Individual differences in the physiological effects of forest therapy based on Type A and Type B behavior patterns

Background

In recent years, the physiological relaxation effects of natural environments have been widely exploited, and although individual differences in the effects of forest therapy are known, assessment methods have not been clearly established. This study used a classification based on Type A and Type B behavior patterns to explain individual differences in physiological responses to forest environments.

Methods

We performed physiological experiments in 44 forest and urban (controls) areas. In total, 485 male university students (age, 21.8 ± 1.6 years) participated in the study. The subjects were asked to visit forest or urban environments randomly and observe each landscape for 15 min. The subjects’ pulse rates and blood pressures were tested to evaluate their physiological responses. The Kwansei Gakuin daily life questionnaire was used to identify Type A and Type B behavior patterns in subjects.

Results

The pulse rate was significantly lower in the Type B group after exposure to forest areas than after exposure to urban areas, whereas no significant difference was observed in the Type A group. In addition, the pulse rate was significantly lower in the low scoring subjects in the Type B group, which was consistent with changes in their diastolic blood pressure.

Conclusions

These results suggest that individual differences in pulse rate and blood pressure in response to forest environments can be explained by Type A and Type B behavior patterns.     

Prevalence of psychological distress in elderly hypertension patients in primary care

Background

Recent guidelines on cardiovascular disease prevention advocate the importance of psychological risk factors, as they contribute to the risk of developing cardiovascular disease. However, most previous research on psychological distress and cardiovascular factors has focused on selected populations with cardiovascular disease.

Aim

The primary aim was to determine the prevalence of depression, anxiety, and Type D personality in elderly primary care patients with hypertension. Secondary aim was to examine the relation between elevated systolic blood pressure and depression, anxiety, and Type D personality.

Design and Setting

A cross-sectional study in primary care practices located in the south of the Netherlands.

Method

Primary care hypertension patients (N = 605), between 60 and 85 years (45 % men, mean age = 70 ± 6.6), were recruited for this study. All patients underwent a structured interview including validated self-report questionnaires to assess depression (PHQ-9), anxiety (GAD-7), and Type D personality (DS14) as well as blood pressure assessment.

Results and Conclusion

Depression was prevalent in 5 %, anxiety in 5 %, and Type D personality in 8 %. None of the distress measures were associated with elevated systolic blood pressure of >160 mmHg (all p-values >0.05). This study showed no relation between psychological distress and elevated systolic blood pressure in elderly primary care patients with hypertension.     

心理护理在A 型性格上消化道出血患者的应用

目的:探讨心理护理应用于A型性格上消化道出血患者的影响。方法:将A型性格上消化道出血患者68例,随机分为观察组(n=34例)和对照组(n=34例)。观察组为实施心理护理组,对照组为非心理护理组。分别观察两组患者的住院时间、二次出血发生率、病死率等指标。结果:两组患者的临床疗效比较,观察组住院时间、二次出血发生率和病死率均明显少于对照组,差异具有统计学意义(P<0.05)。结论:心理护理应用于A型性格上消化道出血患者,能够明显较少患者的住院时间,并有效降低了患者二次出血发生率和病死率,其临床效果优于对照组。     

Left and Right Amygdala - Mediofrontal Cortical Functional Connectivity Is Differentially Modulated by Harm Avoidance

Background

The left and right amygdalae are key regions distinctly involved in emotion-regulation processes. Individual differences, such as personality features, may affect the implicated neurocircuits. The lateralized amygdala affective processing linked with the temperament dimension Harm Avoidance (HA) remains poorly understood. Resting state functional connectivity imaging (rsFC) may provide more insight into these neuronal processes.

Methods

In 56 drug-naive healthy female subjects, we have examined the relationship between the personality dimension HA on lateralized amygdala rsFC.

Results

Across all subjects, left and right amygdalae were connected with distinct regions mainly within the ipsilateral hemisphere. Females scoring higher on HA displayed stronger left amygdala rsFC with ventromedial prefrontal cortical (vmPFC) regions involved in affective disturbances. In high HA scorers, we also observed stronger right amygdala rsFC with the dorsomedial prefrontal cortex (dmPFC), which is implicated in negative affect regulation.

Conclusions

In healthy females, left and right amygdalae seem implicated in distinct mPFC brain networks related to HA and may represent a vulnerability marker for sensitivity to stress and anxiety (disorders).     

