Interactions of age of acquisition and lexical frequency effects with phonological regularity: An ERP study

Event-related brain potentials in lexical processing with Chinese characters show effects of contextual diversity but not word frequency

The diversity of contexts in which a word occurs, operationalized as CD, is strongly correlated with response times in visual word recognition, with higher CD words being recognized faster. CD and token word frequency (WF) are highly correlated but in behavioral studies when other variables that affect word visual recognition are controlled for, the WF effect is eliminated when contextual diversity (CD) is controlled. In contrast, the only event-related potential (ERP) study to examine CD and WF Vergara-Martínez et al., Cognitive, Affective, & Behavioral Neuroscience, 17, 461-474, (2017) found effects of both WF and CD with different distributions in the 225- to 325-ms time window. We conducted an ERP study with Chinese characters to explore the neurocognitive dynamics of WF and CD. We compared three groups of characters: (1) characters high in frequency and low in CD; (2) characters low in frequency and low in CD; and (3) characters high in frequency and high in CD. Behavioral data showed significant effects of CD but not WF. Character CD, but not character frequency, modulated the late positive component (LPC): high-CD characters elicited a larger LPC, widely distributed, with largest amplitude at the posterior sites compared to low-CD characters in the 400-to 600-ms time window, consistent with earlier ERP studies of WF in Chinese, and with the hypothesis that CD affects semantic and context-based processes. No WF effect on any ERP components was observed when CD was controlled. The results are consistent with behavioral results showing CD but not WF effects, and in particular with a "context constructionist" framework.

Electrophysiological evidence of lexical processing impacted by foreign language reading anxiety

Extensive studies have been conducted on the impact of foreign language reading anxiety on reading, primarily focusing on pedagogy and behavior but lacking electrophysiological evidence. The current study aimed to investigate the influence of foreign language reading anxiety on reading and its underlying mechanisms. The results revealed a negative correlation between foreign language reading anxiety and foreign language reading performance, irrespective of the native language. Adults with low levels of foreign language reading anxiety (LFLRA) demonstrated a significant difference in early lexical component N170 amplitude between foreign and native languages. However, this effect was not observed in adults with high levels of foreign language reading anxiety (HFLRA). In terms of N170 latency, HFLRA showed a longer N170 for the foreign language compared to the native language. Furthermore, the N170 effects were predominantly localized over the left occipitotemporal electrodes. Regarding N400 latency, a significant difference was found in LFLRA individuals between foreign and native language processing, while HFLRA individuals did not exhibit this difference. These findings suggest that HFLRA individuals experience inefficient lexical processing (such as orthography or semantics) during reading in foreign language.

Longitudinal changes in qualitative aspects of semantic fluency in presymptomatic and prodromal genetic frontotemporal dementia

BACKGROUND

The semantic fluency test is one of the most widely used neuropsychological tests in dementia diagnosis. Research utilizing the qualitative, psycholinguistic information embedded in its output is currently underexplored in presymptomatic and prodromal genetic FTD.

METHODS

Presymptomatic MAPT (n = 20) and GRN (n = 43) mutation carriers, and controls (n = 55) underwent up to 6 years of neuropsychological assessment, including the semantic fluency test. Ten mutation carriers became symptomatic (phenoconverters). Total score and five qualitative fluency measures (lexical frequency, age of acquisition, number of clusters, cluster size, number of switches) were calculated. We used multilevel linear regression modeling to investigate longitudinal decline. We assessed the co-correlation of the qualitative measures at each time point with principal component analysis. We explored associations with cognitive decline and grey matter atrophy using partial correlations, and investigated classification abilities using binary logistic regression.

RESULTS

The interrater reliability of the qualitative measures was good (ICC = 0.75-0.90). There was strong co-correlation between lexical frequency and age of acquisition, and between clustering and switching. At least 4 years pre-phenoconversion, GRN phenoconverters had fewer but larger clusters (p < 0.001), and fewer switches (p = 0.004), correlating with lower executive function (r = 0.87-0.98). Fewer switches was predictive of phenoconversion, correctly classifying 90.3%. Starting at least 4 years pre-phenoconversion, MAPT phenoconverters demonstrated an increase in lexical frequency (p = 0.009) and a decline in age of acquisition (p = 0.034), correlating with lower semantic processing (r = 0.90). Smaller cluster size was predictive of phenoconversion, correctly classifying 89.3%. Increase in lexical frequency and decline in age of acquisition were associated with grey matter volume loss of predominantly temporal areas, while decline in the number of clusters, cluster size, and switches correlated with grey matter volume loss of predominantly frontal areas.

CONCLUSIONS

Qualitative aspects of semantic fluency could give insight into the underlying mechanisms as to why the "traditional" total score declines in the different FTD mutations. However, the qualitative measures currently demonstrate more fluctuation than the total score, the measure that seems to most reliably deteriorate with time. Replication in a larger sample of FTD phenoconverters is warranted to identify if qualitative measures could be sensitive cognitive biomarkers to identify and track mutation carriers converting to the symptomatic stage of FTD.

