, behavior, perception, and consciousness has been described by Eric Kandel as the "epic challenge" of the biological sciences. The scope of neuroscience has broadened over time to include different approaches used to study the nervous system at different scales. The techniques used by neuroscientists have expanded enormously, from molecular and cellular studies of individual neurons to imaging of sensory, motor and cognitive tasks in the brain. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eriksen Flanker Task
In cognitive psychology, the Eriksen flanker task is a set of response inhibition tests used to assess the ability to suppress responses that are inappropriate in a particular context (language use), context. The target is flanked by non-target stimuli which correspond either to the same directional response as the target (''congruent'' flankers), to the opposite response (''incongruent'' flankers), or to neither (''neutral'' flankers). The task is named for American psychologists Barbara. A. Eriksen & Charles W. Eriksen, who first published the task in 1974, and for the flanker stimuli that surround the target. In the tests, a directional response (usually left or right) is assigned to a central target stimulus (psychology), stimulus. Various forms of the task are used to measure information processing and selective attention. Procedure and method In an Eriksen Flanker Task there are three types of stimuli used: #Congruent stimulus- Flankers call for the same response as the targe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N2pc
N2pc refers to an ERP component linked to selective attention.Luck, S. J. (2005). "The operation of attention—millisecond by millisecond—over the first half second." In H. Ogmen & B. G. Breitmeyer (Eds.), ''The first half second: The microgenesis and temporal dynamics of unconscious and conscious visual processes.'' Cambridge, MA: MIT Press The N2pc appears over visual cortex contralateral to the location in space to which subjects are attending; if subjects pay attention to the left side of the visual field, the N2pc appears in the right hemisphere of the brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ..., and vice versa. This characteristic makes it a useful tool for directly measuring the general direction of a person's attention (either left or right) with fine-gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N200 (neuroscience)
The N200, or N2, is an event-related potential (ERP) component. An ERP can be monitored using a non-invasive electroencephalography (EEG) cap that is fitted over the scalp on human subjects. An EEG cap allows researchers and clinicians to monitor the minute electrical activity that reaches the surface of the scalp from post-synaptic potentials in neurons, which fluctuate in relation to cognitive processing. EEG provides millisecond-level temporal resolution and is therefore known as one of the most direct measures of covert mental operations in the brain. The N200 in particular is a negative-going wave that peaks 200-350ms post-stimulus and is found primarily over anterior scalp sites. Past research focused on the N200 as a mismatch detector, but it has also been found to reflect executive cognitive control functions, and has recently been used in the study of language (Folstein & Van Petten, 2008; Schmitt, Münte, & Kutas, 2000). History The N2 component starts with the discove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N100 (neuroscience)
In neuroscience, the N100 or N1 is a large, negative-going evoked potential measured by electroencephalography (its equivalent in magnetoencephalography is the M100); it peaks in adults between 80 and 120 milliseconds after the onset of a stimulus, and is distributed mostly over the fronto-central region of the scalp. It is elicited by any unpredictable stimulus in the absence of task demands. It is often referred to with the following P200 evoked potential as the "N100-P200" or "N1-P2" complex. While most research focuses on auditory stimuli, the N100 also occurs for visual (see visual N1, including an illustration), olfactory, heat, pain, balance, respiration blocking, and somatosensory stimuli. The auditory N100 is generated by a network of neural populations in the primary and association auditory cortices in the superior temporal gyrus in Heschl's gyrus and planum temporale. It also could be generated in the frontal and motor areas. The area generating it is larger in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mismatch Negativity
The mismatch negativity (MMN) or mismatch field (MMF) is a component of the event-related potential (ERP) to an odd stimulus in a sequence of stimuli. It arises from electrical activity in the brain and is studied within the field of cognitive neuroscience and psychology. It can occur in any sensory system, but has most frequently been studied for hearing and for vision, in which case it is abbreviated to vMMN. The (v)MMN occurs after an infrequent change in a repetitive sequence of stimuli (sometimes the entire sequence is called an ''oddball sequence''.) For example, a rare deviant (d) stimulus can be interspersed among a series of frequent standard (s) stimuli (e.g., ''s s s s s s s s s d s s s s s s d s s s d s s s s''...). In hearing, a deviant sound can differ from the standards in one or more perceptual features such as pitch, duration, loudness, or location. The MMN can be elicited regardless of whether someone is paying attention to the sequence. During auditory sequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Positive Component