Preschool Anxiety Disorders Predict Different Patterns of Amygdala-Prefrontal Connectivity at School-Age

Objective

In this prospective, longitudinal study of young children, we examined whether a history of preschool generalized anxiety, separation anxiety, and/or social phobia is associated with amygdala-prefrontal dysregulation at school-age. As an exploratory analysis, we investigated whether distinct anxiety disorders differ in the patterns of this amygdala-prefrontal dysregulation.

Methods

Participants were children taking part in a 5-year study of early childhood brain development and anxiety disorders. Preschool symptoms of generalized anxiety, separation anxiety, and social phobia were assessed with the Preschool Age Psychiatric Assessment (PAPA) in the first wave of the study when the children were between 2 and 5 years old. The PAPA was repeated at age 6. We conducted functional MRIs when the children were 5.5 to 9.5 year old to assess neural responses to viewing of angry and fearful faces.

Results

A history of preschool social phobia predicted less school-age functional connectivity between the amygdala and the ventral prefrontal cortices to angry faces. Preschool generalized anxiety predicted less functional connectivity between the amygdala and dorsal prefrontal cortices in response to fearful faces. Finally, a history of preschool separation anxiety predicted less school-age functional connectivity between the amygdala and the ventral prefrontal cortices to angry faces and greater school-age functional connectivity between the amygdala and dorsal prefrontal cortices to angry faces.

Conclusions

Our results suggest that there are enduring neurobiological effects associated with a history of preschool anxiety, which occur over-and-above the effect of subsequent emotional symptoms. Our results also provide preliminary evidence for the neurobiological differentiation of specific preschool anxiety disorders.     

Energy metabolism and animal personality

In this paper we show how animal personality could explain some of the large inter-individual variation in resting metabolic rate (MR) and explore methodological and functional linkages between personality and energetics. Personality will introduce variability in resting MR measures because individuals consistently differ in their stress response, exploration or activity levels, all of which influence MR measurements made with respirometry and the doubly-labelled water technique. Physiologists try to exclude these behavioural influences from resting MR measurements, but animal personality research indicates that these attempts are unlikely to be successful. For example, because reactive animals "freeze" when submitted to a stress, their MR could be classified as "resting" because of immobility when in fact they are highly stressed with an elevated MR. More importantly, recent research demonstrating that behavioural responses to novel and highly artificial stimuli are correlated with both behaviour and fitness under more natural circumstances calls into question the wisdom of excluding these behavioural influences on MR measurements. The reason that intra-specific variation in resting MR are so weakly correlated with daily energy expenditure (DEE) and fitness, may be that the latter two measures fully incorporate personality while the former partially excludes its influence. Because activity, exploration, boldness and aggressiveness are energetically costly, personality and metabolism should be correlated and physiological constraints may underlie behavioural syndromes. We show how physiological ecologists can better examine behavioural linkages between personality and metabolism, as required to better understand the physiological correlates of personality and the evolutionary consequences of metabolic variability.     

Fear-conditioning mechanisms associated with trait vulnerability to anxiety in humans

Investigations of fear conditioning in rodents and humans have illuminated the neural mechanisms underlying cued and contextual fear. A critical question is how personality dimensions such as trait anxiety act through these mechanisms to confer vulnerability to anxiety disorders, and whether humans' ability to overcome acquired fears depends on regulatory skills not characterized in animal models. In a neuroimaging study of fear conditioning in humans, we found evidence for two independent dimensions of neurocognitive function associated with trait vulnerability to anxiety. The first entailed increased amygdala responsivity to phasic fear cues. The second involved impoverished ventral prefrontal cortical (vPFC) recruitment to downregulate both cued and contextual fear prior to omission (extinction) of the aversive unconditioned stimulus. These two dimensions may contribute to symptomatology differences across anxiety disorders; the amygdala mechanism affecting the development of phobic fear and the frontal mechanism influencing the maintenance of both specific fears and generalized anxiety.     

A New Look at Bimedial Prefrontal Leukotomy

Forty-four selected patients with “hard core” functional psychiatric illness were treated by bimedial prefrontal leukotomy, in which only the medial half of the prefrontal white matter of both frontal lobes was divided. This operation differs from the conventional or “standard” leukotomy which divides the entire prefrontal white matter. There were six patients with personality disorders, 25 psychoneurotics, 12 schizophrenics, and one with involutional melancholia. Forty-two of the 44 patients had thorough psychiatric follow-up, ranging from one to seven years postoperatively. They were assessed clinically and also on a point-rating scale of assessment.Seventy-six per cent of these patients had excellent or satisfactory outcomes. The most striking benefit was decrease in anxiety and tension.Modified leukotomy is a safe and effective method of reducing the symptoms of excessive tension, anxiety, fear or depression in patients with a variety of illnesses, including anxiety neurosis, phobic psychoneurosis, obsessional neurosis, neurotic or psychotic depressive reactions and schizophrenia. The operation should be considered in such neurotic, personality and psychotic illnesses when medical treatment has failed.     

