Resting heart rate variability and emotion regulation difficulties: Comparing Asian Americans and European Americans.

Asian Americans and European Americans differ in emotion regulation (ER), particularly regarding strategies utilized to adaptively engage in ER. Resting heart rate variability (HRV), a biomarker of ER ability, is suggested to differ between Asian Americans and European Americans, but evidence for such differences has been inconsistent. Yet, research has not considered how Asian Americans and European Americans might differ in the well-established link between resting HRV and ER difficulties, which might lend a better understanding of such inconsistencies. In 374 college-aged individuals (66 Asian Americans; 311 European Americans; 190 women; mean age = 19.3 years [Min. 18, Max 38]), we examined if ethnicity moderated the link between resting HRV and self-reported ER difficulties. Resting HRV was obtained during a 5-min resting-baseline period, and ER difficulties were assessed using the Difficulties in ER Scale, which contained six facets of ER difficulties. Adjusting for gender and body mass index, moderation analyses showed a stronger association between resting HRV and ER difficulties in Asian Americans compared to European Americans. When examining facets of ER, ethnicity moderated only the link between resting HRV and difficulties in accessing ER strategies when facing negative emotions. At lower levels of HRV, Asian Americans reported greater difficulties in ER relative to European Americans. This effect diminished and trended in the opposite direction among those with higher HRV. In sum, these results provide novel evidence that higher resting HRV might be particularly important for adaptive ER among Asian Americans - a marginalized ethnic group - in the U.S.

Heart's eyes to see color: Cardiac vagal tone modulates the impact of ethnicity on selected attention under high load.

The present study tested whether cardiac vagal activity-which is known to play a vital role in social cognition and engagement-predicted the impact of faces of other ethnicity on selective attention under load. Based on the neurovisceral integration theory, we hypothesized that participants with higher resting heart rate variability (HRV) would exhibit better task performance of a target detection task in trials with face distractors of other ethnicity than participants with lower resting HRV, when cognitive resources were scarce under high load. Caucasian participants were instructed to detect a target letter among letter strings superimposed on Black or White male distractor faces under high and low perceptual load. Consistent with the prediction, under high load, HRV was positively correlated with accuracy in trials with Black distractor faces, but not in trials with White distractor faces. The current research demonstrated that individual differences in cardiac vagal tone predicted successful inhibition of an ethnicity-related distractor with limited cognitive resources, which allowed for completing goal-directed behavior more successfully.

The Modulation of Cardiac Vagal Tone on Attentional Orienting of Fair-Related Faces: Low HRV is Associated with Faster Attentional Engagement to Fair-Relevant Stimuli.

The current experiment examined the effect of fair-related stimuli on attentional orienting and the role of cardiac vagal tone indexed by heart rate variability (HRV). Neutral faces were associated with fair and unfair offers in the Ultimatum Game (UG). After the UG, participants performed the spatial cueing task in which targets were preceded by face cues that made fair or unfair offers in the UG. Participants showed faster attentional engagement to fair-related stimuli, which was more pronounced in individuals with lower resting HRV-indexing reduced cardiac vagal tone. Also, people showed delayed attentional disengagement from fair-related stimuli, which was not correlated with HRV. The current research provided initial evidence that fair-related social information influences spatial attention, which is associated with cardiac vagal tone. These results provide further evidence that the difficulty in attentional control associated with reduced cardiac vagal tone may extend to a broader social and moral context.

The Benefit of Gratitude: Trait Gratitude Is Associated With Effective Economic Decision-Making in the Ultimatum Game.

The current research investigated the role of gratitude in economic decisions about offers that vary in fairness yet benefit both parties if accepted. Participants completed a trait/dispositional gratitude measure and then were randomly assigned to recall either an event that made them feel grateful (i.e., induced gratitude condition) or the events of a typical day (i.e., neutral condition). After the gratitude induction task, participants played the ultimatum game (UG), deciding whether to accept or reject fair offers (i.e., proposer: responder ratio $5:5) and unfair offers (i.e., proposer: responder ratios of $9:1, $8:2, or $7:3) from different proposers. Results showed that trait gratitude was positively correlated with respondents' acceptance of unfair offers. However, experimentally induced momentary gratitude did not influence acceptance of unfair offers. The trait or disposition to be grateful involves the enduring capacity across different types of situations and benefactors to see the good that is present, even when that benefit is small. Accordingly, dispositional gratitude - but not momentarily induced gratitude - was associated with a greater propensity to accept even the small benefits within unfair offers which otherwise pose barriers to making the effective economic decision of accepting offers regardless of their relative size.

