Neural network of cognitive emotion regulation--an ALE meta-analysis and MACM analysis

Dynamic Relational Group Psychotherapy: A Neurobiologically Informed Model of Change

In this article we introduce a preliminary, neurobiologically informed model of group therapy that links the timing and nature of specific group interventions with hypothesized changing neurobiological needs of the group. We suggest that the observed phases of group development reflect an underlying reorganization of neuronal circuitry that occurs as members progress through a hierarchically organized treatment, and that this reorganization involves the integration and homeostatic rebalancing of subcortical and neural networks. Our preliminary Dynamic Relational model suggests that an understanding of the neurobiological processes involved in group development may help inform and direct effective group-based psychotherapy interventions.

Executive and semantic processes in reappraisal of negative stimuli: insights from a meta-analysis of neuroimaging studies

Neuroimaging investigations have identified the neural correlates of reappraisal in executive areas. These findings have been interpreted as evidence for recruitment of controlled processes, at the expense of automatic processes when responding to emotional stimuli. However, activation of semantic areas has also been reported. The aim of the present work was to address the issue of the importance of semantic areas in emotion regulation by comparing recruitment of executive and semantic neural substrates in studies investigating different reappraisal strategies. With this aim, we reviewed neuroimaging studies on reappraisal and we classified them in two main categories: reappraisal of stimuli (RS) and reappraisal via perspective taking (RPT). We applied a coordinate-based meta-analysis to summarize the results of fMRI studies on different reappraisal strategies. Our results showed that reappraisal, when considered regardless of the specific instruction used in the studies, involved both executive and semantic areas of the brain. When considering different reappraisal strategies separately, in contrast, we found areas associated with executive function to be prominently recruited by RS, even if also semantic areas were activated. Instead, in RPT the most important clusters of brain activity were found in parietal and temporal semantic areas, without significant clusters in executive areas. These results indicate that modulation of activity in semantic areas may constitute an important aspect of emotion regulation in reappraisal, suggesting that semantic processes may be more important to understand the mechanism of emotion regulation than previously thought.

Neurocognitive evidence for mental imagery-driven hypoalgesic and hyperalgesic pain regulation

Mental imagery has the potential to influence perception by directly altering sensory, cognitive, and affective brain activity associated with imagined content. While it is well established that mental imagery can both exacerbate and alleviate acute and chronic pain, it is currently unknown how imagery mechanisms regulate pain perception. For example, studies to date have been unable to determine whether imagery effects depend upon a general redirection of attention away from pain or focused attentional mechanisms. To address these issues, we recorded subjective, behavioral and ERP responses using 64-channel EEG while healthy human participants applied a mental imagery strategy to decrease or increase pain sensations. When imagining a glove covering the forearm, participants reported decreased perceived intensity and unpleasantness, classified fewer high-intensity stimuli as painful, and showed a more conservative response bias. In contrast, when imagining a lesion on the forearm, participants reported increased pain intensity and unpleasantness, classified more low-intensity stimuli as painful, and displayed a more liberal response bias. Using a mass-univariate approach, we further showed differential modulation of the N2 potentials across conditions, with inhibition and facilitation respectively increasing and decreasing N2 amplitudes between 122 and 180 ms. Within this time window, source localization associated inhibiting vs. facilitating pain with neural activity in cortical regions involved in cognitive inhibitory control and in the retrieval of semantic information (i.e., right inferior frontal and temporal regions). In contrast, the main sources of neural activity associated with facilitating vs. inhibiting pain were identified in cortical regions typically implicated in salience processing and emotion regulation (i.e., left insular, inferior-middle frontal, supplementary motor and precentral regions). Overall, these findings suggest that the content of a mental image directly alters pain-related decision and evaluative processing to flexibly produce hypoalgesic and hyperalgesic outcomes.

Effects of childhood maltreatment on the neural correlates of stress- and drug cue-induced cocaine craving

