The association between adverse childhood events and cluster C personality disorders: A meta-analysis

INTRODUCTION

Studies suggest that adverse childhood events (ACEs) may contribute to the onset and development of cluster C personality disorders. However, the association between ACEs and these disorders remains unclear in terms of consistency across studies and effect magnitude, as well as generalizability within cluster C. The current meta-analysis aimed to examine the associations between ACEs and cluster C personality disorders based on the available literature.

METHODS

Systematic searches were conducted in PubMed, Scopus, Web of Science and PsychInfo. Forty-eight eligible studies were included in the analyses, and pooled effect sizes were estimated both at the level of cluster C and at the level of each specific disorder. Moderation and meta-regression analyses were also conducted.

RESULTS

ACEs were consistently associated with overall cluster C, as well as each of the specific disorders in this cluster. Sources of heterogeneity included type of instrument used to assess ACEs (questionnaires > interviews) and type of instrument used to assess the personality disorders (clinical interviews > questionnaires, as well as their combination with interview). The associations between ACEs and all cluster C personality disorders decreased with age.

CONCLUSIONS

ACEs are consistently associated with all cluster C personality disorders. Future work could approach the mechanisms underlying this association, preferably using longitudinal designs and considering the potential sources of effect variability identified in the present study.

Serotonin and emotion regulation: the impact of tryptophan depletion on emotional experience, neural and autonomic activity

The involvement of serotonin in emotion and psychopathology has been extensively examined. Studies using acute tryptophan depletion (ATD) have found limited effects on mood and aggression, and one of the explanations suggests that serotonin may be involved in higher-order functions, such as emotion regulation. However, there is very limited evidence for this hypothesis. The present study investigated the impact of ATD on emotion regulation in a double-blind, placebo-controlled, crossover design. A sample of psychiatrically healthy men (N = 28) completed a cognitive task assessing reappraisal ability (i.e., the success of using reappraisal, an emotion regulation strategy, to modulate emotional responses), following ATD and placebo. EEG frontal activity and asymmetry, as well as heart-rate variability (HRV), also were assessed in the reappraisal task. Both frequentist and Bayesian methods were employed for statistical analysis. Results indicated that ATD reduced plasma tryptophan, and reappraisal was effective in modulating emotional experience in the emotion regulation task. However, ATD had no significant effect on reappraisal ability, frontal activity, and HRV. These results offer direct and compelling evidence that decreasing serotonin synthesis through ATD does not alter an emotion regulation ability that is considered crucial in mood and aggression and has been linked with transdiagnostic risk of psychopathology.

Childhood maltreatment and emotion regulation in everyday life: an experience sampling study

Childhood maltreatment is a major risk factor for psychopathology, and increasing evidence suggests that emotion regulation is one of the underlying mechanisms. However, most of this evidence comes from single assessments of habitual emotion regulation, which may not overlap with spontaneous emotion regulation in daily life and which fail to account for within-individual variability in emotion regulation across multiple contexts. In the present study, we investigated the relation between history of childhood maltreatment, positive and negative affect, and multiple dimensions of spontaneous emotion regulation (strategy use, emotion regulation goals, emotion regulation success and effort) in everyday life, using experience sampling method (3 assessments/day, for 10 consecutive days), in a sample of healthy volunteers (N = 118). Multilevel modeling results indicated that childhood maltreatment was associated with lower positive affect and higher negative affect. Childhood maltreatment was also related to lower use of reappraisal and savoring (but not suppression, rumination and distraction), reduced emotion regulation success (but not effort), as well as lower levels of and higher within-individual variability of hedonic (but not instrumental) emotion regulation goals. These results provide ecological evidence for multiple differences in emotion regulation in individuals with a history of childhood maltreatment.

Emotion regulation as mediator between childhood adversity and psychopathology: A meta-analysis

