Characteristics of interhemispheric EEG band power distribution in high anxiety individuals under emotionally neutral and aversive arousal conditions

The 62-channel EEG was recorded in control (CI, n = 21) and high anxiety (HA, n = 18) individuals under emotionally neutral (eyes closed, eyes open, and neutral videoclip) as well as under emotionally positive and aversive arousal conditions elicited by affective videoclips. In the present study the first three experimental conditions (eyes closed--eyes open--viewing emotionally neutral films) modeled increasing non-emotional arousal. Findings from this continuum show that in the HA individuals the lowest level of tonic arousal (eyes closed) was associated with stronger right-sided parietotemporal theta1 and beta1 activity. Group differences during cortical arousal increased by sensory stimulation (eyes open, neutral clips presentation) were marked only by persisting favored right hemisphere beta1 activity in high anxiety individuals. Under aversive arousal condition, attended by high intensity experience of emotions of anger, fear, disgust and anxiety, the HA subjects selectively desynchronized the right parietotemporal beta1 power which was initially higher in the control conditions. The obtained findings allow to suggest that peculiarities of right-sided parietotemporal EEG theta1 and beta1 activity in HA individuals under studied emotionally neutral and aversive arousal conditions point to overactivated withdrawal system in "checking" and "control" modes.     

Circadian clock resetting by arousal in Syrian hamsters: the role of stress and activity

Circadian rhythms in the Syrian hamster can be markedly phase shifted by 3 h of wheel running or arousal stimulation during their usual daily rest period ("subjective day"). Continuous wheel running is predictive but not necessary for phase shifts of this "nonphotic" type; hamsters aroused by gentle handling without running can also show maximal shifts. By contrast, physical restraint, a standard stress procedure and thus presumably arousing, is ineffective. To resolve this apparent paradox, phase-shifting effects of 3-h sessions of restraint or other stress procedures were assessed. In a preliminary study, phase shifts to arousal by gentle handling were significantly potentiated by the cortisol synthesis inhibitor metyrapone, suggesting that stress-related cortisol release may inhibit phase shifts to arousal. Next, it was confirmed that restraint in the subjective day does not induce phase shifts, but behavioral observations revealed that it also does not sustain arousal. Restraint combined with noxious compressed air blasts did sustain arousal and induced a significant cortisol response compared with arousal by gentle handling but did not induce shifts. Restraint combined with continuous horizontal rotation was also ineffective, as was EEG-validated arousal via confinement to a pedestal over water. However, 3 h of resident-intruder interactions (an intense psychosocial stress) or exposure to an open field (a mild stress) did induce large shifts that were positively correlated with indexes of forward locomotion. The results indicate that large phase shifts associated with arousal in the usual sleep period are neither induced nor prevented by stress per se, but are dependent on the expression of at least low levels of locomotor activity. Sustained arousal alone is not sufficient.     

Animal models of social avoidance and social fear

Social fear and avoidance of social situations represent the main behavioral symptoms of social anxiety disorder (SAD), a highly prevalent anxiety disorder that is poorly elucidated and has rather unsatisfactory therapeutic options. Therefore, animal models are needed to study the underlying etiology and pathophysiology of SAD and to verify the efficacy of possible novel treatment approaches. In this review, we describe and discuss the most important paradigms that have been shown to induce social avoidance and fear in rodents, including foot shock exposure, restraint stress, social isolation, social instability, social defeat, conditioned defeat, social defeat/overcrowding, chronic subordinate colony housing, chronic mild stress, maternal separation and social fear conditioning. We also describe some of the behavioral paradigms used to assess social avoidance and fear in rodents, including the social interaction test, the social preference-avoidance test, the social approach-avoidance test, the three-chambered social approach test, the partition test and the modified Y-maze test. We focus on the behavioral alterations these paradigms induce, especially on social interaction, general anxiety and depressive-like behavior given that SAD is strongly comorbid with anxiety and affective disorders.     

Matter Over Mind: A Randomised-Controlled Trial of Single-Session Biofeedback Training on Performance Anxiety and Heart Rate Variability in Musicians

Background

Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity. Objective: This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance.

Methods

A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domain measures of HRV.

