Early Age Of Acquisition Research Articles

The Effects of Word Frequency, Age of Acquisition, Animacy, and Grammatical Class on Picture Naming by Volunteers and People with Aphasia

ABSTRACT Background Numerous studies have investigated the effects of word frequency (WF), age of acquisition (AoA), and animacy on picture naming in volunteers and those with aphasia. But none have controlled for any possible interactions among these three variables during noun retrieval and whether WF and AoA influence verb retrieval in ways that are similar to that observed during noun retrieval. Aims The main purpose of this study was to examine the influences of WF, AoA, and animacy on noun retrieval in both volunteers and participants with aphasia and to compare these results to the effects of AoA and WF in both groups during verb retrieval. Methods and Procedures A factorial approach was used to study the effects of (a) WF, AoA, and animacy on picture naming for 249 nouns, and (b) the effects of WF and AoA on picture naming for 88 verbs. Fifteen volunteers with no history of neurologic or psychiatric impairment and 13 people with aphasia participated in this study. Naming latencies using key press procedures were used to assess the effects of the independent variables. Linear mixed effects with random intercepts were modeled to analyze the results. Outcomes and Results Nouns with early AoA and high WF were named significantly faster than all nouns with late AoA. There were no differences between naming speeds for animate vs. inanimate nouns. Animate nouns with early AoA and high frequency were named significantly faster than early, animate nouns with low frequency. Low word frequency facilitated naming by the participants with aphasia for early AoA verbs but slowed the volunteers’ naming for these verbs. Participants responded significantly faster to nouns versus verbs regardless of AoA and WF. Conclusions Controlling for animacy in noun picture naming produces novel findings regarding the effects of WF and AoA on word retrieval. The interaction among WF, AoA, and animacy is more consequential for picture naming speed than the specific effects of any one of these variables alone.

Agents Strongly Preferred: ERP Evidence from Natives and Non-Natives Processing Intransitive Sentences in Spanish.

Are non-native speakers able to process their second language in a native-like way? The present study used the Event-Related Potentials’ (ERPs) method to address this issue by focusing (1) on agent vs. agentless intransitive sentences and (2) on person vs. number agreement morphology. For that purpose, native and high proficiency and early non-native speakers of Spanish were tested while processing intransitive sentences containing grammatical and ungrammatical subject–verb agreement. Results reveal greater accuracy in the agent (unergative) condition as compared with the agentless (unaccusative) condition and different ERP patterns for both types of verbs in all participants, suggesting a larger processing cost for the agentless sentences than for the agentive ones. These effects were more pronounced in the native group as compared with the non-native one in the early time window (300–500 ms). Differences between person and number agreement processing were also found at both behavioral and electrophysiological levels, indicating that those morphological features are distinctively processed. Importantly, this pattern of results held for both native and non-native speakers, thus suggesting that native-like competence is attainable given early Age of Acquisition (AoA), frequent use and high proficiency.

Influence of age of acquisition, language proficiency and language use on Singapore English consonant perception

The present study investigates the extent to which age of acquisition (AoA), English language proficiency and use influence consonant perception in Singapore English (SgE). Consonantal pairs of interest were presented in a gating paradigm to determine the amount of linguistic information participants required for accurate consonant identification as a measure of perceptual acuity. Only the [th]–[?] and [t]–[?] phonetic contrasts emerged sensitive to differences in AoA of English, with the early AoA group outperforming the late AoA group. Language proficiency and use did not significantly influence consonant perception. The findings are discussed in light of how AoA may interact with the universal difficulty and distributional regularities of speech contrasts to affect speech processing. Future studies should investigate a wider range of SgE speakers and identify distributional regularities of speech sounds to gain a more comprehensive picture of the factors that influence consonant perception in SgE.

Levels of skills and predictive patterns of reading comprehension in bilingual children with an early age of acquisition

Bilingualism appears to be related to poor language and reading comprehension in the instructional language (L2). However, in the long term, an early age of second language acquisition (AoA) may produce higher levels of second language skills than a later onset of L2 exposure. Most studies on school-aged second language learners (L2 learners) include children with 3–7 years of second language (L2) exposure. We compared 91 early bilingual (Norwegian and a variety of different native languages) 5th graders with 196 monolingual peers on a range of linguistic skills and their relationships with reading comprehension. All bilingual learners in the sample had been exposed to the instructional language by at least the age of 2. The results, using structural equation modelling and latent variables, show that early bilingual learners’ vocabulary, listening comprehension, and reading comprehension are significantly lower than those of monolingual learners. Nevertheless, they have similar levels of knowledge of conjunctions and decoding skills and corresponding predictive patterns from linguistic skills to reading comprehension. We discuss the implications of the findings.

