Validity and reliability of electroencephalographic frontal alpha asymmetry and frontal midline theta as biomarkers for depression

Electroencephalographic (EEG) frontal alpha asymmetry (FAA) and frontal midline (FM) theta have been suggested as biomarkers for depression and anxiety, but have mostly been assessed in small and non‐clinical studies. In a clinical sample of 79 adults with depression (ICD‐10: F32), resting EEG and scales of depression (MADRS) and anxiety (HADS‐A) were measured at intake and after 3 months. FAA and FM theta values were referenced to a normative population database. Internal consistency, test‐retest reliability, and correlations with psychiatric tests were examined. Reliability was sufficient. However, FAA and FM theta values were close to the general population, and correlations with psychiatric tests were mostly small and non‐significant, with the exception of FAA on F7–F8 z‐scores and HADS‐A. We conclude that the validity of FAA and FM theta and therefore their potential as biomarkers for depression and anxiety remain unclear.     

Collaborative narration of the past and extraversion

We propose that collaborative narration is a process in which narrative identity develops, and we examine individual differences in extraversion in such narration. Two studies are presented: retrospective and experience sampling episodes of collaborative narration, the first with self-defining memories, the second with everyday narration. Across both studies, extraversion was associated with an increased frequency in collaborative narration. This finding was not explained by the ‘talkativeness’ item in the extraversion measures. Further, more extraverted people shared their self-defining memories with more people and were more comfortable sharing than less extraverted people, the impact of extraversion was specific to mutual reminiscence in everyday narration, and mutual reminiscence was more enjoyable for those who are more extraverted than introverted. Implications from these data for understanding individual differences in identity and narrative development are discussed.     

Executive functions and extraversion

Executive functions and extraversion have been linked to similar neurological substrates. Participants were tested on a variety of tasks that assessed performance on three components of executive functioning (i.e., shifting, updating, and inhibition) and two measures of extraversion (Eysenck Personality Questionnaire-Revised and Carver and White’s BIS/BAS scales). More extraverted participants showed different patterns of executive function performance than the more introverted participants. Extraverts performed best on more difficult tasks and on updating tasks. Conversely, introverts performed best on set shifting tasks. These results suggest that executive functioning strengths differ based on degree of extraversion.     

The role of midfrontal theta oscillations across the development of cognitive control in preschoolers and school‐age children

The development of cognitive control enables children to better resist acting based on distracting information that interferes with the current action. Cognitive control improvement serves different functions that differ in part by the type of interference to resolve. Indeed, resisting to interference at the task‐set level or at the response‐preparation level is, respectively, associated with cognitive flexibility and inhibition. It is, however, unknown whether the same neural mechanism underlies these two functions across development. Studies in adults have revealed the contribution of midfrontal theta (MFT) oscillations in interference resolution. This study investigated whether MFT is involved in the resolution of different types of interference in two age groups identified as corresponding to different latent structures of executive functions. Preschool (4–6 years) and school children (6–8 years) were tested with a task involving interference at the response level and/or the task‐set level while (electroencephalogram) EEG was recorded. Behaviorally, response time and accuracy were affected by task‐set. Both age groups were less accurate when the interference occurred at the task‐set level and only the younger group showed decreased accuracy when interference was presented at the response‐preparation level. Furthermore, MFT power was increased, relative to the baseline, during the resolution of both types of interference and in both age groups. These findings suggest that MFT is involved in immature cognitive control (i.e., preschool and school‐ages), by orchestrating its different cognitive processes, irrespective of the interference to resolve and of the level of cognitive control development (i.e., the degree of differentiation of executive functions).     

Social indicators as indexes of neuroticism and extraversion

Lynn and Hampson (1975) and recently Lester (2000) suggested that national level of extraversion (E) and neuroticism (N) could be assessed by using certain national indicators like suicide and divorce rates. In this study, Lynn and Hampson’s (1975) and Lester’s (2000) models were assessed by using 1990s data. Although Lynn and Hampson’s original N and E factors correlated with EPQ N (r=0.48) and E (r=0.60) scores as hypothesised, the factor structure did not recur in the 1990s data. Factor analysis supported Lester’s (2000) model of N and E. However, the factor loadings for EPQ N and E were rather modest (0.49 for N and 0.36 for E). It was concluded that more research with larger datasets and new social indicators are needed before social indicators could replace the EPQ in comparisons of national characteristics of nations.     

