EEG Correlates of Anxiety and Emotional Stability in Adult Healthy Subjects

We studied peculiarities of the spectral characteristics of EEG in 111 healthy adult subjects of both sexes. The levels of situative anxiety (anxiety state) and personal anxiety were estimated using the Spielberger–Khanin test system. To estimate anxiety-related properties of the personality, Cattel’s technique 16 PF (form А) was used. Estimates of situative anxiety demonstrated only two cases of positive correlation with the spectral power density (SPD) of EEG rhythms (SPDs of the beta2 rhythm in the right-hemisphere temporal and occipital regions; recording with the eyes open). Estimates of personal anxiety positively correlated with the SPDs of the beta1 and (especially) beta2 EEG rhythms. Under conditions with the eyes open, the number of significant correlations was greater, and correlations themselves were tighter than with the eyes closed. The closest correlations of the estimates of personal anxiety with the SPDs of the beta rhythm were found in frontal and central leads of both hemispheres and in parietal and occipital loci of the right hemisphere. Only a single case of correlation of the alpha rhythm SPD with personal anxiety (negative correlation, a parietal lead in the left hemisphere) was found. At the same time, rather numerous correlations of the alpha rhythm expression with an index congeneric to anxiety, the C factor by the Cattel’s questionnaire (emotional stability/instability), were found. Thus, the intense beta EEG rhythm can be considered an electrographic correlate of high situative and personal anxieties. At the same time, the alpha rhythm power correlates with the emotional stability of the individual. We suppose that persons with a well-developed alpha rhythm are characterized by active and stable functioning of the cerebral dopaminergic system; this simultaneously serves as a pre-requisite of high emotional stability and social adaptability.     

Changes in Psychological and Physiological Parameters in Girls during the Individual Annual Cycle

Female students (N = 538) of the medical academy and the pedagogical college were psychophysiologically examined in different periods of the individual annual cycle (IAC), which lasts from one birthday to the next, with color, individual minute, and mental arithmetic tests. In addition, heart rhythm variation (HRV), anxiety, number of iris nerve rings, creativity, extroversion/introversion, and salivary cortisol were established, and integral stress reactivity (SR) and psychoemotional stress (PES) indices were calculated. It was found that the lowest anxiety, uneasiness, cortisol, diastolic arterial pressure during the mental arithmetic test, total deviation from the autogenous norm (Luscher's test), SR, and PES were observed in the first trimester (IAC months I–III). On the contrary, the fourth trimester (IAC months X–XII) was characterized by a decrease in extroversion and HRV and an increase in cortisol, anxiety, uneasiness, stress reactivity, and PES. Along with this, the fourth trimester differed from the other IAC periods in that students had the greatest total creativity score, which was considered as a compensatory phenomenon.     

Autonomic tone in branches of the respiratory-hemodynamic system of junior schoolchildren

Periodic variations in the cardiac, vascular, and respiratory branches of the respiratory-hemodynamic system (RHDS) were studied in children 8–11 years of age at rest using spectral analysis. By analogy with studying the autonomous regulation of the cardiac rhythm, the averaged pattern of the autonomic tone (BAT) was determined in all RHDS branches. We aimed at studying various combinations of the autonomic balance (AB) in the same pattern and identifying individual typological peculiarities of the BAT patterns of the RHDS. Groups of children with different autonomic RHDS patterns were determined using cluster analysis; these groups differed significantly in many spectral and hemodynamic parameters.     

A correlation of EEG characteristics of pregnant women with the level of their anxiety

It has been shown that the EEG of pregnant women with high anxiety level is characterized by a lower occipital alpha and theta rhythm spectral power if compared to the EEG of women with low anxiety level. The frequency of the alpha rhythm of their EEG was reliably higher. Pregnant women with high anxiety level with a pregnancy interruption threat diagnosis have an essentially lower occipital alpha rhythm spectral power than women of this group without such a diagnosis. And vice versa, the occipital alpha rhythm spectral power in the EEG of pregnant women with low anxiety level with a pregnancy interruption threat diagnosis is essentially higher and its frequency essentially lower than the EEG of women without that diagnosis. The data received are interpreted as a change in hormone regulation during the pregnancy period, as well as psychogenic influence on the pregnancy.     

Expiratory time determined by individual anxiety levels in humans.

