It is not so much alpha state but the flow state.
In the flow state your mind is functioning at 'whatever' brainwave pattern it requires to do the task. The flow state is where you are 'working' with full focus on the task at hand. During this time nothing distracts you.
The work is just challenging enough to be interesting and at the same time within your level of ability
http://exploreit.net/improvethought/flow1.htm
Check out that site for an explaination of the flow state.
Alex