Motivation and goal orientation in vulnerability to depression

Depression may be related to motivational systems that govern approach and avoidance behaviour such as temperament and goal orientation. Using a remitted depression design we found that previously depressed and never-depressed individuals did not differ on number of approach goals generated, degree of goal commitment or extent of planning to reach goals. However, previously depressed individuals generated more avoidance goals indicating that the tendency to set avoidance goals may be a trait-like vulnerability to depression. Previously depressed individuals also reported higher activation of the behavioural approach system (BAS) raising the possibility that this system is energising approach behaviour in the service of avoiding aversive consequences.     

Degree of extraversion and physiological responses to physical pain and sadness

Extraversion is a personality frequently discussed as one of the strongest and most consistent factors that relates to individual subjective wellbeing. The goal of this study was to better understand how people with varying degrees of extraversion psychologically and physiologically respond differently to unpleasant circumstances. Emotional responses (e.g., levels of intensity, valence, and arousal) were assessed in determining the sensitivity level to negative stimuli that were specifically designed to provoke physical pain and sadness emotion. Physiological changes (e.g., heart rate (HR), blood volume pulse (BVP), and respiratory sinus arrhythmia (RSA)) were also measured during pain and sadness to observe sympathetic and parasympathetic activities. Our results showed that the degree of extraversion was associated with less unpleasant responses to sadness, less HR responses to both pain and sadness, and greater RSA responses to sadness. The findings suggest that the lower HR reactivity to painful and sad situations and greater RSA reactivity to sad situations in extraversion could be possibly due to increased parasympathetic activity. Additionally, enhanced parasympathetic activity to negative situations may explain an important mechanism underlying the positive connection between extraversion and subjective wellbeing.     

A reduction in positive self-judgment bias is uniquely related to the anhedonic symptoms of depression

Identifying patterns of biased cognitive processing specific to depression has proved difficult. The tripartite model of mood disorders [Clark, L. A., & Watson, D. (1991). Tripartite model of anxiety and depression: psychometric evidence and taxonomic implications. Journal of Abnormal Psychology, 100, 316-336] suggests that a clearer processing ‘blueprint’ may emerge if depression is viewed dimensionally rather than categorically and by focusing on variations in the degree of positive, rather than negative, processing bias. To investigate this possibility, the present study examined the extent to which a reduced positive self-judgment bias previously found in depressed individuals relates to depression-specific anhedonic symptoms. Sixty participants with varying levels of anxiety and depression symptoms evaluated their own performance on a working memory task in the absence of external feedback. Overall, participants showed a positive self-judgment bias, overestimating the number of trials they had performed correctly relative to objective criteria. Consistent with the tripartite framework, the extent of this positive self-judgment bias was significantly and uniquely related to depression-specific symptoms, with the positive bias reducing as anhedonia severity increased across three different symptom measures.     

Famous face recognition,face matching,and extraversion

It has been previously established that extraverts who are skilled at interpersonal interaction perform significantly better than introverts on a face-specific recognition memory task. In our experiment we further investigate the relationship between extraversion and face recognition, focusing on famous face recognition and face matching. Results indicate that more extraverted individuals perform significantly better on an upright famous face recognition task and show significantly larger face inversion effects. However, our results did not find an effect of extraversion on face matching or inverted famous face recognition.     

