255 research outputs found
Working memory capacity in L2 processing
In this paper, we review the current state of the second language (L2) processing literature and report data suggesting that this subfield should now turn its attention to working memory capacity as an important factor modulating the possibility of (near)-native-like L2 processing. We first review three major overarching accounts of L2 processing (Clahsen et al. 2006a, Grammatical processing in language learners. Applied Psycholinguistics 27. 3–42; Ullman 2001, The declarative/procedural model of lexicon and grammar. Journal of Psycholinguistic Research 30. 37–69; McDonald 2006, Beyond the critical period: Processing-based explanations for poor grammaticality judgment performance by late second language learners. Journal of Memory and Language 55. 381–401; Hopp 2006, Syntactic features and reanalysis in near-native processing. Second Language Research 22. 369–397, and Hopp 2010, Ultimate attainment in L2 inflection: Performance similarities between non-native and native speakers. Lingua 120. 901–931) and frame their predictions in terms of the qualitative and quantitative differences in processing expected between native speakers and L2 learners. We next review event-related potential (ERP) research on L2 processing and argue that the field’s current understanding of qualitative and quantitative differences in ERPs warrants an additional focus on variables other than L2 proficiency that can also predict individual differences in L2 processing. Recent L2 research (relying on ERPs, self-paced reading, and other online measures) suggests that the most promising such variable is working memory (WM) capacity. We summarize results from our recent L2 WM studies – and report new ERP findings – that point to the possibility of a modulatory effect of WM capacity on the nativelikeness of L2 processing. We conclude that the study of WM capacity is the logical next step for this L2 processing subfield
Structure in the Disk of epsilon Aurigae: Analysis of the ARCES and TripleSpec data obtained during the 2010 eclipse
Context: Worldwide interest in the recent eclipse of epsilon Aurigae resulted
in the generation of several extensive data sets, including those related to
high resolution spectroscopic monitoring. This lead to the discovery, among
other things, of the existence of a mass transfer stream, seen notably during
third contact. Aims: We explored spectroscopic facets of the mass transfer
stream during third contact, using high resolution spectra obtained with the
ARCES and TripleSpec instruments at Apache Point Observatory. Methods: One
hundred and sixteen epochs of data between 2009 and 2012 were obtained, and
equivalent widths and line velocities measured, selected according to reports
of these being high versus low eccentricity disk lines. These datasets also
enable greater detail to be measured of the mid-eclipse enhancement of the He I
10830A line, and the discovery of the P Cygni shape of the Pa beta line at
third contact. Analysis: We found evidence of higher speed material, associated
with the mass transfer stream, persisting between third and fourth eclipse
contacts. We visualize the disk and stream interaction using SHAPE software,
and use CLOUDY software to estimate that the source of the enhanced He I 10830A
absorption arises from a region with log n = 10 (/cm3) and temperature of
20,000 K consistent with a mid B type central star. Results and Next Steps: Van
Rensbergen binary star evolutionary models are somewhat consistent with the
current binary parameters for the case of a 9 plus 8 solar mass initial binary,
evolving into a 2.3 and 14.11 solar mass end product after 35 Myr. Prior to the
next eclipse, it is possible to make predictions which suggest that continued
monitoring will help resolve standing questions about this binary
Dissociating morphological and form priming with novel complex word primes: Evidence from masked priming, overt priming, and event-related potentials
Recent research suggests that visually-presented words are initially morphologically segmented whenever the letter-string can be exhaustively assigned to existing morphological representations, but not when an exhaustive parse is unavailable; e.g., priming is observed for both hunter→HUNT and brother →BROTH, but not for brothel→BROTH. Few studies have investigated whether this pattern extends to novel complex words, and the results to date (all from novel suffixed words) are mixed. In the current study, we examine whether novel compounds (drugrack→RACK) yield morphological priming which is dissociable from that in novel pseudoembedded words (slegrack→RACK). Using masked priming, we find significant and comparable priming in reaction times for word-final elements of both novel compounds and novel pseudoembedded words. Using overt priming, however, we find greater priming effects (in both reaction times and N400 amplitudes) for novel compounds compared to novel pseudoembedded words. These results are consistent with models assuming across-the-board activation of putative constituents, while also suggesting that morpheme activation may persevere despite the lack of an exhaustive morpheme-based parse when an exhaustive monomorphemic analysis is also unavailable. These findings highlight the critical role of the lexical status of the pseudoembedded prime in dissociating morphological and orthographic priming
Sensitivity to Inflectional Morphology in a Non-native Language: Evidence From ERPs