Enhanced Memory for Fair-Related Faces and the Role of Trait Anxiety.

The current research examined whether fair consideration-a social norm that people inherently prefer to confirm-would modulate face recognition. Each neutral face was associated with fair or unfair offers via an economic decision task, the Ultimatum Game (UG) task. After the UG, participants were asked to identify the faces of proposers who made different offers. Enhanced memory was observed for fair-related compared to unfair-related faces. Furthermore, high trait anxiety was associated with reduced memory for fair-related faces. These results were further confirmed by signal detection theory. The current research provided initial evidence that people showed enhanced memory for faces that made fair offers from the economic decision task, and that high trait anxiety was associated with reduced fair-related memory. Possible neural mechanisms and the implication in economic and social situations have been discussed.

Correction: Social Groups Prioritize Selective Attention to Faces: How Social Identity Shapes Distractor Interference.

[This corrects the article DOI: 10.1371/journal.pone.0161426.].

Social Groups Prioritize Selective Attention to Faces: How Social Identity Shapes Distractor Interference.

Human faces automatically attract visual attention and this process appears to be guided by social group memberships. In two experiments, we examined how social groups guide selective attention toward in-group and out-group faces. Black and White participants detected a target letter among letter strings superimposed on faces (Experiment 1). White participants were less accurate on trials with racial out-group (Black) compared to in-group (White) distractor faces. Likewise, Black participants were less accurate on trials with racial out-group (White) compared to in-group (Black) distractor faces. However, this pattern of out-group bias was only evident under high perceptual load-when the task was visually difficult. To examine the malleability of this pattern of racial bias, a separate sample of participants were assigned to mixed-race minimal groups (Experiment 2). Participants assigned to groups were less accurate on trials with their minimal in-group members compared to minimal out-group distractor faces, regardless of race. Again, this pattern of out-group bias was only evident under high perceptual load. Taken together, these results suggest that social identity guides selective attention toward motivationally relevant social groups-shifting from out-group bias in the domain of race to in-group bias in the domain of minimal groups-when perceptual resources are scarce.

Trait Anxiety Is Associated with Negative Interpretations When Resolving Valence Ambiguity of Surprised Faces.

The current research examines whether trait anxiety is associated with negative interpretation bias when resolving valence ambiguity of surprised faces. To further isolate the neuro-cognitive mechanism, we presented angry, happy, and surprised faces at broad spatial frequency (BSF), high spatial frequency (HSF), and low spatial frequency (LSF) and asked participants to determine the valence of each face. High trait anxiety was associated with more negative interpretations of BSF (i.e., intact) surprised faces. However, the modulation of trait anxiety on the negative interpretation of surprised faces disappeared at HSF and LSF. The current study provides evidence that trait anxiety modulates negative interpretations of BSF surprised faces. However, the negative interpretation of LSF surprised faces appears to be a robust default response that occurs regardless of individual differences in trait anxiety.

At the heart of morality lies neuro-visceral integration: lower cardiac vagal tone predicts utilitarian moral judgment.

To not harm others is widely considered the most basic element of human morality. The aversion to harm others can be either rooted in the outcomes of an action (utilitarianism) or reactions to the action itself (deontology). We speculated that the human moral judgments rely on the integration of neural computations of harm and visceral reactions. The present research examined whether utilitarian or deontological aspects of moral judgment are associated with cardiac vagal tone, a physiological proxy for neuro-visceral integration. We investigated the relationship between cardiac vagal tone and moral judgment by using a mix of moral dilemmas, mathematical modeling and psychophysiological measures. An index of bipolar deontology-utilitarianism was correlated with resting heart rate variability (HRV)-an index of cardiac vagal tone-such that more utilitarian judgments were associated with lower HRV. Follow-up analyses using process dissociation, which independently quantifies utilitarian and deontological moral inclinations, provided further evidence that utilitarian (but not deontological) judgments were associated with lower HRV. Our results suggest that the functional integration of neural and visceral systems during moral judgments can restrict outcome-based, utilitarian moral preferences. Implications for theories of moral judgment are discussed.

