Subitizing Project

I have a general interest in numerical cognition. This is partially because of my frustrated experience of learning math in the primary school. I want to find out what kind of factors may determine the learning outcome of math (although I already know a grumpy teacher will definitely lead to a negative result) and I want to understand the neural basis of numerical cognition. Specifically, I am interested in understanding the subitizing ability and how it plays a fundamental role in the development of numerical cognition.