Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults.

Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines.

Younger, not older, children trust an inaccurate human informant more than an inaccurate robot informant.

This study examined preschoolers' trust toward accurate and inaccurate robot informants versus human informants. Singaporean children aged 3-5 years (N = 120, 57 girls, mostly Asian; data collected from 2017 to 2018) viewed either a robot or a human adult label familiar objects either accurately or inaccurately. Children's trust was assessed by examining their subsequent willingness to accept novel object labels provided by the same informant. Regardless of age, children trusted accurate robots to a similar extent as accurate humans. However, while older children (dis)trusted inaccurate robots and humans comparably, younger children trusted inaccurate robots less than inaccurate humans. The results indicate a developmental change in children's reliance on informants' characteristics to decide whom to trust.

How COVID-19 News Affect Older Adults' Mental Health-Evidence of a Positivity Bias.

BACKGROUND: Media affects the trajectory of many individuals' mental health-with media news, individuals experience negative bias more than positive bias. However, there is also evidence of an age-related positivity effect, with negativity bias generally fading with age. With the rise of COVID-19 cases, older adults (aged 55 years and older) who consume media frequently are at a high risk for declining mental health. To date, there has been no research on the positivity vs. negativity bias of media news on older adults. Here, we investigated whether positivity or negativity bias plays a larger role in affecting how older adults react to COVID-19 news. METHODS: Sixty-nine older adults (aged 55-95) answered questions about their weekly media consumption and how closely they followed news relating to COVID-19. They also completed a general health questionnaire. They were then randomly assigned to read either positive or negative COVID-19 news (n = 35 and 34, respectively). The adults were asked if the news made them feel happy or fearful, and if they wanted to read more about the news or ignore the news. RESULTS: An analysis revealed that the more often older adults consumed media and the more closely they followed COVID-19 news, the more they felt unhappy and depressed. Importantly, older adults who read positive news reported stronger responses than those who read negative news. Older adults appeared to have a strong positivity bias for COVID-19 news, reporting feeling happy and wanting to read about positive news. In contrast, negative COVID-19 news did not evoke similar levels of response from the older adults. CONCLUSIONS: Media consumption of COVID-19 news does negatively impact the mental well-being of older adults, but older adults appear to have a strong positivity bias and a lack of negativity bias for COVID-19 news. These findings suggest that older adults can remain hopeful and positive during periods of public health crises and intense stress, which is essential to sustaining their mental well-being during difficult times.

Bilingual language entropy influences executive functions through functional connectivity and signal variability.

How bilinguals' experience in managing multiple languages in different communicative contexts influences the cognitive and neural aspects of executive functions remains unclear. Therefore, we examined whether variations in language experience in young adult bilinguals were associated with data-driven brain functional network patterns (connectivity and signal variability) defined by performance during executive control tasks (Stroop and task-switching). Multiple aspects of language experience, such as the extent of balanced bilingualism in language proficiency and usage, and language diversity across social contexts (i.e., language entropy) were assessed. We found that greater language diversity, rather than balanced bilingualism per se, was related to higher brain network specialization and segregation concentrated on the default mode and executive control networks, and lower signal variability, a pattern linked to smaller RT-indices related to executive functioning of shifting, goal-maintenance, and conflict-monitoring. Our findings underscore the important role of language diversity in influencing bilinguals' neurocognitive characteristics of executive functioning.

Corrigendum to: Attitudes Toward Older Adults: A Cross-Cultural Approach Across Residential Towns in Singapore.

[This corrects the article DOI: 10.1093/geroni/igaa057.3409.].

Willingness to revise own testimony: 3- and 4-year-olds' selective trust in unexpected testimony from accurate and inaccurate informants.

