The initial left anterior negative (commonly referred to as ELAN ) is the potential associated with an event in electroencephalography (EEG), or a component of brain activity that occurs in response to a type of stimulus. It is characterized by negative waves reaching about 200 milliseconds or less after the onset of the stimulus, and most often occurs in response to linguistic stimuli that violate the rules of word category or phrase rules (as in * in rooms instead in the room ). Thus, this is often the topic of study in neurolinguistic experiments, particularly in areas such as sentence processing. Although often used in language research, there is no evidence that it is a language-specific phenomenon.
Video Early+left+anterior+negativity
Characteristics
ELAN was first reported by Angela D. Friederici in response to a German sentence with a violation of phrase structure, such as * the pizza was eaten (compared to pizza eaten i>); it can be caused by a violation of the structure of English phrases like * Max proof (as opposed to Max proof ) or * write you (as opposed to You write ). ELAN is not generated by sentences with other types of grammatical errors, such as subject-verb inequality (* " he goes to the store " rather than " he goes to the store ") or sentence grammatically dispallferred and "awkward" (like " doctors accusing patients of lying " rather than " doctors accusing patients of lying "); it only arises when it is impossible to construct a local phrase structure.
This appears quickly, peaking between 100 and 300 milliseconds after the inception of a grammatically incorrect stimulus (other reports have put the course of time, or latency , between 100 and 200ms, "under 200ms", "around 125 ms ", or" about 160ms "). ELAN velocity may also be influenced by the characteristics of arbitrary stimuli; ELAN appears later to visual impulses that are hazy or hard to see, and may occur earlier in complex morphologic oral words in which much of the information about the meaning of words precedes the point of recognition of words.
Its name comes from the fact that it was taken most powerfully by EEG sensors in the left front area of ​​the scalp; can sometimes, however, have a bilateral distribution (both sides of the scalp).
Some authors consider ELAN as a separate response from the negative left side (LAN), while others refer to it as just an early version of the LAN.
ELAN has been reported in languages ​​like English, German, Dutch, Chinese, and Japanese. However, it is possible that it is not a specific response to the language (in other words, that ELAN may also occur in response to non-linguistic stimuli).
Maps Early+left+anterior+negativity
Use in neurolinguistics
The ELAN response has played an important role in the study of sentence processing, especially in the development of so-called "model series" or "first-syntax-models" of sentence processing. According to this model, the first step of the brain in processing a sentence is to organize the input and construct a local phrase structure (for example, to retrieve the words the and pizza and set them into a noun phrase pizza ), and it does not process information or semantic meaning until after this step succeeds. This model predicts that if the initial building of the local phrase structure fails (as in the example above * Max proof and * write you ) then semantic processing (brain interpretation of the sentence meaning) is not advanced. It has been tested by taking advantage of two brain responses: ELAN, which reflects phrase-structure development, and N400, which reflects semantic processing; the model predicts that the sentence that elicits ELAN (a violation of the local phrase structure) will not produce N400, since the development of the phrase structure is a prerequisite for semantic processing. The types of research have subjects who read or listen to sentences that have syntactic and semantic violations in the same place. Some such research has found such sentences to obtain ELAN and N400, thus supporting the claim of "model series", while others have found ELAN and N400, which challenge the model.
See also
- N400
- P600
Other ERP components
References
Source of the article : Wikipedia
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