Mental Plinko is used to define the path taken by a thought through your mind from one topic to another, seemingly unrelated, topic.
"Sorry I just spaced out there for a second. When you mentioned your car troubles I had a bit of a mental plinko. First I thought of cars, then I thought of those little air fresheners that hang on the mirror, that led me to thinking about smells in general, and then I remembered that horrible fart you ripped off in the cafe the other day."
by EgoAnt November 24, 2004