User:Rjanag/Neurotechniques

Priming

 * Zwitzerlood
 * Cross-modal lexical priming
 * Zurif et al (1993)
 * Long-lag priming
 * Devlin et al (2004)
 * Pylkkanen et al (2008)
 * Masked priming
 * Fiorentino and Poeppel (2007)

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Mismatch paradigm
The mismatch negativity (MMN) is a rigorously documented ERP component frequently used in neurolinguistic experiments. It is an electrophysiological response that occurs in the brain when a subject hears or sees a "deviant" stimulus in a set of perceptually identical "standards" (as in the sequence s s s s s s s d d s s s s s s d s s s s s d). Since the MMN is elicited only in response to a rare "oddball" stimulus in a set of other stimuli that are perceived to be the same, it has been used to test how speakers perceive sounds and organize stimuli categorically. For example, one study presented speakers with numerous /t/ and /d/ stimuli, keeping the ratio of /t/s and /d/s constant to achieve a standard-deviant ratio but varying the voice onset time of all the stimuli within each category; the subjects still showed an MMN, suggesting that even though all the /d/ tokens (and all the /t/ tokens) were physically different in terms of their acoustic properties, the subjects perceptually organized them into the abstract phonemic categories of /d/ and /t/. In addition, the mismatch paradigm has been used to study syntactic processing and the recognition of word category.

Violation-based
Many studies in neurolinguistics take advantage of anomalies or violations of syntactic or semantic rules in experimental stimuli, and analyzing the brain responses elicited when a subject encounters these violations. For example, sentence beginning with phrases such as *the garden was on the worked, which violates an English phrase structure rule, often elicit a brain response called the Early Left Anterior Negativity (ELAN). Violation techniques have been in use since at least 1980, when Kutas and Hillyard first reported that semantic violations elicited an N400 effect. Violation designs have also been used for hemodynamic studies (fMRI and PET): Embick and colleagues, for example, used grammatical and spelling violations to investigate the location of syntactic processing in the brain using fMRI. Another common use of violation designs is to combine two kinds of violations in the same sentence and thus make predictions about how different language processes interact with one another. For example, Ye and colleagues performed a study of syntactic and semantic violations in Mandarin to demonstrate that syntactic structure-building may precede semantic interpretation, and Frisch et al used different kinds of syntactic violations to demonstrate that the semantic interpretation of verbs cannot take place if the language parser fails to build an initial syntactic structure.

Tasks
In many neurolinguistics experiments, subjects do not simply sit and listen to or watch stimuli, but also are instructed to perform some sort of task in response to the stimuli. At least one study has suggested that the task the subject does has an effect on the brain responses and the results of the experiment.


 * Lexical decision

The lexical decision task involves subjects seeing or hearing an isolated word and answering whether or not it is a real word. It is frequently used in priming studies, since subjects are known to make a lexical decision more quickly if a word has been primed by a related word (as in "doctor" priming "nurse").

Many studies, especially violation-based studies, have subjects make a decision about the "acceptability" of stimuli. Such a task is often used to "ensure that subjects [are] reading the sentences attentively and that they [distinguish] acceptable from unacceptable sentences in the way [the experimenter] expected them to do."
 * Grammaticality judgment, acceptability judgment

Experimental evidence has shown that the instructions given to subjects in an acceptability judgment task can influence the subjects' brain responses to stimuli. One experiment showed that when subjects were instructed to judge the "acceptability" of sentences they did not show an N400 brain response (a response commonly associated with semantic processing, but that they did show that response when instructed to ignore structural acceptability and only judge whether or not the sentences "made sense."

Some studies use a "probe verification" task rather than an overt acceptability judgment; in this paradigm, each experimental sentence is followed by a "probe word," and subjects must answer whether or not the probe word had appeared in the sentence. This task, like the acceptability judgment task, ensures that subjects are reading or listening attentively, but may avoid some of the additional processing demands of acceptability judgments, and may be used no matter what type of violation is being presented in the study.
 * Probe verification

Subjects may be instructed not to judge whether or not the sentence is grammatically acceptable or logical, but whether the proposition expressed by the sentence is true or false. It is most commonly used in psycholinguistic studies of child language.
 * Truth-value judgment

Some experiments give subjects a "distractor" task to ensure that subjects are not paying attention to the experimental stimuli; this may be done to test whether a certain computation in the brain is carried out automatically, regardless of whether the subject devotes attentional resources to it. For example, one study had subjects listen to nonlinguistic tones in one ear and speech in the other hear, and instructed subjects to press a button when they perceived an attenuation in the tone; this caused subjects not to pay attention to grammatical violations in the speech stimuli. This experimental task allowed the researchers to conclude that brain responses to grammatical errors reflected automatic syntactic processing, since the subjects were not actively paying attention to grammar.
 * Active distraction