Effects of age and blood sugar levels on the proboscis extension of the blow fly Phormia regina

In some insects the proboscis is extended to imbibe a sugar solution if the concentration of sugar applied to the chemosensilla exceeds the behavioural threshold value. Recently, I found a reversal of the threshold values of this "proboscis extension reflex" (PER) in the blow fly (Phormia regina M.) for glucose and fructose. It depended on maturation and physiological conditions, both of which are explicable in terms of changing concentration of haemolymph trehalose. The direct injection of trehalose into the fly haemocoele brought about a dramatic shift of the threshold values of PER measured on tarsi or labellar sensilla, suggesting a strong dependence of PER on the blood sugar level. Using the tip-recording method, the dose-response (impulse frequency) curves for glucose and fructose were obtained on individual largest labellar chemosensilla. The curves for glucose and fructose crossed at one point because the former had a steeper gradient and higher maximum response than the latter. Injection experiments with trehalose were also carried out to test for changes in gustatory response. The shifting of the behavioural dose-response curves for glucose and fructose two hours after injection of 1 M trehalose (2 μl) into the haemocoele of the fly was associated with significant reduction in responsiveness of labellar chemosensilla to glucose, but less so to fructose. No change in responsiveness was found following injection of mannose. A hypothesis to explain the reversal relation of the PER thresholds, based on a shift in the firing rate in gustatory sensilla and possibly also interneurons, is discussed.     

Cognitive set as a regulation factor in recognition of emotional facial expression

Effect of previous experience on the function of recognition of emotional facial expression was studied with the model of an unconscious visual set. It was found that repeated perception of pictures of face with angry expression caused a substantial effect on subsequent recognition of emotional facial expression. Recognition could be distorted, and expression of the face with "neutral" expression could be erroneously perceived as emotionally negative. Both contrast and assimilative illusions were observed. Evidence is presented that the described effect is the result of the set formation to emotional facial expression. The involvement of the prefrontal cortex into the structural-functional system of facial expression recognition is discussed. Kettel's test revealed significant correlations between the factor of rigidity of the set to emotional facial expression and the scores of personality traits such as social boldness--shyness on the H Scale, on the one hand, and the level of anxiety on the other.     

Minocycline modulates human social decision-making: possible impact of microglia on personality-oriented social behaviors

Background

Microglia, one of the glial cells, play important roles in various brain pathologies including psychiatric disorders. In addition, microglia have recently been proved to monitor synaptic reactions via direct-touching even in normal brain. Human microglia may modulate various social/mental functions, while microglial social/mental roles remain unresolved especially in healthy humans. There is no known drug with the specific effect of modulating microglia. Therefore, using minocycline, a tetracycline antibiotic and the most famous microglial inhibitor, is one of the best alternative approaches to clarify microglial functions on human social/mental activities.

Methodology/Principal Findings

We conducted a double-blind randomized trial of trust game, a monetary decision-making experiment, with ninety-nine human adult males who decided how much to trust an anonymous partner after a four-day administration of minocycline. Our previous pilot trial indicated a positive effect of minocycline, while the underlying mechanisms were not clarified. Therefore, in this trial with larger samples, we additionally measured the effects of anxiety and personality. The monetary score in trust game was significantly lower in the minocycline group. Interestingly, participants’ ways of decision-making were significantly shifted; cooperativeness, one component of personality, proved to be the main modulating factor of decision-making in the placebo group, on the other hand, the minocycline group was mainly modulated by state anxiety and trustworthiness.

Conclusions/Significance

Our results suggest that minocycline led to more situation-oriented decision-making, possibly by suppressing the effects of personality traits, and furthermore that personality and social behaviors might be modulated by microglia. Early-life events may activate human microglia, establish a certain neuro-synaptic connection, and this formation may determine each human’s personality and personality- oriented social behaviors in later life. To explore these mechanisms, further translational research is needed.

Trial Registration

UMIN clinical trial center UMIN000004803     

Type D Personality Predicts Poor Medication Adherence in Chinese Patients with Type 2 Diabetes Mellitus: A Six-Month Follow-Up Study

Background

Type D personality and medication nonadherence have been shown to be associated with poor health outcomes. Type D personality is associated with poor medication adherence in patients with coronary artery disease, myocardial infarction, and heart failure. However, the relationship between type D personality and medication adherence in patients with Type 2 Diabetes Mellitus (T2DM) remains unknown. This study aims to examine whether type D personality was associated with medication adherence in patients with T2DM.

