Examining commonsense epidemiology: The case of asthma

Commonsense epidemiology—how lay people think about diseases and their causes and consequences—can influence how people respond. We examined three lay epidemiological beliefs about 20 triggers and 19 symptoms among 349 caregivers of children with asthma. Our findings contradicted the prevalence-seriousness hypothesis (perceived prevalence and seriousness correlate negatively). The data partially supported the prevalence-control hypothesis (perceived prevalence and asthma control correlate negatively). We found weak support for the seriousness-control hypothesis (perceived seriousness and asthma control correlate negatively). These findings suggest boundary conditions on the application of commonsense epidemiological beliefs.

Code-Switching patterns differentially shape cognitive control: Testing the predictions of the adaptive control hypothesis

Bilinguals engage in qualitatively different code-switching patterns (alternation, insertion, and congruent lexicalization) to different degrees, according to their engagement in different types of interactional contexts (single-language context, dual-language context, and dense code-switching context). Drawing on the adaptive control hypothesis, we examined whether bilinguals’ code-switching patterns would differentially shape multiple aspects of cognitive control (interference control, salient cue detection, and opportunistic planning). We found that a dense code-switching context, which predominantly involves insertion and congruent lexicalization, was positively associated with verbal opportunistic planning but negatively associated with interference control and salient cue detection. In contrast, a dual-language context, which predominantly involves alternation, was not associated with interference control or salient cue detection, but with significantly reduced response times for opportunistic planning. Our findings partially corroborate the theoretical predictions of the adaptive control hypothesis. Altogether, our study illustrates the importance of bilinguals’ disparate code-switching practices in shaping cognitive control outcomes.

Modulatory Effects of Language Context on Executive Functioning in Multilinguals

The advantages of bilingualism on executive functioning have received intense attention over the past decade with recent research patterns converging on multilingualism rather than just bilingualism. However, whether an advantage exists is far from conclusive, with convincing evidence on both sides of the debate. The present study investigated whether multilingual experience predicts better executive functioning (EF), and if language contexts modulate the relationship. 77 English-Mandarin simultaneous multilinguals completed a modified flanker task which varied according to language context (Neutral, Single-language or mixed-language contexts). Participants were instructed to ignore the task-irrelevant words during the single context blocks (English or Mandarin only) and mixed-language block (English & Mandarin). The first key finding is that multilingual experience predicted better performance but only in the mixed-language block. Second, language context moderates the strength of the relationship between multilingualism and flanker task performance. These findings provide direct evidence for the Adaptive Control Hypothesis. Furthermore, the present study demonstrated the use of a novel measure of multilingualism – the Multilingual Language Diversity score – as a significant predictor of enhanced EF in different language contexts. We end this paper by discussing practical guidelines for research moving forward.

Predictions about the Cognitive Consequences of Language Switching on Executive Functioning Inspired by the Adaptive Control Hypothesis Fail More Often than Not

The adaptive control hypothesis developed by Green and Abutalebi is the most influential theory of bilingual language control. The focus of this article is on the predictions that other researchers have derived based on the three different modes of interactional context described by the hypothesis. Foremost, that dual-language contexts should enhance domain-general executive functions more than single-language contexts. Several recent and ambitious behavioral tests of these predictions are reviewed. Although there was some evidence that dual-language contexts are associated with smaller switch costs, the evidence is inconsistent and there were no similar advantages for inhibitory control. The hypothesis also predicts neuroanatomical adaptations to the three types of interactional context. A careful evaluation of the relevant fMRI and ERP studies that take into account whether behavioral differences align with neuroscience differences and resolves valence ambiguities led to the conclusion that the neuroscience evidence for the hypothesis is, at best, inconsistent. The study also includes new analyses of two large-sample studies that enable the identification of relatively pure cases of single-language bilinguals, dual-language bilinguals, and dense-code switchers. Across nine different measures of executive functioning, the predicted advantage of the dual-language context never materialized. The hypotheses derived from the adaptive control hypothesis do not accurately predict behavioral performance on tests of executive functioning and do not advance our understanding as to what dimensions of bilingualism may lead to enhancements in specific components of executive functioning.

The use of a second language enhances the neural efficiency of inhibitory control: an ERP study

This study investigated how natural language use influences inhibition in language-unbalanced bilinguals. We experimentally induced natural patterns of language use (as proposed by the Adaptive Control Hypothesis) and assessed their cognitive after-effects in a group of 32 Polish–English bilinguals. Each participant took part in a series of three language games involving real conversation. Each game was followed by two inhibition tasks (stop-signal task and Stroop task). The manipulation of language use in the form of language games did not affect the behavioural measures, but it did affect ERPs. Performance of the inhibition tasks was accompanied by a reduction of P3 and the N450 amplitude differences after games involving the use of L2. The ERP modulations suggest that for bilinguals living in an L1 context the use of L2 enhances neural mechanisms related to inhibition. The study provides the first evidence for a direct influence of natural language use on inhibition.