Results

Slow breathing groups (n = 30) showed significantly greater improvements in high frequency (HF) and LF/HF ratio measures of HRV relative to control (n = 15) during 5 minute recordings of performance anticipation following the intervention (effect size: η² = 0.122 and η² = 0.116, respectively). The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n = 15) displayed greater reductions in self-reported state anxiety relative to those in the control condition (n = 7) (r = 0.379).

Conclusions

These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of HRV BF as a low-cost, non-pharmacological treatment for music performance anxiety.     

Fear and fitness: An evolutionary analysis of anxiety disorders

This article reviews the evolutionary origins and functions of the capacity for anxiety, and relevant clinical and research issues. Normal anxiety is an emotion that helps organisms defend against a wide variety of threats. There is a general capacity for normal defensive arousal, and subtypes of normal anxiety protect against particular kinds of threats. These normal subtypes correspond somewhat to mild forms of various anxiety disorders. Anxiety disorders arise from dysregulation of normal defensive responses, raising the possibility of a hypophobic disorder (too little anxiety). If a drug were discovered that abolished all defensive anxiety, it could do harm as well as good. Factors that have shaped anxiety-regulation mechanisms can explain prepotent and prepared tendencies to associate anxiety more quickly with certain cues than with others. These tendencies lead to excess fear of largely archaic dangers, like snakes, and too little fear of new threats, like cars. An understanding of the evolutionary origins, functions, and mechanisms of anxiety suggests new questions about anxiety disorders.     

Altered behavioural adaptation in mice with neural corticotrophin-releasing factor overexpression

Overproduction of corticotrophin-releasing factor (CRF), the major mediator of the stress response, has been linked to anxiety, depression and addiction. CRF excess results in increased arousal, anxiety and altered cognition in rodents. The ability to adapt to a potentially threatening stimulus is crucial for survival, and impaired adaptation may underlie stress-related psychiatric disorders. Therefore, we examined the effects of chronic transgenic neural CRF overproduction on behavioural adaptation to repeated exposure to a non-home cage environment. We report that CRF transgenic mice show impaired adaptation in locomotor response to the novel open field. In contrast to wild-type (WT) mice, anxiety-related behaviour of CRF transgenic mice does not change during repeated exposure to the same environment over the period of 7 days or at retest 1 week later. We found that locomotor response to novelty correlates significantly with total locomotor activity and activity in the centre at the last day of testing and at retest in WT but not in CRF transgenic mice. Mice were divided into low responders and high responders on the basis of their initial locomotor response to novelty. We found that differences in habituation and re-exposure response are related to individual differences in locomotor response to novelty. In summary, these results show that CRF transgenic mice are fundamentally different from WT in their ability to adapt to an environmental stressor. This may be related to individual differences in stress reactivity. These findings have implications for our understanding of the role of CRF overproduction in behavioural maladaptation and stress-related psychiatric disorders.     

Ultrasonic Control of Maternal Behavior: Developmental Implications

Infant rodents of many species emit high frequency vocalizationswhen aroused. These signals, when detected by adult femalesof the same species, elicit increased care-giving. The behaviorof the dam towards her offspring influences the developmentof arousal mechanisms of the offspring and appears to alterturnover of brain dopamine. These effects are quite pervasivesince altered maternal care induced by ultrasonic vocalizationsfrom an initial litter is observable in the behavior of thedam towards a subsequent litter; similar alterations in thedevelopment of arousal mechanisms and brain dopamine turnoverare observable in the subsequent litters; and the effects ofthis altered caregiving during the first three weeks of developmentare observable in laboratory rats (Rattus norgevicus) at oneand two years of age.     

Functional Programming of the Autonomic Nervous System by Early Life Immune Exposure: Implications for Anxiety