The extent to which non-native speakers are sensitive to morphological structure during language processing remains a matter of debate. The present study used a masked-priming lexical decision task with simultaneous electroencephalographic (EEG) recording to investigate whether native and non-native speakers of French yield similar or different behavioral and brain-level responses to inflected verbs. The results from reaction time and EEG analyses indicate that both native and non-native French speakers were indeed sensitive to morphological structure, and that this sensitivity cannot be explained simply by the presence of orthographic or semantic overlap between prime and target. Moreover, sensitivity to morphological structure in non-native speakers was not influenced by proficiency (as reflected by the N400); lower-level learners show similar sensitivity at the word level as very advanced learners. These results demonstrate that native-like processing of inflectional morphology is possible in adult learners, even at lower levels of proficiency, which runs counter to proposals suggesting that native-like processing of inflection is beyond non-native speakers' reach
Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog with Measured Completeness and Reliability Based on Data Release 25
We present the Kepler Object of Interest (KOI) catalog of transiting exoplanets based on searching 4 yr of Kepler time series photometry (Data Release 25, Q1–Q17). The catalog contains 8054 KOIs, of which 4034 are planet candidates with periods between 0.25 and 632 days. Of these candidates, 219 are new, including two in multiplanet systems (KOI-82.06 and KOI-2926.05) and 10 high-reliability, terrestrial-size, habitable zone candidates. This catalog was created using a tool called the Robovetter, which automatically vets the DR25 threshold crossing events (TCEs). The Robovetter also vetted simulated data sets and measured how well it was able to separate TCEs caused by noise from those caused by low signal-to-noise transits. We discuss the Robovetter and the metrics it uses to sort TCEs. For orbital periods less than 100 days the Robovetter completeness (the fraction of simulated transits that are determined to be planet candidates) across all observed stars is greater than 85%. For the same period range, the catalog reliability (the fraction of candidates that are not due to instrumental or stellar noise) is greater than 98%. However, for low signal-to-noise candidates between 200 and 500 days around FGK-dwarf stars, the Robovetter is 76.7% complete and the catalog is 50.5% reliable. The KOI catalog, the transit fits, and all of the simulated data used to characterize this catalog are available at the NASA Exoplanet Archive
Planetary Candidates Observed by Kepler IV: Planet Sample From Q1-Q8 (22 Months)
We provide updates to the Kepler planet candidate sample based upon nearly
two years of high-precision photometry (i.e., Q1-Q8). From an initial list of
nearly 13,400 Threshold Crossing Events (TCEs), 480 new host stars are
identified from their flux time series as consistent with hosting transiting
planets. Potential transit signals are subjected to further analysis using the
pixel-level data, which allows background eclipsing binaries to be identified
through small image position shifts during transit. We also re-evaluate Kepler
Objects of Interest (KOI) 1-1609, which were identified early in the mission,
using substantially more data to test for background false positives and to
find additional multiple systems. Combining the new and previous KOI samples,
we provide updated parameters for 2,738 Kepler planet candidates distributed
across 2,017 host stars. From the combined Kepler planet candidates, 472 are
new from the Q1-Q8 data examined in this study. The new Kepler planet
candidates represent ~40% of the sample with Rp~1 Rearth and represent ~40% of
the low equilibrium temperature (Teq<300 K) sample. We review the known biases
in the current sample of Kepler planet candidates relevant to evaluating planet
population statistics with the current Kepler planet candidate sample.Comment: 12 pages, 8 figures, Accepted ApJ Supplemen
Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog With Measured Completeness and Reliability Based on Data Release 25
We present the Kepler Object of Interest (KOI) catalog of transiting
exoplanets based on searching four years of Kepler time series photometry (Data
Release 25, Q1-Q17). The catalog contains 8054 KOIs of which 4034 are planet
candidates with periods between 0.25 and 632 days. Of these candidates, 219 are
new and include two in multi-planet systems (KOI-82.06 and KOI-2926.05), and
ten high-reliability, terrestrial-size, habitable zone candidates. This catalog
was created using a tool called the Robovetter which automatically vets the
DR25 Threshold Crossing Events (TCEs, Twicken et al. 2016). The Robovetter also
vetted simulated data sets and measured how well it was able to separate TCEs
caused by noise from those caused by low signal-to-noise transits. We discusses
the Robovetter and the metrics it uses to sort TCEs. For orbital periods less
than 100 days the Robovetter completeness (the fraction of simulated transits
that are determined to be planet candidates) across all observed stars is
greater than 85%. For the same period range, the catalog reliability (the
fraction of candidates that are not due to instrumental or stellar noise) is
greater than 98%. However, for low signal-to-noise candidates between 200 and
500 days around FGK dwarf stars, the Robovetter is 76.7% complete and the
catalog is 50.5% reliable. The KOI catalog, the transit fits and all of the
simulated data used to characterize this catalog are available at the NASA
Exoplanet Archive.Comment: 61 pages, 23 Figures, 9 Tables, Accepted to The Astrophysical Journal
Supplement Serie
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