We have previously found that individual anxiety levels influence respiratory rates in physical load and mental stress (Y. Masaoka and I. Homma. Int. J. Psychophysiol. 27: 153-159, 1997). On the basis of that study, in the present study we investigated the metabolic outputs during tests and analyzed the respiratory timing relationship between inspiration and expiration, taking into account individual anxiety levels. Disregarding anxiety levels, there were correlations between O2 consumption (VO2) and minute ventilation (VE) and between VO2 and tidal volume in the physical load test, but no correlations were observed in the noxious audio stimulation test. There was a volume-based increase in respiratory patterns in physical load; however, VE increased not only for the adjustment of metabolic needs but also for individual mental factors; anxiety participated in this increase. In the high-anxiety group, the VE-to-VO2 ratio, indicating ventilatory efficiency, increased in both tests. In the high-anxiety group, increases in respiratory rate contributed to a VE increase, and there were negative correlations between expiratory time and anxiety scores in both tests. In an awake state, the higher neural structure may dominantly affect the mechanism of respiratory rhythm generation. We focus on the relationship between expiratory time and anxiety and show diagrams of respiratory output, allowing for individual personality.     

Electrophysiological Correlates of Major Depression Disorder with Anxious Distress in Patients of Different Age Groups

The electrophysiological correlates of major depression disorder with anxious distress in patients of different age groups have been investigated. The spectral characteristics of 19-channel background EEG were analyzed and the power spectra recorded with the eyes closed vs. eyes open in 64 patients with anxiety–depressive disorder and in 194 healthy subjects were compared. The subjects were divided into the two age groups: 18–39 and 40–76 years old. The spectral parameters were calculated for 5 main EEG frequency bands: θ (4–8 Hz), α (8–12 Hz), β₁ (12–20 Hz), β₂ (20–30 Hz), and γ (30–40 Hz). The most statistically significant differences between the groups were found in the α, β, and γ bands. Lower values of spectral power of the α rhythm in occipital areas and the higher values of spectral power of the β and γ rhythms in the frontocentral region were recorded in the group of 18-to-39-year-old patients with the eyes closed. Higher values of spectral power of the β rhythm in the fronto-central region and in the left temporal lobe were recorded in the group of 40-to-76-year-old patients with both the eyes closed and the eyes open. The higher β-activity in the fronto-central regions in both groups of patients may be caused by increased excitability of the cerebral cortex and decreased activity of inhibitory processes. Increased activation of the left temporal lobe in older subjects is probably associated with the severity of anxiety symptoms and may be a distinctive marker of mixed anxiety and depressive disorder. The lower values of α-power revealed only in the group of younger subjects are probably associated with age-related reorganization of EEG in older subjects.     

Relationship between rapid changes in an individual subrange of the electroencephalogram Δ wave and heart rate during sleep

Correlation analysis was used to determine the relationship between the oscillations of the spectral power of the electroencephalogram (EEG) Δ rhythm subrange corresponding to an individual heart rate and the rhythmocardiogram derivative in healthy subjects during sleep. The EEG range most strongly associated with the individual heart rate of each subject was found. Analysis of temporal shifts showed that changes in the heart rate were several seconds ahead of the corresponding changes in the EEG. The time pattern of the relationship between the studied parameters was significantly correlated with the stages of sleep.     

Cardiac Rhythm Variability: Approaches to Mechanisms

Physiological mechanisms of cardiac rhythm variability (CRV) are reviewed. The results of original experiments are discussed together with the history of the problem and data available from the literature. Special emphasis is placed on the spectral analysis of cardiac rhythm. Various mechanisms of the generation of periodic and aperiodic components of CRV are considered. Although the variability of cardiac rhythm has been studied for many years in many laboratories worldwide, fine mechanisms of CRV remain obscure. However, a number of specific features of CRV are presently widely recognized. Periodic CRV components isolated from short-term records in patients at rest are represented by high-frequency, low-frequency, and very low-frequency oscillations. Fourier-transform spectral analysis of cardiac rhythm is the most appropriate method of the detection of these oscillations. High-frequency components are associated with respiration and represent the effects of the parasympathetic nervous system on myocardium. Low-frequency components are due to the activity of the postganglionic sympathetic fibers and represent the processes of cardiac rhythm modulation by the sympathetic nervous system. Genesis of very low-frequency oscillations is still uncertain. Most probably, these oscillations are associated with the effects of suprasegmental (primarily, hypothalamic) centers of autonomic regulation. Aperiodic CRV components represent random events associated with the reflex regulation of the heart rate by external or internal factors. Because aperiodic components significantly modify the results of the CRV analysis, the effects of these factors should be eliminated. It is concluded that because many problems associated with cardiac rhythm variability remain to be solved, extensive research in this direction should be continued.     