Re-assessing age of acquisition effects in recognition, free recall, and serial recall.

Age of acquisition (AoA) refers to the age at which a person learns a word. Research has converged on the conclusion that early AoA words are processed more efficiently than late AoA words on a number of perceptual and reading tasks. However, only a few studies have investigated whether AoA affects memory on recognition, serial recall, and free recall tests, and the results are equivocal. We took advantage of the recent increase in the number of high-quality norms and databases to construct a pool of early and late AoA words that were equated on numerous other dimensions. There was a late AoA advantage in recognition using both pure (Experiment 1) and mixed (Experiment 2) lists, no effect of AoA on serial recall of either pure (Experiment 3) or mixed (Experiment 4) lists, and no effect of AoA on free recall of either pure (Experiment 5) or mixed lists (Experiment 6). We conclude that AoA does reliably affect memory on some memory tasks (recognition), but not others (serial recall, free recall), and that no current account of AoA can explain the findings.

Earlier second language acquisition is associated with greater neural pattern dissimilarity between the first and second languages

It is controversial as to how age of acquisition (AoA) and proficiency level of the second language influence the similarities and differences between the first (L1) and the second (L2) language brain networks. In this functional MRI study, we used representational similarity analysis to quantify the degree of neural similarity between L1 and L2 during sentence comprehension tasks in 26 adult Chinese-English bilinguals, who learned English as L2 at different ages and had different proficiency levels. We found that although L1 and L2 processing activated similar brain regions, greater neural pattern dissimilarity between L1 and L2 was associated with earlier AoA in the left inferior and middle frontal gyri after the effect of proficiency level was controlled. On the other hand, the association between proficiency level and the neural pattern dissimilarity between L1 and L2 was not significant when the effect of AoA was partialled out. The results suggest that the activity pattern of L2 is more distinct from that of L1 in bilingual individuals who acquired L2 earlier and that the contribution of AoA to the neural pattern dissimilarity is greater than that of proficiency level.

AGE OF MUSIC ACQUISITION IMPACTS MEMORY FUNCTIONING IN OLDER ADULT MUSICIANS

Music playing is an involved activity, activating many areas of the brain and relying on integration of multiple cognitive processes simultaneously. Older adult musicians have been found to experience some cognitive benefits compared to non-musicians, seemingly related to their musical training. However, we still do not understand what factors of musical training may be driving these differences. The current study sought to isolate age of acquisition from “dose” of playing (i.e., amount of time spent playing) to explore music learning as a skill acquired during a sensitive period. Participants (n=48) were middle aged and older adults who self-reported on musical experiences, demographics, and underwent extensive neuropsychological assessment of all major domains. The sample was divided into Early Age of Acquisition (≤9 years old), Late Age of Acquisition (>9), and Non-Musicians. Results showed that musicians who began formal training at the age of 9 or younger, had significantly higher scores on tests of verbal memory (California Verbal Learning Test – II: Immediate Recall – p = 0.04, partial η2 = 0.14, Short-Delay Free Recall - p = 0.03, partial η2 = 0.16, Long-Delay Free Recall - p = 0.03, partial η2 = 0.15). Results are discussed in the context of a sensitive period for acquiring musical education, and implications of these results on cognitive aging.

Subcortical Lesions Impact Confrontation Naming in Bilinguals with Later Age of Acquisition

Abstract Objective Multilinguals show greater subcortical activation during language tasks than monolinguals. Among multilinguals, prior studies found later age of acquisition (AoA) of a second language in association with more diffuse, non-traditional language representation. While such findings have clear clinical implications, little research has examined relationships among linguistic history, neuroanatomical integrity, and language skills in a clinical population. This study examined relationships between subcortical lesions and confrontation naming in strong bilinguals who acquired English (L2) later in life compared to those with earlier AoA. Participants and Method Forty-two bilinguals with Spanish as a first language (English L2) were selected from a database of veterans referred for clinical neuropsychological evaluation (M Age = 64 years; M Education = 12 years; 93% men). They reported strong bilingualism after L2 acquisition (M AoA = 10 years), with current English preference. Twenty-nine had neuroimaging, which was coded on a 4-point ordinal scale for lesion burden in white matter and striatum. Moderation models were tested for interaction between AoA and subcortical lesions in bilinguals using different L2 naming outcomes, controlling for age, education, occupation, and English fluency (i.e., Test of Premorbid Functioning). Results Moderation showed significant interaction of AoA with striatal lesion burden for scores on all naming tests, with a similar but less robust relationship between white matter lesions and naming outcomes. Graphical analysis revealed subcortical lesions had a negative impact on naming scores in those with later L2 AoA. Conclusions Results suggest “atypical” subcortical involvement in naming is more likely for bilinguals who acquired L2 later. While clinicians typically associate impaired naming with temporal lobe dysfunction, findings suggest subcortical dysfunction should be considered among bilinguals with later L2 AoA.

