Dr Christian Keitel | Physiological influences on brain state changes and their consequences for subjective perception and performance

Changes in brain state over time impact our perception and may influence performance. I will

present some findings that show that cortical state influences perception beyond the stimulus

detected-vs-not-detected dichotomy, and characterise the fluctuations themselves more

closely in the process. I will also tell you why we may want to consider them more rigorously

in our data analysis using the example of pre-stimulus alpha oscillations. Drawing on another

set of recent results, I will review arousal-linked neuromodulation as one likely source of

cortical state fluctuations. Against a previously held notion of arousal as a global influence on

cortical state, our analysis of simultaneous pupil and MEG recordings show diverse

neuromodulatory influences that differ depending on the targeted cortical region, can express

in brain oscillations of different frequency bands or as broadband effects, and vary in their

timing. Finally, I will show recent results that tie arousal fluctuations to another physiological

rhythm. Taken together, these findings give a better understanding of how, when and where

brain state changes manifest, what their perceptual consequences are and where some of

them may originate.

Poster