A method of independent time and frequency decomposition of bioacoustic signals: inter-individual recognition in four species of penguins

The aim of this paper is to introduce a method for analyzing acoustic signals capable of assessing the potential for individual coding information. Signals are analysed both in the time domain (rhythm of emission of the song independent of its frequency content) and in the spectral domain (spectral content of the song independent of the rhythm of emission). The method is then applied to a comparative study of four penguin species, where the problem posed by inter-individual recognition differs from species to species. A direct relationship was shown between the potential of individual coding and the difficulty in panner identification.     

Possibilities of a pulsogram for estimation of the wave structure of the cardiac rhythm

Visual and computerized analysis of pulsograms revealed the entire daily (24-h) wave structure of the cardiac rhythm in healthy children. Only two waves characteristic of the cardiac rhythm of a healthy child follow each other all 24 h of the day. These are the respiratory and blood pressure waves. Slower waves (from several minutes to several hours in length) are encountered in the cardiac rhythm in the form of interesting regular alternations. Comparison of the periodic structures obtained on the basis of spectral analysis and from the pulsograms illustrates the limited possibilities of the Fourier spectrum in the analysis of nonstationary stochastic processes as compared to the visual analysis of pulsograms.     

The HPA Axis under Stress and Aging: Individual Vulnerability is Associated with Behavioral Patterns and Exposure Time

With aging, incidence of severe stress-related diseases increases. However, mechanisms, underlying individual vulnerability to stress and age-related diseases are not clear. The goal of this review is to analyze finding from the recent literature on age-related characteristics of the hypothalamic-pituitary-adrenal (HPA) axis associated with stress reactivity in animals that show behavioral signs of anxiety and depression under mild stress, and in human patients with anxiety disorders and depression with emphasis on the impact of the circadian rhythm and the negative feedback mechanisms involved in the stress response. One can conclude that HPA axis reaction to psycho-emotional stress, at least acute stress, increases in the aged individuals with anxiety and depression behavior. Elevated stress reactivity is associated with disruption of the circadian rhythm and the mineralocorticoid receptor-mediated glucocorticoid negative feedback. The disordered function of the HPA axis in individuals with anxiety and depression behavior can contribute to aging-related pathology.     

Reaction of Cardiac Activity of Senior Pupils of Schools Providing Differentiated Education upon Examination Stress

Effects of examination stress on psychological characteristics and indices of the autonomic nervous system were studied in pupils of the eighth and tenth grades of high schools providing differential (test group, Neuron gymnasium) and general education (control group). General health state and levels of activity and mood (feeling, activity, mood; FAM) and neuroticism (according to Eysenck) were determined in both groups. Main hemodynamic indices (heart rate and blood pressure) were measured, and mathematical analysis of the heart rate by was performed according to Baevskii. Comparative analysis of psychophysiological tests and heart rate changes in the control and test groups points to a high tension in the cardiac rhythm regulation mechanisms and strong anxiety in schoolchildren in the differential education school. The character and depth of preexamination stress depended on the type of autonomic control of cardiac activity. Schoolchildren with sympathicotonic cardiac rhythm regulation showed the strongest emotional tension. Schoolchildren with the normotonic type of regulation were the most calm.     

Spectral analysis and interpretation of spectral components of heart rate variability

Requirements for a fragment of a random process taken for spectral analysis are formulated. It has been demonstrated that both the random process and its periodic components should be stationary within the fragment selected. Only in this case will the results of spectral analysis reflect the actual characteristics of the process studied. Variations in the depth of breathing and other factors have been shown to cause modulatory fluctuations of the HF and LF waves of the cardiac rhythm. The modulatory fluctuations are expressed as the VLF peak in the heart rate variability spectrum, the position of the peak on the frequency axis and its amplitude being determined by the frequency and depth of modulation, respectively. Depending on the modulation depth and the ratio between the modulation period and the length of the sample studied, spectral analysis of the same process may yield considerably different results. The ambiguity of the results of spectral analysis is the cause of discrepancy about the nature of individual spectral components of heart rate variability.     