Childhood adversity negatively influences all stages of the addiction process and is associated with persistent alterations in neuroendocrine, autonomic and brain responses to stress. We sought to characterize the impact of childhood abuse and neglect on the neural correlates of stress- and drug cue-induced drug craving associated with cocaine addiction. Cocaine-dependent men with (n = 20) and without (n = 18) moderate to severe childhood maltreatment histories underwent functional magnetic resonance imaging during script-guided mental imagery of personalized stress, drug use and neutral experiences. Compared to the neutral script, the stress and drug use scripts activated striatal, prefrontal, posterior cingulate, temporal and cerebellar regions consistent with prior studies of induced states of stress and drug craving. For the stress script, maltreated men exhibited reduced activation of the anterior precuneus and supplementary motor area (SMA); the interaction of maltreatment severity and stress-induced craving responses predicted lesser rostral anterior cingulate cortex activation. For the drug use script, maltreated men exhibited greater left dorsolateral prefrontal cortex activation. The interaction of maltreatment severity and craving responses was associated with greater activation of the visual cortex and SMA, whereas a maltreatment-by-anxiety interaction effect included lesser ventromedial prefrontal cortex activation. The outcomes indicate an association of childhood maltreatment with a heightened appetitive anticipatory response to drug cues and a diminished engagement of regulatory and controlled action selection processes in response to stress- or drug cue-induced drug craving and anxiety responses for cocaine-dependent men. These findings provide novel insights into possible brain mechanisms by which childhood maltreatment heightens risk for relapse in drug-dependent individuals.

Neuroanatomical correlates of the sense of control: Gray and white matter volumes associated with an internal locus of control

A belief that effort is rewarded can develop incentive, achievement motivation, and self-efficacy. Individuals with such a belief attribute causes of events to themselves, not to external, uncontrollable factors, and are thus said to have an internal locus of control. An internal locus of control is a positive personality trait and has been thoroughly studied in applied psychology, but has not been widely examined in neuroscience. In the present study, correlations between locus of control assessment scores and brain volumes were examined in 777 healthy young adults using magnetic resonance imaging. A whole-brain multiple regression analysis with corrections for the effects of age, gender, and intelligence was conducted. Voxel-based morphometry analyses revealed that gray matter volumes in the anterior cingulate cortex, striatum, and anterior insula positively correlated with higher scores, which indicate an internal LOC. In addition, white matter volumes in the striatum showed significant correlations with an internal locus of control. These results suggest that cognitive, socioemotional, self-regulatory, and reward systems might be associated with internal control orientation. The finding of greater volumes in several brain regions in individuals with a stronger internal locus of control indicates that there is a neuroanatomical basis for the belief that one's efforts are rewarded.

Emotional dysfunctions in neurodegenerative diseases

Neurodegenerative diseases are characterized primarily by motor signs but are also accompanied by emotional disturbances. Because of the limited knowledge about these dysfunctions, this Review provides an overview of emotional competencies in Huntington's disease (HD), Parkinson's disease (PD), and multiple sclerosis (MS), with a focus on emotion recognition, emotion regulation, and depression. Most studies indicate facial emotion recognition deficits in HD and PD, whereas data for MS are inconsistent. On a neural level, dysfunctions of amygdala and striatum, among others, have been linked to these impairments. These dysfunctions also tap brain regions that are part of the emotion regulation network, suggesting problems in this competency, too. Research points to dysfunctional emotion regulation in MS, whereas findings for PD and HD are missing. The high prevalence of depression in all three disorders emphasizes the need for effective therapies. Research on emotional disturbances might improve treatment, thereby increasing patients' and caregivers' well-being.

Neural mechanisms associated with reappraisal and attentional deployment

Attentional deployment is an emotion regulation strategy that involves shifting attentional focus within an emotional scene in order to modulate emotional experience. Attentional deployment is widely used and effective at reducing negative affect, yet the supporting neural mechanisms are poorly understood. The rich literature on the neural correlates of reappraisal may help inform our understanding of attentional deployment, as reappraisal recruits common control regions associated with emotion regulation and may tap into specific mechanisms associated with directing attention. We highlight commonalities between reappraisal and attentional deployment and then focus on potentially unique aspects of attentional deployment, including the importance of parietal regions and implications for understanding the normative development of emotion regulation, as well as both well-being and psychopathology.

Emotion regulation in bipolar disorder type I: an fMRI study

BACKGROUND

Bipolar disorder type I (BD-I) is associated with emotion dysregulation. However, experimentally controlled studies of emotion regulation (ER), particularly those examining the brain correlates of the putative deficits, are scarce and their results inconsistent.

METHOD

Nineteen euthymic BD-I patients and 17 healthy controls (HC) underwent functional magnetic resonance imaging while performing a visual ER 2 × 2 factorial task, with instruction (Look or Decrease) and valence (Negative or Neutral) as within-subject factors. Emotional ratings were collected after each picture presentation to assess regulation success.