Childhood adversity is a major risk factor for multiple forms of psychopathology, and recent efforts have focused on understanding the underlying psychological mechanisms. One outstanding candidate is emotion regulation, which has been associated with both childhood adversity, and psychopathology. Based on the available evidence, the present meta-analysis set out to investigate the mechanistic involvement of emotion regulation in the relation between childhood adversity and psychopathology. Systematic searches in three databases (PubMed; PsycINFO; Web of Science) identified 215 eligible studies. Using meta-analytic structural equation modeling, we fitted a partial mediation model to the available data across studies, in which childhood adversity was related to psychopathology both directly and through emotion regulation. Multiple emotion regulation dimensions were analyzed, including emotion regulation difficulties and the habitual use of rumination, distraction, reappraisal, and suppression. Measures of psychopathology included a wide range of internalizing and externalizing symptoms in both clinical and non-clinical samples. The results indicated that childhood adversity was positively associated with emotion regulation difficulties, as well as with the habitual use of rumination and suppression. In turn, these measures of emotion regulation were positively associated with psychopathology. Habitual reappraisal use showed negative relations with both childhood adversity and psychopathology. All these emotion regulation measures were supported as mediators in the relation between childhood adversity and psychopathology. In contrast, distraction was not related to childhood adversity or psychopathology, and its mediator role was not supported. These results suggest that altered emotion regulation is a consistent marker of childhood adversity and contributes to risk of psychopathology.

Childhood adversity and impaired reward processing: A meta-analysis

BACKGROUND

Childhood adversity (CA) is associated with increased risk of psychopathology, and reward processing (RP) may be one of the underlying mechanisms. However, evidence on impaired RP in childhood adversity is theoretically and methodologically heterogeneous.

OBJECTIVE

To provide a quantitative overview of studies on the relation between childhood adversity and RP assessed at the behavioral and subjective levels, and identify differences between studies that influence the effect size.

PARTICIPANTS AND SETTING

Twenty-seven studies (overall N = 6801) were included.

METHODS

Peer-reviewed publications describing empirical studies on the relation between CA and behavioral and self-report measures of RP in humans were identified through systematic searches in six bibliographic databases. Effect sizes (r) were pooled using random-effects models. The potential moderator role of RP dimension, type of RP assessment, type of childhood adversity assessment, and age were examined.

RESULTS

Results indicated a small, but consistent association between CA and impaired RP (r = 0.12; 95% CI: 0.07, 0.16), with medium heterogeneity (I² = 62.43). The effect size was significantly larger (i.e., medium-sized) in studies that focused on reward learning rather than reward valuation and reward responsiveness; used cognitive tasks rather than self-report assessments of RP; and relied on official records rather than subjective reports of CA. There was evidence of publication bias, but overall effect size remained significant after imputation.

CONCLUSIONS

These results suggest that multidimensional RP impairments (e.g., deficits in reward learning, biased reward valuation) are a consistent marker of CA, and may represent mechanisms underlying the increased risk of psychopathology.

Childhood maltreatment and expressive flexibility: specific effects of threat and deprivation?

While childhood maltreatment has been consistently associated with a high risk for psychopathology, the mechanisms underlying this relation are still unclear. Dysfunctional emotion regulation has been singled out as a potential mechanism and recent perspectives emphasise the importance of measuring flexibility over habitual patterns of regulating strategies when assessing it. The present study has investigated the relation between childhood maltreatment and expressive flexibility, the ability to control emotional expression according to situational demands. Participants completed a retrospective self-report maltreatment questionnaire, which measured levels of childhood abuse and neglect, and an experimental task, which measured expressive flexibility. Depressive symptoms and trait anxiety were also evaluated. Results indicated an association between childhood maltreatment and reduced expressive flexibility. When investigated separately, both abuse and neglect were associated with reduced expressive flexibility, but when analyzed concurrently, only the former relation remained significant. Expressive flexibility negatively correlated with depressive symptoms. Our findings suggest that childhood maltreatment, a distal risk factor for psychopathology, impacts expressive flexibility, a form of emotion regulation flexibility.

Shame in Anxiety and Obsessive-Compulsive Disorders

PURPOSE OF REVIEW

Studies on the relations between shame and anxiety and obsessive-compulsive and related disorders (OCRDs) are reviewed, with a focus on recent work.

RECENT FINDINGS

Medium-sized positive correlations have been consistently found across anxiety disorders and OCRDs, suggesting that this relation is transdiagnostic. Most studies focused on shame-proneness and found similar relations across multiple types (e.g. internal, external) and domains (e.g. bodily, characterological, behavioural) of shame, with little variation between clinical and non-clinical populations and different age categories. However, most studies are cross-sectional and correlational and by separately studying clinical and non-clinical populations, they do not give a unitary dimensional view of the relation between shame and symptoms. Emerging findings suggest that shame may be a marker of the response to treatment in these disorders, and its relation with symptoms may be bidirectional. The consistent but medium-sized associations between shame and symptoms of anxiety and OCRDs warrant the future search for mediators and moderators.

