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Ergebnisse 5 Einträge

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Abstracts
  • Irrmischer, M., Houtman, S. J., Mansvelder, H. D., Tremmel, M., Ott, U., & Linkenkaer-Hansen, K. (2018). Controlling the temporal structure of brain oscillations by focused attention meditation. Human Brain Mapping, 39(4), 1825–1838. https://doi.org/10.1002/hbm.23971

    Our focus of attention naturally fluctuates between different sources of information even when we desire to focus on a single object. Focused attention (FA) meditation is associated with greater control over this process, yet the neuronal mechanisms underlying this ability are not entirely understood. Here, we hypothesize that the capacity of attention to transiently focus and swiftly change relates to the critical dynamics emerging when neuronal systems balance at a point of instability between order and disorder. In FA meditation, however, the ability to stay focused is trained, which may be associated with a more homogeneous brain state. To test this hypothesis, we applied analytical tools from criticality theory to EEG in meditation practitioners and meditation-naïve participants from two independent labs. We show that in practitioners-but not in controls-FA meditation strongly suppressed long-range temporal correlations (LRTC) of neuronal oscillations relative to eyes-closed rest with remarkable consistency across frequency bands and scalp locations. The ability to reduce LRTC during meditation increased after one year of additional training and was associated with the subjective experience of fully engaging one's attentional resources, also known as absorption. Sustained practice also affected normal waking brain dynamics as reflected in increased LRTC during an eyes-closed rest state, indicating that brain dynamics are altered beyond the meditative state. Taken together, our findings suggest that the framework of critical brain dynamics is promising for understanding neuronal mechanisms of meditative states and, specifically, we have identified a clear electrophysiological correlate of the FA meditation state.

  • Sparby, T., & Ott, U. (2018). A qualitative study of motivations for meditation in anthroposophic practitioners. PloS One, 13(9), e0203184. https://doi.org/10.1371/journal.pone.0203184

    Research on meditation is advancing, but few studies about the motivations of meditators exist. Additionally, many forms and traditions of meditation have yet to be investigated. This study addresses both of these issues by presenting an overview of different forms of motivations found in contemporary Anthroposophic meditation practice. 30 Anthroposophic meditators were interviewed about their meditation experiences. The interviews were examined using thematic analysis. 14 data-driven themes were extracted and organized within a framework consisting of three superordinate theory-driven forms of motivation: External, internal and service. A developmental trajectory running from external and internal to service motivations is indicated. This approach improves upon a scheme developed by Shapiro by including additional types of motivations and being able to differentiate between forms of motivations that are fundamentally different: Self-related (heteronomous and autonomous) motivations and other-related motivations.

  • Wehrum, S., Degé, F., Ott, U., Walter, B., Stippekohl, B., Kagerer, S., Schwarzer, G., Vaitl, D., & Stark, R. (2011). Can you hear a difference? Neuronal correlates of melodic deviance processing in children. Brain Research, 1402, 80–92. https://doi.org/10.1016/j.brainres.2011.05.057

    Many studies investigating music processing in adult musicians and nonmusicians point towards pronounced behavioral and neurophysiological differences between the two groups. Recent studies indicate that these differences can already be found in early childhood. Further, electro-encephalography studies using musical discrimination tasks have demonstrated that differences in music processing become more pronounced when explicitly rather than implicitly trained musical abilities are required. Exploring the functional neuroanatomy underlying the processing of different expectation violations in children and its association with musical training, we investigated neural responses to different melodic deviances in musically trained and untrained children. Using functional magnetic resonance imaging, children (aged 11-14 years) were examined while comparing pairs of short melodies that were either identical or differed with respect to four notes. The implemented deviances were either subtle (by inserting plausible in-key notes) or obvious (by inserting implausible out-of-key notes). Our results indicate a strong association between musical training and functional neuroanatomy of the brain. Similar to research on music processing in adults, the processing of obvious melodic deviances activated a network involving inferior frontal, premotor and anterior insula regions in musically trained and untrained children. By contrast, subtle deviances led to activation in the inferior frontal and premotor cortex, the anterior insula, the superior temporal gyrus, and the supramarginal gyrus in musically trained children only. Our work provides further insights into the functional neuroanatomy of melody processing and its association with musical training in children, providing the basis for further studies specifying distinct musical processes (e.g. contour and interval processing).

  • Ott, U., Reuter, M., Hennig, J., & Vaitl, D. (2005). Evidence for a common biological basis of the Absorption trait, hallucinogen effects, and positive symptoms: epistasis between 5-HT2a and COMT polymorphisms. American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics : The Official Publication of the International Society of Psychiatric Genetics, 137B(1), 29–32. https://doi.org/10.1002/ajmg.b.30197

    Absorption represents a disposition to experience altered states of consciousness characterized by intensively focused attention. It is correlated with hypnotic susceptibility and includes phenomena ranging from vivid perceptions and imaginations to mystical experiences. Based on the assumption that drug-induced and naturally occurring mystical experiences share common neural mechanisms, we hypothesized that Absorption is influenced by the T102C polymorphism affecting the 5-HT2a receptor, which is known to be an important target site of hallucinogens like LSD. Based on the pivotal role ascribed to the prefrontal executive control network for absorbed attention and positive symptoms in schizophrenia, it was further hypothesized that Absorption is associated with the VAL158MET polymorphism of the catechol-O-methyltransferase (COMT) gene affecting the dopaminergic neurotransmitter system. The Tellegen Absorption Scale was administered to 336 subjects (95 male, 241 female). Statistical analysis revealed that the group with the T/T genotype of the T102C polymorphism, implying a stronger binding potential of the 5-HT2a receptor, indeed had significantly higher Absorption scores (F = 10.00, P = 0.002), while no main effect was found for the COMT polymorphism. However, the interaction between T102C and COMT genotypes yielded significance (F = 3.89; P = 0.049), underlining the known functional interaction between the 5-HT and the dopaminergic system. These findings point to biological foundations of the personality trait of Absorption.

  • Stark, R., Schienle, A., Walter, B., Kirsch, P., Sammer, G., Ott, U., Blecker, C., & Vaitl, D. (2003). Hemodynamic responses to fear and disgust-inducing pictures: an fMRI study. International Journal of Psychophysiology : Official Journal of the International Organization of Psychophysiology, 50(3), 225–234. https://doi.org/10.1016/s0167-8760(03)00169-7

    The majority of neuroimaging studies on affective processing have indicated that there are specific brain structures, which are selectively responsive to fear and disgust. Whereas the amygdala is assumed to be fear-related, the insular cortex is most likely involved in disgust processing. Since these findings are mainly a result of studies focusing exclusively either on fear, or on disgust, but rarely on both emotions together, the present experiment explored the neural effects of viewing disgusting and fear-inducing pictures in contrast to neutral pictures. This was done by means of functional magnetic resonance imaging (fMRI) with 19 subjects (nine males, ten females), who also gave affective ratings for the presented pictures. The fear and the disgust pictures were able to induce the target emotions and they received comparable valence and arousal ratings. The processing of both aversive picture types was associated with an increased brain activation in the occipital-temporal lobe, in the prefrontal cortex, and in the thalamus. The amygdala was significantly activated by disgusting, but not by fear-inducing, pictures. Thus, our data are in contrast with the idea of highly emotion-specific brain structures and rather suggest the existence of a common affective circuit.

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Last update from database: 11.08.25, 05:41 (UTC)