In everyday conversation, bilingual individuals switch between languages not only in reaction to monolinguals with different language profiles but also voluntarily and naturally. However, whether and how various switching contexts dynamically modulate the domain-general control were still illusive. Using a cross-task paradigm which flanker task was interleaved with language switching task trial-by-trial, the present study manipulated forced, voluntary and natural switching contexts. A group of unbalanced Chinese-English bilinguals performed a flanker task in the three switching contexts. The results showed that the cross-domain interaction on the P3 effect revealed an atypical flanker effect in forced switching contexts only, and P3 amplitude of incongruent trials in forced switching contexts was smaller than both natural and voluntary switching contexts. Furthermore, the robust brain-brain and brain-behavior relationships between language control and domain-general control were significantly emerged in the forced switching context only. Altogether, our findings support the dynamic adaptation of language control to cognitive control and highlight the importance of switching contexts.

The aperiodic slope of the EEG power spectrum (characterized by a 1/fx distribution in which power decreases as frequency increases) is hypothesized to index the excitatory-inhibitory balance and has been associated with various neurodevelopmental outcomes in older children and adults. However, the dearth of research early in development led us to investigate associations among EEG aperiodic slope, temperament, and maternal internalizing (anxiety and depression) symptoms in a large cohort of typically developing infants. Steeper slope was associated with higher scores on the temperament domains of orienting/regulation and surgency but was not associated with negative affectivity. Maternal symptoms did not appear to be directly associated with slope, but slope moderated the association between maternal symptoms and temperament. Specifically, steeper slope was associated with a stronger negative association between maternal internalizing symptoms and infant orienting/regulation. These results demonstrate associations between slope and behavior as early as infancy, which may reflect early differences in the development of global inhibitory networks. Longitudinal research in early childhood is necessary to better understand the nature of these relations during development and their potential impact on later socioemotional outcomes.

It is commonly agreed that power modulations in alpha oscillatory activity serve as an inhibitory neural mechanism, selectively routing information within neural circuits. In visuo-spatial attention, alpha oscillations enhance the processing of relevant targets and suppress potential distractors. However, there are inconsistencies regarding alpha power modulations with increasing load in common working memory (WM) tasks. Particularly, high WM load is associated with either decreased or increased alpha power, depending on the type of WM task deployed (i.e., N-back vs. Sternberg task). Next to existing cognitive interpretations of this variation of alpha power with load, recent considerations suggest the involvement of oculomotor action as a complementary explanation. In the present report we attempt to test this complementary view. We will conduct a large-scale combined electroencephalography and eye tracking study with 120 participants to examine the relationship between alpha power modulation and oculomotor action in the context of an N-back task and a Sternberg task. We aim to explore whether different gaze patterns during these tasks offer explanatory value in addressing the variations in alpha power with WM load. To this end, statistical tests on scalp-level power for the alpha band (8-14 Hz) and gaze deviation metrics will be conducted.

Worry and rumination are common forms of perseverative cognition (PC) and repetitive negative thinking towards stressors. PC can generate psychophysiological stress before or after exposure to stressors and is linked to chronic stress, diseases, and adverse health outcomes. PC has been associated with vagally-mediated heart rate variability (vmHRV). In the present meta-analytic review, effect sizes for the relationship between PC and vmHRV were computed for baseline, stressor, and recovery conditions vmHRV among studies using within-subject and between-subject analyses. A total of 55 effect sizes were extracted from 24 eligible articles (17 for baseline, 15 for reactivity, 8 for recovery). Small to medium effect sizes were observed for the correlations between PC and baseline vmHRV (g = .40, SE = .10), within-subject reactivity vmHRV (g = .27, SE = .07), and between-subject recovery vmHRV (g = .44, SE = .18). The other meta-analyses did not yield statistically significant effect sizes. High heterogeneity was detected across the meta-analyses and statistical tests suggested the absence of publication biases. Overall, PC in laboratory studies was observed to differentially associate with baseline, reactivity, and recovery vmHRV. The scarcity of vmHRV recovery studies was discussed.