Early-life adversity and cortisol response to social stress: a meta-analysis

Early-life adversity has been associated with a life-long increased risk for psychopathology and chronic health problems. These long-term negative effects have been explained through stress sensitization, which may involve dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis through either increased or decreased reactivity. The present meta-analysis assessed for the first time the effect of early-life adversity on cortisol response to social stress. Thirty data sets were included in the meta-analysis, in which early-life adversity and salivary cortisol response to social stress were assessed in 4292 individuals of different ages. Results indicated a moderate effect size (g = -0.39) in overall cortisol levels across studies. Separate analyses of cortisol at different stages of response showed large effect sizes at peak and recovery, and a moderate effect at baseline. Heterogeneity was large in this sample of studies and several moderators were identified. The effect size was larger in studies that focused on maltreatment compared to those that included other adversities, and in adults compared to children and adolescents. Percent of women in each sample and methodological quality were positive predictors of the effect size. Publication bias may be present, but the analysis was hampered by the high heterogeneity. Therefore, these results support the association between early-life adversity and blunted cortisol response to social stress, and they suggest that the long-term negative effects of early-life adversity may reach maximum levels in adults.

Behavioral and cortisol responses to stress in newborn infants: Effects of mode of delivery

Suboptimal birth characteristics have been associated with altered reactivity to stress in infants. However, previous studies have not controlled for mode of delivery, which may influence the neonatal onset of stress responses. The present study assessed stress-related behavior and salivary cortisol before and after an inoculation at two hours after birth, and compared infants born through VD (N=70) and elective CS (N=72). The results indicated that overall stress behavior and body movements were increased immediately after inoculation in infants born through CS compared to VD. Infants born through CS did not show significant cortisol increases following inoculation and their overall cortisol reactivity (i.e., AUC_G) was lower compared to infants born through VD. However, unexpectedly, cortisol levels in infants born through VD were highest before inoculation and subsequently decreased. Cortisol was significantly related to behavior in both groups, but in opposite directions. These results support the view that mode of delivery influences neonatal stress reactivity, although future studies should try to disentangle the effects of mode of delivery and related variables.

Individual Differences in Emotion Regulation, Childhood Trauma and Proneness to Shame and Guilt in Adolescence

Dispositional shame and guilt have been associated with psychopathology and an increasing number of studies have traced this relation back to adolescence. This developmental period is thought to be characterized by maturational changes in emotion regulation, which also play an important role in vulnerability to psychopathology, but little is known about the links between emotion regulation and dispositional shame and guilt. The current study investigated the relations between individual differences in the habitual use of a wide range of emotion regulation strategies and proneness to shame and guilt in a large sample of adolescents (N = 706), aged 13 to 17 years. History of childhood trauma was also assessed. Our results showed that emotion regulation independently explained about 20% of the variance of shame-proneness and guilt-proneness. Higher use of maladaptive (e.g., Self-Blaming, Catastrophizing) and lower use of adaptive (e.g., Refocus on Planning, Positive Reappraisal) emotion regulation strategies were positively associated with shame-proneness. In contrast, lower use of maladaptive (e.g., Catastrophizing, Blaming Others) and higher use of adaptive (e.g., Refocus on Planning, Positive Reappraisal) emotion regulation strategies were associated with guilt-proneness, independent of the influence of childhood trauma, which also explained a relatively minor portion of guilt-proneness. Although there were age differences (i.e., rumination was used more by older adolescents, and the influence of emotion regulation on depression and anxiety symptoms increased with age) and sex differences (i.e., girls reported higher use of Putting into Perspective and Other Blaming compared to boys) in emotion regulation, age and sex were not significantly associated with proneness to shame and guilt. The positive relations with maladaptive emotion regulation underscores the dysfunctional nature of shame-proneness. Future studies could use longitudinal measures to establish that emotion regulation drives dispositional shame and guilt, and also investigate whether emotion regulation optimization is able to normalize proneness to shame and guilt and reduce risk for psychopathology.

Allelic distribution of BDNF Val66Met polymorphism in healthy Romanian volunteers

Population stratification of functional gene polymorphisms is a potential confounding factor in genetic association studies. The Val66Met (rs6265) single-nucleotide polymorphism in the brain-derived neurotrophic factor gene (BDNF) exhibits one of the highest variabilities in terms of allelic distribution between populations. The present study reports the distribution of BDNF Val66Met alleles in a sample of healthy volunteers (N = 1124) selected from the Romanian population. Frequencies were 80.74% for the Val allele and 19.26% for the Met allele. The data from this study extends efforts to map the allelic distribution of BDNF Val66Met in populations around the world and emphasizes that population stratification should be controlled for in future studies that report phenotypic associations in samples from different populations.

