After a few failed attempts, I finally got clear results!
I could not wait any longer for the weather to be cloudy again, so I tried doing the run during the dimmed sunset gap. We had to set up and do the Poptahof-run fast in order to avoid darkness.
The results were quite astonishing. The eye-tracked video shows clearly where the subject is looking at, while the EEG data shows peaks in the brain-wave activity.
Next step… analysis!