I‘m with you that „2nd brain“ makes little sense. It‘s clever marketing though.
I mean categorization, metaphorical structuring, embodied cognition, and kinesthetic image schemas in particular. It seems to me that these universal patterns are more or less directly applicable to user interface design. That‘s just a hypothesis, I haven’t seen any papers that make that connection directly, but it makes a lot of sense to me. It’s probably more likely to find some research in data visualization where a lot of how we understand things like bar charts, line graphs, or scatter plots makes extensive use of spatial metaphors, e.g. More is Up. From there, thinking about interactive data visualization and exploratory data analysis, it‘s not that far to general UI/UX.
I find all this especially appealing, as we are moving towards an AR world where gestures and physicality will play an even more important role than they do already in touch screen interfaces. The trend of „bouncy“ animations and drag operations that emulate „weight“ are not just fashion but exist for good reasons. If you ever wondered what a user interface framework needs a physics engine for, embodied cognition seems a pretty compelling argument to me.
And there are likely applications beyond just UI/UX. Since these patterns are universally understood across languages and cultures, they can also be useful in teaching concepts more effectively by explaining abstract concepts like e.g. set theory with the intuitively understood container schema. Which is kind of what our intuition for these abstract mathematical concepts is based on anyway, but we usually have to stare at a lot of abstract symbol manipulation to magically absorb that intuitive understanding ourselves. This should be at least as relevant if not even more relevant to teaching programming.
I realize that I spent a significant amount of time in that particular rabbit hole to emerge from it with a shiny new hammer, and now there‘s a lot of nails everywhere I look… I‘m sure it‘ll work on at least a few of them though.