Aesthetic Emotions Across Arts: A Comparison Between Painting and Music

Emotional responses to art have long been subject of debate, but only recently have they started to be investigated in affective science. The aim of this study was to compare perceptions regarding frequency of aesthetic emotions, contributing factors, and motivation which characterize the experiences of looking at painting and listening to music. Parallel surveys were filled in online by participants (N = 971) interested in music and painting. By comparing self-reported characteristics of these experiences, this study found that compared to listening to music, looking at painting was associated with increased frequency of wonder and decreased frequencies of joyful activation and power. In addition to increased vitality, as reflected by the latter two emotions, listening to music was also more frequently associated with emotions such as tenderness, nostalgia, peacefulness, and sadness. Compared to painting-related emotions, music-related emotions were perceived as more similar to emotions in other everyday life situations. Participants reported that stimulus features and previous knowledge made more important contributions to emotional responses to painting, whereas prior mood, physical context and the presence of other people were considered more important in relation to emotional responses to music. Self-education motivation was more frequently associated with looking at painting, whereas mood repair and keeping company motivations were reported more frequently in relation to listening to music. Participants with visual arts education reported increased vitality-related emotions in their experience of looking at painting. In contrast, no relation was found between music education and emotional responses to music. These findings offer a more general perspective on aesthetic emotions and encourage integrative research linking different types of aesthetic experience.

Reactivity to Social Stress in Subclinical Social Anxiety: Emotional Experience, Cognitive Appraisals, Behavior, and Physiology

Recent research indicates that subclinical social anxiety is associated with dysfunctions at multiple psychological and biological levels, in a manner that seems reminiscent of social anxiety disorder (SAD). This study aimed to describe multidimensional responses to laboratory-induced social stress in an analog sample selected for social anxiety symptoms. State anxiety, cognitive biases related to negative social evaluation, speech anxiety behaviors, and cortisol reactivity were assessed in the Trier Social Stress Test (TSST). Results showed that social anxiety symptoms were associated with increased state anxiety, biased appraisals related to the probability and cost of negative social evaluations, behavioral changes in facial expression that were consistent with speech anxiety, and lower cortisol reactivity. In addition, multiple interrelations between responses in the TSST were found, with positive associations between subjective experience, cognitive appraisals, and observable behavior, as well as negative associations between each of the former two types of response and cortisol reactivity. These results show that in response to social stressors, subclinical social anxiety is associated with significant changes in emotional experience, cognitive appraisals, behaviors, and physiology that could parallel those previously found in SAD samples.

Shame and Guilt-Proneness in Adolescents: Gene-Environment Interactions

Rooted in people’s preoccupation with how they are perceived and evaluated, shame and guilt are self-conscious emotions that play adaptive roles in social behavior, but can also contribute to psychopathology when dysregulated. Shame and guilt-proneness develop during childhood and adolescence, and are influenced by genetic and environmental factors that are little known to date. This study investigated the effects of early traumatic events and functional polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and the serotonin transporter gene promoter (5-HTTLPR) on shame and guilt in adolescents. A sample of N = 271 healthy adolescents between 14 and 17 years of age filled in measures of early traumatic events and proneness to shame and guilt, and were genotyped for the BDNF Val66Met and 5-HTTLPR polymorphisms. Results of moderator analyses indicated that trauma intensity was positively associated with guilt-proneness only in carriers of the low-expressing Met allele of BDNF Val66Met. This is the first study that identifies a gene-environment interaction that significantly contributes to guilt proneness in adolescents, with potential implications for developmental psychopathology.

Emotional non-acceptance links early life stress and blunted cortisol reactivity to social threat

Early life stress (ELS) has been recently associated with blunted cortisol reactivity and emotion dysregulation, but no study until now examined whether these characteristics are related. The main goal of this study was to examine the potential mediator role of emotion dysregulation in the relation between ELS and cortisol reactivity to social threat. Only women who were free of psychiatric and endocrine disorders, had regular menstrual cycle and did not use oral contraceptives were selected for this study (N=62). After filling in ELS and multidimensional emotion dysregulation measures, participants underwent the Trier Social Stress Test during which cortisol and autonomic responses were assessed. Most participants (85.5%) reported one or more major stressful events (i.e., physical abuse, sexual abuse, major parental conflicts, death of a family or close friend, severe illness) experienced before age 17. ELS was negatively associated with cortisol reactivity and positively associated with skin conductance level (SCL) reactivity, but it did not influence heart rate and respiratory sinus arrhythmia. In addition, ELS was positively related to emotional non-acceptance (i.e., a tendency to develop secondary emotional responses to one's negative emotions), and the latter was negatively related to cortisol responses and positively related to SCL responses. Bootstrapping analyses indicated that emotional non-acceptance was a significant mediator in the relationships between ELS and both cortisol and SCL responses. Emotional non-acceptance is thus one of the psychological mechanisms underlying blunted cortisol and increased sympathetic reactivity in young healthy volunteers with a history of ELS.