心肌细胞团搏动的整数倍节律的实验观察

实验报道了心肌细胞团自发性同步化搏动的一类新节律——整数倍节律。这种稳定的节律模式由两种相关的搏动形式的随机交替出现形成,这两种搏动形式中任何一种的出现间期具有整数倍特征。在静息状态和周期1搏动间的随机交替形成0-1整数倍节律,在周期1搏动和周期2搏动之间的随机交替形成l-2整数倍节律。0-1整数倍是居于静息状态和周期1节律之间的节律模式,1-2整数倍是居于周期1节律和周期2节律之间的节律模式,实验所见的节律转迁过程清楚地展示了静息状态、0-1整数倍节律、周期1节律、1-2整数倍节律、周期2节律等顺序地构成的一种“节律谱系”。“节律谱系”的观念可以为认识正常和异常心律的关系和其间的转迁机制提供深刻的理论启示。     

大学生人格特征与社交焦虑的相关研究

目的:探讨大学生人格特征与社交焦虑的关系,为高校大学生心理教育工作提供理论依据.方法:采用分层整群抽样的方法,对1600名大学生进行心理测评,测评工具包括社交焦虑量表(IAS)和艾森克人格问卷(EPQ).结果:本研究发现,高社交焦虑的大学生为370人,占总体被试的25.6%;女大学生社交焦虑水平高于男大学生,农村、矿区的学生其社交焦虑水平高于城镇学生;逐步多元回归结果发现,内外向、神经质为社交焦虑的有效预测因素,联合解释变异量为23.7%.结论:高社交焦虑的大学生占总体调查人数的25.6%;人格特征、性别、家庭住址是社交焦虑的影响因素;应加强大学生健康个性的培养及社交焦虑的相关干预.     

Sleep phenotyping in a mouse model of extreme trait anxiety

Background

There is accumulating evidence that anxiety impairs sleep. However, due to high sleep variability in anxiety disorders, it has been difficult to state particular changes in sleep parameters caused by anxiety. Sleep profiling in an animal model with extremely high vs. low levels of trait anxiety might serve to further define sleep patterns associated with this psychopathology.

Methodology/Principal Findings

Sleep-wake behavior in mouse lines with high (HAB), low (LAB) and normal (NAB) anxiety-related behaviors was monitored for 24 h during baseline and recovery after 6 h sleep deprivation (SD). The amounts of each vigilance state, sleep architecture, and EEG spectral variations were compared between the mouse lines. In comparison to NAB mice, HAB mice slept more and exhibited consistently increased delta power during non-rapid eye movement (NREM) sleep. Their sleep patterns were characterized by heavy fragmentation, reduced maintenance of wakefulness, and frequent intrusions of rapid eye movement (REM) sleep. In contrast, LAB mice showed a robust sleep-wake rhythm with remarkably prolonged sleep latency and a long, persistent period of wakefulness. In addition, the accumulation of delta power after SD was impaired in the LAB line, as compared to HAB mice.

Conclusions/Significance

Sleep-wake patterns were significantly different between HAB and LAB mice, indicating that the genetic predisposition to extremes in trait anxiety leaves a biological scar on sleep quality. The enhanced sleep demand observed in HAB mice, with a strong drive toward REM sleep, may resemble a unique phenotype reflecting not only elevated anxiety but also a depression-like attribute.     

Modulation of Low-Frequency EEG Rhythms under Conditions of an Activation Reaction: Dependence on Psychological Characteristics of Personality

