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Ergebnisse 3 Einträge
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Phobic responses are strong emotional reactions towards phobic objects, which can be described as a deficit in the automatic regulation of emotions. Difficulties in the voluntary cognitive control of these emotions suggest a further phobia-specific deficit in effortful emotion regulation mechanisms. The actual study is based on this emotion regulation conceptualization of specific phobias. The aim is to investigate the neural correlates of these two emotion regulation deficits in spider phobics. Sixteen spider phobic females participated in a functional magnetic resonance imaging (fMRI) study in which they were asked to voluntarily up- and down-regulate their emotions elicited by spider and generally aversive pictures with a reappraisal strategy. In line with the hypothesis concerning an automatic emotion regulation deficit, increased activity in the insula and reduced activity in the ventromedial prefrontal cortex was observed. Furthermore, phobia-specific effortful regulation within phobics was associated with altered activity in medial prefrontal cortex areas. Altogether, these results suggest that spider phobic subjects are indeed characterized by a deficit in the automatic as well as the effortful regulation of emotions elicited by phobic compared with aversive stimuli. These two forms of phobic emotion regulation deficits are associated with altered activity in different medial prefrontal cortex subregions.
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This study investigated differences in brain activation during meditation between meditators and non-meditators. Fifteen Vipassana meditators (mean practice: 7.9 years, 2h daily) and fifteen non-meditators, matched for sex, age, education, and handedness, participated in a block-design fMRI study that included mindfulness of breathing and mental arithmetic conditions. For the meditation condition (contrasted to arithmetic), meditators showed stronger activations in the rostral anterior cingulate cortex and the dorsal medial prefrontal cortex bilaterally, compared to controls. Greater rostral anterior cingulate cortex activation in meditators may reflect stronger processing of distracting events. The increased activation in the medial prefrontal cortex may reflect that meditators are stronger engaged in emotional processing.
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Dopamine is known as the main neurotransmitter modulating the activation of the reward system of the brain. The DRD2 TaqIA polymorphism is associated with dopamine D2 receptor density which plays an important role in the context of reward. Persons carrying an A1 allele have a lower D2 receptor density and a higher risk to show substance abuse. The present study was designed to investigate the influence of the DRD2 TaqIA polymorphism and the selective D2 receptor agonist bromociptine on the activation of the reward system by means of functional magnetic resonance imaging (fMRI). In a double-blind crossover study with 24 participants we found an increase of reward system activation from placebo to bromocriptine only in subjects carrying the A1 allele. Furthermore, only A1 carrier showed an increase of performance under bromocriptine. The results are interpreted as reflecting a specific sensitivity for dopamine agonists in persons carrying an A1 allele and may complement actual data and theories of the development of addiction disorders postulating a higher genetic risk for substance abuse in carrier of the A1 allele.
Erkunden
Team
- Vaitl (3)
Eintragsart
Sprache
- Englisch (3)
Thema
- Image Processing, Computer-Assisted/methods
- Adolescent (1)
- Adult (2)
- Animals (1)
- Brain/blood supply/*drug effects/physiology (1)
- *Brain Mapping (2)
- Bromocriptine/*pharmacology (1)
- Case-Control Studies (1)
- Cross-Sectional Studies (1)
- Dopamine Agonists/*pharmacology (1)
- Double-Blind Method (1)
- Emotions/*physiology (1)
- Expressed Emotion/*physiology (1)
- Feedback, Psychological/drug effects/physiology (1)
- Female (3)
- Frontal Lobe/blood supply/*physiology (1)
- Functional Laterality/physiology (1)
- Gyrus Cinguli/blood supply/*physiology (1)
- Humans (3)
- Magnetic Resonance Imaging/methods (3)
- Male (2)
- Mathematics (1)
- *Meditation (1)
- Mental Processes/*physiology (1)
- Neuronal Plasticity/physiology (1)
- Oxygen/blood (3)
- Pattern Recognition, Visual/physiology (1)
- Phobic Disorders/*psychology (1)
- Photic Stimulation/methods (1)
- *Polymorphism, Genetic (1)
- Prefrontal Cortex/blood supply/physiopathology (1)
- Psychophysics (1)
- Reaction Time/drug effects/genetics (1)
- Receptors, Dopamine D2/*genetics (1)
- Reflex, Startle/physiology (1)
- Reverse Transcriptase Polymerase Chain Reaction/methods (1)
- *Reward (1)
- Self Concept (1)
- *Spiders (1)