RESULTS

BD-I patients were successful at downregulating their emotions, although to a lesser degree than HC. Both groups engaged brain regions previously implicated in ER; however, unlike HC, patients engaged some of those regions, particularly the ventrolateral prefrontal cortex (VLPFC) in the Negative Look and Neutral Decrease conditions. Moreover, patients failed to show the reduced amygdala activation in the Negative Decrease condition observed in HC.

CONCLUSION

Our findings suggest that BD-I patients are able to downregulate their emotions when instructed to do so. However, they also appear to engage their ER network, particularly the VLPFC, even when not required to do so. These findings may help explain their often-reported difficulty in regulating emotions in everyday life despite their attempts to do so.

Broca's area network in language function: a pooling-data connectivity study

Background and Objective: Modern neuroimaging developments have demonstrated that cognitive functions correlate with brain networks rather than specific areas. The purpose of this paper was to analyze the connectivity of Broca’s area based on language tasks.

Methods: A connectivity modeling study was performed by pooling data of Broca’s activation in language tasks. Fifty-seven papers that included 883 subjects in 84 experiments were analyzed. Analysis of Likelihood Estimates of pooled data was utilized to generate the map; thresholds at p < 0.01 were corrected for multiple comparisons and false discovery rate. Resulting images were co-registered into MNI standard space.

Results: A network consisting of 16 clusters of activation was obtained. Main clusters were located in the frontal operculum, left posterior temporal region, supplementary motor area, and the parietal lobe. Less common clusters were seen in the sub-cortical structures including the left thalamus, left putamen, secondary visual areas, and the right cerebellum.

Conclusion: Broca’s area-44-related networks involved in language processing were demonstrated utilizing a pooling-data connectivity study. Significance, interpretation, and limitations of the results are discussed.

An fMRI Pilot Study of Cognitive Reappraisal in Children: Divergent Effects on Brain and Behavior

Although neuroimaging studies in adults demonstrate that cognitive reappraisal effectively down-regulates negative affect and results in increased prefrontal and decreased amygdala activity, very limited empirical data exist on the neural basis of cognitive reappraisal in children. This study aimed to pilot test a developmentally-appropriate guided cognitive reappraisal task in order to examine the effects of cognitive reappraisal on children's self-reports of affect and brain responses. Study 1 (N =19, 4-10 years-old) found that children successfully employed guided cognitive reappraisal to decrease subjective ratings of negative affect, supporting the effectiveness of the guided cognitive reappraisal task. Study 2 (N =15, ages 6-10 years-old) investigated the neural responses to guided cognitive reappraisal and found that the neural responses showed increased activation in the amygdala and ventromedial prefrontal cortex during the cognitive reappraisal condition compared to the no regulation condition. In addition, amygdala activity was positively correlated with ventromedial prefrontal cortex activation during cognitive reappraisal. Findings suggest that the neural networks supporting cognitive reappraisal in children involve similar brain regions but brain responses deviate from findings in adults. Our findings suggest that the neural networks supporting emotion regulation are still developing during middle childhood, and future research is necessary to delineate age-related development of the neural network involved in cognitive reappraisal.

Childhood poverty and recruitment of adult emotion regulatory neurocircuitry

One in five American children grows up in poverty. Childhood poverty has far-reaching adverse impacts on cognitive, social and emotional development. Altered development of neurocircuits, subserving emotion regulation, is one possible pathway for childhood poverty's ill effects. Children exposed to poverty were followed into young adulthood and then studied using functional brain imaging with an implicit emotion regulation task focused. Implicit emotion regulation involved attention shifting and appraisal components. Early poverty reduced left dorsolateral prefrontal cortex recruitment in the context of emotional regulation. Furthermore, this emotion regulation associated brain activation mediated the effects of poverty on adult task performance. Moreover, childhood poverty also predicted enhanced insula and reduced hippocampal activation, following exposure to acute stress. These results demonstrate that childhood poverty can alter adult emotion regulation neurocircuitry, revealing specific brain mechanisms that may underlie long-term effects of social inequalities on health. The role of poverty-related emotion regulatory neurocircuitry appears to be particularly salient during stressful conditions.