Influence of spatial frequency and emotion expression on face processing in patients with panic disorder.

BACKGROUND: Deficits in facial emotion processing is a major characteristic of patients with panic disorder. It is known that visual stimuli with different spatial frequencies take distinct neural pathways. This study investigated facial emotion processing involving stimuli presented at broad, high, and low spatial frequencies in patients with panic disorder. METHODS: Eighteen patients with panic disorder and 19 healthy controls were recruited. Seven event-related potential (ERP) components: (P100, N170, early posterior negativity (EPN); vertex positive potential (VPP), N250, P300; and late positive potential (LPP)) were evaluated while the participants looked at fearful and neutral facial stimuli presented at three spatial frequencies. RESULTS: When a fearful face was presented, panic disorder patients showed a significantly increased P100 amplitude in response to low spatial frequency compared to high spatial frequency; whereas healthy controls demonstrated significant broad spatial frequency dependent processing in P100 amplitude. Vertex positive potential amplitude was significantly increased in high and broad spatial frequency, compared to low spatial frequency in panic disorder. Early posterior negativity amplitude was significantly different between HSF and BSF, and between LSF and BSF processing in both groups, regardless of facial expression. LIMITATION: The possibly confounding effects of medication could not be controlled. CONCLUSIONS: During early visual processing, patients with panic disorder prefer global to detailed information. However, in later processing, panic disorder patients overuse detailed information for the perception of facial expressions. These findings suggest that unique spatial frequency-dependent facial processing could shed light on the neural pathology associated with panic disorder.

Early visual processing for low spatial frequency fearful face is correlated with cortical volume in patients with schizophrenia.

Patients with schizophrenia present with dysfunction of the magnocellular pathway, which might impair their early visual processing. We explored the relationship between functional abnormality of early visual processing and brain volumetric changes in schizophrenia. Eighteen patients and 16 healthy controls underwent electroencephalographic recordings and high-resolution magnetic resonance imaging. During electroencephalographic recordings, participants passively viewed neutral or fearful faces with broad, high, or low spatial frequency characteristics. Voxel-based morphometry was performed to investigate brain volume correlates of visual processing deficits. Event related potential analysis suggested that patients with schizophrenia had relatively impaired P100 processing of low spatial frequency fearful face stimuli compared with healthy controls; patients' gray-matter volumes in the dorsolateral and medial prefrontal cortices positively correlated with this amplitude. In addition, patients' gray-matter volume in the right cuneus positively correlated with the P100 amplitude in the left hemisphere for the high spatial frequency neutral face condition and that in the left dorsolateral prefrontal cortex negatively correlated with the negative score of the Positive and Negative Syndrome Scale. No significant correlations were observed in healthy controls. This study suggests that the cuneus and prefrontal cortex are significantly involved with the early visual processing of magnocellular input in patients with schizophrenia.

From the heart to the mind: cardiac vagal tone modulates top-down and bottom-up visual perception and attention to emotional stimuli.

The neurovisceral integration model (Thayer and Lane, 2000) posits that cardiac vagal tone, indexed by heart rate variability (HRV), can indicate the functional integrity of the neural networks implicated in emotion-cognition interactions. Our recent findings begin to disentangle how HRV is associated with both top-down and bottom-up cognitive processing of emotional stimuli. Higher resting HRV is associated with more adaptive and functional top-down and bottom-up cognitive modulation of emotional stimuli, which may facilitate effective emotion regulation. Conversely, lower resting HRV is associated with hyper-vigilant and maladaptive cognitive responses to emotional stimuli, which may impede emotion regulation. In the present paper, we recapitulate the neurovisceral integration model and review recent findings that shed light on the relationship between HRV and top-down and bottom-up visual perception and attention to emotional stimuli, which may play an important role in emotion regulation. Further implications of HRV on individual well-being and mental health are discussed.

