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Abstracts
  • Alexander, N., Klucken, T., Koppe, G., Osinsky, R., Walter, B., Vaitl, D., Sammer, G., Stark, R., & Hennig, J. (2012). Interaction of the serotonin transporter-linked polymorphic region and environmental adversity: increased amygdala-hypothalamus connectivity as a  potential mechanism linking neural and endocrine hyperreactivity. Biological Psychiatry, 72(1), 49–56. https://doi.org/10.1016/j.biopsych.2012.01.030

    BACKGROUND: Gene by environment (G×E) interaction between genetic variation in the promoter region of the serotonin transporter gene (serotonin transporter-linked polymorphic region [5-HTTLPR]) and stressful life events (SLEs) has been extensively studied in the context of depression. Recent findings suggest increased neural and endocrine stress sensitivity as a possible mechanism conveying elevated vulnerability to psychopathology. Furthermore, these G×E mediated alterations very likely reflect interrelated biological processes. METHODS: In the present functional magnetic resonance imaging study, amygdala reactivity to fearful stimuli was assessed in healthy male adults (n = 44), who were previously found to differ with regard to endocrine stress reactivity as a function of 5-HTTLPR × SLEs. Furthermore, functional connectivity between the amygdala and the hypothalamus was measured as a potential mechanism linking elevated neural and endocrine responses during stressful/threatening situations. The study sample was carefully preselected regarding 5-HTTLPR genotype and SLEs. RESULTS: We report significant G×E interaction on neural response patterns and functional amygdala-hypothalamus connectivity. Specifically, homozygous carriers of the 5-HTTLPR S' allele with a history of SLEs (S'S'/high SLEs group) displayed elevated bilateral amygdala activation in response to fearful faces. Within the same sample, a comparable G×E interaction effect has previously been demonstrated regarding increased cortisol reactivity, indicating a cross-validation of heightened biological stress sensitivity. Furthermore, S'S'/high SLEs subjects were characterized by an increased functional coupling between the right amygdala and the hypothalamus, thus indicating a potential link between neural and endocrine hyperreactivity. CONCLUSIONS: The present findings contribute to the ongoing debate on 5-HTTLPR × SLEs interaction and are discussed with respect to clinical implications.

  • Klucken, T., Schweckendiek, J., Koppe, G., Merz, C. J., Kagerer, S., Walter, B., Sammer, G., Vaitl, D., & Stark, R. (2012). Neural correlates of disgust- and fear-conditioned responses. Neuroscience, 201, 209–218. https://doi.org/10.1016/j.neuroscience.2011.11.007

    The understanding of individual differences in responses to disgusting stimuli is important to gain more insight into the development of certain psychiatric disorders. The aim of this study was to investigate conditioned disgust responses, its potential overlap with conditioned fear responses (CRs) and the influence of disgust sensitivity on blood oxygen level-dependent responses. Yet even though current studies report evidence that disgust sensitivity is a vulnerability factor, the knowledge about the underlying neural mechanisms remains very limited. Two groups were exposed either to a disgust- or a fear-conditioning paradigm. Using functional magnetic resonance imaging, we identified a conjoint activated network including the cingulate cortex, the nucleus accumbens, the orbitofrontal cortex, and the occipital cortex within the disgust- and the fear-conditioning group. Moreover, we report evidence of increased insula activation in the disgust-conditioning group. In addition, functional connectivity analysis revealed increased interconnections, most pronounced within the insula in the high disgust sensitivity group compared with the low disgust sensitivity group. The conjunction results suggest that the conditioned responses in disgust and fear conditioning recruit the same neural network, implicating that different conditioned responses of aversive learning depend on a common neural network. Increased insula activation within the disgust-conditioning group might be attributable to heightened interoceptive processes, which might be more pronounced in disgust. Finally, the findings regarding disgust sensitivity are discussed with respect to vulnerability factors for certain psychiatric disorders.

