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3.3 SUMMARY OF RESULTS

3.1 ENGLISH NATIVE SPEAKERS 3.2 GERMAN L2 GROUP 3.3 DIRECT COMPARISION L1 AND L2 (Diff waves)

Putting the critical period hypothesis to the test:

A new paradigm allows a critical view on the ELAN in L1 and L2 speakers Stefanie Nickels and Karsten Steinhauer McGill University ▪ Centre for Research on Brain, Language and Music (CRBLM)

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Stefanie.Nickels@mail.mcgill.ca

1.1 INTRODUCTION Event-related potentials (ERPs) have frequently been used to assess the similarity between first (L1) and second (L2) language online processing due to their exceptional temporary resolution. Thus, ERPs are also particularly suitable to inform the debate around critical period and proficiency-based accounts for second language acquisition. Generally, the more ERP signatures in late L2 learners resemble those of native speakers, the harder it is to argue for fundamental differences between early and late acquisition. Friederici's auditory sentence processing model (2002) has reached prominence in both L1 and L2 thanks to ample supporting evidence, and the ease with which assumptions can be tested. The model assumes three strictly serial stages of analysis for each incoming word: The ELAN has received particular attention in L2 research since it has been claimed to be an automatic, early marker for syntax processing, that might be absent in late L2 learners, whereas later components reflecting more controlled processes were found to be similar in L1 and L2 (Hahne & Friederici, 2001; Weber-Fox and Neville, 1996). Findings on the ELAN have been far from unanimous. While some found no ELAN in L2 speakers (Hahne, 2001), others did report ELANs even in subjects that were entirely unaware of the target language (Mueller, 2005), or in groups of both low proficient and high proficient L2 speakers (Rossi et al., 2006). Recently, however, serious doubt has been cast on the validity of the ELAN as a reliable and independent marker of early word category processing (Steinhauer & Drury, 2012). Most seminal ELAN studies in both L1 and L2 used one very similar, context-manipulating design with sentences like (1) and (2) to create word category violations. Note how the pre-target words differ both semantically and prosodically.

(1) Das Brot wurde gegessen. (The bread was eaten.) (2) Das Eis wurde *im gegessen. (The ice-cream was *in-the eaten.) (Hahne, 2001)

This design is very unfortunate for an ERP study, because having similar baselines (i.e. pre-target contexts) is crucial in order to compare conditions reliably. In cases where the context prior to the target word already differs, it is impossible to tell if early differences stem from the differing context or from the phrase structure (PS) violation on the target word.

1.2 RESEARCH QUESTIONS 1. How much is left of the ELAN if an unconfounded paradigm is used? 2. Are there still differences between L1 and high proficient L2 speakers using the counter-

balanced approach? 3. If so, how does that inform the debate about critical period and proficiency-based models for

second language processing ?

Phase 1 (100-300 ms):

Word Category

• Violations result in ELANs (“early left anterior negativity)

Phase 2 (300-600 ms):

Semantics and Morhphosyntax

• Violations result in N400s or LANs respectively

Phase 3 (after 600 ms):

Integration of all channels

• Violations result in P600s

2.2 SUBJECTS Twenty German high proficient, late learners of English (9 ♀) were compared to 20 Canadian native speakers of English (native data from Pauker et al., poster presented at NCL 2009). L2 speakers received on average 8.9 (3.0) years of English education, with the education starting at 11.7 (1.6) years of age.

2.3 MATERIALS In order to avoid the confounds present in earlier studies, we employed a counter-balanced target- and context-manipulating design that allows us to eliminate the influence of different contexts on the word category violation. A The man hoped to enjoy the meal with friends. B The man cooked the meal to enjoy with friends. C The man hoped to *meal the enjoy with friends. D The man cooked the *enjoy to meal with friends.

2.4 DATA RECORDING AND ANALYSIS ERPs were recorded from 19 cap-mounted Ag/AgCl electrodes. Data processing was identical to Pauker at al. (2011). For the graphics in the results section, we employed a -100 to 0 baseline time-locked to the onset of the underlined target word. Statistical analysis included the factors Condition (AvsD, 2 levels: A and D; or ABvsCB, 2 levels: AB and CD), Hemisphere (2: left, right), Laterality (2: medial, lateral) and AnteriorPosterior (3: frontal, central, posterior).

1. Comparison A versus D We expect to find early differences that are exclusively due to context effects and not due to the PS violation. 2. Comparison A/B versus C/D After eliminating the influence of differing contextsand target words we expect no early effects, but a sustained negativity (Hasting & Kotz, 2008).

