neural correlates of second language word learning: minimal instruction produces rapid change

Brief CommunicationNature Neuroscience, Volume 7 Number 7, Jul 2004

123 Cognitive Neuroscience of Language Lab (University of Washington)

http://faculty.washington.edu/losterho/research1.htm

Presenter: Gabriel Guillen

LIN 275 NEUROBIOLOGY OF LANGUAGE

Neural correlates of second language word learning: minimal instruction produces rapid change

Judith McLaughin1, Lee Osterhout2 & Albert Kim3

What's good, if

brief, twice good

http://faculty.washington.edu/losterho/research1.htm


Popular claimAdult Second Language (L2) learning is supposed to be slower and harder than native First Language (L1) acquisition. My claim: However, L2 instructors and learners tend to see more progress during the first stages of learning (example: Beginning Spanish 1 compared to Beginning Spanish 3).

Research Question How much exposure to L2 do we need before the brain (activity) reflects the lexical status and meaning of L2 words?


Participants -18 college students (mean age: 21.3 years) studying French for the first time (although they had at least one year of experience with other foreign languages). They also used 8 nonlearners (27.6 years) as control group. -The experiment was longitudinal: 9 months (126-150 hours of instruction).-Did they measure ERPs among learners before session 1? "By session 3, learners' ERP responses were qualitatively similar to analogous native language responses" (p704)... Remember note 5 (Chwilla et al 1995).


Method (ERPs + lexicality judgments) First, they used event-related potentials (ERPs). http://faculty.washington.edu/losterho/erp_tutorial.htmERPs are positive and negative electrical fluctuations related to sensory, motor, or cognitive events (stimulus). In order to represent ERPs, polarity and peak latency (in milliseconds) are used.

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http://faculty.washington.edu/losterho/erp_tutorial.htm


Method (ERPs + lexicality judgments) -As it is common practice, they focused on the N400 component. The N400 peaks at 400 ms after the visual presentation of a word. -The N400 is sensitive to lexical status (word or pseudoword) and word meaning. It is larger for legal pseudo-words (mot, nasier), intermediate for unrelated words (maison, soif) and smaller for related words (chien, chat).

chien, chat (cat, related)

mot, nasier (pseudoword)

maison, soif (thirst, unrelated)


Method (ERPs + lexicality judgments) -They had 3 sessions during the 9 months: Session 1: 5-28 hours of instruction (mean: 14 hours)Session 2: 59-57 hours of instruction (mean: 63 hours) Session 3: 126-150 hours of instruction (mean: 138 hours)-Is it self-reported?

-The stimuli were 2 lists of 112 prime-target pairs of words (40 semantically related, 40 unrelated and 32 pseudowords).

mot, nasier (pseudoword)

maison, soif (thirst, unrelated)chien, chat (cat, related)


Method (ERPs + lexicality judgments) -The prime and target words were the most frequent? adjectives, nouns and verbs from the assigned textbook. Pseudowords came from the textbook but they replaced one or two central letters. -The researchers had just 2 lists so they repeated lists -the list in session 1 was repeated for session 3.

Lexical sensitivity: d'-Participants were not passive. They had to make lexical decisions. Is it a word or a non-word? -They measured the lexical sensitivity from 0 (no sensitivity) to 4 (near-perfect sensitivity, recognize all or almost all of the target words).

d'= z (h) - z(fa)z(h) proportion of real words identified as words (hits) z(fa) proportion of non-words identifed as words (false alarms)


Results-The lexical sensitivity index (d') was near 0 for learners and nonlearners. Bad news? C'mon, they are still beginners... -In fact, learners show "moderate increases in sensitivity during session 2 and 3" (p703).


Results-They did not find N400 amplitude modulations for nonlearners. -Personal question: why do we find negative polarity for Session 2 and 3 and not for Session 1? -At any case, notice there is no significant difference between pseudo-words, related words and unrelated words with nonlearners.


Results-Among learners, pseudo-words elicited larger N400than unrelated or related words. -"By session 3, learners' ERP responses were qualitatively similar to analogous native language responses" (704)


Results-According to the authors, the most remarkable finding is the N400 effect for word and pseudo-wordsafter just 14 hours of instruction.


Results-Is there a real correlation between N400 differences in session 1 and hours of instruction?-They regressed the N400 differences and d' scores with the hours of instruction before session 1.


Results-Caveat. Was there a smaller mean grapheme co-ocurrence values for the pseudowords? In other words, letter and sounds combinations that were less frequent? They computed the frequencies and there were no bigram (2 letter together, i.e. th) or trigram frequency differences between words and pseudowords. There was a difference for quadragram frequency but the associate it with target word frequency.


Conclusions-After minimal instruction, adult L2 beginners show significant knowledge about L2 words (word form first and word meaning after).-ERPs to words and pseudo-word show this "early learning" before the lexicality judgements. -Ergo... "adult L2 learning is not uniformly slow and laborious" (704). In fact,"certain aspects of the language are acquired with remarkable speed" (704).-Also, ERPs seem to be more accurate than explicit or categorical assessments, such as the lexicality judgments. -This method can be used (is used) with L1-L2 similarity, instructional methods and age. http://scholar.google.com/scholar?hl=en&q=%22neural+correlates+of+second+language%22&as_sdt=1%2C5&as_ylo=2004&as_vis=0

http://scholar.google.com/scholar?hl=en&q=%22neural+correlates+of+second+language%22&as_sdt=1%2C5&as_ylo=2004&as_vis=0



neural correlates of second language word learning: minimal instruction produces rapid change

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