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The stress hormone cortisol is known to influence declarative memory and associative learning. In animals, stress has often been reported to have opposing effects on memory and learning in males and females. In humans, the effects of cortisol have mainly been studied at the behavioral level. The aim of the present experiment was to characterize the effects of a single cortisol dose (30 mg) on the hemodynamic correlates of fear conditioning. In a double-blind group comparison study subjects (17 females and 17 males) received 30 mg cortisol or placebo orally before participating in a discriminative fear conditioning paradigm. Results revealed that cortisol impaired electrodermal signs of learning (the first interval response) in males, while no conditioned SCRs emerged for the females independent of treatment. fMRI results showed that cortisol reduced activity for the CS+ > CS- comparison in the anterior cingulate, the lateral orbitofrontal cortex and the medial prefrontal cortex in males. Opposite findings (increase in these regions under cortisol) were detected in females. In addition, cortisol reduced the habituation in the CS+ > CS- contrast in the dorsolateral prefrontal cortex independent of sex. Finally, cortisol also modified the response to the electric shock (the UCS) by enhancing the activity of the anterior as well as the posterior cingulate. In sum, these findings demonstrate that in humans cortisol mostly influences prefrontal brain activation during fear conditioning and that these effects appear to be modulated by sex.
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The aim of this fMRI study was to explore brain structures that are involved in the processing of erotic and disgust-inducing pictures. The stimuli were chosen to trigger approach and withdrawal tendencies, respectively. By adding sadomasochistic (SM) scenes to the design and examining 12 subjects with and 12 subjects without sadomasochistic preferences, we introduced a picture category that induced erotic pleasure in one sample and disgust in the other sample. Since we also presented neutral pictures, all subjects viewed pictures of four different categories: neutral, disgust-inducing, erotic, and SM erotic pictures. The analysis indicated that several brain structures are commonly involved in the processing of disgust-inducing and erotic pictures (occipital cortex, hippocampus, thalamus, and the amygdala). The ventral striatum was specifically activated when subjects saw highly sexually arousing pictures. This indicates the involvement of the human reward system during the processing of visual erotica.
Erkunden
Team
- Vaitl (2)
Eintragsart
Sprache
- Englisch (2)
Thema
- Hemodynamics/physiology
- Adult (2)
- *Affect (1)
- Amygdala/blood supply/metabolism (1)
- Basal Ganglia/blood supply/metabolism (1)
- Brain/*blood supply/metabolism (1)
- Conditioning, Psychological/*drug effects (1)
- Double-Blind Method (1)
- *Erotica (1)
- Fear/*drug effects (1)
- Female (2)
- Functional Laterality/physiology (1)
- Galvanic Skin Response/physiology (1)
- Hippocampus/blood supply/metabolism (1)
- Humans (2)
- Hydrocortisone/*pharmacology (1)
- Magnetic Resonance Imaging (2)
- Male (2)
- Occipital Lobe/blood supply/metabolism (1)
- Personality (1)
- Personality Inventory (1)
- Photic Stimulation (1)
- *Photic Stimulation (1)
- Prefrontal Cortex/*physiology (1)
- Reward (1)
- Sex Characteristics (1)
- Sexual Behavior/physiology (1)
- Thalamus/blood supply/metabolism (1)