Macroscopic Oscillatory Neuronal Correlates of Phantom Perception

Description

A growing body of evidence exists, showing that distinct oscillatory brain dynamics accompany normal as well as abnormal brain functions. However their functional relevance has remained elusive up to date. Next to studying brain oscillations in normal participants and in various disorders (such as tinnitus, pain etc.), the present project aims at deepening understanding, by investigating features of ongoing brain oscillations that are related to sensory experience and / or motor output (induced e.g. by Transcranial Magnetic Stimulation, TMS). Furthermore, a real-time EEG platform will be developed and interfaced to our stimulus presentation software as well as our TMS system, to 'probe' brain function in dependence of distinct parameters of the ongoing spontaneous brain activity.

Participants
  • Hartmann, Thomas - Academic staff
  • Keil, Julian - Academic staff
  • Müller, Nadia - Academic staff
  • Weisz, Nathan - Project leader
  • Franzkowiak, Stephanie - Academic staff
Institutions
  • Department of Psychology
  • Zukunftskolleg
Publications
    (2012): On the variability of the McGurk effect : Audiovisual integration depends on prestimulus brain states Cerebral Cortex. 2012, 22(1), pp. 221-231. ISSN 1047-3211. eISSN 1460-2199. Available under: doi: 10.1093/cercor/bhr125

On the variability of the McGurk effect : Audiovisual integration depends on prestimulus brain states

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The McGurk effect demonstrates the influence of visual cues on auditory perception. Mismatching information from both sensory modalities can fuse to a novel percept that matches neither the 10 auditory nor the visual stimulus. This illusion is reported in 60--80% of trials. We were interested in the impact of ongoing brain oscillations—indexed by fluctuating local excitability and interareal synchronization—on upcoming perception of identical stimuli. The perception of the McGurk effect is preceded by high beta activity in 15 parietal, frontal, and temporal areas. Beta activity is pronounced in the left superior temporal gyrus (lSTG), which is considered as a site of multimodal integration. This area is functionally (de)coupled to distributed frontal and temporal regions in illusion trials. The disposition to fuse multisensory information is enhanced as the 20 lSTG is more strongly coupled to frontoparietal regions. Illusory perception is accompanied by a decrease in poststimulus thetaband activity in the cuneus, precuneus, and left superior frontal gyrus. Event-related activity in the left middle temporal gyrus is pronounced during illusory perception. Thus, the McGurk effect 25 depends on fluctuating brain states suggesting that functional connectedness of left STS at a prestimulus stage is crucial for an audiovisual percept.

Origin (projects)

Funding sources
Name Finanzierungstyp Kategorie Project no.
Emmy-Noether-Programm third-party funds research funding program 789/08
Further information
Period: 15.05.2008 – 12.01.2014