The present study investigated whether the interaction of resting RSA (respiratory sinus arrhythmia) and RSA reactivity was associated with mobile phone addiction in adolescents. Physiological and psychological data were collected from 165 Chinese adolescents (80 boys; Mage = 12.68, Sage = 0.69). The results revealed that (1) resting RSA and RSA reactivity were both significantly negatively correlated with adolescents’ mobile phone addiction; and (2) resting RSA and RSA reactivity interactively to predict adolescents’ mobile phone addiction. Specifically, adolescents with higher resting RSA and higher RSA reactivity showed the lowest level of mobile phone addiction. The findings suggest the importance of considering the combined indices of respiratory sinus arrhythmia in predicting adolescent problem behaviors.

We tested whether decreasing respiratory frequency would stabilise both behavioural attention and pupil diameter oscillatory activity, compared to a spontaneously breathing control group. Pupil diameter was used as a proxy measure for Locus Coeruleus (LC) activity in order to directly test a prediction from a dynamical systems model (Melnychuk et al 2018) that posits the LC as a mediating nexus between respiration and attention. A novel task was designed, Paced Auditory Cue Entrainment (PACE) task, in which participants responded rhythmically to auditory cues, providing a continuous measure of sustained attention, and additionally, a breath guide for the experimental group. In Experiment 1, the respiratory frequency was guided from 0.15 Hz → 0.1 Hz → 0.15 Hz. In Experiment 2, participants spent a longer duration in each frequency, guided at 0.15 Hz → 0.1 Hz only. The two experiments yielded highly consistent results. Despite no group differences in the variation of the timing of responses, the control group committed significantly more lapses of attention in contrast to the breathing group, which barely committed any of such errors. Additionally, the oscillatory activity of pupil diameter in the breathing group closely tracked the frequency of the instructed breathing, implicating the possibility of LC-noradrenaline activity being entrained by the breath intervention. From these findings we conclude that decreasing respiratory frequency did indeed stabilise attention, mitigating lapses, possibly through stabilising fluctuations in LC activity.

Research has shown that exposure to higher rates of neighborhood disadvantage and contextual threat increases risk for the development of psychopathology in youth, with some evidence that these effects may differ across racial/ethnic groups. Although studies have shown that direct exposure to stress impacts neural responses to threat-relevant stimuli, less is known about how neighborhood characteristics more generally (e.g., living in neighborhood characterized by high crime risk, whether or not the individual directly experiences any crime) may impact children’s neural responses to threat. To address this question, we examined links between census-derived indices of neighborhood crime and neural reactivity to emotional stimuli in a sample of 100 children (Mage = 9.64, 54% girls, 65% non-Hispanic White) and whether these relations differ for children from minority backgrounds compared to non-Hispanic White children. Focusing on the late positive potential (LPP) event-related potential (ERP) component, we examined neural reactivity to threat-relevant stimuli (fearful faces) as well as non-threat relevant negative (sad faces) and positive (happy faces) stimuli across low, medium, and high intensities (morph levels). We found that levels of neighborhood crime were associated with LPP response to high intensity fearful, but not happy or sad, faces, but only among children from racial/ethnic minority backgrounds. This suggests that levels of crime within one’s neighborhood may be a more salient stressor for children from minority racial-ethnic groups than for non-Hispanic White children.

Reward-related brain activity has most often been examined during monetary reward paradigms, but it has also been examined in response to other types of reward (e.g., social reward) that often necessitate modifications to procedure and task design. It is important to investigate whether task factors impact the ability to assess the neural response common across different types of reward (i.e., domain-general) and specific to each type of reward (i.e., domain-specific). The present study involved a sample of 303 18-year-olds (49.5% female) who completed the Monetary Doors task and two social tasks: Social Reward, which was designed to be analogous to Monetary Doors, and Island Getaway, which differed procedurally from the other two tasks. Using electroencephalography to measure the time-domain reward positivity (RewP) and time-frequency delta and theta activity, we found that all three tasks elicited a RewP and greater delta activity to favorable outcomes (i.e., monetary win, social like/acceptance), and greater theta activity to unfavorable outcomes (i.e., monetary loss, social dislike/rejection). The RewP was positively correlated across all three tasks, indicating the ability to measure domain-general neural response, but the neural responses during Monetary Doors and Social Reward were more strongly correlated compared to the other task pairwise correlations for the RewP and delta activity. The present study suggests that different monetary and social reward tasks can elicit both domain-general and domain-specific brain activity but are influenced by task design. Recommendations are made regarding factors to consider when attempting to examine domain-general and domain-specific neural response to reward.

