Transient cardiac responses to witnessing horrible events in young adult female exercisers and non-exercisers

ObjectivesIt has been proposed that regular exercisers may be less vulnerable to the effects of stress and better able to cope with aversive events than people who are sedentary, but findings have not been consistent. In the present study, physiological variables indicating specific relevant psychological processes were used to objectively assess women's responses to stressful events.Design and MethodNon-exercising (n = 56) and regularly exercising women (up to 4 h, n = 62, and more than 4 h per week, n = 50) were viewing an aversive film consisting of scenes of real injury and death, and their transient cardiac responses to sudden horrifying events happening to persons in the film were obtained, as well as changes of prefrontal-posterior coupling, measured by EEG.ResultsCompared to regularly exercising women, non-exercising women showed a clearly more pronounced second accelerative component of the transient heart rate response to the terrifying events, indicating greater sensitivity of the avoidance (defensive) motivational system and heightened sensitivity to aversive stimuli. Moreover, non-exercising women did not show the expected characteristic initial heart rate acceleration when the scene approached its fatal end, that is, more rigid responding, and EEG data indicated less susceptibility to affect-laden information at the perceptual level.ConclusionsThe findings support the notion of less adaptive coping with adverse events in sedentary compared to exercising women and add to the growing evidence suggesting a stress-buffering effect of regular exercise, therefore promoting resilience and resistance to the negative impact of stressor and trauma exposure.     

Prosodic modulations in child-directed language and their impact on word learning

Child-directed language can support language learning, but how? We addressed two questions: (1) how caregivers prosodically modulated their speech as a function of word familiarity (known or unknown to the child) and accessibility of referent (visually present or absent from the immediate environment); (2) whether such modulations affect children's unknown word learning and vocabulary development. We used data from 38 English-speaking caregivers (from the ECOLANG corpus) talking about toys (both known and unknown to their children aged 3–4 years) both when the toys are present and when absent. We analyzed prosodic dimensions (i.e., speaking rate, pitch and intensity) of caregivers’ productions of 6529 toy labels. We found that unknown labels were spoken with significantly slower speaking rate, wider pitch and intensity range than known labels, especially in the first mentions, suggesting that caregivers adjust their prosody based on children's lexical knowledge. Moreover, caregivers used slower speaking rate and larger intensity range to mark the first mentions of toys that were physically absent. After the first mentions, they talked about the referents louder with higher mean pitch when toys were present than when toys were absent. Crucially, caregivers’ mean pitch of unknown words and the degree of mean pitch modulation for unknown words relative to known words (pitch ratio) predicted children's immediate word learning and vocabulary size 1 year later. In conclusion, caregivers modify their prosody when the learning situation is more demanding for children, and these helpful modulations assist children in word learning.

Research Highlights

• In naturalistic interactions, caregivers use slower speaking rate, wider pitch and intensity range when introducing new labels to 3–4-year-old children, especially in first mentions.
• Compared to when toys are present, caregivers speak more slowly with larger intensity range to mark the first mentions of toys that are physically absent.
• Mean pitch to mark word familiarity predicts children's immediate word learning and future vocabulary size.

     

A multimethod assessment to study the relationship between rumination and gender differences

Rumination is described as the propensity of responding to distress by repetitively and passively focusing on one’s negative emotions, and failures, and their consequences (Nolen-Hoeksema, 1991, 1998). Therefore, given that rumination is characterized especially by difficulties in managing and controlling negative emotional states, it is considered as the most common (impaired) emotional regulation strategy, and can be defined as an emotional process related to a repetitive, undesired, and past-oriented negatively inclined thought (Compare, Zarbo, Shonin, Van Gordon, & Marconi, 2014; Smith & Alloy, 2009). Recent evidence suggested that because of problems related to monitoring of negative states, rumination may be associated with exaggerated physiological reactivity relative to demands from the environment, and to some difficulties in attentional control abilities. The current study aimed at deepening our understanding of the role that a maladaptive emotional regulation strategy – such as rumination – might play in physiological response changes and in engaging dysfunctional attentional strategies. We used a multimethod assessment including self-reports (i.e., Rumination and Reflection Questionnaire, and Difficulties in Emotion Regulation Scale), physiological measures, (i.e., Heart Rate Variability recording), and attention tasks (i.e., Stroop Task) in order to examine the multiple aspects of rumination across genders. Sixty-eight individuals (30 males and 38 females) were administered DERS −16, RRQ and, soon after them, the Stroop task. Immediately after completing the Stroop task (T1), participants were exposed to a three-phase, baseline-stress-recovery experimental paradigm while their heart rate variability (HRV) was recorded. After completing the experimental paradigm, Stroop stimuli were presented for the second time (T2), in order to examine possible intra-individual differences between the two performances in the Stroop task. Our findings showed that rumination was higher in females than in males, but in men it appeared to be strongly associated with an overall impaired emotional regulation. However, no gender differences in rumination and emotion dysregulation were found when inspecting physiological data. The current study aims to contribute towards a better understanding which emotion regulation strategies and which physiological mechanisms are associated with rumination.     

