Erwin Lemche

Human attachment security is mediated by the amygdala: Evidence from combined fMRI and psychophysiological measures

The neural basis of human attachment security remains unexamined. Using event‐related functional magnetic resonance imaging (fMRI) and simultaneous recordings of skin conductance levels, we measured neural and autonomic responses in healthy adult individuals during a semantic conceptual priming task measuring human attachment security “by proxy”. Performance during a stress but not a neutral prime condition was associated with response in bilateral amygdalae. Furthermore, levels of activity within bilateral amygdalae were highly positively correlated with attachment insecurity and autonomic response during the stress prime condition. We thereby demonstrate a key role of the amygdala in mediating autonomic activity associated with human attachment insecurity. Hum Brain Mapp, 2005.

Mentalizing Language Development in a Longitudinal Attachment Sample: Implications for Alexithymia

Background: The construct of alexithymia implies a deficit in symbolization for emotional, somatic, and mental states. However, the etiologic factors for alexithymia have not yet been fully elucidated. The present study investigated the use of mentalizing language, i.e. the utterance of internal states, from a developmental perspective according to attachment organization and disorganization. Methods: A longitudinal design across 4 time points was applied to a volunteer sample of 42 children. At 12 months, children were tested with the strange situation procedure, the standard measure of attachment at the optimal age, and attachment classifications were taken of videotapes. At ages 17, 23, 30 and 36 months, mother and child were observed in simplified separation episodes of 30 min duration. Transcripts of the sessions were subject to coding of internal state words. Results: During the investigated span, securely attached children rapidly acquired emotion, physiology, cognition and emotion-regulatory language, whereas insecurely attached and disorganized children either completely lacked internal state language or displayed a considerable time lag in the use of emotion and cognition vocabulary. Conclusion: The results raise the possibility that alexithymia might be a consequence of deficits in the development of internal state language in the context of insecure or disorganized childhood attachment relationships.

Limbic and prefrontal responses to facial emotion expressions in depersonalization

Depersonalization disorder, characterized by emotional detachment, has been associated with increased prefrontal cortical and decreased autonomic activity to emotional stimuli. Event-related fMRI with simultaneous measurements of skin conductance levels occurred in nine depersonalization disorder patients and 12 normal controls to neutral, mild and intense happy and sad facial expressions. Patients, but not controls, showed decreases in subcortical limbic activity to increasingly intense happy and sad facial expressions, respectively. For both happy and sad expressions, negative correlations between skin conductance measures in bilateral dorsal prefrontal cortices occurred only in depersonalization disorder patients. Abnormal decreases in limbic activity to increasingly intense emotional expressions, and increases in dorsal prefrontal cortical activity to emotionally arousing stimuli may underlie the emotional detachment of depersonalization disorder.

Cerebral and autonomic responses to emotional facial expressions in depersonalisation disorder

BACKGROUND Depersonalisation disorder is characterised by emotion suppression, but the cerebral mechanisms of this symptom are not yet fully understood. AIMS To compare brain activation and autonomic responses of individuals with the disorder and healthy controls. METHOD Happy and sad emotion expressions in increasing intensities (neutral to intense) were presented in an implicit event-related functional magnetic resonance imaging (fMRI) design with simultaneous measurement of autonomic responses. RESULTS Participants with depersonalisation disorder showed fMRI signal decreases, whereas the control group showed signal increases in response to emotion intensity increases in both happy and sad expressions. The analysis of evoked haemodynamic responses from regions exhibiting functional connectivity between central and autonomic nervous systems indicated that in depersonalisation disorder initial modulations of haemodynamic response occurred significantly earlier (2 s post-stimulus) than in the control group (4-6 s post-stimulus). CONCLUSIONS The results suggest that fMRI signal decreases are possible correlates of emotion suppression in depersonalisation disorder.