Neonatal exposure of rodents to an immune challenge alters a variety of behavioural and physiological parameters in adulthood. In particular, neonatal lipopolysaccharide (LPS; 0.05 mg/kg, i.p.) exposure produces robust increases in anxiety-like behaviour, accompanied by persistent changes in hypothalamic-pituitary-adrenal (HPA) axis functioning. Altered autonomic nervous system (ANS) activity is an important physiological contributor to the generation of anxiety. Here we examined the long term effects of neonatal LPS exposure on ANS function and the associated changes in neuroendocrine and behavioural indices. ANS function in Wistar rats, neonatally treated with LPS, was assessed via analysis of tyrosine hydroxylase (TH) in the adrenal glands on postnatal days (PNDs) 50 and 85, and via plethysmographic assessment of adult respiratory rate in response to mild stress (acoustic and light stimuli). Expression of genes implicated in regulation of autonomic and endocrine activity in the relevant brain areas was also examined. Neonatal LPS exposure produced an increase in TH phosphorylation and activity at both PNDs 50 and 85. In adulthood, LPS-treated rats responded with increased respiratory rates to the lower intensities of stimuli, indicative of increased autonomic arousal. These changes were associated with increases in anxiety-like behaviours and HPA axis activity, alongside altered expression of the GABA-A receptor α2 subunit, CRH receptor type 1, CRH binding protein, and glucocorticoid receptor mRNA levels in the prefrontal cortex, hippocampus and hypothalamus. The current findings suggest that in addition to the commonly reported alterations in HPA axis functioning, neonatal LPS challenge is associated with a persistent change in ANS activity, associated with, and potentially contributing to, the anxiety-like phenotype. The findings of this study reflect the importance of changes in the perinatal microbial environment on the ontogeny of physiological processes.     

Hypoxic postconditioning corrects behavioral abnormalities in a model of post-traumatic stress disorder in rats

Protective effects of the novel technique of hypoxic postconditioning with a hypobaric hypoxia paradigm were studied in "stress-restress" model ofposttraumatic stress disorder in rats. It was shown that repeated (3 times) exposure of rats that survived after severe traumatic stress to mild hypobaric hypoxia (postconditioning mode) efficiently abolished the development of stress-induced anxiety state. Postconditioning had a clear anxiolytic effect both when it was delivered after traumatic stress and after restress, but the intensity of this effect depended on the period ofpathogenesis of the posttraumatic stress disorder, when postconditioning was given. The results indicate that suggested postconditioning model with repetitive mild hypobaric hypoxia exerts potent anxiolytic and stress-protective action.     

Activation of the arousal response and impairment of performance increase with anxiety and stressor intensity.

The purpose of this study was to determine the effect of trait anxiety and stressor intensity on arousal and motor performance during a pinch task. We examined the steadiness of a precision task in the presence and absence of an imposed stressor on subjects with moderate and low trait anxiety. Subjects with the 26 highest and 14 lowest anxiety scores were assigned to one of three groups: a control group (5 women, 5 men), a moderate-anxiety group (8 women, 8 men), or a low-anxiety group (7 women, 7 men). Subjects in the anxiety groups received electric shocks and experienced significant increases in cognitive and physiological arousal compared with baseline and control subjects, especially subjects in the moderate-anxiety group. Heart rate, systolic blood pressure, and electrodermal activity were elevated during the stressor, whereas diastolic blood pressure was unchanged. Cognitive and physiological arousal tended to increase with stressor intensity and was accompanied by changes in steadiness. Although steadiness was markedly reduced with the highest intensity of shock, the average electromyogram activity was unaffected by the stressor. These findings indicate that the increase in arousal and the impairment of steadiness increased with trait anxiety and with the intensity of the noxious stimulus.     

Auditory affective norms for German: testing the influence of depression and anxiety on valence and arousal ratings

Background

The study of emotional speech perception and emotional prosody necessitates stimuli with reliable affective norms. However, ratings may be affected by the participants'' current emotional state as increased anxiety and depression have been shown to yield altered neural responding to emotional stimuli. Therefore, the present study had two aims, first to provide a database of emotional speech stimuli and second to probe the influence of depression and anxiety on the affective ratings.

Methodology/Principal Findings

We selected 120 words from the Leipzig Affective Norms for German database (LANG), which includes visual ratings of positive, negative, and neutral word stimuli. These words were spoken by a male and a female native speaker of German with the respective emotional prosody, creating a total set of 240 auditory emotional stimuli. The recordings were rated again by an independent sample of subjects for valence and arousal, yielding groups of highly arousing negative or positive stimuli and neutral stimuli low in arousal. These ratings were correlated with participants'' emotional state measured with the Depression Anxiety Stress Scales (DASS). Higher depression scores were related to more negative valence of negative and positive, but not neutral words. Anxiety scores correlated with increased arousal and more negative valence of negative words.

