Significant grey matter changes in a region of the orbitofrontal cortex in healthy participants predicts emotional dysregulation.

The traditional concept of 'categorical' psychiatric disorders has been challenged as many of the symptoms display a continuous distribution in the general population. We suggest that this is the case for emotional dysregulation, a key component in several categorical psychiatric disorder constructs. We used voxel-based magnetic resonance imaging morphometry in healthy human subjects (n = 87) to study how self-reported subclinical symptoms associated with emotional dysregulation relate to brain regions assumed to be critical for emotion regulation.

The Hidden Snake in the Grass: Superior Detection of Snakes in Challenging Attentional Conditions.

Snakes have provided a serious threat to primates throughout evolution. Furthermore, bites by venomous snakes still cause significant morbidity and mortality in tropical regions of the world. According to the Snake Detection Theory (SDT Isbell, 2006; 2009), the vital need to detect camouflaged snakes provided strong evolutionary pressure to develop astute perceptual capacity in animals that were potential targets for snake attacks.

BDNFval66met affects neural activation pattern during fear conditioning and 24 h delayed fear recall.

Brain-derived neurotrophic factor (BDNF), the most abundant neutrophin in the mammalian central nervous system, is critically involved in synaptic plasticity. In both rodents and humans, BDNF has been implicated in hippocampus- and amygdala-dependent learning and memory and has more recently been linked to fear extinction processes. Fifty-nine healthy participants, genotyped for the functional BDNFval66met polymorphism, underwent a fear conditioning and 24h-delayed extinction protocol while skin conductance and blood oxygenation level dependent (BOLD) responses (functional magnetic resonance imaging) were acquired.

Finding an emotional face in a crowd: emotional and perceptual stimulus factors influence visual search efficiency.

In this article, we examine how emotional and perceptual stimulus factors influence visual search efficiency. In an initial task, we run a visual search task, using a large number of target/distractor emotion combinations. In two subsequent tasks, we then assess measures of perceptual (rated and computational distances) and emotional (rated valence, arousal and potency) stimulus properties.

Using facial emotional stimuli in visual search experiments: the arousal factor explains contradictory results.

For more than two decades, visual search experiments using pictures of emotional faces as stimuli have generated contradictory results. Evidence of a superior detection of angry faces compared to happy faces have been mixed with an equal amount of evidence in the opposite direction. In this article, we review this literature, and examine the hypothesis that the neglected stimulus factor of emotional arousal may explain these contradictory results.

Other people as means to a safe end: vicarious extinction blocks the return of learned fear.

Information about what is dangerous and safe in the environment is often transferred from other individuals through social forms of learning, such as observation. Past research has focused on the observational, or vicarious, acquisition of fears, but little is known about how social information can promote safety learning. To address this issue, we studied the effects of vicarious-extinction learning on the recovery of conditioned fear.

Attention biases and habituation of attention biases are associated with 5-HTTLPR and COMTval158met.

Fundamental biases in affective information processing are modulated by individual differences in the emotional response to environmental stimuli that may be partly based on the individual's genetic make-up. To extend prior dot probe studies on attention genetics, we used a visual-search paradigm (VSP) with pictures of angry and happy faces of both sexes as targets, neutral faces as distractors, and a varying set size. Participants were selected a priori depending on their 5-HTTLPR (s/s, s/l, l/l; on a constant rs25531 A-allele background) and COMTval158met (val/val, valmet, met/met) genotypes and were matched for sex and age.

Changes in the neural correlates of implicit emotional face processing during antidepressant treatment in major depressive disorder.

An emerging hypothesis regarding the mechanisms underlying antidepressant pharmacotherapy suggests that these agents benefit depressed patients by reversing negative emotional processing biases (Harmer, 2008). Neuropsychological indices and functional neuroimaging measures of the amygdala response show that antidepressant drugs shift implicit and explicit processing biases away from the negative valence and toward the positive valence. However, few studies have explored such biases in regions extensively connected with the amygdala, such as the pregenual anterior cingulate cortex (pgACC) area, where pre-treatment activity consistently has predicted clinical outcome during antidepressant treatment.

Temporal properties of fear extinction--does time matter?

Fear extinction can be defined as the weakening of the expression of a conditioned response (CR) by extended experience of nonreinforcement. Conceptually, two distinct models have been invoked to account for extinction. R.

Are fear memories erasable?-reconsolidation of learned fear with fear-relevant and fear-irrelevant stimuli.

Recent advances in the field of fear learning have demonstrated that a single reminder exposure prior to extinction training can prevent the return of extinguished fear by disrupting the process of reconsolidation. These findings have however proven hard to replicate in humans. Given the significant implications of preventing the return of fear, the purpose of the present study was to further study the putative effects of disrupting reconsolidation.

Distinct contributions of the dorsolateral prefrontal and orbitofrontal cortex during emotion regulation.

The lateral prefrontal and orbitofrontal cortices have both been implicated in emotion regulation, but their distinct roles in regulation of negative emotion remain poorly understood. To address this issue we enrolled 58 participants in an fMRI study in which participants were instructed to reappraise both negative and neutral stimuli. This design allowed us to separately study activations reflecting cognitive processes associated with reappraisal in general and activations specifically related to reappraisal of negative emotion.

The extended functional neuroanatomy of emotional processing biases for masked faces in major depressive disorder.

Background: Major depressive disorder (MDD) is associated with a mood-congruent processing bias in the amygdala toward face stimuli portraying sad expressions that is evident even when such stimuli are presented below the level of conscious awareness. The extended functional anatomical network that maintains this response bias has not been established, however.