When tonic cardiac vagal tone predicts changes in phasic vagal tone: the role of fear and perceptual load.

We examined the relationship between tonic--a correlate of self-regulatory functioning--and phasic cardiac vagal activity (indexed by heart rate variability; HRV) during a selective attentional task with varying levels of load. Participants detected a target letter among letter strings superimposed on either fearful or neutral face distractors. Letter strings consisted of six target letters under low load and one target letter and five nontarget letters under high load. With fearful distractors, lower tonic HRV was associated with phasic HRV suppression, suggesting an autonomic stress response under both low and high load. In contrast, higher tonic HRV was associated with phasic HRV enhancement, suggesting greater self-regulatory effort under low load and an absence of phasic HRV suppression under high load. The current research suggests that tonic cardiac vagal tone is associated with the ability to flexibly adapt autonomic responses.

Cardiac vagal tone predicts attentional engagement to and disengagement from fearful faces.

The current research examines individual differences in flexible emotional attention. In two experiments, we investigated the relationship between individual differences in cardiac vagal tone and top-down and bottom-up processes associated with emotional attention. To help determine the role of cortical and subcortical mechanisms underlying top-down and bottom-up emotional attention, fearful faces at broad, high, and low spatial frequency were presented as cues that triggered either exogenous or endogenous orienting. Participants with lower heart rate variability (HRV) exhibited faster attentional engagement to low-spatial-frequency fearful faces at short stimulus-onset asynchronies, but showed delayed attentional disengagement from high-spatial-frequency fearful faces at long stimulus-onset asynchronies in contrast to participants with higher HRV. This research suggests that cardiac vagal tone is associated with more adaptive top-down and bottom-up modulation of emotional attention. Implications for various affective disorders, including depression, anxiety disorders, and posttraumatic stress disorder, are discussed.

Gender difference in event related potentials to masked emotional stimuli in the oddball task.

OBJECTIVE: We investigated gender differences in event-related potential (ERP) responses to subliminally presented threat-related stimuli. METHODS: Twenty-four participants were presented with threat-related and neutral pictures for a very brief period of time (17 ms). To explore gender differences in ERP responses to subliminally presented stimuli, we examined six ERP components [P1, N170, N250, P300, Early Posterior Negativity (EPN) and Late Positive Potential (LPP)]. RESULTS: The result revealed that only female participants showed significant increases in the N170 and the EPN in response to subliminally presented threat-related stimuli compared to neutral stimuli. CONCLUSION: Our results suggest that female participants exhibit greater cortical processing of subliminally presented threat-related stimuli than male participants.

Cardiac vagal tone is correlated with selective attention to neutral distractors under load.

We examined whether cardiac vagal tone (indexed by heart rate variability, HRV) was associated with the functioning of selective attention under load. Participants were instructed to detect a target letter among letter strings superimposed on either fearful or neutral distractor faces. Under low load, when letter strings consisted of six target letters, there was no difference between people with high and low HRV on task performance. Under high load, when letter strings consisted of one target letter and five nontarget letters, people with high HRV were faster in trials with neutral distractors, but not with fearful distractors. However, people with low HRV were slower in trials with both fearful and neutral distractors. The current research suggests cardiac vagal tone is associated with successful control of selective attention critical for goal-directed behavior, and its impact is greater when fewer cognitive resources are available.

Individual differences in cardiac vagal tone are associated with differential neural responses to facial expressions at different spatial frequencies: an ERP and sLORETA study.