Imaginal exposure is a standard procedure of cognitive behavioural therapy for the treatment of anxiety and panic disorders. It is often used when in vivo exposure is not possible, too stressful for patients, or would be too expensive. The Bio-Informational Theory implies that imaginal exposure is effective because of the perceptual proximity of mental imagery to real events, whereas empirical findings suggest that propositional thought of fear stimuli (i.e., thinking about the stimuli without seeing them in the mind’s eye) could be sufficient. To investigate whether mental imagery or propositional thought is crucial for the success of imaginal exposure, participants with the rare state of aphantasia (= absence of sensory mental imagery) and two control groups were subjected to a fear conditioning paradigm followed by imaginal exposure and a reinstatement procedure. During imaginal exposure, a control group (N = 30) stared at a bright screen to disrupt visual imagery by incoming luminance (= simulated aphantasia), while a second control group (N = 30) and participants with actual aphantasia (N = 30) kept their eyes closed. Results showed successful extinction in all groups, thus demonstrating that imaginal extinction is possible using propositional thought. Moreover, results indicate that people with aphantasia experience less emotional distress during the fear conditioning procedure, most likely due to similar mechanisms as in alexithymia, i.e., a decoupling between physiological arousal and emotional experience.

Speech production interferes with accurate measurement of cardiac vagal activity during acute stress, attenuating the expected drop in heart rate variability in the respiratory frequency band. Speech also induces sympathetic changes similar to those induced by psychological stress. In the laboratory, confounding of physiological stress reactivity by speech may be controlled experimentally. In ambulatory assessments, however, detection of speech episodes is necessary to separate the physiological effects of psychosocial stress from those of speech. Using supervised machine learning (https://osf.io/bk9nf), we trained and tested speech classification models on data obtained from 56 participants (ages 18-39). They were equipped with privacy-secure wearables measuring thoracoabdominal respiratory inductance plethysmography (RIP from a single and a dual-band set-up), thoracic impedance pneumography, and an upper-sternum positioned unit with triaxial accelerometers and gyroscopes. Following an 80/20 train-test set split, nested cross-validations were run with the machine learning algorithms XGBoost, Gradient Boosting, Random Forest, and Logistic Regression on the training set to get unbiased generalized performance estimates. Speech classification by the best model per method was then validated in the unseen test-set. Speech versus no-speech classification performance (AUC) for both nested cross-validation and test-set predictions was excellent for thorax-abdomen RIP (nested cross-validation: 96.6%, test-set prediction: 98.5%), thorax-only RIP (97.5%, 99.1%), impedance (97.0%, 97.8%) and accelerometry (99.3%, 99.6%). The sternal accelerometer outperformed the other methods. These novel open-access models that leverage privacy-secure biosignals will enable researchers to detect speech and control for its confounding effects in ambulatory recordings, thereby enhancing the trustworthiness of psychophysiological findings.

Anxiety is an interactive disorder of the mind and body, characterized by excessive worry about uncertain future events and a dysfunction of the autonomic nervous system. Previous studies have shown that slow, deep breathing can affect the body’s internal organs by increasing the activity levels of the vagus nerve, reducing physical tension, and anxiety. Although we know that slow and deep breathing techniques can effectively regulate anxiety and other emotions, the psychological and neurophysiological mechanisms of slow breathing on anxiety have not been systematically explored. In the study, we combined the paced breathing task with the threat uncertainty task for the first time to investigate the role of slow breathing in regulating anxiety. Here we investigated this question, using Spectral analysis of EEG to assess brain activity relating respiratory rate and he mechanism of respiratory rate impact on the anxious. Twenty-seven individuals participated in the experiment, which followed a 2 (respiratory rate: fast breathing, slow breathing) × 2 (certainty: certain, uncertain). The results of showed that: (1) Slow breathing effectively reduced anxiety, the valence and arousal are lower under the slow breathing. (2) The EEG of fast and slow breathing showed different characteristics. The delta, theta and alpha EEG power are increased during the slow-paced breathing. (3) The EEG of Respiratory rate and certainty had a significant effect on the theta power. When individuals are faced with uncertain information the theta EEG power decreased during the slow-paced breathing, however, the theta EEG power increased during the fast-paced breathing.