Design and Settings

A follow-up study was conducted in general hospital of the People''s Liberation Army in Beijing.

Methods

412 T2DM patients (205 females), who were recruited by circular systematic random sampling, provided demographic and baseline data about medical information and completed measures of Type D personality. Then, 330 patients went on to complete a self-report measure of medication adherence at the sixth month after baseline data collection. Chi-square test, t tests, and hierarchical multiple regression analyses were conducted, as needed.

Results

Patients with type D personality were significantly more likely to have poor medication adherence (p<0.001). Type D personality predicts poor medication adherence before and after controlling for covariates when it was analyzed as a categorical variable. However, the dimensional construct of type D personality was not associated with medication adherence when analyzed as a continuous variable.

Conclusion

Although, as a dimensional construct, type D personality may not reflect the components of the personality associated with poor medication adherence in patients with T2DM, screening for type D personality may help to identify those who are at higher risk of poor medication adherence. Interventions, aiming to improve medication adherence, should be launched for these high-risk patients.     

Amygdala Perfusion Is Predicted by Its Functional Connectivity with the Ventromedial Prefrontal Cortex and Negative Affect

Background

Previous studies have shown that the activity of the amygdala is elevated in people experiencing clinical and subclinical levels of anxiety and depression (negative affect). It has been proposed that a reduction in inhibitory input to the amygdala from the prefrontal cortex and resultant over-activity of the amygdala underlies this association. Prior studies have found relationships between negative affect and 1) amygdala over-activity and 2) reduced amygdala-prefrontal connectivity. However, it is not known whether elevated amygdala activity is associated with decreased amygdala-prefrontal connectivity during negative affect states.

Methods

Here we used resting-state arterial spin labeling (ASL) and blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) in combination to test this model, measuring the activity (regional cerebral blood flow, rCBF) and functional connectivity (correlated fluctuations in the BOLD signal) of one subregion of the amygdala with strong connections with the prefrontal cortex, the basolateral nucleus (BLA), and subsyndromal anxiety levels in 38 healthy subjects.

Results

BLA rCBF was strongly correlated with anxiety levels. Moreover, both BLA rCBF and anxiety were inversely correlated with the strength of the functional coupling of the BLA with the caudal ventromedial prefrontal cortex. Lastly, BLA perfusion was found to be a mediator of the relationship between BLA-prefrontal connectivity and anxiety.

Conclusions

These results show that both perfusion of the BLA and a measure of its functional coupling with the prefrontal cortex directly index anxiety levels in healthy subjects, and that low BLA-prefrontal connectivity may lead to increased BLA activity and resulting anxiety. Thus, these data provide key evidence for an often-cited circuitry model of negative affect, using a novel, multi-modal imaging approach.     

Social groups with diverse personalities mitigate physiological stress in a songbird

Social groups often consist of diverse phenotypes, including personality types, and this diversity is known to affect the functioning of the group as a whole. Social selection theory proposes that group composition (i.e. social environment) also influences the performance of individual group members. However, the effect of group behavioural composition on group members remains largely unexplored, and it is still contentious whether individuals benefit more in a social environment with homogeneous or diverse behavioural composition. We experimentally formed groups of house sparrows Passer domesticus with high and low diversity of personality (exploratory behaviour), and found that their physiological state (body condition, physiological stress and oxidative damage) improved with increasing group-level diversity of personality. These findings demonstrate that group personality composition affects the condition of group members and individuals benefit from social heterosis (i.e. associating with a diverse set of behavioural types). This aspect of the social life can play a key role in affiliation rules of social animals and might explain the evolutionary coexistence of different personalities in nature.     

Real‐time monitoring prefrontal activities during online video game playing by functional near‐infrared spectroscopy

A growing body of literature has suggested that video game playing can induce functional and structural plasticity of the brain. The underlying mechanisms, however, remain poorly understood. In this study, functional near‐infrared spectroscopy (fNIRS) was used to record prefrontal activities in 24 experienced game players when they played a massively multiplayer online battle arena video game, League of Legends (LOL), under naturalistic conditions. It was observed that game onset was associated with significant activations in the ventrolateral prefrontal cortex (VLPFC) and concomitant deactivations in the dorsolateral prefrontal cortex (DLPFC) and frontal pole area (FPA). Game events, such as slaying an enemy and being slain by an enemy evoked region‐specific time‐locked hemodynamic/oxygenation responses in the prefrontal cortex (PFC). It was proposed that the VLPFC activities during LOL playing are likely responses to visuo‐motor task load of the game, while the DLPFC/FPA activities may be involved in the constant shifts of attentional states and allocation of cognitive resources required by game playing. The present study demonstrated that it is feasible to use fNIRS to monitor real‐time prefrontal activity during online video game playing.      

