What a cool detail to notice! I remember a bit about that connection between blinking and different types of thought and memory access from some neuro research I did as a result of having a neuro disorder that it took a while to get diagnosed and just generally feeling it's good to be informed about my conditions. Anyway, once again I am in awe of SebStan and his acting ability. Even if he didn't know the connection specifically, the way his blinking connected Bucky's interest/mental presence to what was happening around him was one of the many, many little details that sold a character with so little dialogue and so little screentime (and then so little of it with his face showing), but that even really attentive viewers (like fans) wouldn't consciously pick up on until the umpteenth meticulous rewatch. I also feel like the way the blinking ties to Pierce's speech specifically shows that even when Bucky doesn't consciously remember, he's rebelling against the programming. It's still my headcanon that's a trait he encouraged in baby!Natasha. I think maybe that's what the "been out of cryo too long" comment was all about.

I can't cognitively parse Tumblr, so I only ever go there when given a specific link like this. That's one of my main gripes with the site; I find it really, really inaccessible for my particular set of issues.