Somatization Severity Associated with Postero-Medial Complex Structures

Somatisation is a frequent problem in various psychiatric disorders, yet the cerebral mechanisms of somatisation remain unexamined. To test if somatisation is susceptible to emotional states, we investigated relationships between somatisation severity, neural effective connectivity, and autonomic responses to emotional facial expressions. Volunteering participants (N = 20) were presented with facial expressions of happy and sad emotion at three intensity levels (0%–50%–100%) in a fast implicit ER-fMRI design with concurrent derivation of skin conductance levels (SCL). Self-reported somatisation severity as assessed with Riefs SOMS-2 index was correlated with neural response controlling for other clinical traits to ascertain brain bases of somatisation. Regression analyses estimated effective connectivity of main clusters so determined with peripheral autonomic responses. Regions in which magnitude of activity correlated with somatisation severity consisted in both happy and sad conditions of the anterior ventral precuneus (BA7), along with posterior cingulate gyrus (PCC, BA23, sad condition) and anteromedial thalamus (happy condition).

Interoceptive-reflective regions differentiate alexithymia traits in depersonalization disorder

It is unclear to what degree depersonalization disorder (DPD) and alexithymia share abnormal brain mechanisms of emotional dysregulation. We compared cerebral processing of facial expressions of emotion in individuals with DPD to normal controls (NC). We presented happy and sad emotion expressions in increasing intensities from neutral (0%) through mild (50%) to intense (100%) to DPD and non-referred NC subjects in an implicit event-related fMRI design, and correlated respective brain activations with responses on the 20-item Toronto Alexithymia Scale (TAS-20) and its three subscales F1-F3. The TAS-20 predicts clinical diagnosis of DPD with a unique variance proportion of 38%. Differential regression analysis was utilized to ascertain brain regions for each alexithymia subscale. Differential regions of total alexithymia severity for happy emotion were the globus pallidus externus; for identifying feelings (TAS-20 F1 subscale), the right anterior insula; for description of feelings (F2), the right dorsal mid-anterior cingulate gyrus (BA 24); and for externally oriented cognitive style (F3), the left paracingulate gyrus (BA 32). For sad emotion, the differential region for the total TAS-20 score was the dorsal anterior cingulate gyrus (BA 24); for TAS-20 F1, the left inferior anterior insula; for TAS-20 F2, the right PCC (BA 31); and for TAS-20 F3, the right orbital gyrus (BA 10). Supporting our hypotheses, the ascertained brain regions for TAS-20 subscales subserve interoception, monitoring and reflection of internal states and emotion. The presented analyses provide evidence that alexithymia plays a substantial role in emotional dysregulation in DPD, presumably based on restrictions in interoception.

Attachment organization and the early development of internal state language : A longitudinal perspective

There are many postulates of a relation between quality of attachment with theory of mind and language functions (e.g., de Rosnay & Hughes, 2006). The current study examined in longitudinal design how different patterns of attachment are associated with usage of internal state language at ages 17, 23, 30 and 36 months. Transcripts of mother—child play situations were coded for eleven categories of internal state language: positive emotion, negative emotion, valence reversal, physiology, ability, volition, obligation, moral, cognition, emotion-modulatory particles and cognitive-contrast particles. Repeated-measures ANOVAs revealed that securely attached children exhibit more frequent utterances of positive emotion, valence reversal, physiology, ability, cognition, emotion-modulatory, and cognitive-contrast particles at relatively earlier times. Negative emotion terms were more frequently uttered by avoidant-insecure children at 30 months and by disorganized children at 36 months.

