Since the turn of the year, Wenger's men have been comprehensively beaten at Liverpool, Chelsea and Everton - conceding 14 goals during those matches.
A 5-1 loss at Anfield and 6-0 thrashing at Stamford Bridge saw Arsenal drop out of the title race, though Sunday's 3-0 defeat at Goodison Park was a big blow in their bid for a UEFA Champions League spot.
Everton are now just a point behind Arsenal with a game in hand, also holding the momentum of five consecutive wins under their belt.
Wenger acknowledged heavy defeats away from home have taken their toll but refused to question the spirit within the Arsenal dressing room.
He said: "Maybe our big defeats away from home have taken some charisma away from the team. Is that fear? Is that belief? Is that confidence? Maybe a bit all together.
"Until (the 6-1 defeat at Liverpool) we were very strong away from home, we had the best record in the league away from home, and psychologically we have lost confidence.
"I wouldn't question the spirit of this team because they are focused and want to do well.
"I just feel they have lost something on the confidence front that you could see and we looked a little disjointed when we had to run after the score (against Everton)."
Wenger's side take a break from their faltering Premier League campaign next weekend as they are in FA Cup semi-final action against holders Wigan Athletic.