Hong Kong Chinese character psycholinguistic norms: ratings of 4376 single Chinese characters on semantic radical transparency, age-of-acquisition, familiarity, imageability, and concreteness

Several norms of psycholinguistic features of Chinese characters exist in Mandarin Chinese, but only a few are available in Cantonese or in the traditional script, and none includes semantic radical transparency ratings. This study presents subjective ratings of age-of-acquisition (AoA), familiarity, imageability, concreteness, and semantic radical transparency in 4376 Chinese characters. The single Chinese characters were rated individually on the five dimensions by 20 native Cantonese speakers in Hong Kong to form the Hong Kong Chinese Character Psycholinguistic Norms (HKCCPN). The split-half reliability and intra-class correlations testified to the high internal reliability of the ratings. Their convergent and discriminant patterns in relations to other psycholinguistic measures echoed previous findings reported on Chinese. There were high correlations for semantic radical transparency, imageability and concreteness, and moderate-to-high correlations for AoA and familiarity among subsets of items that had been collected in previous studies. Concurrent validity analyses showed convergence in predicting behavioral response times in various tasks (lexical decision, naming, and writing-to-dictation) when compared with other Chinese character databases. High predictive validity was shown in writing-to-dictation data from an independent sample of 20 native Cantonese speakers. Several objective psycholinguistic measures (character frequency, stroke number, number of words formed, number of homophones and number of meanings) were included in this database to facilitate its use. These new ratings extend the currently available norms in language and reading research in Cantonese Chinese for researchers, clinicians, and educators, as well as provide them with a wider choice of stimuli.

The neural dynamics associated with lexicality effect in reading single Chinese words, pseudo-words and non-words

In previous word reading studies, lexicality has been used as a variable to examine the impacts of word form and meaning information on the many stages of word recognition process. Yet the neural dynamics associated with lexicality effect of various information processing for Chinese visual word recognition has not been well elucidated. In this study, Chinese native speakers were instructed to read Chinese disyllabic compound words, morphological legal (pseudo-words) and illegal non-words with their brain potentials recorded. Event-related potentials (ERP) results showed that N200 was related to Chinese orthographic processing, where three lexical conditions elicited comparable patterns. A semantic discrimination was found for N400 between pseudo-words/non-words and real words, which is in favor of the lexical view of the N400 effect. Further, a later ERP component P600 exhibited the difference between the non-words and pseudo-words, reflecting a re-analysis of word meaning or grammatical operation on Chinese morphological legality. Therefore, we argue that Chinese morphological information might have an independent representation (the P600 effect) in mental lexicon.

Objective ages of acquisition for 3300+ simplified Chinese characters

We report the construction of two age-of-acquisition (AoA) norms for 3300+ characters in simplified Chinese, which make up about 99% of the texts used in daily life. We determined a character's AoA according to the time in which the character is formally learned in two sets of leading textbooks of Chinese in compulsory education, published respectively on the basis of the 2001 and 2011 national curriculum. Apart from having a significantly larger coverage of characters than previous norms, the current norms also outperformed them in explaining accuracy and reaction times in four large-scale databases for character decision, character naming, or character handwriting, even after controlling for the effects of frequency, number of meanings, and number of strokes. The explanatory advantage of the current norms suggests that, compared to earlier norms, the current norms capture more up-to-date character AoAs; these findings also highlight the diachronic nature of some lexical variables such as AoA and frequency. The developed objective AoA norms can be used for subsequent research on Chinese character recognition or production.

Age of acquisition effects on traditional Chinese character naming and lexical decision

Across languages, age of acquisition (AoA) is a critical psycholinguistic factor in lexical processing, reflecting the influence of learning experience. Early-acquired words tend to be processed more quickly and accurately than late-acquired words. Recently, an integrated view proposed that both the mappings between representations and the construction of semantic representations contribute to AoA effects, thus, predicting larger AoA effects for words with arbitrary mappings between representations as well as for tasks requiring greater semantic processing. We investigated how these predictions generalize to the Chinese language system that differs from alphabetic languages regarding the ease of mappings and semantic involvement in lexical processing. A cross-task investigation of differential psycholinguistic effects was conducted with large character naming and lexical decision datasets to establish the extent to which semantics is involved in the two tasks. We focused on examining the effect sizes of lexical-semantic variables and AoA, and the interaction between AoA and consistency. The results demonstrated that semantics influenced Chinese character naming more than lexical decision, which is in contrast with the findings related to English language, though, critically, AoA effects were more pronounced for character naming than for lexical decision. Additionally, an interaction between AoA and consistency was found in character naming. Our findings provide cross-linguistic evidence supporting the view of multiple origins of AoA effects in the language-processing system.