Dissociable brain correlates for depression, anxiety, dissociation, and somatization in depersonalization-derealization disorder

OBJECTIVE The cerebral mechanisms of traits associated with depersonalization-derealization disorder (DPRD) remain poorly understood. METHOD Happy and sad emotion expressions were presented to DPRD and non-referred control (NC) subjects in an implicit event-related functional magnetic resonance imaging (fMRI) design, and correlated with self report scales reflecting typical co-morbidities of DPRD: depression, dissociation, anxiety, somatization. RESULTS Significant differences between the slopes of the two groups were observed for somatization in the right temporal operculum (happy) and ventral striatum, bilaterally (sad). Discriminative regions for symptoms of depression were the right pulvinar (happy) and left amygdala (sad). For dissociation, discriminative regions were the left mesial inferior temporal gyrus (happy) and left supramarginal gyrus (sad). For state anxiety, discriminative regions were the left inferior frontal gyrus (happy) and parahippocampal gyrus (sad). For trait anxiety, discriminative regions were the right caudate head (happy) and left superior temporal gyrus (sad). Discussion The ascertained brain regions are in line with previous findings for the respective traits. The findings suggest separate brain systems for each trait. CONCLUSION Our results do not justify any bias for a certain nosological category in DPRD.

Alexithymia as a risk factor for type 2 diabetes mellitus in the metabolic syndrome: a cross-sectional study

Alexithymia is a clinical trait consisting of diminished introspective and interoceptive capacities that has been shown to implicate elevated autonomic outflow and to bias for hypertension. To estimate relative risk associated with alexithymia in the metabolic syndrome (MetS), we conducted a cross-sectional analysis of patients with manifest type 2 diabetes mellitus (T2DM) or familial diabetes risk (N=101; 67 females; age 45.6±13.96) in a nationwide sampled treatment cohort for MetS in the Ukrainian governmental health care system. Laboratory data of single components of the MetS according to International Diabetes Federation Consensus were dependent measures in multivariable regression models with self-reported alexithymia severity (TAS-20) and socio-demographic data. TAS-20 as the sole surviving psychometric predictor for T2DM in the simplest regression equation provided the best model fit: OR 1.073, Z=19.04, (95%CIs 1.065-1.081). For microalbuminuria, the best fitting model was OR 1.030, Z=3.49 (95%CIs 1.013-1.048). TAS-20 predicted also triglyceride level at Wald-χ(2)=1299.27, Z=36.05 (95%CIs 0.052-0.058) and blood pressure maximum at Wald-χ(2)=2309.05, Z=48.05 (95%CIs 2.402-2.606). Our results show that alexithymia severity contributes to MetS by covarying with several of its single components, and that it may be a substantial concurrent indicator of T2DM and cardiovascular risks in MetS.

Neuroendorine and Epigentic Mechanisms Subserving Autonomic Imbalance and HPA Dysfunction in the Metabolic Syndrome

Impact of environmental stress upon pathophysiology of the metabolic syndrome (MetS) has been substantiated by epidemiological, psychophysiological, and endocrinological studies. This review discusses recent advances in the understanding of causative roles of nutritional factors, sympathomedullo-adrenal (SMA) and hypothalamic-pituitary adrenocortical (HPA) axes, and adipose tissue chronic low-grade inflammation processes in MetS. Disturbances in the neuroendocrine systems for leptin, melanocortin, and neuropeptide Y (NPY)/agouti-related protein systems have been found resulting directly in MetS-like conditions. The review identifies candidate risk genes from factors shown critical for the functioning of each of these neuroendocrine signaling cascades. In its meta-analytic part, recent studies in epigenetic modification (histone methylation, acetylation, phosphorylation, ubiquitination) and posttranscriptional gene regulation by microRNAs are evaluated. Several studies suggest modification mechanisms of early life stress (ELS) and diet-induced obesity (DIO) programming in the hypothalamic regions with populations of POMC-expressing neurons. Epigenetic modifications were found in cortisol (here HSD11B1 expression), melanocortin, leptin, NPY, and adiponectin genes. With respect to adiposity genes, epigenetic modifications were documented for fat mass gene cluster APOA1/C3/A4/A5, and the lipolysis gene LIPE. With regard to inflammatory, immune and subcellular metabolism, PPARG, NKBF1, TNFA, TCF7C2, and those genes expressing cytochrome P450 family enzymes involved in steroidogenesis and in hepatic lipoproteins were documented for epigenetic modifications.