A previous study has shown that greater cardiac vagal tone, reflecting effective self-regulatory capacity, was correlated with superior visual discrimination of fearful faces at high spatial frequency Park et al. (Biological Psychology 90:171-178, 2012b). The present study investigated whether individual differences in cardiac vagal tone (indexed by heart rate variability) were associated with different event-related brain potentials (ERPs) in response to fearful and neutral faces. Thirty-six healthy participants discriminated the emotion of fearful and neutral faces at broad, high, and low spatial frequencies, while ERPs were recorded. Participants with low resting heart rate variability-characterized by poor functioning of regulatory systems-exhibited significantly greater N200 activity in response to fearful faces at low spatial frequency and greater LPP responses to neutral faces at high spatial frequency. Source analyses-estimated by standardized low-resolution brain electromagnetic tomography (sLORETA)-tended to show that participants with low resting heart rate variability exhibited increased source activity in visual areas, such as the cuneus and the middle occipital gyrus, as compared with participants with high resting heart rate variability. The hyperactive neural activity associated with low cardiac vagal tone may account for hypervigilant response patterns and emotional dysregulation, which heightens the risk of developing physical and emotional problems.

Clinical implications of quantitative electroencephalography and current source density in patients with Alzheimer's disease.

This study examined whether quantitative electroencephalography (qEEG) and current source density (CSD) can be used to evaluate symptom severity in Alzheimer's disease (AD) patients. Thirty AD patients (13 mild and 17 moderate severity) and 30 normal control (NC) subjects were recruited. The Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet and the Global Deterioration Scale were measured. qEEG and CSD data were analyzed in five frequency bands: delta (1-3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-25 Hz), and gamma (30-50 Hz). Compared with the NC subjects, the moderate AD patients had significantly increased theta and decreased beta power. Compared with the mild AD patients, the moderate AD patients had significantly decreased beta power. In the AD patients, the theta power was significantly correlated with a poor performance for global cognition; however, beta power was positively correlated with a good performance for global cognition, attention, memory, visuospatial function, and executive function. The CSD of the theta band in the superior temporal gyrus, transverse temporal gyrus, insula, postcentral gyrus, cuneus, and lingual gyrus was significantly different between NC subjects and moderate AD patients and between mild and moderate AD patients. The theta CSD of these regions was significantly correlated with a poor performance for global cognition, memory, visuospatial function, execution, and language. The results suggest that qEEG and the CSD of the theta and beta bands are useful biological markers in AD patients.

Cardiac vagal tone predicts inhibited attention to fearful faces.

The neurovisceral integration model (Thayer, J. F., & Lane, R. D., 2000, A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 201-216. doi:10.1016/S0165-0327(00)00338-4) proposes that individual differences in heart rate variability (HRV)-an index of cardiac vagal tone-are associated with attentional and emotional self-regulation. In this article, we demonstrate that individual differences in resting HRV predict the functioning of the inhibition of return (IOR), an inhibitory attentional mechanism highly adaptive to novelty search, in response to affectively significant face cues. As predicted, participants with lower HRV exhibited a smaller IOR effect to fearful versus neutral face cues than participants with higher HRV, which shows a failure to inhibit attention from affectively significant cues and instigate novelty search. In contrast, participants with higher HRV exhibited similar IOR effects to fearful and neutral face cues, which shows an ability to inhibit attention from cues and instigate novelty search. Their ability to inhibit attention was most pronounced to high spatial frequency fearful face cues, suggesting that this effect may be mediated by cortical mechanisms. The current research demonstrates that individual differences in HRV predict attentional inhibition and suggests that successful inhibition and novelty search may be mediated by cortical inhibitory mechanisms among people with high cardiac vagal tone.

From the heart to the mind's eye: cardiac vagal tone is related to visual perception of fearful faces at high spatial frequency.

The neurovisceral integration model (Thayer and Lane, 2000) proposes that vagally mediated heart rate variability (HRV)--an index of cardiac vagal tone--is associated with autonomic flexibility and emotional self-regulation. Two experiments examined the relationship between vagally mediated HRV and visual perception of affectively significant stimuli at different spatial frequencies. In Experiment 1, HRV was positively correlated with superior performance discriminating the emotion of affectively significant (i.e., fearful) faces at high spatial frequency (HSF). In Experiment 2, processing goals moderated the relationship between HRV and successful discrimination of HSF fearful faces. In contrast to Experiment 1, discriminating the expressiveness of HSF fearful faces was not correlated with HRV. The current research suggests that HRV is positively associated with superior visual discrimination of affectively significant stimuli at high spatial frequency, and this relationship may be sensitive to the top-down influence of different processing goals.