Transfer of conditioned fear and avoidance: Concurrent measurement of arousal and operant responding

A reversal design was employed for the analysis of transfer of fear and avoidance through equivalence classes. Two 5-member equivalence classes (A1-B1-C1-D1-E1 and A2-B2-C2-D2-E2) were established. Then B1 and C1 were paired with shock (CS+) and served as S^Ds in avoidance training (B2 and C2 were trained as CS-/S^∆s for avoidance). Further avoidance training followed with D1 and E1 (as S^Ds) and D2 and E2 (as S^∆s), with the first presentation of each of these stimuli serving as the first transfer test. Afterwards, aversive conditioning contingencies were reversed: B2 and D2 were paired with shock and trained as S^Ds for avoidance, B1 and D1 were presented without shock (CS-/S^∆s). Transfer was tested again with C1, E1, C2 and E2. This reversal was implemented to allow for the within-subject replication of transfer effects upon changes in the function of only a subset of each class's elements. Avoidance (key presses) and conditioned fear (skin conductance and heart rate) were simultaneously measured. Results show a clear transfer effect for avoidance, with between- and within-subject replications. For physiological measures, transfer effects in the first test could only be imputed on the basis of group-based inferential statistical analysis. Evidence for between-subject replication was weaker, with only a limited proportion of participants meeting the individual criterion for transfer.     

The relationship between resting heart rate and aggression in males is racially variant

Although resting heart rate is thought to be a generalizable risk factor for aggression, very little research has examined whether this relationship varies by race. We addressed this limitation using longitudinal data from the Pittsburgh Youth Study. Current data are from 197 men who participated in a teenage biosocial study (mean age = 15.7 years) and adult follow-up study (mean age = 32.1 years). Teenage resting heart rate interacted with race to predict teenage and adult aggression. The relationship between heart rate and aggression was significant in White, but not in Black males. To our knowledge, this is the first study to find that the relationship between resting heart rate and aggression is racially variant, suggesting that resting heart rate may not be a generalizable biomarker for conduct problems. At an intervention-level, findings could contribute to the development of more accurate risk assessment tools that take into account racial variance in risk factors.     

Electroencephalographic and autonomic alterations in subjects with frequent nightmares during pre-and post-REM periods

Abnormal arousal processes, sympathetic influences, as well as wake-like alpha activity during sleep were reported as pathophysiological features of Nightmare Disorder. We hypothesized that in Nightmare Disorder, wake-like cortical activity and peripheral measures linked to arousals would be triggered by physiological processes related to the initiation of REM periods. Therefore, we examined electroencephalographic (EEG), motor and autonomous (cardiac) activity in a group of nightmare (NM) and healthy control (CTL) subjects during sleep-state-transitions while controlling for the confounding effects of trait anxiety. Based on the second-nights’ polysomnographic recordings of 19 Nightmare Disordered (NM) and 21 control (CTL) subjects, we examined the absolute power spectra focusing on the alpha range, measures of heart rate variability (HRV) and motor (muscle tone) activity during pre-REM and post-REM periods, separately. According to our results, the NM group exhibited increased alpha power during pre-REM, but not in post-REM, or stable, non-transitory periods. While CTL subjects showed increased HRV during pre-REM periods in contrast to post-REM ones, NM subjects did not exhibit such sleep state-specific differences in HRV, but showed more stable values across the examined sleep stages and less overall variability reflecting generally attenuated parasympathetic activity during sleep-state-transitions and during stable, non-transitory NREM states. These differences were not mediated by waking levels of trait anxiety. Moreover, in both groups, significant differences emerged regarding cortical and motor (muscle tone) activity between pre-REM and post-REM conditions, reflecting the heterogeneity of NREM sleep. Our findings indicate that NM subjects’ sleep is compromised during NREM–REM transitions, but relatively stabilized after REM periods. The coexistence of sleep-like and wake-like cortical activity in NM subjects seems to be triggered by REM/WAKE promoting neural activity. We propose that increased arousal-related phenomena in NREM–REM transitions might reflect altered emotional processing in NM subjects.     

Subjective and physiological responses to the 35% carbon dioxide challenge in healthy and non-clinical control populations: a meta-analysis and systematic review

Background/Rationale: The carbon dioxide (CO₂) challenge has been reliably used in laboratory settings as a panicogen in clinical populations. However, the magnitude of these effects on healthy and non-clinical control populations are not clear. The aim of this meta-analysis and systematic review is to provide quantitative estimates of those effects. Specifically, the current paper will evaluate the relative efficacy of the CO₂ challenge in eliciting both subjective and physiological arousal in healthy and non-clinical control populations.

Method: A total of 16 articles with 35 independent samples were included in the meta-analysis, while 37 studies with 74 independent samples were included in the systematic review.

Results: Both the meta-analysis and systematic review found the CO₂ challenge to elicit an increase in subjective distress via self-reported anxiety and fear. Physiological responses via blood pressure and heart rate were heterogeneous in studies sampled, with no significant changes observed across studies. Moderator analyses revealed the variations in findings may be attributed to participant screening and invasive sampling.

Discussion: Findings highlight the CO₂ challenge as a useful tool in the provocation of subjective distress. Implications for both the use of the CO₂ challenge and its anticipated effects in healthy and non-clinical control populations are discussed.     

The relationship between anomalistic belief,misperception of chance and the base rate fallacy

Abstract

A poor understanding of probability may lead people to misinterpret every day coincidences and form anomalistic (e.g., paranormal) beliefs. We investigated the relationship between anomalistic belief (including type of belief) and misperception of chance and the base rate fallacy across both anomalistic and control (i.e., neutral) contexts. Greater anomalistic belief was associated with poorer performance for both types of items; however there were no significant interactions between belief and context. For misperception of chance items, only experiential (vs. theoretical) anomalistic beliefs predicted more errors. In contrast, overall anomalistic belief was positively related to the base rate fallacy but no specific subtype of anomalistic belief was a significant predictor. The results indicate misperception of chance may lead people to interpret coincidental events as having an anomalistic cause, and a poor understanding of base rates may make people more prone to forming anomalistic beliefs.