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“ELAN”

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No “ELAN”

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Statistical effects at lateral electrodes (midline effects were the same)

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“ELAN” AvsD: >.01 AvsD*Lat: >.01 AvsD*AntPost: >.01 AvsD*Hemi*Group: >.03

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N400 AvsD: >.01 AvsD*Lat: >.01 AvsD*AntPost*Hemi*Group: =.0662

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P600 AvsD*AntPost: >.01 AvsD*AntPost*Group: >.05 AvsD*Lat: >.01

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Sust. Neg. (only at F7 & F8)

AvsD: >.03

Statistical effects at lateral electrodes (midline effects were the same)

100-300

“ELAN” ABvsCD*Hemi*Group: >.03

300-800

N400 ABvsCD: >.01 ABvsCD*Lat: >.05 ABvsCD*AntPost*Hemi*Group: >.01

800-1700

P600 ABvsCD*AntPost: >.01 ABvsCD*AntPost*Group: >.03 ABvsCD*Lat: >.01 ABvsCD*AntPost*Hemi*Group: >.01

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Sust. Neg. (only at F7 and F8)

ABvsCD: >.03 ABvsCD*Group: =.0642 (for Group seperately: English: ABvsCD: >.02 German: ABvsCD: .63 (n.s.))

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Counter-balanced Analysis - allows independent assessment of PS violation effects

Shared effects between Groups : Sustained negativity only in L1 group, N400, P600 Differences: Early right lateralized negativity, right-central N400, occipital P600, sustained negativity Early left lateralized negativity, left-centro-parietal N400, parietal P600, no sustained negativity

Traditional Analysis - mirrors most previous ELAN studies

Shared effects between Groups: Early negativity, sustained negativity, N400, P600 Differences: Early right-central negativity, right-central N400, occipital P600 – no difference in sustained negativity Early left-parietal negativity, left-centro-parietal N400, parietal P600 – no difference in sustained negativity

Referring back to our research question, we can draw these conclusions: 1. ELAN as an independent marker of PS violations

• ELAN disappears when a counter-balanced design is used. What remains is a sustained negativity.

2. Differences between L1 and high proficient L2 speakers

• Neither the ELAN nor the sustained negativity are present in the L2 speakers group.

• However, as demonstrated here the ELAN itself is most likely a context artifact and does not represent the PS violation. Therefore the absence of the ELAN should not be interpreted as a lack of early automatic processing.

• The sustained negativity however cannot be attributed to artifacts and must be viewed as the unconfounded effect of a PS violation.

3. Critical Period vs. Proficiency • Subjects in this study were late learners of English. Yet, their brain

signatures have shown mostly quantitative differences compared to L1 speakers.

• The lack of the sustained negativity in L2 speakers, however, is a qualitative difference between L1 and L2.

• It has been argued that increases in proficiency can lead to both qualitative and quantitative changes in ERPs.

• In this context, we predict that the sustained negativity would eventually emerge once native-like attainment has been reached, independent of age of acquisition.

• In summary, we take the similarity between L1 and L2 in this study as evidence against a strict critical hypothesis account, which claims that there are fundamental differences between L1 and L2 processing.

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Funding provided by:

4.1 SUMMARY OF RESULTS

• ELAN: • Using the traditional approach, patterns from previous ELAN studies

were replicated (but with unusual topography). • In our opinion, the topography of the ”ELAN” is strongly

dependent on the specific nature of the differences (semantic and prosodic) of the pre-target words, creating different artifacts in the early time window.

• We believe that the specific topography in this study is due to already more similar pre-target words in our study (both function words) as compared to e.g. Hahne (2001) (one function, one content word).

• Sustained negativity:

• This component is only present in native, but not in L2 speakers. • Has been linked to working memory processes in various language

related tasks (see Steinhauer et al., 2010), particularly to subvocal rehearsing in the phonological buffer.

• N400: • Somewhat surprising because N400s should be blocked in presence

of a PS violation. Steinhauer & Drury (2012) argue that this “semantic blocking” is another artifact created by the very limited stimulus materials employed in traditional ELAN studies.

• Thus here, where such artifacts had been avoided, we assume that the N400 reflects a conceptual/semantic anomaly.

• P600:

• Reflects classical repair/reanalysis processes due to the violation.

No “ELAN”

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Sustained Negativity No “ELAN”

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No Sustained Negativity