Principal dimensions of the Framingham Type A scale: differential relationships to cardiovascular reactivity and anxiety

The present investigation sought to identify the principal dimensions of the Framingham Type A scale (FTAS) and then to examine their physiological and psychological correlates. A factor analysis of the FTAS items, which was cross-validated, revealed two factors. Items concerning achievement and competitive-striving loaded primarily on the first factor. Scores on a subscale composed of these items (labeled Competitive Drive) were related to systolic blood pressure reactivity during an interpersonal task but were unrelated to anxiety. FTAS items concerning impatient, time urgent, and domineering propensities loaded primarily on the second factor. Scores on a subscale composed of these items (labeled Speed and Impatience) were not related to cardiovascular reactivity during the task but were related to anxiety. Results are discussed in terms of the psychological heterogeneity of the Type A behavior pattern and possible differences between dimensions of the overall Type A pattern and their association with different manifestations of coronary heart disease.     

Causal Hierarchy within the Thalamo-Cortical Network in Spike and Wave Discharges

Background

Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges.

Methodology and Principal Findings

We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1.

Conclusion

Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy.     

Polymorphism of the serotonin 2A receptor gene (5HTR2A) and personality traits

The interindividual variation of temperament features (such as anxiety, neuroticism, harm avoidance) is determined, in particular, by allele polymorphism of genes involved in serotonin metabolism and has earlier been associated with the insertion/deletion polymorphism of the serotonin transporter gene. Polymorphic alleles of the serotonin 2A receptor gene (5HTR2A) were tested for association with personality traits assessed with several tests. The T102C and A1438G polymorphisms were associated with a variation in emotionality, activity, and sociability, which are integral characteristics of temperament. With each polymorphism, differences were significant only between heterozygotes and homozygotes. Carriers of T102C genotype A1/A2 displayed a lower level of anxiety-related traits, a higher score on scale Hypomania, and a lower score on scale Social Introversion and were assumed to have higher activity and sociability. Carriers of A1428G genotype A/G differed from homozygotes G/G in having a lower level of social introversion and a lower score on scale No close friends, which testified to higher sociability of heterozygotes. Thus, the polymorphic alleles of SHTR2A proved to be associated with personality traits in mentally healthy people.     

Perspectives on environmental adaptability and physiological polymorphism in thermoregulation

The environmental adaptability of human beings has progressed according to various environments experienced in the course of evolution. Therefore, various phenotypes for environmental adaptability exist and are considered to be physiological polymorphism. Physiological polymorphism in thermoregulation is influenced by genotype, individual characteristics, environmental factors, cultural factors, etc. Moreover, it is thought that physiological polymorphism is evidenced more clearly in physiological responses to extreme situations and/or changing conditions than in environments where homeostasis is easily maintained. In the field of physiological anthropology, I think that it is important not only to discover the physiological responses that demonstrate polymorphism, but also to hypothesize about the mechanisms and the processes by which such polymorphisms were formed, and their meaning for human beings. Such discussions may be supposed to lead to an evaluation of the environmental adaptability of humans from the viewpoint of physiological anthropology.     

Subtle Alterations in Brain Anatomy May Change an Individual’s Personality in Chronic Pain

It is well established that gross prefrontal cortex damage can affect an individual’s personality. It is also possible that subtle prefrontal cortex changes associated with conditions such as chronic pain, and not detectable until recent advances in human brain imaging, may also result in subtle changes in an individual’s personality. In an animal model of chronic neuropathic pain, subtle prefrontal cortex changes including altered basal dendritic length, resulted in altered decision making ability. Using multiple magnetic resonance imaging techniques, we found in humans, although gray matter volume and on-going activity were unaltered, chronic neuropathic pain was associated with reduced free and bound proton movement, indicators of subtle anatomical changes, in the medial prefrontal cortex, anterior cingulate cortex and mediodorsal thalamus. Furthermore, proton spectroscopy revealed an increase in neural integrity in the medial prefrontal cortex in neuropathic pain patients, the degree of which was significantly correlated to the personality temperament of novelty seeking. These data reveal that even subtle changes in prefrontal cortex anatomy may result in a significant change in an individual’s personality.