In a sweet mood? Effects of experimental modulation of blood glucose levels on mood-induction during fMRI

Glucose is the primary source of energy for the human brain. Previous literature has shown that varying blood glucose levels may have a strong impact on behaviour, subjective mood, and the intensity of the BOLD signal measured in fMRI. Therefore, blood glucose levels varying even within the normal range may interact with cognitive and emotional processing as well as BOLD signal. Here, in a placebo-controlled, double-blind crossover study on 20 healthy women, we show that overnight fasting, compared to an elevated glucose condition, influences brain activation and the affective state during mood induction. Results indicate that our brain may compensate for low glucose levels during fasting by stronger recruitment of the brain areas relevant to the task at hand. Additionally, we systematically tested the effect of prior cognitive effort on behavioural and neural patterns and found that elevated activation is only associated with maintained performance as long as no prior cognitively challenging task is administered. Prior cognitive effort leads to deteriorated performance and a further increase in emotion-associated brain activation in the pregenual anterior and posterior cingulate, the superior frontal gyrus, and the pre-SMA. These results are in line with the strength model of self-regulation. Our results corroborate the strength model of self-regulation and extend it to affect regulation processes. Additionally, our observations suggest that experimentally controlling for fasting state or glucose levels may be beneficial, especially when studying processes that involve self-regulation.

Recent Advances in Laboratory Assessment of Emotion Regulation

Over the past 15 years, the emotion regulation perspective has been widely integrated into theoretical and applied contexts in clinical psychology and beyond. Recent refinements to behavioral, subjective, psychophysiological and neuroimaging methods allow emotion regulation to be captured and assessed in the laboratory with greater precision. Technological advances enabling investigators to leverage information from multiple modalities are increasingly accessible, and as such, will further efforts to generate testable hypotheses about specific mechanisms implicated in emotion regulation and difficulties therein. In combination with theory-driven design, progressively sophisticated methods for laboratory assessment have potential to further emotion regulation as both a valid scientific construct and a useful paradigm for human emotion and behavior that has applicability to both clinical and non-clinical contexts.

Changes in brain activation following psychotherapy for youth with mood dysregulation at familial risk for bipolar disorder

BACKGROUND

Psychotherapy for youth with mood dysregulation can help stabilize mood and improve functioning, but the neural mechanisms of this improvement are not known. In this study we investigated the changes in brain activation underlying improvement in mood symptoms.

METHODS

Twenty-four subjects (ages 13-17) participated: 12 patients with clinically significant symptoms of depression and/or mania, and 12 healthy comparison subjects (HC) matched for age and sex. All subjects completed functional magnetic resonance imaging while viewing facial expressions. The patients then received up to 4 months of psychotherapy and were rescanned at end of treatment. Whole brain differences between patient and control groups were assessed with a voxel-wise analysis. Changes in activation from pre- to post-treatment within the patient group were tested for correlation with changes in mood symptoms.

RESULTS

At baseline the patient group had hypoactivation in the dorsolateral prefrontal cortex (DLPFC) and hyperactivation in the posterior cingulate cortex compared to the HC group. Between pre- and post-treatment activation increased in the DLPFC and decreased in the amygdala. Increases in DLPFC activation were significantly correlated with improvement in mania symptoms.

DISCUSSION

Enhancement of frontal executive control brain regions may underlie improvement in mood dysregulation in pediatric patients at familial risk for bipolar disorder.

A Critical Review of Attentional Threat Bias and Its Role in the Treatment of Pediatric Anxiety Disorders

Threat bias, or exaggerated selective attention to threat, is considered a key neurocognitive factor in the etiology and maintenance of pediatric anxiety disorders. However, upon closer examination of the literature, there is greater heterogeneity in threat-related attentional biases than typically acknowledged. This is likely impacting progress that can be made in terms of interventions focused on modifying this bias and reducing anxiety, namely attention bias modification training. We suggest that the field may need to "take a step back" from developing interventions and focus research efforts on improving the methodology of studying attention bias itself, particularly in a developmental context. We summarize a neurocognitive model that addresses the issue of heterogeneity by broadly incorporating biases toward and away from threat, linking this variation to key neurodevelopmental factors, and providing a basis for future research aimed at improving the utility of threat bias measures and interventions in clinical practice.