Animal Assisted Interventions (AAIs) have been shown to have several effects in humans but the underlying cerebral mechanisms are still widely unknown. This research explored the neurological aspects of human–animal interactions. Specifically, we focused on frontal alpha asymmetry (FAA), a feature indicating differences in alpha power between the left and right frontal cortex, which is recognized as a correlate of approach motivation and positive affect. Twenty-nine healthy adults participated in this study, in which we used electroencephalography to measure their brain activity. The study comprised five phases: baseline measurements, interaction with a real dog, interaction with a replica dog, interaction with a plant, and a neutral phase. Participants had both physical and visual contact with all the stimuli, and the procedure was repeated three times for each participant. We also assessed participants’ subjective experiences of mental states and intrinsic motivation through the Multidimensional Well-Being and the Intrinsic Motivation Inventory questionnaires. The objective measurements of motivation and positive affect through FAA did not show a significant difference between interactions with a real dog and control conditions, but the subjective assessments differed. Participants reported significantly higher motivation and a more positive state of mind after interacting with a real dog compared to the control conditions. In summary, this study highlights the complexity of human–animal interactions and shows an intricate interplay between objective and subjective measurements. Our findings emphasize the importance of considering both neural markers and subjective experiences for understanding the nuanced mechanisms involved in the meaningful connections humans have with animals.

The processing stage (i.e., the early semantic representation stage, the late response-selection stage, or both) at which the spatial-numerical association of response codes (SNARC) effect occurs is still controversial. The two-stage processing model hypothesizes that the SNARC effect involves both stages and that different interference factors acting at the two stages might be the core reason for the observed stage flexibility of the SNARC effect. To test this hypothesis, the present study was designed to elicit the SNARC, Stroop (semantic-representation stage related), and Simon (response-selection stage related) effects together in one magnitude comparison task and used the event-related potentials (ERPs) to observe the temporal dynamics of these effects. The behavioral results showed no interaction between the Stroop and Simon effects, while these two effects both interacted with the SNARC effect. Furthermore, the ERP results showed an interaction of the Stroop effect with the SNARC effect for the early sensory P1 component, while the interaction of the Simon effect with the SNARC effect was evident for the late N2 and P300 components. The current study repeatedly verified the independence of Stroop and Simon effects. Most importantly, the temporal-specific interactions among the SNARC effect and the other two stage-related factors provided further evidence to support the two-stage processing model that the SNARC effect involves both the representation and response-selection stages.

Alpha oscillations are associated with various cognitive functions. However, the determinants of alpha power variation remain ambiguous, primarily due to its inconsistent associations with autonomic responses and subjective states under different experimental conditions. To thoroughly examine the correlations between alpha power variation and these factors, we implemented a range of experimental conditions, encompassing attentional and emotional tasks, as well as a resting state. In addition to the electroencephalogram data, we gathered a suite of autonomic response measurements and subjective ratings. We employed multivariate linear regression analysis, utilizing autonomic responses and subjective reports as predictors of alpha power. We also subtracted the aperiodic components for better estimation of the power of periodic alpha oscillations. Our results demonstrated that the combined use of autonomic response measurements and subjective ratings effectively predicted the periodic alpha power variation across a range of conditions. These predictions were supported by leave-one-participant-out cross-validation, confirming that multivariate linear relationships can be generalized to new participants. This study demonstrates the links of alpha power variations with autonomic responses and subjective states, suggesting that during investigations of the cognitive functions of alpha oscillations, it is important to consider the potential influences of autonomic responses and subjective states on alpha oscillations.

