The power Itachi gave Naruto, it definitly has something to do with either making him a bit smarter, or allowing him to learn/master new jutsus faster.
I think it's the latter, if you've noticed his progress since he went to the frog mountain, he has learned one of the hardest type of training (according to Fukusaku) so quickly.
I think it's the latter, if you've noticed his progress since he went to the frog mountain, he has learned one of the hardest type of training (according to Fukusaku) so quickly.