An Affective Cognitive Neuroscience-Based Approach to PTSD Psychotherapy: The TARGET Model

Adaptations or alternative versions of cognitive psychotherapy for posttraumatic stress disorder (PTSD) are needed because even the most efficacious cognitive or cognitive-behavioral psychotherapies for PTSD do not retain or achieve sustained clinically significant benefits for a majority of recipients. Cognitive affective neuroscience research is reviewed which suggests that it is not just memory (or memories) of traumatic events and related core beliefs about self, the world, and relationships that are altered in PTSD but also memory (and affective information) processing A cognitive psychotherapy is described that was designed to systematically make explicit these otherwise implicit trauma-related alterations in cognitive emotion regulation and its application to the treatment of complex variants of PTSD-Trauma Affect Regulation: Guide for Education and Therapy (TARGET). TARGET provides therapists and clients with (a) a neurobiologically informed strengths-based meta-model of stress-related cognitive processing in the brain and how this is altered by PTSD and (b) a practical algorithm for restoring the executive functions that are necessary to make implicit trauma-related cognitions explicit (i.e., experiential awareness) and modifiable (i.e., planful refocusing). Results of randomized clinical trial studies and quasi-experimental effectiveness evaluations of TARGET with adolescents and adults are reviewed.

Grey matter alterations in patients with depersonalization disorder: a voxel-based morphometry study

BACKGROUND

To our knowledge, no whole brain investigation of morphological aberrations in dissociative disorder is available to date. Previous region-of-interest studies focused exclusively on amygdalar, hippocampal and parahippocampal grey matter volumes and did not include patients with depersonalization disorder (DPD). We therefore carried out an explorative whole brain study on structural brain aberrations in patients with DPD.

METHODS

We acquired whole brain, structural MRI data for patients with DPD and healthy controls. Voxel-based morphometry was carried out to test for group differences, and correlations with symptom severity scores were computed for grey matter volume.

RESULTS

Our study included 25 patients with DPD and 23 controls. Patients exhibited volume reductions in the right caudate, right thalamus and right cuneus as well as volume increases in the left dorsomedial prefrontal cortex and right somatosensory region that are not a direct function of anxiety or depression symptoms.

LIMITATIONS

To ensure ecological validity, we included patients with comorbid disorders and patients taking psychotropic medication.

CONCLUSION

The results of this first whole brain investigation of grey matter volume in patients with a dissociative disorder identified structural alterations in regions subserving the emergence of conscious perception. It remains unknown if these alterations are best understood as risk factors for or results of the disorder.

Assessing dynamic brain graphs of time-varying connectivity in fMRI data: application to healthy controls and patients with schizophrenia

Graph theory-based analysis has been widely employed in brain imaging studies, and altered topological properties of brain connectivity have emerged as important features of mental diseases such as schizophrenia. However, most previous studies have focused on graph metrics of stationary brain graphs, ignoring that brain connectivity exhibits fluctuations over time. Here we develop a new framework for accessing dynamic graph properties of time-varying functional brain connectivity in resting-state fMRI data and apply it to healthy controls (HCs) and patients with schizophrenia (SZs). Specifically, nodes of brain graphs are defined by intrinsic connectivity networks (ICNs) identified by group independent component analysis (ICA). Dynamic graph metrics of the time-varying brain connectivity estimated by the correlation of sliding time-windowed ICA time courses of ICNs are calculated. First- and second-level connectivity states are detected based on the correlation of nodal connectivity strength between time-varying brain graphs. Our results indicate that SZs show decreased variance in the dynamic graph metrics. Consistent with prior stationary functional brain connectivity works, graph measures of identified first-level connectivity states show lower values in SZs. In addition, more first-level connectivity states are disassociated with the second-level connectivity state which resembles the stationary connectivity pattern computed by the entire scan. Collectively, the findings provide new evidence about altered dynamic brain graphs in schizophrenia, which may underscore the abnormal brain performance in this mental illness.

Evidence-informed person-centered healthcare part I: do 'cognitive biases plus' at organizational levels influence quality of evidence?

INTRODUCTION

There is increasing concern about the unreliability of much of health care evidence, especially in its application to individuals.

HYPOTHESIS

Cognitive biases, financial and non-financial conflicts of interest, and ethical violations (which, together with fallacies, we collectively refer to as 'cognitive biases plus') at the levels of individuals and organizations involved in health care undermine the evidence that informs person-centred care.

METHODS

This study used qualitative review of the pertinent literature from basic, medical and social sciences, ethics, philosophy, law etc.

RESULTS

Financial conflicts of interest (primarily industry related) have become systemic in several organizations that influence health care evidence. There is also plausible evidence for non-financial conflicts of interest, especially in academic organizations. Financial and non-financial conflicts of interest frequently result in self-serving bias. Self-serving bias can lead to self-deception and rationalization of actions that entrench self-serving behaviour, both potentially resulting in unethical acts. Individuals and organizations are also susceptible to other cognitive biases. Qualitative evidence suggests that 'cognitive biases plus' can erode the quality of evidence.