Three-way interaction of neuroticism,extraversion, and conscientiousness in the internalizing disorders: Evidence of disorder specificity in a psychiatric sample

It is well-established that neuroticism, extraversion, and conscientiousness are individually associated with internalizing disorders, but research suggests that these main effects may be qualified by a three-way interaction when predicting depression. The current study was the first to examine this three-way interaction in a psychiatric sample (N = 463) with a range of internalizing symptoms as the outcomes. Using two omnibus personality inventories and a diagnostic interview, the expected three-way interaction emerged most consistently for symptoms of major depression, and there was also evidence of synergistic effects for post-traumatic stress disorder and generalized anxiety disorder. Findings indicate that, even in a clinically-distressed and currently-disordered sample, high levels of extraversion and conscientiousness protect against distress disorders for those with high levels of neuroticism.     

Regional and inter-regional theta oscillation during episodic novelty processing

Recent event-related potential (ERP) and functional magnetic resonance imaging (fMRI) studies suggest that novelty processing may be involved in processes that recognize the meaning of a novel sound, during which widespread cortical regions including the right prefrontal cortex are engaged. However, it remains unclear how those cortical regions are functionally integrated during novelty processing. Because theta oscillation has been assumed to have a crucial role in memory operations, we examined local and inter-regional neural synchrony of theta band activity during novelty processing. Fifteen right-handed healthy university students participated in this study. Subjects performed an auditory novelty oddball task that consisted of the random sequence of three types of stimuli such as a target (1000 Hz pure tone), novel (familiar environmental sounds such as dog bark, buzz, car crashing sound and so on), and standard sounds (950 Hz pure tone). Event-related spectra perturbation (ERSP) and the phase-locking value (PLV) were measured from human scalp EEG during task. Non-parametric statistical tests were applied to test for significant differences between stimulus novelty and stimulus targets in ERSP and PLV. The novelty P3 showed significant higher amplitude and shorter latency compared with target P3 in frontocentral regions. Overall, theta activity was significantly higher in the novel stimuli compared with the target stimuli. Specifically, the difference in theta power between novel and target stimuli was most significant in the right frontal region. This right frontal theta activity was accompanied by phase synchronization with the left temporal region. Our results imply that theta phase synchronization between right frontal and left temporal regions underlie the retrieval of memory traces for unexpected but familiar sounds from long term memory in addition to working memory retrieval or novelty encoding.     

Concurrent and lagged effects of counterdispositional extraversion on vitality

There are two contrasting perspectives on the effects of state extraversion. One states that people benefit from behaving extraverted, regardless of their level of trait extraversion. The second entails that behaving concordant to one’s trait is natural while deviations from the trait level— counterdispositional behaviors—are effortful to maintain, leading to mental fatigue. We test the possibility that both perspectives are correct, with beneficial effects of high state extraversion showing immediately, while the depleting counterdispositional effects are delayed. Experience sampling data from 67 employees (N = 1,664), shows that extraverted behaviors are associated with high levels of vitality in the short-term, however, if the extraverted behaviors are not congruent with one’s trait level, they backfire, leading to depleted levels of vitality about one later.     

The role of BIS/BAS in the vulnerability for depression in adolescent girls

Reinforcement Sensitivity Theory (RST), the original (i.e. Gray, 1982) or revised (Gray & McNaughton, 2000), has yet to be used as a framework for investigating vulnerability to Major Depressive Disorder (MDD) in adolescents. The present study employed a high-risk design to examine whether aberrant BIS-FFFS/BAS activity was similarly present in both depressed girls and girls at high risk for depression.MethodsN = 85 age-matched biological daughters of mothers with differential MDD status: (a) MDD (n = 17), (b) high-risk (n = 34), and (c) healthy controls (n = 34) completed measures of the BIS/BAS, depression, and anxiety.ResultsMDD girls scored significantly higher on BIS than healthy controls but not high-risk girls, and the high-risk and control groups did not differ. No group differences were found on BAS or FFFS-Fear.ConclusionsElevated BIS was not identified as a vulnerability factor for MDD; however, it does distinguish depressed adolescents from healthy controls.     