Behavioural research over several decades has found that concrete words are processed more quickly and accurately than abstract words (concreteness effect). This advantage is also reflected in their different processing and representation in the human brain. In this electrophysiological study, we explored the interplay of concreteness as a continuous measure and task effects on word processing. Electrophysiological responses of 58 participants were recorded during semantic, affective, and grammatical decision tasks on words parametrically varied in concreteness. Our findings uncovered a fine-grained concreteness effect within four distinct spatiotemporal windows when a coding of semantic information is required. In the semantic decision task, we detected a higher parietal positivity within the P300 time range and an increased left temporo-lateral negative-going amplitude for less concrete concepts. We also identified a concreteness effect characterised by greater negativity in the N400 component. In the affective task, we observed a more pronounced parietal P600-like component for more abstract concepts. Interestingly, we found that the neural representational similarity (starting from 450 ms with a widespread scalp distribution) conformed to the concreteness similarity among concepts (regardless of the task), implying that their semantic representations may be characterised along the concreteness dimension in the brain. Our study transcends the conventional dichotomy of abstract versus concrete words, unearthing not only varied processing dynamics along the concreteness dimension but also distinct fine-grained neural representations. This novel insight positions concreteness as a structural dimension, enriching our comprehension of how the brain organises and processes semantic information.

Processing negative stimuli holds profound significance for survival, yet excessive focus on this information can lead to poor social adaptation. Trust violations, common occurrences in negative interpersonal interactions, result in individuals allocating greater cognitive resources towards processing negative stimuli. However, it is still unclear how trust violations influence the ability to control interference from negative stimuli. Therefore, this study employed the Emotional Stroop paradigm (Experiment 1) and the cued Ultimatum game (Experiment 2), using ERP technology to explore how trust violations influence emotional interference control abilities. In Experiment 1, the results showed that the violation group exhibited smaller SP amplitudes in the negative interference condition compared to the no-interference condition during the emotional Stroop paradigm. In Experiment 2, the violation group exhibited smaller SP amplitudes when benign cues were contaminated by threatening information relative to when they were not. Moreover, the violation group displayed higher P3 amplitudes for untrustworthy cues and angry faces than for trustworthy cues and happy faces, respectively. These findings were not observed in the control group. Collectively, these results suggest that trust violations not only draw more cognitive resources towards processing negative stimuli but also undermine interference control ability towards these stimuli.

The current study explores an emerging cardiac metric, heart rate fragmentation (HRF), as a novel biomarker for allostatic load (AL). HRF may better address the limitations of existing cardiac biomarkers (e.g., confounds and interpretation consistency) in applied research settings, with nonclinical samples. The study’s objectives were: 1) can HRF represent response to psychological stress and 2) can resting HRF be used as a measure of predicting subclinical mental health symptoms. One hundred and fifty-six (n = 156; 75% female) undergraduate students were fitted with a chest band to monitor cardiovascular activity, and completed online demographic and psychosocial surveys in which they were grouped as healthy or displaying probable mental health symptoms (pMH; n = 94, 60.25%) based on respective inventory thresholds for depression, anxiety, and posttraumatic stress disorder. Cardiovascular activity was measured capturing the three R’s of cardiac vagal control: a resting baseline, a reactive acute stressor task, and a paced breathing recovery. Results supported the first hypothesis, in that that HRF significantly differentiated between each RRR condition (p < 0.001). While healthy and pMH individuals did not significantly differ within individual conditions, exploratory analyses revealed healthy individuals displayed significantly larger change in HRF reactivity between conditions (p’s < 0.001) in comparison to pMH, which displayed a more blunted pattern. Overall, this study establishes associations between HRF and mental health, and serves as a promising new biomarker that may identify AL in samples that may be otherwise considered “healthy”, while addressing the limitations of prior biomarkers in non-clinical studies.

Despite growing evidence that associations between autonomic nervous system (ANS) responsivity and psychopathic traits vary across stress tasks only a single study has systematically assessed cross-task differences in associations. To advance this limited literature the current study randomized subjects into either a noise blast (countdown) task or a social stressor speech task. Analyses estimated associations between ANS (heart rate, skin conductance) and measures of psychopathic traits (Self-Report Psychopathy Scale-III, Inventory of Callous-Unemotional traits, Levenson Self-Report Psychopathy Scale, Sensation Seeking Scale – Form V). Results indicated that associations between ANS activity and psychopathic traits varied across stress task, ANS measure, and psychopathy measure. Associations that were consistent across analyses included a negative association between heart rate reactivity to the countdown task and SRP total scores, and a negative association between skin conductance reactivity to the social stressor speech task the interpersonal manipulation scale in the SRP. In addition, there was a negative association between resting skin conductance and SSS-V total scores.