EXPRESS: Differential impacts of natural L2 immersion and intensive classroom L2 training on cognitive control

The relationship between bilingualism and cognitive control has been controversial. We believe that the discrepant findings are likely driven by the complexities of the bilingual experience, which is consistent with the Adaptive Control Hypothesis. The current study investigates whether the natural language immersion experience and the classroom intensive language training experience have differential impacts on cognitive control. Among unbalanced Chinese-English bilingual students, a natural L2 (second language) immersion group, an L2 public speaking training group, and a control bilingual group without immersion or training experience were compared on their cognitive control abilities, with the participants’ demographic factors strictly controlled. The results showed that the L2 immersion group and the L2 speaking group had faster speed than the control group in the Flanker task, whereas the L2 immersion group had fewer errors than the other two groups in the Wisconsin Card Sorting Test (WCST). These results generally provide evidence in favor of the Adaptive Control Hypothesis, specifying that natural L2 immersion and L2 public speaking training experiences are distinctively related to cognitive control. The current study is the first of its kind to link specific bilingual experiences (natural L2 immersion vs. intensive L2 public speaking) with different components of cognitive control.

Response bias reveals the role of interhemispheric inhibitory networks in movement preparation and execution

Human movement is influenced by various cognitive processes, such as bias, that dynamically shape competing movement representations. However, the neurophysiological mechanisms underlying the effects of bias on movement selection across the lifespan remains poorly understood.Healthy young (n = 21) and older (n = 20) adults completed a choice reaction time task necessitating left- or right-hand responses to imperative stimuli (IS). Response bias was manipulated via a cue that informed participants a particular response was 70% likely (i.e., the IS was either congruent, or incongruent, with the cue); biasing was either fixed for blocks of trials (block-wise bias) or varied from trial-to-trial (trial-wise bias). As well as assessing the behavioural manifestations of bias, we used transcranial magnetic stimulation to determine changes in corticospinal excitability (CSE) and short- and long-interval interhemispheric inhibition (SIHI, LIHI) during movement preparation and execution. Participants responded more quickly, and accurately, in congruent compared to incongruent trials. CSE decreases occurred in both hands following the cue, consistent with the ‘inhibition for impulse control’ hypothesis of preparatory inhibition. In contrast, IHI modulations occurred in a hand-specific manner. Greater SIHI was observed during movement preparation in the hand biased away from, compared to the hand biased towards, the cue; furthermore, greater SIHI was observed during movement execution in the hand biased towards the cue when it was not required to respond (i.e., incongruent trial) compared to when it was required to respond (congruent trial). Additionally, during the movement preparation period, the LIHI ratio of the hand biased towards, compared to the hand biased away from, the cue was greatest when the cue varied trial-by-trial. Overall, the IHI results provide support for the ‘inhibition for competition resolution’ hypothesis, with hand specific modulation of inhibition during movement preparation and execution.

Parameters research on time-varying stiffness of the ball bearing system without race control hypothesis

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson (N-R) method with dynamic declined factors is presented. The effect of the dispersion of bearing parameters and the installation errors on the time-varying carrying characteristics of the ball-raceway contact and the bearing stiffness are investigated. Numerical simulation illustrates that besides the load and the rotating speed, the dispersion of bearing parameters and the installation errors have noticeable effect on the ball-raceway contact load, ball-inner raceway contact state and bearing stiffness, which should be given full consideration during the process of design and fault diagnosis for the rotor-bearing system.

High fluid intelligence is characterized by flexible allocation of attentional resources: Evidence from EEG

Recently, the integrated control hypothesis (Lu et al., 2020) was proposed to explain the relationship between fluid intelligence (Gf) and attentional resource allocation. This hypothesis suggested that individuals with higher Gf tend to flexibly and adaptively allocate their limited resources according to the task type and task difficulty rather than simply exert more or fewer resources in any conditions. To examine this hypothesis, the present study used electroencephalogram (EEG) indicators (i.e., frontal theta-ERS and parietal-occipital alpha-ERD) as the measurement of participants’ resource allocation during the exploration task and exploitation task with different difficulties. The results found that higher Gf individuals tend to allocate fewer resources in all difficulty levels in the exploitation task compared to average Gf participants. In contrast, in the exploration task, higher Gf participants would allocate more resources in the medium- and high-difficulty levels than average Gf participants, but this phenomenon was only found in males. These findings provided supportive evidence for the integrated control hypothesis that flexible and adaptive attentional control ability are important characteristics of human intelligence.

Is there an effect of diglossia on cognition? An investigation of the relationship between diglossia and Executive Functions in young adults.

Recent studies investigating whether bilingualism has effects on cognitive abilities beyond language have produced mixed results, with evidence from young adults typically showing no effects. These inconclusive patterns have been attributed to many uncontrolled factors, including linguistic similarity and the conversational contexts the bilinguals find themselves in, including the opportunities they get to switch between their languages. In this study, we focus on the effects on cognition of diglossia, a linguistic situation where two varieties of the same language are spoken in different and clearly separable contexts. We used linear mixed models to compare 32 Arabic diglossic young adults, and 38 English monolinguals on cognitive tasks assessing the Executive Functions domains of inhibition, switching and working memory. Results revealed that, despite both groups performing as expected on all tasks, there were no effects of diglossia on their performance in any of these domains. These results are discussed in relation to the Adaptive Control Hypothesis. Considering that this is the first study to investigate the diglossic advantages in Arabic, we propose that any effects on Executive Functions that may be attributed to the use of more than one language or language variety should not be expected when the two are used in exclusive contexts with limited opportunity to switch between them.