• A "blank stare"
• Reduced ability to focus
• Emotionally distant, not as passionate. Will not get heated up about anything.
• A bit slower on the uptake, requires repeating things. Not as common.

These things may be characteristic of some people and it's not a value judgement. I'm talking here about consistent changes I've noticed in the vaccinated.

Edit: Adding some psychomotor signs:

• fatigue or lethargy
• clumsiness