Event-related brain potentials elicited during word recognition by adult good and poor phonological decoders

Visual recognition of identical cognates involves sublexical inhibition and lexical facilitation

The study investigated the consequences of cross-language activation on the time course of bilingual word recognition. Twenty-two Spanish-English bilinguals and 21 English monolingual controls decided whether visually presented letter strings were English words, while behavioral and event-related potential responses were recorded. The language status of words was manipulated experimentally, such that words were either identical cognates between English and Spanish (e.g. CLUB) or noncognates (e.g. CLOCK). Participants were equally fast in responding to cognate and noncognate words. Bilinguals were more accurate in responding to cognates, whereas monolinguals exhibited higher accuracy in response to noncognates. Critically, bilinguals produced larger P200 followed by smaller N400 responses to cognates than noncognates, whereas monolinguals showed a pattern of reduced N400 responses to cognates. The results of the current study indicate that cross-language activation may not only result in lexical facilitation (indexed by a reduction of the N400 response to cognates) as a result of shared form-meaning associations across languages but also in sublexical inhibition (indexed by a larger P200 response to cognates) as a consequence of cross-language competition among phonological forms. Results support the language-nonselective view of bilingual lexical access and suggest that while lexical facilitation for identical cognates may be observed at most levels of second language proficiency, sublexical inhibition in response to identical cognates may be a marker of advanced levels of proficiency.

No Morphological Markers, No Problem: ERP Study Reveals Semantic Contribution to Distinct Neural Substrates Between Noun and Verb Processing in Online Sentence Comprehension

Neural mechanisms behind noun and verb processing during the course of language comprehension are ubiquitously separate, yet it remains highly controversial as to which factor, syntax or semantics, should be responsible for this separation. This paper conducted an event-related potential (ERP), sentence comprehension experiment as an attempt to resolve this issue. The experiment used Chinese sentences in the configuration of noun phrase + (“not/no”) + noun/verb/noun-verb-ambiguous-word, which excluded grammatical or syntactic factors that could hint at the lexical categories of sentence-final target words. Results showed significantly distinct ERP components of P200, N400, and P600 between noun and verb processing in native speakers, indicating that semantic factors are essential for the differentiated neural mechanisms behind noun and verb processing. Distinct P200, N400, and P600 also manifested between noun and noun-verb-ambiguous-word processing, but not between verb and noun-verb-ambiguous-word processing. This suggests that lacking clues on lexical category renders the dynamic properties of the ambiguous words more salient than the static properties, thus causing interpretation of such words more likely as verbs. This further elaborates the crucial role of semantic factors in noun and verb processing.

When a hit sounds like a kiss: An electrophysiological exploration of semantic processing in visual narrative

Researchers have long questioned whether information presented through different sensory modalities involves distinct or shared semantic systems. We investigated uni-sensory cross-modal processing by recording event-related brain potentials to words replacing the climactic event in a visual narrative sequence (comics). We compared Onomatopoeic words, which phonetically imitate action sounds (Pow!), with Descriptive words, which describe an action (Punch!), that were (in)congruent within their sequence contexts. Across two experiments, larger N400s appeared to Anomalous Onomatopoeic or Descriptive critical panels than to their congruent counterparts, reflecting a difficulty in semantic access/retrieval. Also, Descriptive words evinced a greater late frontal positivity compared to Onomatopoetic words, suggesting that, though plausible, they may be less predictable/expected in visual narratives. Our results indicate that uni-sensory cross-model integration of word/letter-symbol strings within visual narratives elicit ERP patterns typically observed for written sentence processing, thereby suggesting the engagement of similar domain-independent integration/interpretation mechanisms.

N1 and P2 to words and wordlike stimuli in late elementary school children and adults

In an investigation of the development of fine-tuning for word processing across the late elementary school years as indexed by the posterior N1 and P2 components of the ERP waveform, third, fourth, and fifth graders and a comparison group of adults viewed words, pseudowords, nonpronounceable letter strings, and false font strings in a semantic categorization task. In adults, N1 was larger to and P2 was later to words as compared to pseudowords, a finely tuned effect of lexicality reflecting specialization for word processing. In contrast, in each group of children, N1 was larger to letter strings than false font strings and P2 was larger to false font strings than letter strings, reflecting coarse encoding for orthography. In regression analyses, scores on standardized behavioral test measures of orthographic knowledge, decoding skill, and fluency predicted N1 amplitude; these effects were not significant with age included as a separate predictor. None of the behavioral scores, in models including or not including age, predicted P2 amplitude. In direct comparisons between groups, there were multiple differences between the child and adult groups for both N1 and P2 amplitude effects, and only a single significant difference between two child groups. Overall, the findings suggest a lengthy developmental time course for the fine-tuning of early word processing as indexed by N1 and P2.

ERP correlates of the development of orthographical and phonological processing during Chinese sentence reading

An event-related potential (ERP) experiment was conducted to investigate the development of orthographic and phonological processing during Chinese sentence reading between school children and adult readers. Participants were visually presented with sentences, word-by-word, and were asked to judge whether the sentences were semantically acceptable. The crucial manipulation was on the sentence-final two-character compound words, which were either correct or incorrect. For the incorrect compounds, the second characters of the base words were replaced by homophonic or orthographically similar characters. ERP results showed that, across participant groups, the peak of P200 appeared earlier for the homophonic condition than for the orthographic and the baseline conditions. Importantly, for both child and adult readers, relative to the baseline, both orthographic mismatch in the homophonic condition and phonological mismatch in the orthographic condition elicited N400 effects. While for adults these effects appeared to be equal in size, the peak of the N400 component appeared earlier for orthographic mismatch than for phonological mismatch. For children the N400 effect was larger for orthographic mismatch than for phonological mismatch. The N400 component was also more negative for children than for adults in the homophonic condition, and its peak appeared later for children than for adults in the homophonic and the baseline conditions. Moreover, the offset of the N400 effects appeared earlier for adults than for children and for orthographic mismatch than for phonological mismatch. These findings suggest that both Chinese adult readers and school children rely more on orthographic information than on phonological information to access lexical semantics in reading Chinese sentences. However, the differential effects between orthography and phonology may have different ERP manifestations in adults and children.