Aims: To identify neural network differences in the hemodynamic response to implicitly presented facial expressions between depressed and healthy control participants.

Fear extinction in humans: effects of acquisition-extinction delay and masked stimulus presentations.

Fear extinction can be viewed as an inhibitory learning process. This is supported by post-extinction phenomena demonstrating the return of fear, such as reinstatement. Recent work has questioned this account, claiming that extinction initiated immediately after fear acquisition can abolish the return of fear.

Emotional responses in spider fear are closely related to picture awareness.

Theories of emotion propose that responses to emotional pictures can occur independently of whether or not people are aware of the picture content. Because evidence from dissociation paradigms is inconclusive, we manipulated picture awareness gradually and studied whether emotional responses varied with degree of awareness. Spider fearful and non-fearful participants viewed pictures of spiders and flowers at four levels of backward masking while electrodermal activity and heart rate were measured continuously.

The face is more than its parts--brain dynamics of enhanced spatial attention to schematic threat.

A rapid response to environmental threat is crucial for survival and requires an appropriate attention allocation toward its location. Visual search paradigms have provided evidence for the enhanced capture of attention by threatening faces. In two EEG experiments, we sought to determine whether the detection of threat requires complete faces or salient features underlying the facial expression.

5-HTTLPR and COMTval158met genotype gate amygdala reactivity and habituation.

Amygdala reactivity is a heritable trait, potentiated in affective disorders and associated with both the 5-HTTLPR and the COMTval158met polymorphism. Fifty-four healthy volunteers selected a priori based on gender and 5-HTTLPR/rs25531 and COMTval158met genotypes performed a passive viewing task of angry facial expressions using fMRI. Amygdala reactivity and habituation were investigated using the a priori anatomical region of interest (ROI) approach.

The COMTval158met polymorphism is associated with symptom relief during exposure-based cognitive-behavioral treatment in panic disorder.

Background: Cognitive behavioral therapy (CBT) represents a learning process leading to symptom relief and resulting in long-term changes in behavior. CBT for panic disorder is based on exposure and exposure-based processes can be studied in the laboratory as extinction of experimentally acquired fear responses. We have recently demonstrated that the ability to extinguish learned fear responses is associated with a functional genetic polymorphism (COMTval158met) in the COMT gene and this study was aimed at transferring the experimental results on the COMTval158met polymorphism on extinction into a clinical setting.

Relationship between amygdala responses to masked faces and mood state and treatment in major depressive disorder.

Context: Major depressive disorder (MDD) is associated with behavioral and neurophysiological evidence of mood-congruent processing biases toward explicitly presented, emotionally valenced stimuli. However, few studies have investigated such biases toward implicitly presented stimuli.

Objective: To investigate differential amygdala responses to sad, happy, and neutral faces presented below the level of explicit conscious awareness using a backward masking task in unmedicated participants with MDD and healthy controls (HCs).

Amygdala-dependent fear conditioning in humans is modulated by the BDNFval66met polymorphism.

The brain-derived neurotrophic factor (BDNF) is critically involved in neuroplasticity, as well as the acquisition, consolidation, and retention of hippocampal- and amygdala-dependent learning. A common functional A-->G single nucleotide polymorphism (BDNFval66met) in the prodomain of the human BDNF gene is associated with abnormal intracellular trafficking and reduced activity-dependent BDNF release. We studied the effect of BDNFval66met in an aversive differential fear conditioning, and a delayed extinction paradigm in 57 healthy participants.

Of snakes and faces: an evolutionary perspective on the psychology of fear.

Snakes and faces are unique stimuli because they are deeply grounded in evolutionarily shaped behavior systems. Snakes are the prototypical stimulus in a predatory defense system promoting escape from predators, which prepares primates for efficient processing, attentional priority, and rapid fear acquisition to snakes and other stimuli related to predation. The social submissiveness system plays a similar role on the social arena by promoting yielding to dominant individuals without jeopardizing the protection of the group.

Distinct control networks for cognition and emotion in the prefrontal cortex.

The activation of dorsolateral prefrontal cortex (dlPFC) has been suggested to reflect the engagement of a control mechanism for top-down biasing of context processing in resource-demanding memory tasks. Here we tested the hypothesis that the dlPFC subserves a similar function also in attention and emotion tasks. 18 healthy young adults were tested in a functional magnetic resonance imaging (fMRI) study where the demands for context processing were manipulated in three different cognitive domains: auditory attention, episodic retrieval, and emotion regulation.

Some animal specific fears are more specific than others: Evidence from attention and emotion measures.

Using a visual search methodology we investigated the effect of feared animal stimuli on attention. Our results confirmed the important role of emotion on attention. All participants detected fear-relevant stimuli (snakes and spiders) faster than neutral (mushrooms) ones against a background of fruits.

The symptomatic profile of panic disorder is shaped by the 5-HTTLPR polymorphism.

The short allele of a functional polymorphism (5-HTTLPR) in the serotonin transporter (5-HTT) promoter is associated with reduced serotonin transporter expression, lower in vivo 5-HTT binding, higher neuroticism and amygdala reactivity as well as facilitated fear conditioning and is a candidate variant for panic disorder. However, case-control studies have consistently failed to show an association between 5-HTTLPR and panic disorder. As psychiatric disorders are broadly defined phenotypes merging different symptoms to syndromes, they may not be very well suited for genetic association studies.