Ihre Suche

Suche zurücksetzen
Team
Thema

Ergebnisse 2 Einträge

Neueste zuerstÄlteste zuerstAutor A-ZAutor Z-ATitel A-ZTitel Z-A
Abstracts
  • Kornmeier, J., Friedel, E., Hecker, L., Schmidt, S., & Wittmann, M. (2019). What happens in the brain of meditators when perception changes but not the stimulus? PloS One, 14(10), e0223843. https://doi.org/10.1371/journal.pone.0223843

    During the observation of an ambiguous figure our perception alternates between mutually exclusive interpretations, although the stimulus itself remains unchanged. The rate of these endogenous reversals has been discussed as reflecting basic aspects of endogenous brain dynamics. Recent evidence indicates that extensive meditation practice evokes long-term functional and anatomic changes in the brain, also affecting the endogenous brain dynamics. As one of several consequences the rate of perceptual reversals during ambiguous figure perception decreases. In the present study we compared EEG-correlates of endogenous reversals of ambiguous figures between meditators and non-meditating controls in order to better understand timing and brain locations of this altered endogenous brain dynamics. A well-established EEG paradigm was used to measure the neural processes underlying endogenous perceptual reversals of ambiguous figures with high temporal precision. We compared reversal-related ERPs between experienced meditators and non-meditating controls. For both groups we found highly similar chains of reversal-related ERPs, starting early in visual areas, therewith replicating previous findings from the literature. Meditators, however, showed an additional frontal ERP signature already 160 ms after stimulus onset (Frontal Negativity). We interpret the additional, meditation-specific ERP results as evidence that extensive meditation practice provides control of frontal brain areas over early sensory processing steps. This may allow meditators to overcome phylogenetically evolved perceptual and attentional processing automatisms.

  • Kornmeier, J., Friedel, E., Wittmann, M., & Atmanspacher, H. (2017). EEG correlates of cognitive time scales in the Necker-Zeno model for bistable perception. Consciousness and Cognition, 53, 136–150. https://doi.org/10.1016/j.concog.2017.04.011

    The Necker-Zeno model of bistable perception provides a formal relation between the average duration of meta-stable percepts (dwell times T) of ambiguous figures and two other basic time scales (t(0), ΔT) underlying cognitive processing. The model predicts that dwell times T covary with t(0), ΔT or both. We tested this prediction by exploiting that observers, in particular experienced meditators, can volitionally control dwell times T. Meditators and non-meditators observed bistable Necker cubes either passively or tried to hold their current percept. The latencies of a centro-parietal event-related potential (CPP) were recorded as a physiological correlate of t(0). Dwell times T and the CPP latencies, correlated with t(0), differed between conditions and observer groups, while ΔT remained constant in the range predicted by the model. The covariation of CPP latencies and dwell times, as well as their quadratic functional dependence extends previous psychophysical confirmation of the Necker-Zeno model to psychophysiological measures.

RIS

Empfohlenes Format für die meisten Literaturverwaltungsprogramme

BibTeX

Empfohlenes Format für BibTeX-fähige software

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