6533b861fe1ef96bd12c4335

RESEARCH PRODUCT

Kognitive Prozesse und dynamische Zeitstrukturen. Vorstellung eines Meßgerätes zur Untersuchung der Mikro-Vigilanz-Shift-(MVS-)Hypothese. Cognitive Processes and Dynamical Time Structures. Introduction of a Method for Testing the Microvigilance Shift (MVS) Hypothesis

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The psychophysiological measuring method for the determination of the auditory order threshold (OT) is steadily gaining in importance, both for the diagnosis and treatment of speech disorders. Observed intraindividual variability of (macro-) vigilance led to the hypothesis of discontinuous cognitive processing in the central nervous system. The base for the variability of microvigilance is hypothesized to be in the phase difference of the alpha rhythm. To test for this hypothesis, we developed an EEG-comparator, which allows for a phase-dependent triggering of external stimuli. In direct comparison with stochastic (i.e. non-phase-dependent) stimulus presentation, the threshold in phase-dependent OT-testing is distinctly lower. Optimal results occurred at phase angels of phi = 90 degrees and phi = 270 degrees. Our findings support the hypothesis of a correlation between alpha rhythm and vigilance processes. Furthermore, there seems to be evidence that memory processes go with changes in vigilance, and in this context the alpha phase correlation seems to be important.