Incidental emotions in moral dilemmas: the influence of emotion regulation

Recent theories have argued that emotions play a central role in moral decision-making and suggested that emotion regulation may be crucial in reducing emotion-linked biases. The present studies focused on the influence of emotional experience and individual differences in emotion regulation on moral choice in dilemmas that pit harming another person against social welfare. During these "harm to save" moral dilemmas, participants experienced mostly fear and sadness but also other emotions such as compassion, guilt, anger, disgust, regret and contempt (Study 1). Fear and disgust were more frequently reported when participants made deontological choices, whereas regret was more frequently reported when participants made utilitarian choices. In addition, habitual reappraisal negatively predicted deontological choices, and this effect was significantly carried through emotional arousal (Study 2). Individual differences in the habitual use of other emotion regulation strategies (i.e., acceptance, rumination and catastrophising) did not influence moral choice. The results of the present studies indicate that negative emotions are commonly experienced during "harm to save" moral dilemmas, and they are associated with a deontological bias. By efficiently reducing emotional arousal, reappraisal can attenuate the emotion-linked deontological bias in moral choice.

Reappraisal as a mediator in the link between 5-HTTLPR and social anxiety symptoms

Social anxiety symptoms have been related to (a) polymorphisms in the serotonin-transporter gene-promoter region (also, serotonin-transporter-linked polymorphic region; 5-HTTLPR) and (b) reduced use of adaptive forms of emotion regulation such as reappraisal. It is not known, however, whether reappraisal functions as a mediator in the link between 5-HTTLPR and social anxiety. To address this issue, 182 unselected community volunteers were tested for 5-HTTLPR status, and self-report measures of social anxiety symptoms and reappraisal use were obtained. Relative to other participants, those with two low-expressing alleles displayed increased social anxiety and decreased reappraisal. As predicted, the influence of 5-HTTLPR on social anxiety symptoms was transmitted via reappraisal, and this effect of 5-HTTLPR was observed using two different measures of reappraisal. These findings suggest that cognitive reappraisal may be an intermediate phenotype of the social anxiety spectrum, and that individuals with low-expressing 5-HTTLPR genotypes may benefit the most from cognitive-behavioral psychotherapy because they do not appear to engage as frequently as others in reappraisal.

Emotional face processing in neurotypicals with autistic traits: implications for the broad autism phenotype

The present study investigated emotional face processing in neurotypicals selected for autistic traits (AT). Participants (N=81), who obtained scores one standard deviation above or below average on the Autism Spectrum Quotient, were tested using observational fear conditioning (FC), a face version of the attention probe task, and the "Reading the Mind in the Eyes" test. The results indicated that high AT participants displayed enhanced observational FC, no attentional bias to fearful faces, and increased latency (but normal accuracy) to recognizing the mental state of another. To a certain extent, this pattern resembles the social-emotional phenotype that was previously described in autism spectrum disorders. Therefore, these results may contribute to the broad autism phenotype perspective.

Empathy manipulation impacts music-induced emotions: a psychophysiological study on opera

This study investigated the effects of voluntarily empathizing with a musical performer (i.e., cognitive empathy) on music-induced emotions and their underlying physiological activity. N = 56 participants watched video-clips of two operatic compositions performed in concerts, with low or high empathy instructions. Heart rate and heart rate variability, skin conductance level (SCL), and respiration rate (RR) were measured during music listening, and music-induced emotions were quantified using the Geneva Emotional Music Scale immediately after music listening. Listening to the aria with sad content in a high empathy condition facilitated the emotion of nostalgia and decreased SCL, in comparison to the low empathy condition. Listening to the song with happy content in a high empathy condition also facilitated the emotion of power and increased RR, in comparison to the low empathy condition. To our knowledge, this study offers the first experimental evidence that cognitive empathy influences emotion psychophysiology during music listening.

