Dr. Ivan Chakalov Universitätsmedizin Göttingen Klinik für Anästhesiologie Robert-Koch-Str. 40 D-37099 Göttingen E-mail: chakalov.ivan@googlemail.com Website

PhD in 2014

Research Project

Neuroimaging of primary and schema-based auditory stream segregation, involving peripheral and central neuronal mechanisms

The ability of humans and animals to focus their attention on a single sound source among other surrounding sounds and background noises was described in the framework of the well-known “cocktail party effect”. Auditory Scene Analysis (ASA) is a widely accepted cognitive model concerned with resolving the “cocktail party effect” (Bregman AS 1990). The model explains the perceptual organization of sounds based on the main principles of Gestalt psychology. These principles include perceptual-segregation of acoustical patterns into separated sound-streams also known as “stream-segregation” or “fission”, and the complementary process, the perceptual-integration of sound-streams into one unified auditory object, also known as “stream integration” or “fusion”. Despite of the general knowledge about the psychophysical bases of ASA, its neural underpinnings are still poorly understood. My project investigated the neural correlates of auditory scene analysis by introducing novel perceptual paradigms in three different studies published in peer-review scientific journals. Magnetoencephalography (MEG) was used to explore the neural effects in the three experiments. The three studies propose advanced techniques and experimental paradigms for analysis of various aspects of auditory perception and their underlying neural mechanisms via different neuroimaging techniques.

PhD Committee

Prof. Dr. Christo Pantev , Institute for Biomagnetism and Biosignalanalysis, WWU Münster, Supervisor
Prof. Dr. Norbert Sachser, Institute of Psychology, WWU Münster
Prof. Dr. Markus Lappe , Department Of Behavioural Biology, WWU Münster

Publications (first authorships)

Chakalov I, Paraskevopoulos E, Wollbrink A, Pantev C. 2014 Mismatch negativity to acoustical illusion of beat: what and where change detection takes place? NeuroImage, DOI: 10.1016/j.neuroimage.2014.06.026. Web.

Chakalov I, Draganova R, Wollbrink A, Preissl H, Pantev C. 2013. Perceptual organization of auditory streaming-task relies on neural entrainment of the stimulus-presentation rate: MEG evidence.
BMC Neuroscience 14:120-2202-14-120. Web.

Chakalov I, Draganova R, Wollbrink A, Preissl H, Pantev C. 2012. Modulations of neural activity in auditory streaming caused by spectral and temporal alternation in subsequent stimuli: A magnetoencephalographic study.
BMC Neuroscience 13:72-2202-13-72. Web.

Conference Contributions (first authorships)

Chakalov I, Wollbrink A, Pantev C. Perceptual organization of sequential auditory objects relies on oscillatory entrainment of the stimulus presentation rate: MEG evidence. Poster presentation at Neurovisionen – 9 (Neuro NRW), 29 November 2013, Köln, Germany

Chakalov I, Draganova R, Wollbrink A, Preissl H, Pantev C. Modulations of neural activity in auditory streaming induced by spectral and temporal alternations of the prior stimuli: an MEG study. Poster Presentation at 18th International Conference on Biomagnetism - Biomag 2012, 26-30 August 2012, Paris, France

Chakalov I, Draganova R, Wollbrink A, Preissl H, Pantev C. Neural bases of auditory stream segregation: magnetoencephalographic study. Poster Presentation at Lifelong Learning conference Tübingen, 25-27 November 2010, Tübingen, Germany

Work Experience

CV