I actually had the opposite effect this past weekend.
Went to my buddies house, and was shooting with him in his backyard. We were shooting at a Block Target with 10 different spots, and X's , and other different stuff going on on the face of the target.
I only shoot at bails with a plain cardboard target I cut out and put a couple white accents on the belly, etc to give it a real life feel, or a 3D deer target.
I could not for the life of me concentrate on one of the 10 spots on the target. There was so much going on with that target, I couldn't concentrate for heck...
I prefer shooting at things that force me to "find a spot" and concentrate. If a target is too diluted with spots to look at, I crumble..