Conclusions/Significance

These results underscore the importance of representatively distributed depression and anxiety scores in participants of affective rating studies. The LANG-audition database, which provides well-controlled, short-duration auditory word stimuli for the experimental investigation of emotional speech is available in Supporting Information S1.     

Effectiveness of multiple-site EMG biofeedback in the reduction of arousal

During the training phase, 36 subjects received (a) EMG biofeedback from multiple muscle sites, (b) EMG biofeedback from the frontal site, or (c) no biofeedback. Results indicated that neither biofeedback procedure reduced self-reports of anxiety, but that multiple-site biofeedback was effective in reducing several indices of autonomic arousal (pulse rate, finger pulse volume, and skin temperature) while frontal biofeedback was not. During the generalization/stress phase, all subjects were threatened with and received electric shocks and were told to apply the relaxation techniques they learned during the training phase even though no additional biofeedback would be provided. Results indicated that multiple-site biofeedback was effective in reducing self-reports of anxiety and autonomic arousal but that frontal biofeedback was not. These results confirm previous data indicating that frontal biofeedback is not an effective procedure for controlling stress, but suggest that EMG biofeedback can be effective in reducing self-reported anxiety and autonomic arousal if a multiple muscle-site feedback procedure is employed.     

Dissociable effects of valence and arousal in adaptive executive control

Background

Based on introspectionist, semantic, and psychophysiological experimental frameworks, it has long been assumed that all affective states derive from two independent basic dimensions, valence and arousal. However, until now, no study has investigated whether valence and arousal are also dissociable at the level of affect-related changes in cognitive processing.

Methodology/Principal Findings

We examined how changes in both valence (negative vs. positive) and arousal (low vs. high) influence performance in tasks requiring executive control because recent research indicates that two dissociable cognitive components are involved in the regulation of task performance: amount of current control (i.e., strength of filtering goal-irrelevant signals) and control adaptation (i.e., strength of maintaining current goals over time). Using a visual pop-out distractor task, we found that control is exclusively modulated by arousal because interference by goal-irrelevant signals was largest in high arousal states, independently of valence. By contrast, control adaptation is exclusively modulated by valence because the increase in control after trials in which goal-irrelevant signals were present was largest in negative states, independent of arousal. A Monte Carlo simulation revealed that differential effects of two experimental factors on control and control adaptation can be dissociated if there is no correlation between empirical interference and conflict-driven modulation of interference, which was the case in the present data. Consequently, the observed effects of valence and arousal on adaptive executive control are indeed dissociable.

Conclusions/Significance

These findings indicate that affective influences on cognitive processes can be driven by independent effects of variations in valence and arousal, which may resolve several heterogeneous findings observed in previous studies on affect-cognition interactions.     

Reconciliation, relationship quality, and postconflict anxiety: testing the integrated hypothesis in captive chimpanzees

Reconciliation is a conflict resolution mechanism that is common to many gregarious species with individualized societies. Reconciliation repairs the damaged relationship between the opponents and decreases postconflict (PC) anxiety. The "integrated hypothesis" links the quality of the opponents' relationship to PC anxiety, since it proposes that conflicts among partners with high relationship quality will yield high levels of PC anxiety, which in turn will lead to an increased likelihood of reconciliation. We tested the integrated hypothesis in captive chimpanzees (Pan troglodytes) in the Arnhem Zoo, The Netherlands. We applied the standard PC/matched control (MC) method. Our results mostly support the integrated hypothesis, in that more valuable and compatible partners (i.e., males and frequent groomers) reconciled more often than less valuable and weakly compatible partners (i.e., females and infrequent groomers). In addition, PC anxiety was higher after conflicts among males than among females. Emotional arousal thus appears to be a mediator facilitating reconciliation. However, in contrast to the predictions derived from the integrated hypothesis, PC anxiety appeared only in aggressees, and not in aggressors, of conflicts. This suggests that while relationship quality determines PC anxiety, it is dependent on the role of the participants in the conflict.     