Frontal EEG activation asymmetry reflects cognitive biases in anxiety: evidence from an emotional face Stroop task

Electroencephalography (EEG) has been extensively used in studies of the frontal asymmetry of emotion and motivation. This study investigated the midfrontal EEG activation, heart rate and skin conductance during an emotional face analog of the Stroop task, in anxious and non-anxious participants. In this task, the participants were asked to identify the expression of calm, fearful and happy faces that had either a congruent or incongruent emotion name written across them. Anxious participants displayed a cognitive bias characterized by facilitated attentional engagement with fearful faces. Fearful face trials induced greater relative right frontal activation, whereas happy face trials induced greater relative left frontal activation. Moreover, anxiety specifically modulated the magnitude of the right frontal activation to fearful faces, which also correlated with the cognitive bias. Therefore, these results show that frontal EEG activation asymmetry reflects the bias toward facilitated processing of fearful faces in anxiety.

Genetic contributions of the serotonin transporter to social learning of fear and economic decision making

Serotonin (5-HT) modulates emotional and cognitive functions such as fear conditioning (FC) and decision making. This study investigated the effects of a functional polymorphism in the regulatory region (5-HTTLPR) of the human 5-HT transporter (5-HTT) gene on observational FC, risk taking and susceptibility to framing in decision making under uncertainty, as well as multidimensional anxiety and autonomic control of the heart in healthy volunteers. The present results indicate that in comparison to the homozygotes for the long (l) version of 5-HTTLPR, the carriers of the short (s) version display enhanced observational FC, reduced financial risk taking and increased susceptibility to framing in economic decision making. We also found that s-carriers have increased trait anxiety due to threat in social evaluation, and ambiguous threat perception. In addition, s-carriers also show reduced autonomic control over the heart, and a pattern of reduced vagal tone and increased sympathetic activity in comparison to l-homozygotes. This is the first genetic study that identifies the association of a functional polymorphism in a key neurotransmitter-related gene with complex social-emotional and cognitive processes. The present set of results suggests an endophenotype of anxiety disorders, characterized by enhanced social learning of fear, impaired decision making and dysfunctional autonomic activity.

Genetic contributions to individual differences in emotion: a primer

The methodological and empirical development of cognitive, affective and clinical neuroscience has brought these fields into the ideal position of being able to benefit from the increasing number of techniques and interdisciplinary applications developed since the completion of the sequencing of the human genome. An increasingly investigated topic in behavioral, molecular and neuroimaging genetics concerns genetic influences on emotional reactivity and regulation. The estimation of the heritability of emotional traits and states, and the identification of functional genetic polymorphisms that are associated with emotional aspects of behavior, hold great promise for understanding the etiology and pathogenesis of mood and anxiety disorders. This article briefly reviews evidence from twin, genetic association, and neuroimaging genetic studies of individual differences in emotion reactivity and regulation, with an emphasis on trends in recent research, and their potential to contribute to the clinical neuroscience of emotional dysfunction.

Reduced heart rate variability and vagal tone in anxiety: trait versus state, and the effects of autogenic training

This study investigated heart rate variability (HRV) in healthy volunteers that were selected for extreme scores of trait anxiety (TA), during two opposite psychophysiological conditions of mental stress, and relaxation induced by autogenic training. R-R intervals, HF and LF powers, and LF/HF ratios were derived from short-term electrocardiographic recordings made during mental stress and relaxation by autogenic training, with respiratory rate and skin conductance being controlled for in all the analyses. The main finding was that high TA was associated with reduced R-R intervals and HF power across conditions. In comparison to mental stress, autogenic training increased HRV and facilitated the vagal control of the heart. There were no significant effects of TA or the psychophysiological conditions on LF power, or LF/HF ratio. These results support the view that TA, which is an important risk factor for anxiety disorders and predictor of cardiovascular morbidity and mortality, is associated with autonomic dysfunction that seems likely to play a pathogenetic role in the long term.

Anxiety and decision-making: toward a neuroeconomics perspective

PURPOSE

This chapter focuses on individual differences in anxiety, by reviewing its neurobiology, cognitive effects, with an emphasis on decision-making, and recent developments in neuroeconomics.

METHODOLOGY

A review and discussion of anxiety and decision-making research.

PRACTICAL IMPLICATIONS

This chapter argues that by making the step from emotional states to individual differences in emotion, neuroeconomics can extend its neurobiological roots and outreach its current clinical relevance. VALUE OF CHAPTER: This chapter contributes to the literature on individual differences in emotion and their effects on decision-making, which is increasingly important in mainstream behavioral economics and neuroeconomics.

