Invited talk "Visual perception and alpha rhythms in the brain: new twists in an ongoing story"

by Christian Keitel,

Centre of Cognitive Neuroimaging (CCNi),

University of Glasgow


will take place on Thursday, 5 April 2018 from 16:00 to 17:00 hours in CBBM, Ground Floor, B1/B2.

Host: Prof. Jonas Obleser
Institute of Psychology I
University of Lübeck


Nearly a century ago Hans Berger first described the human alpha rhythm. Since then we have covered considerable ground in learning about the role of this periodic brain activity in perception and cognition. Still, with the precision of our instruments constantly evolving, our picture of alpha and its functional role grows ever more complex. My talk will touch on two trendy aspects of alpha in visual processing. First, I will critically discuss whether the alpha rhythm can be externally driven or "entrained" through periodic visual stimulation and pit this notion against seemingly contradictory findings from frequency-tagging research (i.e. studying visual processing with flicker). Secondly, fluctuations in alpha influence the perception of subsequently presented stimuli. We tend to think of these pre-stimulus fluctuations as spontaneous, stochastic processes. Challenging this idea in a recent line of M/EEG, we found that at least part of this pre-stimulus variability in alpha can be accounted for by long term trends in alpha power and frequency (1-2 hrs) during continuous task performance. I will discuss implications of these findings for studying the relationship of pre-stimulus alpha and (measures of) behavioural performance.

Research Focus

During my PhD at the University of Leipzig in Germany I studied visual and audio-visual processing in the human brain through frequency tagging. Thus grown up scientifically in a world of flicker, to date, I remain interested in how the visual system deals with ongoing dynamic stimulation. Also, I still undertake frequent excursions into the realms of multisensory processing, intrinsic brain rhythms and, most recently, the relationship between brain activity and bodily tell-tale signs such as fluctuations in pupil size.