bioRxiv preprint doi: https://doi.org/10.1101/2021.02.27.433162; this version posted March 1, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Dynamic signatures of the Eureka effect: An EEG study Yiqing Lu a, b, c, d * and Wolf Singer a, b, c a Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt am Main, Germany b Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany c Department of Neurophysiology, Max Planck Institute for Brain Research, 60528 Frankfurt am Main, Germany d Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany * Correspondence:
[email protected] Abstract The Eureka effect refers to the common experience of suddenly solving a problem. Here we study this effect in a pattern recognition paradigm that requires the segmentation of complex scenes and recognition of objects on the basis of Gestalt rules and prior knowledge. In the experiments both sensory evidence and prior knowledge were manipulated in order to obtain trials that do or do not converge towards a perceptual solution. Subjects had to detect objects in blurred scenes and signal recognition with manual responses. Neural dynamics were analyzed with high-density Electroencephalography (EEG) recordings. The results show significant changes of neural dynamics with respect to spectral distribution, coherence, phase locking, and fractal dimensionality. The Eureka effect was associated with increased coherence of oscillations in the alpha and theta band over widely distributed regions of the cortical mantle predominantly in the right hemisphere.