Aluminum and Alzheimer's disease: A new look

Despite the circumstantial and sometimes equivocal support, the hypothetic involvement of aluminum (Al) in the etiology and pathogenesis of Alzheimer's disease (AD) has subsisted in neuroscience. There are very few other examples of scientific hypotheses on the pathogenesis of a disease that have been revisited so many times, once a new method that would allow a test of Al's accumulations in the brain of AD patients or a comparison between Al-induced and AD neuropathological signs has become available. Although objects of methodological controversies for scientists and oversimplification for lay spectators, several lines of evidence have strongly supported the involvement of Al as a secondary aggravating factor or risk factor in the pathogenesis of AD. We review evidence on the similarities and dissimilarities between Al-induced neurofibrillary degeneration and paired helical filaments from AD, the accumulation of Al in neurofibrillary tangles and senile plaques from AD, the neuropathological dissociation between AD and dialysis associated encephalopathy, and the epidemiological relations between Al in drinking water and the prevalence of AD. We also critically analyze the prospects of Al-amyloid cascade studies and other evolving lines of evidence that might shed insights into the link between Al and AD. The message between the lines of the following article is that the involvement of Al in the pathogenesis of AD should not be discarded, especially in these times when the amyloid dogma of AD etiology shows its myopia.

Behavioral effects of corpus callosum transection and environmental enrichment in adult rats

A common assumption about the corpus callosum transection (CCX) is that it only affects behaviors heavily relying on interhemispheric communication. However, cerebral laterality is ubiquitous across motor and perceptual, cognitive and emotional domains, and the corpus callosum is important for its establishment. Several recent studies showed that the partial denervation of the sensorimotor isocortex through CCX derepressed neural growth processes that were sensitive to motor demand (experience-dependent neural plasticity). We investigated whether the facilitatory effects of CCX on cortical neural plasticity, shaped by differential housing, extended beyond the motor domain. Adult rats were housed in enriched (EE), standard (SE) or impoverished environments (IE) for 10 weeks, that is, 2 weeks before they underwent CCX or sham surgery, and, then, 8 weeks throughout the experiments. After they recovered from surgery, the behavioral performance of rats was tested using open-field, spontaneous alternation in the T-maze, paw preference, Morris water maze, and tone fear conditioning. The results indicated that the effects of CCX and housing on open-field behavior were independent, with CCX increasing the time spent in the center of the field at the beginning of the observation (i.e., emotionality), and EE and IE increasing rearing (emotionality) and reducing teeth-chattering (habituation), respectively. CCX reduced the frequency of spontaneous alternation, denoting spatial working memory deficits, while housing did not influence this performance. Neither CCX, nor housing significantly affected paw preference lateralization, although CCX was associated with a leftward bias in paw preference. In the Morris water maze, housing had effects on spatial acquisition, while CCX reduced activity, without interfering with spatial memory. CCX did not influence tone fear conditioning, but context fear conditioning seemed to benefit from EE. We conclude that CCX in adult rats has subtle, but specific behavioral effects pertaining to emotionality, spatial working memory, and, possibly, aversively motivated exploration, and these effects are either independent or only peripherally interact with the effects of housing.

Emotion-induced retrograde amnesia and trait anxiety

Emotional arousal can both enhance and impair memory. Considering that both emotional memory and trait anxiety (TA) have been associated with adrenergic activity, the authors investigated whether there is an association between 2 opposite emotional memory biases and the TA. The authors used a procedure recently put forward by B. A. Strange, R. Hurlemann, and R. J. Dolan (2003) to elicit an emotion-induced retrograde amnesia (ERA) coupled to an emotional memory enhancement (EME). The authors contrasted the association between these emotional memory biases and the TA in several conditions involving different levels of encoding and types of recall. The results presented here indicated a significant interaction of the TA with EME and ERA and the dependency of these biases on the consciously controlled use of memory.

High levels of homocysteine and low serum paraoxonase 1 arylesterase activity in children with autism

Autism is a behaviorally defined disorder of unknown etiology that is thought to be influenced by genetic and environmental factors. High levels of homocysteine and oxidative stress are generally associated with neuropsychiatric disorders. The purpose of this study was to compare the level of homocysteine and other biomarkers in children with autism to corresponding values in age-matched healthy children. We measured total homocysteine (tHcy), vitamin B(12), paraoxonase and arylesterase activities of human paraoxonase 1 (PON1) in plasma and glutathione peroxidase (GPx) activity in erythrocytes from 21 children: 12 with autism (age: 8.29 +/- 2.76 years) and 9 controls (age: 8.33 +/- 1.82 years). We found statistically significant differences in tHcy levels and in arylesterase activity of PON1 in children with autism compared to the control group: 9.83 +/- 2.75 vs. 7.51 +/- 0.93 micromol/L (P < or =0.01) and 72.57 +/- 11.73 vs. 81.83 +/- 7.39 kU/L (P < or =0.005). In the autistic group there was a strong negative correlation between tHcy and GPx activity and the vitamin B(12) level was low or suboptimal. In conclusion, our study shows that in children with autism there are higher levels of tHcy, which is negatively correlated with GPx activity, low PON1 arylesterase activity and suboptimal levels of vitamin B(12).

