Default mode network connectivity of fear- and anxiety-related cue and context conditioning.

Classical fear conditioning is an important mechanism to adequately respond and adapt to environmental threats and has been related to the development of fear and anxiety. Both cue and context conditioning have been studied but little is known about their relation to relevant resting state networks. The default mode network (DMN) has been reported to be involved in affective learning and described as facilitating a state of readiness in responding to environmental changes. We examined resting state brain connectivity patterns of the default mode network (DMN) in 119 healthy volunteers. Specifically, we carried out correlation analyses between the DMN and skin conductance responses (SCRs) as well as arousal, valence and contingency ratings during learning. In addition, we examined the role of trait anxiety. Two different DMN patterns were identified in which stronger connectivity was linked to lower differential SCRs during fear and anxiety learning. One was related to cue conditioning and involved the amygdala and the medial prefrontal cortex, and one was associated with context conditioning and included the hippocampal formation and sensorimotor areas. These results were replicated in an independent sample. Functional connectivity of the DMN with these key regions at rest was also predictive of trait anxiety but this association could not be replicated in the second sample. We showed that DMN connectivity is differently associated with cued versus contextual learning mechanisms. Uncovering individual differences in baseline network connectivity of the DMN with these key regions might lead to a better understanding of fear and anxiety. Such findings could indeed help to identify vulnerability factors linked to network alterations at rest with dysregulation of learning processes involved in the pathophysiology of stress and anxiety disorders.

Different roads to the same destination - The impact of impulsivity on decision-making processes under risk within a rewarding context in a healthy male sample.

The results of research about the influences of impulsivity on decision-making in situations of risk have been inconsistent. In this study, we used functional magnetic resonance imaging to examine the neural correlates of decision-making under risk in 12 impulsive, as defined by the Barratt Impulsiveness Scale-11, and 13 normal men. Although both groups showed similar decision-making behavior, neural activation regarding decision-making processes differed significantly. Impulsive persons revealed stronger activation in the (ventro-) medial prefrontal cortex and less deactivation of the orbitofrontal cortex while playing for potential gains. These brain regions might be associated with the emotional components of decision-making processes. Significant differences in brain areas linked to cognitive decision-making components were not found. This activation pattern might be seen as an indication for a hypersensitivity to rewarding cues in impulsive persons and might be linked to the propensity for inappropriate risk-taking behavior in persons with more extreme impulsivity levels, especially in situations in which they have a strong emotional involvement in the decision process.

On the relationship between negative affective priming and prefrontal cognitive control mechanisms.

Although several studies have examined inhibition of affective stimuli, valence-dependent cognitive control effects remain poorly understood. Behavioural and functional imaging (functional magnetic resonance imaging) data were collected from 17 healthy participants to examine neural correlates of the Negative Affective Priming (NAP) task. We created relative ratio scores considering the reaction times of prime trials in order to assess the amount of interference after the presentation of negative and positive distracter words. Behavioural results showed an attenuated NAP effect for negative distracters compared to neutral stimuli. Furthermore, priming negative distracters generated more interference by reacting to the probe target than positive distracters. Neuroimaging data revealed a stronger prefrontal activation during negative NAP trials compared to positive NAP and neutral control trials, which was reflected in a heightened activation of superior and middle frontal gyrus as well as parietal cortex. The findings show the impact of negative distracters on prefrontal response, contributing to the understanding of NAP effects in healthy subjects.

Brain morphology correlates of interindividual differences in conditioned fear acquisition and extinction learning.

The neural circuits underlying fear learning have been intensively investigated in pavlovian fear conditioning paradigms across species. These studies established a predominant role for the amygdala in fear acquisition, while the ventromedial prefrontal cortex (vmPFC) has been shown to be important in the extinction of conditioned fear. However, studies on morphological correlates of fear learning could not consistently confirm an association with these structures. The objective of the present study was to investigate if interindividual differences in morphology of the amygdala and the vmPFC are related to differences in fear acquisition and extinction learning in humans. We performed structural magnetic resonance imaging in 68 healthy participants who underwent a differential cued fear conditioning paradigm. Volumes of subcortical structures as well as cortical thickness were computed by the semi-automated segmentation software Freesurfer. Stronger acquisition of fear as indexed by skin conductance responses was associated with larger right amygdala volume, while the degree of extinction learning was positively correlated with cortical thickness of the right vmPFC. Both findings could be conceptually replicated in an independent sample of 53 subjects. The data complement our understanding of the role of human brain morphology in the mechanisms of the acquisition and extinction of conditioned fear.

Examining cognitive emotion regulation in frontal lobe patients: The mediating role of response inhibition.

BACKGROUND: Previous investigations have demonstrated the relationship between inhibitory deficits and maladaptive emotion regulation. Although several neuropsychological studies show that frontal lobe damage can lead to extreme inhibition impairments, there have been no investigations regarding the influence of frontal lobe damage and related inhibition impairments on the use of maladaptive strategies. OBJECTIVE: The goal of the current study was to examine the impact of executive functions impairments due to frontal lobe damage on cognitive emotion regulation. METHODS: Fifteen patients with frontal lobe damage were compared to twenty-two healthy controls on their reported use of maladaptive strategies. The effect of behavioral inhibition deficits among the frontal lobe damage group was examined. RESULTS: Patients reflected a heightened use of maladaptive strategies compared to healthy controls, significantly mediated by Go/NoGo task errors, which are an indicator for response inhibition deficits. CONCLUSIONS: Results suggest that a heightened use of maladaptive strategies by patients relies to a strong extent on their impaired impulse control, highlighting the complex interplay between executive functions and emotional regulation.

Hypersensitivity in borderline personality disorder during mindreading.

BACKGROUND: One of the core symptoms of borderline personality disorder (BPD) is the instability in interpersonal relationships. This might be related to existent differences in mindreading between BPD patients and healthy individuals. METHODS: We examined the behavioural and neurophysiological (fMRI) responses of BPD patients and healthy controls (HC) during performance of the 'Reading the Mind in the Eyes' test (RMET). RESULTS: Mental state discrimination was significantly better and faster for affective eye gazes in BPD patients than in HC. At the neurophysiological level, this was manifested in a stronger activation of the amygdala and greater activity of the medial frontal gyrus, the left temporal pole and the middle temporal gyrus during affective eye gazes. In contrast, HC subjects showed a greater activation in the insula and the superior temporal gyri. CONCLUSION: These findings indicate that BPD patients are highly vigilant to social stimuli, maybe because they resonate intuitively with mental states of others.

Borderline personality disorder and psychosis: a review.

Early views of borderline personality disorder (BPD) were based on the idea that patients with this pathology were "on the border" of psychosis. However, more recent studies have not supported this view, although they have found evidence of a malevolent interpersonal evaluation and a significant proportion of BPD patients showing psychotic symptoms. For example, in one study, 24% of BPD patients reported severe psychotic symptoms and about 75% had dissociative experiences and paranoid ideation. Thus, we start with an overview regarding the prevalence of psychotic symptoms in BPD patients. Furthermore, we report findings of studies investigating the role of comorbidity (eg, post-traumatic stress disorder) in the severity and frequency of psychotic symptoms in BPD patients. We then present results of genetic and neurobiological studies comparing BPD patients with patients with schizophrenia or nonschizophrenic psychotic disorders. In conclusion, this review reveals that psychotic symptoms in BPD patients may not predict the development of a psychotic disorder but are often permanent and severe and need careful consideration by clinicians. Therefore, adequate diagnosis and treatment of psychotic symptoms in BPD patients is emphasized.