Effects of Estrogen on Activity and Fear-Related Behaviors in Mice

Estrogen has been shown to affect nonreproductive behaviors in humans and rodents, including anxiety, fear, and activity levels. Rat studies have shown increases and decreases in these behaviors. Inconsistencies may be due to differences in testing conditions and the extent to which each test measures anxiety, fear, or activity. Few mouse studies have been performed. The present study was conducted to address these issues by examining the effect of estradiol benzoate (EB) in ovariectomized (OVX), C57BL/6 mice on a range of behavioral paradigms measuring anxiety [open field (OF), dark-light transition (DLT), elevated plus maze (EP)], activity [running wheel (RW)], and conditioned fear learning (FCon). In OF, vehicle (Veh) animals spent more time in the center than EB-treated animals and were more active overall. In DLT, Veh animals were more active than EB-treated animals in both the dark and light compartments and made more transitions between the two. In EP, Veh animals entered a greater number of arms. During FCon, EB animals froze more than Veh to the conditioned stimulus. In contrast, in the home cage RW, EB animals were more active than Veh. Factor analysis was used to characterize intertask correlations of females' behavior and to explore the possibility that estrogen may have an impact on a general arousal factor. In sum, estrogen treatment heightened fear responses in a range of fear and anxiety-provoking situations (OF, DLT, EP, and FCon), while increasing activity in the safer RW. We suggest that EB treatment may result in a generally more aroused animal.     

Mixing pleasures: Review of the effects of drugs on sex behavior in humans and animal models

Drugs of abuse act on the brain circuits mediating motivation and reward associated with natural behaviors. There is ample evidence that drugs of abuse impact male and female sexual behavior. First, the current review discusses the effect of drugs of abuse on sexual motivation and performance in male and female humans. In particular, we discuss the effects of commonly abused drugs including psychostimulants, opiates, marijuana/THC, and alcohol. In general, drug use affects sexual motivation, arousal, and performance and is commonly associated with increased sexual risk behaviors. Second, studies on effects of systemic administration of drugs of abuse on sexual behavior in animals are reviewed. These studies analyze the effects on sexual performance and motivation but do not investigate the effects of drugs on risk-taking behavior, creating a disconnect between human and animal studies. For this reason, we discuss two studies that focus on the effects of alcohol and methamphetamine on inhibition of maladaptive sex-seeking behaviors in rodents. Third, this review discusses potential brain areas where drugs of abuse may be exerting their effect on sexual behavior with a focus on the mesolimbic system as the site of action. Finally, we discuss recent studies that have brought to light that sexual experience in turn can affect drug responsiveness, including a sensitized locomotor response to amphetamine in female and male rodents as well as enhanced drug reward in male rats.     

Integrating music in breathing training and relaxation: I. Background, rationale, and relevant elements

Quasiformal reports of widespread use of music in counterarousal techniques abound despite little evidence of its psychophysiological effects. Some known effects are presented here, and they suggest, among other things, an influence on hemispheric dominance, changes in autonomic nervous system activity, and relaxation by paradoxical arousal patterns contrary to those in cognitive function and anxiety. Hypothetical subcortical reflexes are postulated as mediators. Different types of music and their effect are described. Of particular relevance is that some forms of music have been reliably shown to have a profound beneficial effect on breathing.     

Assessing the consultation: method for measuring changes in patient stress and arousal.

A method has been developed to assess anxiety levels in terms of stress and arousal in patients before and after a consultation with a general practitioner. The MACL self report mood scale has been used in hospital outpatient studies. An adaptation of the scale using 26 items of low vocabulary was applied to general practice patients in a novel way to show appreciable reductions in stress and increases in arousal after consultations. Since arousal is related to efficiency of performance and stress has been inversely related to recall of information given in the consultation factors that affect stress and arousal in patients could usefully be identified.     

Coping with Stress: The Effectiveness of Different Types of Music

Listening to classical and self-selected relaxing music after exposure to a stressor should result in significant reductions in anxiety, anger, and sympathetic nervous system arousal, and increased relaxation compared to those who sit in silence or listen to heavy metal music. Fifty-six college students, 15 males and 41 females, were exposed to different types of music genres after experiencing a stressful test. Several 4 x 2 mixed design analyses of variance were conducted to determine the effects of music and silence conditions (heavy metal, classical, or self-selected music and silence) and time (pre-post music) on emotional state and physiological arousal. Results indicate listening to self-select or classical music, after exposure to a stressor, significantly reduces negative emotional states and physiological arousal compared to listening to heavy metal music or sitting in silence.