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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. ==Characteristics of the ELAN== The ELAN was first reported by Angela D. Friederici as a response to German sentences with phrase structure violations, such as *''the pizza was in the eaten'' (as opposed to ''the pizza was eaten''); it can be elicited by English phrase structure violations such as *''Max's of proof'' (as opposed to ''Max's proof'') or *''your write'' (as opposed to ''you write'').〔 The ELAN is not elicited by sentences with other kinds of grammatical errors, such as subject-verb disagreement ( *"''he go to the store''" rather than "''he goes to the store''") or grammatically dispreferred and "awkward" sentences (such as "''the doctor charged the patient was lying''" rather than "''the doctor charged that the patient was lying''"); it only appears when it is impossible to build local phrase structure. It appears rapidly, peaking between 100 and 300 milliseconds after the onset of the grammatically incorrect stimulus〔 (other reports have placed its time course, or ''latency'', between 100 and 200ms, "under 200ms,"〔 "around 125 ms,"〔 or "about 160ms"). The speed of the ELAN may also be affected by characteristic of the violating stimuli; the ELAN appears later to visual stimuli that are fuzzy or difficult to see, and may occur earlier in morphologically complex spoken words where much information about the meaning of the word precedes the word's recognition point.〔 Its name derives from the fact that it is picked up most robustly by EEG sensors on the left front regions of the scalp;〔 it may sometimes, however, have a bilateral (both sides of the scalp) distribution. Some authors consider the ELAN to be a separate response from the Left anterior negativity (LAN),〔〔 while others label it as just an early version of the LAN.〔 The ELAN has been reported in languages such as English, German, Dutch, Chinese, and Japanese.〔 It is possible, though, that it is not a response specific to language (in other words, that the ELAN might also occur in response to non-linguistic stimuli.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Early left anterior negativity」の詳細全文を読む スポンサード リンク
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