The late positive component or late positive complex (LPC) is a positive-going event-related brain potential (ERP) component that has been important in studies of explicit recognition memory.Munte, T. F., Urbach, T. P., Duzel, E., & Kutas, M., (2000). Event-related brain potentials in the study of human cognition and neuropsychology, In: F. Boller, J. Grafman, and G. Rizzolatti (Eds.) Handbook of Neuropsychology, Vol. 1, 2nd edition, Elsevier Science Publishers B.V., 97. It is generally found to be largest over parietal scalp sites (relative to reference electrodes placed on the mastoid processes), beginning around 400–500 ms after the onset of a stimulus and lasting for a few hundred milliseconds. It is an important part of the ERP "old/new" effect, which may also include modulations of an earlier component similar to an N400. Similar positivities have sometimes been referred to as the P3b, P300, and P600.Finnigan, S., Humphreys, M.S., Dennis, S., Geffen, G. (2002). ERP 'o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error-related Negativity
Error-related negativity (ERN), sometimes referred to as the Ne, is a component of an event-related potential (ERP). ERPs are electrical activity in the brain as measured through electroencephalography (EEG) and time-locked to an external event (e.g., presentation of a visual stimulus) or a response (e.g. an error of commission). A robust ERN component is observed after errors are committed during various choice tasks, even when the participant is not explicitly aware of making the error; however, in the case of unconscious errors the ERN is reduced. An ERN is also observed when non-human primates commit errors. History The ERN was first discovered in 1968 by Natalia Bekhtereva and was called "error detector". Later in 1990 ERN was developed by two independent research teams; Michael Falkenstein, J. Hohnsbein, J. Hoormann, & L. Blanke (1990) at the Institute for Work Physiology and Neurophysiology in Dortmund, Germany (who called it the "Ne"), and W.J. "Bill" Gehring, M.G.H. Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Left Anterior Negativity
The early left anterior negativity (commonly referred to as ELAN) is an event-related potential in electroencephalography (EEG), or component of brain activity that occurs in response to a certain kind of stimulus. It is characterized by a negative-going wave that peaks around 200 milliseconds or less after the onset of a stimulus, and most often occurs in response to linguistic stimuli that violate word-category or phrase structure rules (as in *''the in room'' instead of ''in the room''). As such, it is frequently a topic of study in neurolinguistics experiments, specifically in areas such as sentence processing. While it is frequently used in language research, there is no evidence yet that it is necessarily a language-specific phenomenon. More recent work has criticized the design of many of the foundational studies that characterized the ELAN, such that apparent ELAN effects might be the result of spillover from words prior to the onset of the critical word. This raises i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difference Due To Memory
Difference due to memory (Dm) indexes differences in neural activity during the study phase of an experiment for items that subsequently are remembered compared to items that are later forgotten. It is mainly discussed as an event-related potential (ERP) effect that appears in studies employing a subsequent memory paradigm, in which ERPs are recorded when a participant is studying a list of materials and trials are sorted as a function of whether they go on to be remembered or not in the test phase. For meaningful study material, such as words or line drawings, items that are subsequently remembered typically elicit a more positive waveform during the study phase (see Main Paradigms for further information on subsequent memory). This difference typically occurs in the range of 400–800 milliseconds (ms) and is generally greatest over centro-parietal recording sites, although these characteristics are modulated by many factors.Wagner, AD., Koutstaal, W., & Schacter, D.L. (1999)When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C1 And P1 (neuroscience)
The C1 and P1 (also called the P100) are two human scalp-recorded event-related brain potential (event-related potential (ERP)) components, collected by means of a technique called electroencephalography (EEG). The C1 is named so because it was the first component in a series of components found to respond to visual stimuli when it was first discovered. It can be a negative-going component (when using a mastoid reference point) or a positive going component with its peak normally observed in the 65–90 ms range post-stimulus onset. The P1 is called the P1 because it is the first positive-going component (when also using a mastoid reference point) and its peak is normally observed in around 100 ms. Both components are related to processing of visual stimuli and are under the category of potentials called visually evoked potentials (VEPs). Both components are theorized to be evoked within the visual cortices of the brain with C1 being linked to the primary visual cortex (s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contingent Negative Variation
The contingent negative variation (CNV) is a negative slow surface potential, as measured by electroencephalography (EEG), that occurs during the period between a warning stimulus or signal and an imperative ("go") stimulus. The CNV was one of the first event-related potential (ERP) components to be described. The CNV component was first described by W. Grey Walter and colleagues in an article published in Nature in 1964. The importance of this finding was that it was one of the first studies which showed that consistent patterns of the amplitude of electric responses could be obtained from the large background noise which occurs in EEG recordings and that this activity could be related to a cognitive process such as expectancy. Main paradigms In their study, Grey Walter et al. (1964) presented a "warning stimulus" (e.g., a single click or flash of light) to a human subject. The warning stimulus was randomly followed (or not followed) by an "imperative stimulus" (repetitive cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
