I think it's the exact opposite. Not concentrating enough...and a situation that can lead to target panic if you do not nip it in the bud...

A target with no bullseye or spot requires intense focus. A big bullseye or spot causes the subconcious & concious to get a little whacked out at times.."closer, closer, close enough, SHOOT" and you hammer the trigger home...and 99% of the time do not follow through either.

There is an old saying..."aim small".....I find I shoot my best when I'm shooting at 3D targets or otherwise picking a teeny spot on a blank target or such. Sometime I'll pick up a small leaf and pin it to my target..other days I'll stand a small branch up on it and shoot the width of the branch, and once I get focused, I start nailing that branch..yet I can go to the range and shoot very poor at a 3 or 5 spot target...just too much bullseye...can't focus enough on that X with my aging eyes and no scope.