Have no fear, erythropoietin is here: erythropoietin protects fear conditioning performances after functional inactivation of the amygdala

This study investigated the capacity of erythropoietin (EPO) to protect fear conditioning performances against functional inactivation of the amygdala. We infused an excitotoxic dose of glutamate in the lateral nucleus of the amygdala (LA) of adult rats in order to block the output projections to brainstem areas controlling the expression of conditioned fear responses. Subsequently, animals with excitotoxic lesions in the LA displayed altered short and long-term fear conditioned responses, but the integrity of their general emotional reactivity was preserved, as indicated by their open-field behavior. EPO infused immediately after glutamate succeeded to protect the conditioned fear performances of rats. This effect was reliably represented on both short, and long-term memory tests of conditioned fear. This and other studies have supported the potent neuroprotective activity of EPO, discriminable both morphologically, and behaviorally.

A behavioral and ultrastructural dissection of the interference of aluminum with aging

The persistence of neuroscientists in exploring aluminium's (Al) possible contribution to the pathogenesis of Alzheimer's disease (AD) has resulted in a wealth of researches detailing the biological toxicity of this metal. However, to date, there have been few accounts of the interference of Al with aging and its relevance to the pathogenesis of AD. We investigated the behavioral and the ultrastructural signatures of Al in the hippocampus on young and aging rats which were exposed for three months to aluminium gluconate. The aging animals displayed decreased scores of activity and emotionality, and the Al-exposed aging males had altered emotional reactivity behaviors. The electron-microscopic analysis indicated that Al promoted in the aging hippocampus a variety of cellular and ultrastructural degenerative signs, such as granulo-vacuolar degenerations, deposition of lipofuscin and amyloid in the cytoplasm of neurons and astrocytes, and in extracellular compartments, Hirano bodies, demyelination and the atrophy of the mitochondria. Moreover, the quantitation of myelin sheath width and the diameter of mitochondria measured on randomly selected samples confirmed that myelin and mitochondria are primary targets of Al's toxicity. Demyelination and mitochondrial atrophy seemed more advanced in the hippocampus of Al-exposed aging males, supporting the effect of sex suggested by the behavioral results. These findings and other collateral results also reported here are discussed in the context of a possible involvement of Al in AD, mediated by aging and catalyzed by hepatic morphopathology.

A behavioral and histological study of the effects of long-term exposure of adult rats to aluminum

Aluminum (Al) has been etiologically and epidemiologically related to several neurologic conditions, including Alzheimer's disease (AD). The effects of Al long-term exposure were investigated to describe the associated behavioral and brain modifications. Adult rats were intraperitoneally injected three times a week for 6 months with ecological doses of Al gluconate (0.85 mg/kg). The Al overload was confirmed by the significantly increased level of Al in serum. We assessed fear conditioning, spatial memory and emotional reactivity by shuttle-box task, Morris water maze, and open-field, respectively. The performance of the experimental animals at the shuttle-box task was significantly lower (p <.01) compared to that of control. The experimental animals had impaired spatial memory, with lower and more fluctuant performance at Morris water maze. The noxious-driven behavior of the experimental animals was also altered, with significantly lower activity scores (p <.05), and high emotionality scores (p <.01) at the open-field. We recovered and processed the brain for aluminum and amyloid deposits. The brains of experimental animals, studied by optical microscopy, displayed a massive cellular depletion in the hippocampal formation, particularly, the CAl field, and also in the temporal and parietal cortex. We observed numerous ghost-like neurons with cytoplasmic and nuclear vacuolations, and with Al deposits. The hippocampus contained extracellular accumulations of Al and amyloid surrounded by nuclei of degenerating cells, which we interpreted as neuritic plaques. The cerebrovasculature was distorted, with a significant thickening of the wall of capillaries, associated with amyloid deposits. These behavioral and neuropathological modifications associated with long-term exposure to Al are reminiscent of those observed in AD.