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"Walter, Bertram"

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Brain Mapping

Ergebnisse 6 Einträge

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Schienle, A., Schäfer, A., Walter, B., Stark, R., & Vaitl, D. (2005). Brain activation of spider phobics towards disorder-relevant, generally disgust- and fear-inducing pictures. Neuroscience Letters, 388(1), 1–6. https://doi.org/10.1016/j.neulet.2005.06.025

The present functional magnetic resonance imaging study investigated the fear and disgust reactivity of patients suffering from spider phobia. Ten phobics and 13 control subjects were scanned while viewing alternating blocks of phobia-relevant, generally fear-inducing, disgust-inducing and affectively neutral pictures. The patient group rated the spider pictures as being more disgust and fear evoking than the control group, and showed greater activation of the visual association cortex, the amygdalae, the right dorsolateral prefrontal cortex and the right hippocampus. Specific phobia-related activation occurred in the supplementary motor area. The patients also showed greater amygdala activation during the presentation of generally disgust- and fear-inducing pictures. This points to an elevated sensitivity to repulsive and threatening stimuli in spider phobics and implicates the amygdala as a crucial neural substrate.
Schienle, A., Schäfer, A., Stark, R., Walter, B., & Vaitl, D. (2005). Relationship between disgust sensitivity, trait anxiety and brain activity during disgust induction. Neuropsychobiology, 51(2), 86–92. https://doi.org/10.1159/000084165

We examined the influence of disgust sensitivity and trait anxiety on disgust processing via functional magnetic resonance imaging. Data of 63 healthy females were combined across four studies, where the same disgusting and affectively neutral pictures had been presented. The disgust pictures, rated as highly repulsive, provoked activation in the occipital cortex, the left prefrontal cortex and both amygdalae. Disgust sensitivity and trait anxiety were positively, and independently from each other, correlated with the activation of the right amygdala. This points to the role of the amygdala as an integrative brain structure, whose activation can be modulated by different affective styles.
Schienle, A., Schäfer, A., Stark, R., Walter, B., & Vaitl, D. (2005). Gender differences in the processing of disgust- and fear-inducing pictures: an fMRI study. Neuroreport, 16(3), 277–280. https://doi.org/10.1097/00001756-200502280-00015

We examined whether males and females differ in the intensity and laterality of their hemodynamic responses towards visual disgust and fear stimuli. Forty-one female, and 51 male subjects viewed disgust-inducing, fear-inducing and neutral pictures in an fMRI block design. Self-report data indicated that the target emotions had been elicited successfully with women responding stronger than men. While viewing the fear pictures, which depicted attacks by humans or animals, men exhibited greater activation in the bilateral amygdala and the left fusiform gyrus than women. This response pattern may reflect greater attention from males to cues of aggression in their environment. Further, the lateralization of brain activation was comparable in the two genders during both aversive picture conditions.
Hermann, A., Schäfer, A., Walter, B., Stark, R., Vaitl, D., & Schienle, A. (2007). Diminished medial prefrontal cortex activity in blood-injection-injury phobia. Biological Psychology, 75(2), 124–130. https://doi.org/10.1016/j.biopsycho.2007.01.002

We examined the effects of symptom induction on neural activation in blood-injection-injury (BII) phobia. Nine phobic and 10 non-phobic subjects participated in an fMRI study in which they were presented with disorder-relevant, generally disgust-inducing, generally fear-evoking and neutral pictures. We observed diminished medial prefrontal cortex (MPFC) activity in patients compared to controls for phobia-relevant and disgust-inducing pictures. The MPFC has been shown to be critically involved in the automatic and effortful cognitive regulation of emotions. Therefore, the results might reflect reduced cognitive control of emotions in BII phobics during the experience of phobic symptoms as well as during states of disgust. The latter response component might be a result of the elevated disgust sensitivity of BII phobics.
Stippekohl, B., Winkler, M., Mucha, R. F., Pauli, P., Walter, B., Vaitl, D., & Stark, R. (2010). Neural responses to BEGIN- and END-stimuli of the smoking ritual in nonsmokers, nondeprived smokers, and deprived smokers. Neuropsychopharmacology : Official Publication of the American College of Neuropsychopharmacology, 35(5), 1209–1225. https://doi.org/10.1038/npp.2009.227

Drug-associated stimuli (cues) have a prominent role in addiction research because they are able to provoke craving and relapses. Generally, drug cues are seen as conditioned excitatory stimuli, which elicit drug seeking and usage. However, newer data suggest differential effects for smoking stimuli depending on their stage in the smoking ritual. Specifically, stimuli associated with the terminal stage of smoke consumption (END-stimuli) may evoke reactivity opposite to the reactivity evoked by stimuli associated with the beginning of smoke consumption (BEGIN-stimuli). This fMRI study compared 20 nondeprived smokers with 20 nonsmokers to unravel the influence of smoking-related pictures displaying the beginning (BEGIN-stimuli) and termination (END-stimuli) of the smoking ritual on neural activity in the addiction network. In addition, 20 deprived smokers (12 h deprivation) were investigated to explore the effects of deprivation on the processing of these stimuli. In nondeprived smokers, BEGIN-stimuli reliably activated the addiction network (for example, the ventral striatum, orbitofrontal cortex, and anterior cingulate cortex (ACC)). In contrast, END-stimuli triggered a differential pattern of activations as well as deactivations; deactivations were found in the ventral striatum and the ACC. Deprivation had no clear effect on the responses triggered by BEGIN-stimuli, but affected the reactivity to END-stimuli. Our data clearly suggest that stimuli associated with different stages of the smoking ritual trigger differential neuronal responses. While BEGIN-stimuli generally seem to activate the addiction network, END-stimuli presumably have some inhibitory properties. This new finding might add to a more differentiated understanding of cue reactivity and addiction.
Klucken, T., Alexander, N., Schweckendiek, J., Merz, C. J., Kagerer, S., Osinsky, R., Walter, B., Vaitl, D., Hennig, J., & Stark, R. (2013). Individual differences in neural correlates of fear conditioning as a function of 5-HTTLPR and stressful life events. Social Cognitive and Affective Neuroscience, 8(3), 318–325. https://doi.org/10.1093/scan/nss005

Fear learning is a crucial process in the pathogeneses of psychiatric disorders, which highlights the need to identify specific factors contributing to interindividual variation. We hypothesized variation in the serotonin transporter gene (5-HTTLPR) and stressful life events (SLEs) to be associated with neural correlates of fear conditioning in a sample of healthy male adults (n = 47). Subjects were exposed to a differential fear conditioning paradigm after being preselected regarding 5-HTTLPR genotype and SLEs. Individual differences in brain activity as measured by functional magnetic resonance imaging (fMRI), skin conductance responses and preference ratings were assessed. We report significant variation in neural correlates of fear conditioning as a function of 5-HTTLPR genotype. Specifically, the conditioned stimulus (CS(+)) elicited elevated activity within the fear-network (amygdala, insula, thalamus, occipital cortex) in subjects carrying two copies of the 5-HTTLPR S' allele. Moreover, our results revealed preliminary evidence for a significant gene-by-environment interaction, such as homozygous carriers of the 5-HTTLPR S' allele with a history of SLEs demonstrated elevated reactivity to the CS(+) in the occipital cortex and the insula. Our findings contribute to the current debate on 5-HTTLPR x SLEs interaction by investigating crucial alterations on an intermediate phenotype level which may convey an elevated vulnerability for the development of psychopathology.

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Last update from database: 04.06.25, 15:35 (UTC)

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