The influence of native English-speaking environment on Akan-English bilinguals’ production of English inter-dental fricatives

Aims and Objectives: This study examined how age of acquisition, immersion in a native English-speaking environment, and phonological environment influence Akan-English bilinguals’ production of English inter-dental fricatives. Design/Methodology: Forty-five Akan-English bilinguals who immigrated to the USA between the ages of 10 and 64 participated. English inter-dental fricatives occurring in word-initial, intervocalic, and word-final positions were elicited through a production task using sentence frames. Accuracy of production was analyzed relative to age of acquisition, relative length of immersion, and phonological environment. Findings/Conclusion: Performance was better overall on the voiceless than the voiced inter-dental, but the phonological environment mattered: performance was at ceiling for both in the medial position, but less good in the initial and final positions. Early age of acquisition conspired with length of residence in the USA to foster better production for both sounds. However, substitutions for target segments were still observed in the most fluent speakers. These results indicate that in determining speakers’ proficiency in the second language, we must consider all of these factors—phonological environment, age of acquisition, and length of stay—together to gain a comprehensive picture of development. Originality: Few studies have examined Ghanaian speakers’ English, even though English is the official language of Ghana. Further, previous studies on second-language speakers’ abilities with inter-dental fricatives have largely focused on word-initial environments. The present study reveals that distinct phonological environments may not show the same effect. Here, speakers were particularly accurate in intervocalic positions. Significance: This study contributes to theoretical debates concerning the roles of input and age of acquisition for second-language learning. It also provides insights on some of the possible hurdles that second-language learners face as they strive to acquire additional languages, which can assist second-language teachers in designing appropriate methodologies to help learners.

L2 and Heritage Korean Tense Morphology in Discourse: Interplay between Lexical and Discursive Meaning

This article reports on a study examining the tense and aspect morphology in oral narratives from L1 English L2 learners and heritage speakers of Korean, focusing on the relative contribution of lexical and discursive meaning in non-European languages by comparing the predictions of Discourse Hypothesis and Aspect Hypothesis. We also examine heritage speakers’ acquisition to discover whether an early age of acquisition, despite significant attrition later in life, leads to more native-like attainment of Korean. Unlike previous studies, our results suggest that discursive factors play a more significant role than lexical factors in determining the tense/aspect choice, and that temporal categories are interpreted indexically in the early stage of development.

Bilingual experience and resting-state brain connectivity: Impacts of L2 age of acquisition and social diversity of language use on control networks

We investigated the independent contributions of second language (L2) age of acquisition (AoA) and social diversity of language use on intrinsic brain organization using seed-based resting-state functional connectivity among highly proficient French-English bilinguals. There were two key findings. First, earlier L2 AoA related to greater interhemispheric functional connectivity between homologous frontal brain regions, and to decreased reliance on proactive executive control in an AX-Continuous Performance Task completed outside the scanner. Second, greater diversity in social language use in daily life related to greater connectivity between the anterior cingulate cortex and the putamen bilaterally, and to increased reliance on proactive control in the same task. These findings suggest that early vs. late L2 AoA links to a specialized neural framework for processing two languages that may engage a specific type of executive control (e.g., reactive control). In contrast, higher vs. lower degrees of diversity in social language use link to a broadly distributed set of brain networks implicated in proactive control and context monitoring.

Age of Acquisition Effects on Word Processing for Chinese Native Learners' English: ERP Evidence for the Arbitrary Mapping Hypothesis.

The present study aimed at distinguishing processing of early learned L2 words from late ones for Chinese natives who learn English as a foreign language. Specifically, we examined whether the age of acquisition (AoA) effect arose during the arbitrary mapping from conceptual knowledge onto linguistic units. The behavior and ERP data were collected when 28 Chinese-English bilinguals were asked to perform semantic relatedness judgment on word pairs, which represented three stages of word learning (i.e., primary school, junior and senior high schools). A 3 (AoA: early vs. intermediate vs. late) × 2 (regularity: regular vs. irregular) × 2 (semantic relatedness: related vs. unrelated) × 2 (hemisphere: left vs. right) × 3 (brain area: anterior vs. central vs. posterior) within-subjects design was adopted. Results from the analysis of N100 and N400 amplitudes showed that early learned words had an advantage in processing accuracy and speed; there is a tendency that the AoA effect was more pronounced for irregular word pairs and in the semantic related condition. More important, ERP results showed early acquired words induced larger N100 amplitudes for early AoA words in the parietal area and more negative-going N400 than late acquire words in the frontal and central regions. The results indicate the locus of the AoA effect might derive from the arbitrary mapping between word forms and semantic concepts, and early acquired words have more semantic interconnections than late acquired words.