CONCLUSIONS

'Cognitive biases plus' are hard wired, primarily at the unconscious level, and the resulting behaviours are not easily corrected. Social behavioural researchers advocate multi-pronged measures in similar situations: (i) abolish incentives that spawn self-serving bias; (ii) enforce severe deterrents for breaches of conduct; (iii) value integrity; (iv) strengthen self-awareness; and (v) design curricula especially at the trainee level to promote awareness of consequences to society. Virtuous professionals and organizations are essential to fulfil the vision for high-quality individualized health care globally.

Sex differences in cognitive regulation of psychosocial achievement stress: brain and behavior

Although cognitive regulation of emotion has been extensively examined, there is a lack of studies assessing cognitive regulation in stressful achievement situations. This study used functional magnetic resonance imaging in 23 females and 20 males to investigate cognitive downregulation of negative, stressful sensations during a frequently used psychosocial stress task. Additionally, subjective responses, cognitive regulation strategies, salivary cortisol, and skin conductance response were assessed. Subjective response supported the experimental manipulation by showing higher anger and negative affect ratings after stress regulation than after the mere exposure to stress. On a neural level, right middle frontal gyrus (MFG) and right superior temporal gyrus (STG) were more strongly activated during regulation than nonregulation, whereas the hippocampus was less activated during regulation. Sex differences were evident: after regulation females expressed higher subjective stress ratings than males, and these ratings were associated with right hippocampal activation. In the nonregulation block, females showed greater activation of the left amygdala and the right STG during stress than males while males recruited the putamen more robustly in this condition. Thus, cognitive regulation of stressful achievement situations seems to induce additional stress, to recruit regions implicated in attention integration and working memory and to deactivate memory retrieval. Stress itself is associated with greater activation of limbic as well as attention areas in females than males. Additionally, activation of the memory system during cognitive regulation of stress is associated with greater perceived stress in females. Sex differences in cognitive regulation strategies merit further investigation that can guide sex sensitive interventions for stress-associated disorders.

Altered resting-state amygdala functional connectivity after 36 hours of total sleep deprivation

Objectives

Recent neuroimaging studies have identified a potentially critical role of the amygdala in disrupted emotion neurocircuitry in individuals after total sleep deprivation (TSD). However, connectivity between the amygdala and cerebral cortex due to TSD remains to be elucidated. In this study, we used resting-state functional MRI (fMRI) to investigate the functional connectivity changes of the basolateral amygdala (BLA) and centromedial amygdala (CMA) in the brain after 36 h of TSD.

Materials and Methods

Fourteen healthy adult men aged 25.9±2.3 years (range, 18–28 years) were enrolled in a within-subject crossover study. Using the BLA and CMA as separate seed regions, we examined resting-state functional connectivity with fMRI during rested wakefulness (RW) and after 36 h of TSD.

Results

TSD resulted in a significant decrease in the functional connectivity between the BLA and several executive control regions (left dorsolateral prefrontal cortex [DLPFC], right dorsal anterior cingulate cortex [ACC], right inferior frontal gyrus [IFG]). Increased functional connectivity was found between the BLA and areas including the left posterior cingulate cortex/precuneus (PCC/PrCu) and right parahippocampal gyrus. With regard to CMA, increased functional connectivity was observed with the rostral anterior cingulate cortex (rACC) and right precentral gyrus.

Conclusion

These findings demonstrate that disturbance in amygdala related circuits may contribute to TSD psychophysiology and suggest that functional connectivity studies of the amygdala during the resting state may be used to discern aberrant patterns of coupling within these circuits after TSD.

Repeated administration of a synthetic cannabinoid receptor agonist differentially affects cortical and accumbal neuronal morphology in adolescent and adult rats

