Lexical frequency and sentence context influence the brain’s response to single words

Typical adults read remarkably quickly. Such fast reading is facilitated by brain processes that are sensitive to both word frequency and contextual constraints. It is debated as to whether these attributes have additive or interactive effects on language processing in the brain. We investigated this issue by analysing existing magnetoencephalography data from 99 participants reading intact and scrambled sentences. Using a cross-validated model comparison scheme, we found that lexical frequency predicted the word-by-word elicited MEG signal in a widespread cortical network, irrespective of sentential context. In contrast, index (ordinal word position) was more strongly encoded in sentence words, in left front-temporal areas. This confirms that frequency influences word processing independently of predictability, and that contextual constraints affect word-byword brain responses. With a conservative multiple comparisons correction, only the interaction between lexical frequency and surprisal survived, in anterior temporal and frontal cortex, and not between lexical frequency and entropy, nor between lexical frequency and index. However, interestingly, the uncorrected index*frequency interaction revealed an effect in left frontal and temporal cortex that reversed in time and space for intact compared to scrambled sentences. Finally, we provide evidence to suggest that, in sentences, lexical frequency and predictability may independently influence early (<150ms) and late stages of word processing, but also interact during late stages of word processing (>150-250ms), thus helping to converge previous contradictory eye-tracking and electrophysiological literature. Current neuro-cognitive models of reading would benefit from accounting for these differing effects of lexical frequency and predictability on different stages of word processing.

EXPRESS: Predictability effects and parafoveal processing of compound words in natural Chinese reading

We report a boundary paradigm eye movement experiment to investigate whether the predictability of the second character of a two-character compound word affects how it is processed prior to direct fixation during reading. The boundary was positioned immediately prior to the second character of the target word, which itself was either predictable or unpredictable. The preview was either a pseudocharacter (nonsense preview), or an identity preview. We obtained clear preview effects in all conditions, but more importantly, skipping probability for the second character of the target word and the whole target word from pretarget was greater when it was predictable than when it was not predictable from the preceding context. Interactive effects for later measures on the whole target word (gaze duration and go-past time) were also obtained. These results demonstrate that predictability information from preceding sentential context and information regarding the likely identity of upcoming characters are used concurrently to constrain the nature of lexical processing during natural Chinese reading.

Processing Mandarin Tone 3 Sandhi at the Morphosyntactic Interface: Reduplication and Lexical Compounds

Mandarin tone 3 sandhi is a phonological alternation in which the initial tone 3 (i.e., low tone) syllable changes to a tone 2 (i.e., rising tone) when followed by another tone 3. The present study used a cross-modal syllable-morpheme matching experiment to examine how native speakers process the sandhi sequences derived from verb reduplication and compounding, respectively. Embedded in a visually-presented sentential context, a disyllabic sequence containing a sandhi target was displayed simultaneously with a monosyllabic audio, either a tone 1 (i.e., high-level tone), tone 2 (i.e., rising tone) or tone 3 (i.e., low tone), and participants judged whether the audio syllable matched the visual morpheme. Results showed that the tone 3 sandhi was processed differently in the two constructions. The underlying tone and the surface tone were co-activated and competed with each other in sandhi compounds whereas predominant activation of the underlying tone, over the surface tone, was observed in reduplication. The processing of tone 3 sandhi offers support for distinctive morphological structures: a lexical compound is represented both as a whole-word unit and as a combination of two individual morphemes whereas a verb reduplication is represented and accessed as a monomorphemic unit in the mental lexicon.

EEG theta responses induced by emoji semantic violations

This study investigated emoji semantic processing by measuring changes in event-related electroencephalogram (EEG) power. The last segment of experimental sentences was designed as either words or emojis consistent or inconsistent with the sentential context. The results showed that incongruent emojis led to a conspicuous increase of theta power (4–7 Hz), while incongruent words induced a decrease. Furthermore, the theta power increase was observed at midfrontal, occipital and bilateral temporal lobes with emojis. This suggests a higher working memory load for monitoring errors, difficulty of form recognition and concept retrieval in emoji semantic processing. It implies different neuro-cognitive processes involved in the semantic processing of emojis and words.

Vois-tu le kem? Do you see the bos? Foreign word learning at 14-months

How easily can infants regularly exposed to only one language begin to acquire a second one? In three experiments, we tested 14‐month‐old English and French monolingual infants’ ability to learn words presented in foreign language sentence frames. Infants were trained on two novel word‐object pairings and then tested using a preferential looking task. Word forms were phonetically and phonotactically legal in both languages, and cross‐spliced across conditions, so only the sentence frames established the word as native or foreign. In Experiment 1, infants were taught one native and one foreign word and successfully learned both. In Experiment 2 and 3, infants were taught two foreign words, but only showed successful learning of the first word they encountered. These results demonstrate that infants can successfully learn words embedded in foreign language sentences, but this is more challenging than native word learning. More broadly, they show that the sentential context of a novel word, and not just the word form itself, influences infants’ early word learning.

Attraction Effects for Verbal Gender and Number Are Similar but Not Identical: Self-Paced Reading Evidence From Modern Standard Arabic

Previous work on the comprehension of agreement has shown that incorrectly inflected verbs do not trigger responses typically seen with fully ungrammatical verbs when the preceding sentential context furnishes a possibly matching distractor noun (i.e., agreement attraction). We report eight studies, three being direct replications, designed to assess the degree of similarity of these errors in the comprehension of subject-verb agreement along the dimensions of grammatical gender and number in Modern Standard Arabic. A meta-analysis of the results demonstrate the presence of agreement attraction effects in reading comprehension for gender and number on verbs. Moreover, the meta-analysis demonstrates that these two features do not behave identically: gender effects are larger and occur later relative to number attraction effects. These results challenge models of agreement that predict agreement features to be equipotent and show that real-time models of agreement require modifications in the form of cue-weighting in order to account for these differential results.

Idiomatic Expression Identification using Semantic Compatibility

Idiomatic expressions are an integral part of natural language and constantly being added to a language. Owing to their non-compositionality and their ability to take on a figurative or literal meaning depending on the sentential context, they have been a classical challenge for NLP systems. To address this challenge, we study the task of detecting whether a sentence has an idiomatic expression and localizing it when it occurs in a figurative sense. Prior research for this task has studied specific classes of idiomatic expressions offering limited views of their generalizability to new idioms. We propose a multi-stage neural architecture with attention flow as a solution. The network effectively fuses contextual and lexical information at different levels using word and sub-word representations. Empirical evaluations on three of the largest benchmark datasets with idiomatic expressions of varied syntactic patterns and degrees of non-compositionality show that our proposed model achieves new state-of-the-art results. A salient feature of the model is its ability to identify idioms unseen during training with gains from 1.4% to 30.8% over competitive baselines on the largest dataset.

EEG Theta Responses Induced by Emoji Semantic Violations

This study investigated emoji semantic processing by measuring changes in event-related electroencephalogram (EEG) power. The last segment of experimental sentences was designed as either words or emojis consistent or inconsistent with the sentential context. The results showed that incongruent emojis led to a conspicuous increase of theta power (4-7Hz), while incongruent words induced a decrease. Furthermore, the theta power increase was observed at midfrontal, occipital and bilateral temporal lobes with emojis. This suggests a higher working memory load for monitoring errors, difficulty of form recognition and concept retrieval in emoji semantic processing. It implies different neuro-cognitive processes involved in the semantic processing of emojis and words.