Deaf children's non-verbal working memory is impacted by their language experience.

Several recent studies have suggested that deaf children perform more poorly on working memory tasks compared to hearing children, but these studies have not been able to determine whether this poorer performance arises directly from deafness itself or from deaf children's reduced language exposure. The issue remains unresolved because findings come mostly from (1) tasks that are verbal as opposed to non-verbal, and (2) involve deaf children who use spoken communication and therefore may have experienced impoverished input and delayed language acquisition. This is in contrast to deaf children who have been exposed to a sign language since birth from Deaf parents (and who therefore have native language-learning opportunities within a normal developmental timeframe for language acquisition). A more direct, and therefore stronger, test of the hypothesis that the type and quality of language exposure impact working memory is to use measures of non-verbal working memory (NVWM) and to compare hearing children with two groups of deaf signing children: those who have had native exposure to a sign language, and those who have experienced delayed acquisition and reduced quality of language input compared to their native-signing peers. In this study we investigated the relationship between NVWM and language in three groups aged 6–11 years: hearing children (n = 28), deaf children who were native users of British Sign Language (BSL; n = 8), and deaf children who used BSL but who were not native signers (n = 19). We administered a battery of non-verbal reasoning, NVWM, and language tasks. We examined whether the groups differed on NVWM scores, and whether scores on language tasks predicted scores on NVWM tasks. For the two executive-loaded NVWM tasks included in our battery, the non-native signers performed less accurately than the native signer and hearing groups (who did not differ from one another). Multiple regression analysis revealed that scores on the vocabulary measure predicted scores on those two executive-loaded NVWM tasks (with age and non-verbal reasoning partialled out). Our results suggest that whatever the language modality—spoken or signed—rich language experience from birth, and the good language skills that result from this early age of acquisition, play a critical role in the development of NVWM and in performance on NVWM tasks.

The effect of age of L2 acquisition on the organization of the bilingual lexicon: Evidence from masked priming

This study investigates the role of age of acquisition (AoA) on the bilingual mental lexicon. Four groups of participants were tested: (i) English native speakers with minimal exposure to French; (ii) late English–French bilinguals; (iii) early English–French bilinguals; and (iv) simultaneous English–French bilinguals. We used a masked priming paradigm to investigate early, automatic lexical processing at the semantic level by testing both a within-language semantic condition and a cross-language translation condition. AoA was investigated both through group effects and a correlation analysis. We found significant translation priming effects for the simultaneous and early bilinguals only, and a significant correlation between AoA and translation priming effects. Due to the matched L2 proficiency of the early and late bilinguals, these results support our hypothesis that an early AoA, regardless of L2 proficiency, is crucial in order to find the L2-to-L1 priming effects that have often been elusive in recent studies.

Differential impacts of age of acquisition on letter and semantic fluency in Alzheimer's disease patients and healthy older adults

The degree to which the typical age of acquisition (AoA) of words and word frequency have separable influences on verbal production tasks has been strongly debated. To examine the overlap between these factors in verbal fluency tasks, the performance of Alzheimer's disease (AD) patients (N = 34) and normal elderly controls (N = 36) was compared on semantic (e.g., vegetables) and letter (e.g., words that begin with F) fluency tasks. These comparisons revealed that words generated for the semantic fluency task had an earlier AoA while words generated for the letter fluency task had a higher word frequency. Differences in AoA between AD patients and controls were larger for semantic than letter fluency. These results suggest that AoA has an effect on verbal production that is independent of word frequency and that AoA has a semantic locus.

