Positive reinforcement mechanism

1. Ventral Tegmental Area vs. Nucleus Accumbens (Neuroscience Tips)
2. Active Users vs Registered Users (Player-Centric Gamification Tips)
3. Player Goals vs Game Goals (Gamification Achievement Systems Tips)
4. Substantia Nigra vs. Ventral Tegmental Area (Neuroscience Tips)
5. Game Difficulty vs Challenge Difficulty (Gamification Player Progression Tips)
6. Player Training vs Player Education (Gamification Achievement Systems Tips)