  • Stark, R., Schienle, A., Walter, B., Kirsch, P., Blecker, C., Ott, U., Schäfer, A., Sammer, G., Zimmermann, M., & Vaitl, D. (2004). Hemodynamic effects of negative emotional pictures - a test-retest analysis. Neuropsychobiology, 50(1), 108–118. https://doi.org/10.1159/000077948

    We investigated subjective and hemodynamic responses towards disgust-inducing, fear-inducing, and neutral pictures in a functional magnetic resonance imaging study. Within an interval of 1 week, 24 male subjects underwent the same block design twice in order to analyze possible response changes to the repeated picture presentation. The results showed that disgust-inducing and fear-inducing scenes provoked a similar activation pattern in comparison to neutral scenes. This included the thalamus, primary and secondary visual fields, the amygdala, the hippocampus, and various regions of the prefrontal cortex. During the retest, the affective ratings hardly changed. In contrast, most of the previously observed brain activations disappeared, with the exception of the temporo-occipital activation. An additional analysis, which compared the emotion-related activation patterns during the two presentations, showed that the responses to the fear-inducing pictures were more stable than the responses to the disgust-inducing ones.

  • Schienle, A., Stark, R., Walter, B., Blecker, C., Ott, U., Kirsch, P., Sammer, G., & Vaitl, D. (2002). The insula is not specifically involved in disgust processing: an fMRI study. Neuroreport, 13(16), 2023–2026. https://doi.org/10.1097/00001756-200211150-00006

    fMRI studies have shown that the perception of facial disgust expressions specifically activates the insula. The present fMRI study investigated whether this structure is also involved in the processing of visual stimuli depicting non-mimic disgust elicitors compared to fear-inducing and neutral scenes. Twelve female subjects were scanned while viewing alternating blocks of 40 disgust-inducing, 40 fear-inducing and 40 affectively neutral pictures, shown for 1.5 s each. Afterwards, affective ratings were assessed. The disgust pictures, rated as highly repulsive, induced activation in the insula, the amygdala, the orbitofrontal and occipito-temporal cortex. Since during the fear condition the insula was also involved, our findings do not fit the idea of the insula as a specific disgust processor.

  • Schienle, A., Stark, R., Walter, B., Blecker, C., Ott, U., Kirsch, P., Sammer, G., & Vaitl, D. (2002). The insula is not specifically involved in disgust processing: an fMRI study. Neuroreport, 13(16), 2023–2026. https://doi.org/10.1097/00001756-200211150-00006

    fMRI studies have shown that the perception of facial disgust expressions specifically activates the insula. The present fMRI study investigated whether this structure is also involved in the processing of visual stimuli depicting non-mimic disgust elicitors compared to fear-inducing and neutral scenes. Twelve female subjects were scanned while viewing alternating blocks of 40 disgust-inducing, 40 fear-inducing and 40 affectively neutral pictures, shown for 1.5 s each. Afterwards, affective ratings were assessed. The disgust pictures, rated as highly repulsive, induced activation in the insula, the amygdala, the orbitofrontal and occipito-temporal cortex. Since during the fear condition the insula was also involved, our findings do not fit the idea of the insula as a specific disgust processor.

  • Hamm, A. O., Cuthbert, B. N., Globisch, J., & Vaitl, D. (1997). Fear and the startle reflex: blink modulation and autonomic response patterns in animal and mutilation fearful subjects. Psychophysiology, 34(1), 97–107. https://doi.org/10.1111/j.1469-8986.1997.tb02420.x

    The present study was designed to examine the pattern of startle reflex modulation and autonomic responses for individuals high in animal or blood-injury fear when viewing pictures of their feared objects. Sixteen individuals in each fear group and 16 low-fear control individuals viewed 32 color slides depicting fear-relevant, unpleasant but fear-unrelated, neutral, and pleasant scenes. Free viewing times were assessed in a second phase of the procedure as an index of avoidance behavior. Exposure to pictures of feared objects resulted in a consistent startle reflex potentiation and behavioral avoidance in both fear groups. This activation of the basic aversive system was independent of the autonomic pattern of the fear responses, which differed for the high-fear groups. These results suggest that the probe startle response indexes the organism's basic motivational disposition and add new information to the assessment of fear.

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