Arteta thinks that a lack on concentration is undermining his team's efforts to finish in the top four.
The Spanish midfielder told the club's official website: "When they equalised, I could not believe it. They did not even go through the middle of the park in the second half. The first time they did, on the break from our corner, they scored a goal.
"It was very disappointing but we kept trying, kept believing and I think we were rewarded at the end because we deserved to win the game. I don't know if it's nerves, but when things aren't going in your direction, like the Blackburn game [where] you analyse the stats of the game, it's absolutely amazing that we haven't won the game.
"Sometimes [mistakes come from] a bit of a lack of concentration. Or [if] a team-mate makes a mistake, the second one cannot be a mistake again. For every small detail, the other teams are taking advantage and it's costing us a lot of points."