Finke's men face Mali in Malabo on Tuesday in their opening Group D campaign with a point to prove after bowing out of the World Cup in Brazil after three defeats.
"I really think the spirit, the mentality has changed," the German said, who surprised many by staying on after the World Cup. "The last two or three months there has been a closed dressing room. Good work starts from there. Nothing has leaked out of the dressing room. The group is united and all working together."
When pressed to recall the events of last summer, a clearly irritated Finke said: "There was one very good experience, which was the preparation in Austria, at the end of which we drew (2-2) with Germany, with a really good performance of the team.
"It was maybe a bit dangerous to go into the World Cup with everyone thinking it was going to be great. Then afterwards all these reasons why we had this unacceptable World Cup...it's not the day, it's not the time, it's over now.
"We are just working towards the future. I know what was going on and this is why we always pay attention to make sure we keep going in the same direction."
Cameroon also face Côte d'Ivoire and Guinea in their group at the Cup of Nations.