I don't know if there's a word for it, but 'unconscious multitasking' is the best one I can make up. Basically, when I try to switch tasks, one part of my brain is still focused on the previous task, and the other part is focused on the new task. I can barely think about the new task, and I feel like I'm in a mental fog. The thing is, I can still work on both tasks, just not at 100%. Two different processes are going on in my brain and they are both fighting for the same resources. The other day, I ended up working on two different coding projects at once. One of them was a crazy homebrew AI, and the other was a system which is basically AI dungeon with a background simulation of the world. Every five minutes I'd alt-tab to the other project to write another five lines of code before switching back.
Historically, I've had similar things happen when I was extremely emotional or in shock. I would sort of split into two thought processes running at the same time. I remember once I was crying because I was having a psychotic-depressive episode, and I was simultaneously having negative thoughts about myself, thinking about how to coordinate these negative thoughts with my wailing, and criticizing myself for being disingenuous for planning my own ability to express my emotions!
I don't know if this is some AuDHD thing, or just unique to me. I haven't been diagnosed with ADHD, but my brother has it, and a psychiatrist once did an EEG on me and said I had 'similar brainwaves to a person with ADHD.' I don't really have any traditional symptoms of ADHD (inattentiveness, distractibility, hyperactivity, etc.) So I'm wonder if any of you, especially those with AuDHD, have had similar experiences.