Villa were leading 2-0 with a little over half an hour to play when Brentford scored three goals in nine minutes before Ollie Watkins netted an equaliser to salvage a point.
The result leaves Villa in fourth with 60 points from 32 games, three points ahead of Tottenham Hotspur who have two games in hand.
"In the 50th minute we lost everything we did. But in the last 20 minutes we recovered. I'm a little bit disappointed but at the same time I'm trying to understand and analyse in the 50th minute why we conceded three goals," Emery told BBC.
"It was really strange, we have to analyse. Tactically it is how we can manage that moment better, because it was not just one mistake. We can't lose the control like we did in that moment.
"Of course it is the Premier League, if you are losing control or some focus, they will score. They were amazing in nine minutes scoring three goals. They were clinical as well."
Villa suffered another blow late in the game when influential midfielder Douglas Luiz received his 10th yellow card of the season to earn a suspension.
Luiz has nine goals and five assists for Villa in the league this season but the Brazilian will miss the next two games away at title contenders Arsenal and at home to Bournemouth as the top-four race heats up.
"For me there is no pressure. We are enjoying. We've got to remember the first day (of the season), we played Newcastle and lost 5-1," Emery added.
"Now we are fourth. Of course we are not as consistent as we were before. Maybe we lose the fourth position, maybe we lose the fifth position. But the most important thing now is to have to try to keep balanced."