In a group of 118 adults of both sexes, we studied modulation of the low-frequency EEG components (δ and θ rhythms) under conditions of an activation reaction resulting from opening of the eyes. Typical changes of the α rhythm (considerable depression in a great majority of the tested subjects) was accompanied by diverse, in their direction, shifts of the spectral power (SP) of the δ and θ components in different subjects. The δ rhythm power increased upon the reaction of activation in 79 subjects and decreased in 29 subjects, while changes in this index in different hemispheres were of opposite directions in 10 persons. According to the reactivity of the θ rhythm, the respective subgroups included 36, 75, and 7 subjects. Values of the differential coefficients of reactivity (DCR) for the δ and θ rhythms demonstrated significant positive correlation (r = 0.616 and 0.603 for the left and right hemispheres, respectively). Indices of reactivity of the α and θ rhythms also correlated but less closely (r about 0.3). At the same time, there was practically no correlation between the DCR values of the α and δ rhythms. Within the entire studied group, we found significant negative correlations between the DCRs of the δ and θ activity with the estimates of some psychological characteristics of the subjects (levels of extroversion, psychoticism, ergicity, plasticity, dominance, and a few others) measured using the questionnaires RTS (Strelau), EPQ (Eysenck), OST (Rusalov), and 16 PF (Kettel). We also found positive correlations with the levels of normativity of behavior and development of imagination. At a rather high significance of such correlations, coefficients of the latter were, as a rule, relatively low (usually less than 0.2). Results of dispersion analysis showed that significant or close to significant intergroup differences of the mean values of estimates of psychological characteristics diagnosed according to the above-mentioned questionnaires were typical of the subgroups of subjects with increases and decreases in the SPs of the δ and θ rhythms or with opposite changes of these indices in the hemispheres. Probable mechanisms of modulation of the low-frequency EEG components under conditions of the activation reaction and correlations of such changes with psychological peculiarities of the personality are discussed.     

Moderation of Increased Anxiety in Children and Teenagers with the Use of Neurotherapy: Estimation of the Efficacy

We estimated the efficacy of using the technique of feedback (FB) by EEG characteristics (EEG-FB, neurotherapy) with the aim of reducing increased anxiety levels in healthy 10- to 14-year-old children. The anxiety level was estimated using the Prikhojan anxiety test, the Spielberger–Khanin questionnaire, and the House–Tree–Person projective drawing technique. Positive effects of series of neurotherapy sessions were obvious. After training was completed, we observed significant increases in the ratios of the amplitudes of alpha and theta rhythms, semsorimotor and theta rhythms, as well as of the modal frequency of the EEG alpha rhythm in tested persons of the experimental group (n = 7). In the control group (n = 10), changes in these values did not reach the significance level. In the experimental group of tested persons subjected to EEG-FB sessions, the anxiety level decreased appreciably; in addition, the indices “feeling of inferiority” and “frustration” decreased significantly. In the control group, alterations of these psychological indices were not unidirectional. Therefore, modifications of the EEG pattern, which occurred in the course of training and were accompanied by a decrease in the anxiety level in the experimental group, can be indicative of the expediency of EEG-FB for the reduction of high anxiety levels in children and teenagers.     

Dynamics of spectral characteristics of theta- and alpha-range EEG during negative emotional reactions]

Power characteristics of the EEG theta and alpha rhythms were studied in a human in neutral state and during a conditioned negative emotional reaction (Fp1, Fp2, F3, F4, C3, C4, P3, P4, O1, O2, F7, F8, T3, T4, T5, and T6 derivations). A significant increase in the relative spectral power in the narrow theta band of 7.4-8.1 Hz in the frontocentral and temporal brain regions was observed during the development of the negative emotional reaction. The alpha-rhythm dynamics during the negative reaction was substantially individual and could be expressed in either an increase, or decrease in relative spectral power of different alpha-frequencies. No pronounced changes in their dynamics could also be observed. In some subjects the spectral power of the medium-frequency alpha-rhythm significantly decreased, that of the high-frequency rhythm increased, and changes in the spectral power of the low-frequency alpha range varied.     

The Relationship between Anxiety and the Social Judgements of Approachability And Trustworthiness

The aim of the current study was to examine the relationship between individual differences in anxiety and the social judgements of trustworthiness and approachability. We assessed levels of state and trait anxiety in eighty-two participants who rated the trustworthiness and approachability of a series of unexpressive faces. Higher levels of trait anxiety (controlling for age, sex and state anxiety) were associated with the judgement of faces as less trustworthy. In contrast, there was no significant association between trait anxiety and judgements of approachability. These findings indicate that trait anxiety is a significant predictor of trustworthiness evaluations and illustrate the importance of considering the role of individual differences in the evaluation of trustworthiness. We propose that trait anxiety may be an important variable to control for in future studies assessing the cognitive and neural mechanisms underlying trustworthiness. This is likely to be particularly important for studies involving clinical populations who often experience atypical levels of anxiety.