Cosmetic surgery and the relationship between appearance satisfaction and extraversion: Testing a transactional model of personality

Few studies have tested potential explanatory mechanisms for the high stability of extraversion. In this study, the relationship between extraversion, appearance evaluation, and cosmetic surgery was investigated to examine such mechanisms. The “Big Five” personality traits were assessed in 155 female cosmetic surgery patients prior to and 6 months after surgery, as well as from a representative sample of 907 women. Patients showed higher extraversion scores prior to surgery than were found in the representative sample; further, extraversion scores increased after surgery, while the increase diminished when controlled for appearance evaluation. The results are in accordance with a transactional model, whereby extraverts engage in actions that reinforce extravert tendencies, which may account for the high stability of extraversion.     

Neuroticism and extraversion share genetic and environmental effects with negative and positive mood spillover in a nationally representative sample

Work-family spillover research focuses on how negative and positive moods in one life domain carry over to another. Domain-specific etiologies (e.g., family conflict) are often emphasized to explain spillover. Yet, strong correlations exist between spillover variables of the same emotional valence but originating from different domains, suggesting individual differences in the tendencies to prolong mood-states. The current study (N = 1143 individuals) examined whether these general tendencies are associated with neuroticism and extraversion and how genetic and environmental effects contribute to these associations. Findings revealed that neuroticism and extraversion are related to these tendencies through both genetic and environmental pathways.     

A meta-analysis of linguistic markers of extraversion: Positive emotion and social process words

Past literature has shown that extraversion is related to the use of positive emotion and social process words. However, the strength of the relationships varies substantially across studies. In this research, we conducted a meta-analysis (k = 37, N = 82,132) to estimate the overall effect size of the two linguistic correlates of extraversion. In addition, we tested potential moderators including demographic variables (e.g., age and gender) and communication contexts (e.g., synchronous vs. asynchronous, public vs. private). Our random effects models revealed a small correlation between extraversion and positive emotion words (r = 0.069, 95% CI = [0.041, 0.096]), and a small correlation between extraversion and social process words (r = 0.077, 95% CI = [0.044, 0.109]). In addition, the strength of the relationship between extraversion and positive emotion words varies across communication contexts, while the relationship between extraversion and social process words remains consistent across contexts. Our results suggest that positive emotion words and social process words are linguistic correlates of extraversion, but they are small in magnitude.     

Unpacking the relation between extraversion and volunteering in later life: The role of social capital

This study tested the hypothesis that the relation between extraversion and volunteering by older adults is fully mediated by social capital (participation in clubs and organizations, church attendance, and contact with friends). Data for this study come from 888 adults between the ages of 65–90 years old who participated in the Later Life Study of Social Exchanges (LLSSE). In support of our hypothesis, structural equation modeling revealed that extraversion exerted: (a) a significant total effect on volunteering (0.122), (b) significant indirect effects on volunteering via contact with friends (0.042), church attendance (0.034), and clubs and organizations (females only: 0.042), and (c) a non-significant direct effect on volunteering (0.010). These findings suggest that social capital provides a viable explanation for the association between extraversion and volunteering.     

The extraversion continuum in evolutionary perspective: A review of recent theory and evidence

We review research on the ultimate and proximate origins of variation along the extraversion continuum. After describing the cost-benefit tradeoffs that may have maintained variation in extraversion over human evolution, we consider the evidence bearing on multiple distinct evolutionary hypotheses regarding the causal underpinnings of such variation. On the basis of the reviewed evidence, we argue that fluctuating selection on specific polymorphic genotypes is unlikely to explain the origins of individual differences in extraversion. Rather, adaptively patterned variation in extraversion is likely orchestrated primarily by facultative adaptations designed to calibrate behavioral strategies to cues available in ontogeny. For example, emerging research supports the hypothesis that extraversion may be “reactively heritable” by virtue of its calibration to heritable condition-dependent phenotypic features – which in turn helps explain extraversion’s genetic variance, as well as its consistent positive association with reproductive success. Finally, evidence suggests that some of the inter-individual variance in extraversion is fundamentally noisy, arising as a side effect of mutation–selection balance or pleiotropic polymorphisms maintained via pathogen–host coevolution. If correct, these conclusions indicate that future research should focus on elucidating the facultative adaptations designed to regulate the production of behaviors falling on the extraversion continuum.