Recent studies demonstrate a differential trajectory for cannabinoid receptor expression in cortical and sub-cortical brain areas across postnatal development. In the present study, we sought to investigate whether chronic systemic exposure to a synthetic cannabinoid receptor agonist causes morphological changes in the structure of dendrites and dendritic spines in adolescent and adult pyramidal neurons in the medial prefrontal cortex (mPFC) and medium spiny neurons (MSN) in the nucleus accumbens (Acb). Following systemic administration of WIN 55,212-2 in adolescent (PN 37-40) and adult (P55-60) male rats, the neuronal architecture of pyramidal neurons and MSN was assessed using Golgi-Cox staining. While no structural changes were observed in WIN 55,212-2-treated adolescent subjects compared to control, exposure to WIN 55,212-2 significantly increased dendritic length, spine density and the number of dendritic branches in pyramidal neurons in the mPFC of adult subjects when compared to control and adolescent subjects. In the Acb, WIN 55,212-2 exposure significantly decreased dendritic length and number of branches in adult rat subjects while no changes were observed in the adolescent groups. In contrast, spine density was significantly decreased in both the adult and adolescent groups in the Acb. To determine whether regional developmental morphological changes translated into behavioral differences, WIN 55,212-2-induced aversion was evaluated in both groups using a conditioned place preference paradigm. In adult rats, WIN 55,212-2 administration readily induced conditioned place aversion as previously described. In contrast, adolescent rats did not exhibit aversion following WIN 55,212-2 exposure in the behavioral paradigm. The present results show that synthetic cannabinoid administration differentially impacts cortical and sub-cortical neuronal morphology in adult compared to adolescent subjects. Such differences may underlie the disparate development effects of cannabinoids on behavior.

Reconceptualizing major depressive disorder as an infectious disease

In this article, I argue for a reconceptualization of major depressive disorder (major depression) as an infectious disease. I suggest that major depression may result from a parasitic, bacterial, or viral infection and present examples that illustrate possible pathways by which these microorganisms could contribute to the etiology of major depression. I also argue that the reconceptualization of the human body as an ecosystem for these microorganisms and the human genome as a host for non-human exogenous sequences may greatly amplify the opportunity to discover genetic links to the illness. Deliberately speculative, this article is intended to stimulate novel research approaches and expand the circle of researchers taking aim at this vexing illness.

Focal and aberrant prefrontal engagement during emotion regulation in veterans with posttraumatic stress disorder

BACKGROUND

Collectively, functional neuroimaging studies implicate frontal-limbic dysfunction in the pathophysiology of posttraumatic stress disorder (PTSD), as reflected by altered amygdala reactivity and deficient prefrontal responses. These neural patterns are often elicited by social signals of threat (fearful/angry faces) and traumatic reminders (combat sounds, script-driven imagery). Although PTSD can be conceptualized as a disorder of emotion dysregulation, few studies to date have directly investigated the neural correlates of volitional attempts at regulating negative affect in PTSD.

METHODS

Using functional magnetic resonance imaging and a well-validated task involving cognitive regulation of negative affect via reappraisal and known to engage prefrontal cortical regions, the authors compared brain activation in veterans with PTSD (n = 21) and without PTSD (n = 21, combat-exposed controls/CEC), following military combat trauma experience during deployments in Afghanistan or Iraq. The primary outcome measure was brain activation during cognitive reappraisal (i.e., decrease negative affect) as compared to passive viewing (i.e., maintain negative affect) of emotionally evocative content of aversive images

RESULTS

The subjects in both groups reported similar successful reduction in negative affect following reappraisal. The PTSD group engaged the dorsolateral prefrontal cortex (dlPFC) during cognitive reappraisal, albeit to a lesser extent than the CEC group. Although the amygdala was engaged in both groups during passive viewing of aversive images, neither group exhibited attenuation of amygdala activation during cognitive reappraisal.

CONCLUSIONS

Veterans with combat-related PTSD showed less recruitment of the dlPFC involved in cognitive reappraisal, suggesting focal and aberrant neural activation during volitional, self-regulation of negative affective states.

Lateral prefrontal cortex activity during cognitive control of emotion predicts response to social stress in schizophrenia

LPFC dysfunction is a well-established neural impairment in schizophrenia and is associated with worse symptoms. However, how LPFC activation influences symptoms is unclear. Previous findings in healthy individuals demonstrate that lateral prefrontal cortex (LPFC) activation during cognitive control of emotional information predicts mood and behavior in response to interpersonal conflict, thus impairments in these processes may contribute to symptom exacerbation in schizophrenia. We investigated whether schizophrenia participants show LPFC deficits during cognitive control of emotional information, and whether these LPFC deficits prospectively predict changes in mood and symptoms following real-world interpersonal conflict. During fMRI, 23 individuals with schizophrenia or schizoaffective disorder and 24 healthy controls completed the Multi-Source Interference Task superimposed on neutral and negative pictures. Afterwards, schizophrenia participants completed a 21-day online daily-diary in which they rated the extent to which they experienced mood and schizophrenia-spectrum symptoms, as well as the occurrence and response to interpersonal conflict. Schizophrenia participants had lower dorsal LPFC activity (BA9) during cognitive control of task-irrelevant negative emotional information. Within schizophrenia participants, DLPFC activity during cognitive control of emotional information predicted changes in positive and negative mood on days following highly distressing interpersonal conflicts. Results have implications for understanding the specific role of LPFC in response to social stress in schizophrenia, and suggest that treatments targeting LPFC-mediated cognitive control of emotion could promote adaptive response to social stress in schizophrenia.

Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., “bark,” “bank”). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretation of an ambiguous word. Here we used fMRI to investigate this hypothesis. 20 native British English monolinguals were scanned whilst listening to sentences that contained an ambiguous word. To induce semantic reinterpretation, the disambiguating information was presented after the ambiguous word and delayed until the end of the sentence (e.g., “the teacher explained that the BARK was going to be very damp”). These sentences were compared to well-matched unambiguous sentences. Supporting the reinterpretation hypothesis, these ambiguous sentences produced more activation in both the LIFG and the left posterior inferior temporal cortex. Importantly, all but one subject showed ambiguity-related peaks within both regions, demonstrating that the group-level results were driven by high inter-subject consistency. Further support came from the finding that activation in both regions was modulated by meaning dominance. Specifically, sentences containing biased ambiguous words, which have one more dominant meaning, produced greater activation than those with balanced ambiguous words, which have two equally frequent meanings. Because the context always supported the less frequent meaning, the biased words require reinterpretation more often than balanced words. This is the first evidence of dominance effects in the spoken modality and provides strong support that frontal and temporal regions support the updating of semantic representations during speech comprehension.

Disrupting SMA activity modulates explicit and implicit emotional responses: an rTMS study

Supplementary Motor Area (SMA) has been considered as an interface between the emotional/motivational system and motor effector system. Here, we investigated whether it is possible to modulate emotional responses using non-invasive brain stimulation of the SMA. 1Hz repetitive transcranial magnetic stimulation (rTMS) trains were applied over the SMA of healthy subjects performing a task requiring to judge the valence and arousal of emotional stimuli. rTMS trains over the SMA increased the perceived valence of emotionally negative visual stimuli, while decreasing the perceived valence of emotionally positive ones. The modulatory effect on emotional valence was specific for stimuli with emotional content, since it was not observed for neutral visual stimuli. The effect was also specific for the site of stimulation, since rTMS of the visual cortex failed to modulate either perceived valence or arousal. These findings provide the first example of neuromodulation of emotional responses based on non-invasive brain stimulation.

Regional gray matter density associated with emotional conflict resolution: evidence from voxel-based morphometry

Successful emotion regulation is a fundamental prerequisite for well-being and dysregulation may lead to psychopathology. The ability to inhibit spontaneous emotions while behaving in accordance with desired goals is an important dimension of emotion regulation and can be measured using emotional conflict resolution tasks. Few studies have investigated the gray matter correlates underlying successful emotional conflict resolution at the whole-brain level. We had 190 adults complete an emotional conflict resolution task (face-word task) and examined the brain regions significantly correlated with successful emotional conflict resolution using voxel-based morphometry. We found successful emotional conflict resolution was associated with increased regional gray matter density in widely distributed brain regions. These regions included the dorsal anterior cingulate/dorsal medial prefrontal cortex, ventral medial prefrontal cortex, supplementary motor area, amygdala, ventral striatum, precuneus, posterior cingulate cortex, inferior parietal lobule, superior temporal gyrus and fusiform face area. Together, our results indicate that individual differences in emotional conflict resolution ability may be attributed to regional structural differences across widely distributed brain regions.

The neural correlates of regulating another person's emotions: an exploratory fMRI study

Studies investigating the neurophysiological basis of intrapersonal emotion regulation (control of one's own emotional experience) report that the frontal cortex exerts a modulatory effect on limbic structures such as the amygdala and insula. However, no imaging study to date has examined the neurophysiological processes involved in interpersonal emotion regulation, where the goal is explicitly to regulate another person's emotion. Twenty healthy participants (10 males) underwent fMRI while regulating their own or another person's emotions. Intrapersonal and interpersonal emotion regulation tasks recruited an overlapping network of brain regions including bilateral lateral frontal cortex, pre-supplementary motor area, and left temporo-parietal junction. Activations unique to the interpersonal condition suggest that both affective (emotional simulation) and cognitive (mentalizing) aspects of empathy may be involved in the process of interpersonal emotion regulation. These findings provide an initial insight into the neural correlates of regulating another person's emotions and may be relevant to understanding mental health issues that involve problems with social interaction.