In most of the neuroscience studies I conduct, participants complete tasks with minimal environmental variability (meaning how much they can do and how many things they can look at). Movement is important for cognition but EEG is extremely sensitive to muscular activity, and I want the signal to reflect cognitive processing, not noise.
As a result, participants tend to look at the same screen, at roughly the same place, with fewer competing visual choices. They can still move a bit, take notes, and think freely, but the number of ways the information can be visually processed is limited. When I later see strong memory for the content, it reminds me that the lack of variability helps with information encoding.
Which leads to a practical guideline: if you want people to remember your main message (I call this the 10% message because people tend to forget 90%), reduce the number of ways they can process it. This could mean fewer layouts if you're using slides, or one strong visual or mental model, rather than several competing ones.