Prior work has shown that young children trust single accurate and inaccurate individuals to a similar extent in their endorsement of novel information. However, it remains unknown to what extent children trust a credible or noncredible individual when given information that is pitted against their own beliefs. The current study examined whether children, when given unexpected testimony that contradicted their initial beliefs but was not completely unbelievable, would selectively revise their beliefs depending on the informant's past history of accuracy. The participants (3- and 4-year-olds; N = 100) were familiarized with an informant who labeled a series of common objects either accurately or inaccurately. Following that, all children saw a picture of an ambiguous hybrid artifact that consisted of features of two typical common artifacts and were asked to identify the hybrid object with their own label. Subsequently, children watched the previously accurate or inaccurate informant give the same hybrid object a different but plausible label. Children expressed a greater tendency to override their initial judgments and endorse the unexpected testimony from a previously accurate informant than from someone who had consistently made naming errors. The findings provide novel understandings of the circumstances under which 3- and 4-year-old preschoolers may or may not rely on the informant's prior reliability in their selective learning.

The influence of language behavior in social preferences and selective trust of monolingual and bilingual children.

Experiences living in a community where people share more than one language may affect children's strategies to selective learning. Language mixing may be one type of speakers' characteristics that bilingual children, but not monolingual children, use to evaluate speakers. A total of 120 English-speaking monolingual (n = 40) and English-Mandarin bilingual (n = 80) 4- and 5-year-olds heard a pair of speakers each tell a story either with or without language mixing and indicated their preferences for either speaker in friendship, explicit judgment, and novel label endorsement. Bilingual children, but not their monolingual counterparts, preferred the single-language speaker to the language-mix speaker across different test questions. Our findings suggest that social relevance in the larger communicative context may contribute to the development of children's social preferences and selective learning based on certain characteristics of the speakers.

A bilingual advantage in 54-month-olds' use of referential cues in fast mapping.

Research has demonstrated a bilingual advantage in how young children use referential cues such as eye gaze and pointing gesture to locate an object or to categorize objects. This study investigated the use of referential cues (i.e. eye gaze) in fast mapping in three groups of children that differed in their language exposure. One hundred and seven 54-month-old children who were English monolinguals (n = 28), English-Mandarin bilinguals (n = 48), and English-Mandarin bilinguals with exposure to a third language (i.e. trilinguals, n = 31) were assessed with a word learning task using two types of test - a referent test and a mutual exclusivity test. During the task, following the gaze of an adult speaker was needed to be able to indicate the correct referent of a novel word at test. All three groups of children demonstrated successful word learning in explicit selection of and implicit looking time toward the target object during testing. However, bilingual and trilingual children outperformed their monolingual peers in both types of test when they were asked to explicitly select the correct objects. These findings suggest positive effects of bilingualism on children's use of referential cues in fast mapping.

Children Increase Their Sensitivity to a Speaker's Nonlinguistic Cues Following a Communicative Breakdown.

Bilingual children regularly face communicative challenges when speakers switch languages. To cope with such challenges, children may attempt to discern a speaker's communicative intent, thereby heightening their sensitivity to nonverbal communicative cues. Two studies examined whether such communication breakdowns increase sensitivity to nonverbal cues. English-speaking monolingual (n = 64) and bilingual (n = 54) 3- to 4-year-olds heard instructions in either English only or English mixed with a foreign language. Later, children played a hiding game that relied on nonverbal cues. Hearing a foreign language switch improved both monolingual and bilingual children's use of these cues. Moreover, bilinguals with more prior code-switching exposure outperformed those with less prior code-switching exposure. Children's short-term strategies to repair communication breakdowns may evolve into a more generalizable set of skills.

Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter.

Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English-Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number-letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number-letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting.

Monolingual and bilingual preschoolers' use of gestures to interpret ambiguous pronouns.

Young children typically do not use order-of-mention to resolve ambiguous pronouns, but may do so if given additional cues, such as gestures. Additionally, this ability to utilize gestures may be enhanced in bilingual children, who may be more sensitive to such cues due to their unique language experience. We asked monolingual and bilingual four-year-olds and adults to determine referents of ambiguous pronouns given order-of-mention and co-referential localizing gestures. Results showed that bilingual children, like adults, but not monolingual children, used order-of-mention with gestures to resolve ambiguous pronouns. This highlights a wider implication of bilingualism for socio-cognitive development in children.