The Effects of Age-of-Acquisition on Ambiguity Resolution: Evidence from Eye Movements

Words that are rated as acquired earlier in life receive shorter fixation durations than later acquired words, even when word frequency is adequately controlled (Juhasz & Rayner, 2003; 2006). Some theories posit that age-of-acquisition (AoA) affects the semantic representation of words (e.g., Steyvers & Tenenbaum, 2005), while others suggest that AoA should have an influence at multiple levels in the mental lexicon (e.g. Ellis & Lambon Ralph, 2000). In past studies, early and late AoA words have differed from each other in orthography, phonology, and meaning, making it difficult to localize the influence of AoA. Two experiments are reported which examined the locus of AoA effects in reading. Both experiments used balanced ambiguous words which have two equally-frequent meanings acquired at different times (e.g. pot, tick). In Experiment 1, sentence context supporting either the early- or late-acquired meaning was presented prior to the ambiguous word; in Experiment 2, disambiguating context was presented after the ambiguous word. When prior context disambiguated the ambiguous word, meaning AoA influenced the processing of the target word. However, when disambiguating sentence context followed the ambiguous word, meaning frequency was the more important variable and no effect of meaning AoA was observed. These results, when combined with the past results of Juhasz and Rayner (2003; 2006) suggest that AoA influences access to multiple levels of representation in the mental lexicon. The results also have implications for theories of lexical ambiguity resolution, as they suggest that variables other than meaning frequency and context can influence resolution of noun-noun ambiguities.

REEXAMINING THE FUNDAMENTAL DIFFERENCE HYPOTHESIS

The fundamental difference hypothesis (FDH), as formulated by Bley-Vroman (1990), claims that SLA tends to be nonconvergent because domain-specific linguistic mechanisms available in early childhood cannot be used for language learning in adulthood: Instead, second language (L2) learners deploy domain-general problem solving skills. I claim that nonconvergence is also true of some cases of unbalanced early bilingualism, when the target language was acquired in childhood, suggesting that nontarget attainment in these cases may have different roots—namely, inefficient learning mechanisms in L2 learners but insufficient input in early bilinguals. The FDH then predicts that early bilinguals should still be more successful at attaining nativelike knowledge than the L2 learners due to their early age of acquisition. This review article examines this prediction in light of recent studies of postpuberty L2 learners and unbalanced early bilinguals with nonconvergent knowledge of their first language. I show that the incidence of nativelike achievement is higher in the early bilingual groups than in the L2 groups and that differential performance by the two populations on different tasks lends some support to the processing claims of the FDH.

Participant and Word Gender in Age of Acquisition Effects: The Role of Gender Socialization

The age of acquisition (AoA) effect represents the processing advantage for developmentally earlier-acquired words. An initial norming study identified early and late AoA words having either a strong female-oriented (e.g., flute) or male-oriented (e.g., cigar) semantic bias. Forty-seven female and 45 male Scottish university students participated in a lexical decision task using 100 early and late AoA female- and male-oriented words. Reaction time data showed significant AoA effects for both females and males across both female- and male-oriented words, with faster responses to earlier than later acquired words. Females, however, took longer to respond to male-oriented words, particularly late AoA ones. Males demonstrated no effect of semantic gender. The pattern of effects is consistent with differential gender role socialization.

Determining the time course of lexical frequency and age of acquisition using ERP

The main goal of the present study was to dissociate the effects on reading of frequency, age of acquisition (AoA) and imageability using the evoked response potential paradigm. Twenty participants read words from three experimental conditions: high and low frequency, late and early age of acquisition and high and low imageability. High frequency words produced more positive mean amplitude than low frequency words in the 175-360 ms post-stimulus onset time window and late AoA produced more negative amplitudes than early AoA in the 400-610 ms window. Imageability did not produce any effect in any time window tested. Brain electromagnetic tomography showed the most activated cortical areas for each category of stimuli. The lexical frequency of words seems to affect an early phase in the recognition process, perhaps at the level of the orthographic input lexicon, while AoA was observed at a later stage, indicating that this variable influence processing at a semantic level or at the links between semantics and phonology. EEG permits the researcher to investigate the time course, and approximate location in the brain, of psycholinguistic variables.

The Distinct Contributions of Age of Acquisition and Word Frequency in Auditory Word Perception

We report two studies of the distinct effects that a word's age of acquisition (AoA) and frequency have on the mental lexicon. In the first study, a purely statistical analysis, we show that AoA and frequency are related in different ways to the phonological form and imageability of different words. In the second study, three groups of participants (34 seven-year-olds, 30 ten-year-olds, and 17 adults) took part in an auditory lexical decision task, with stimuli varying in AoA, frequency, length, neighbourhood density, and imageability. The principal result is that the influence of these different variables changes as a function of AoA: Neighbourhood density effects are apparent for early and late AoA words, but not for intermediate AoA, whereas imageability effects are apparent for intermediate AoA words but not for early or late AoA. These results are discussed from the perspective that AoA affects a word's representation, but frequency affects processing biases.