There is a 4 part discussion series on YouTube about the the MRI study, part 1 is here:
https://youtu.be/I5ZjNUWnhgk You can follow the links below that video for the other parts.
And the actual MRI video:
https://youtu.be/I5kogDrivvQ Also, if you want to play with blues in the key of A, using 2nd position/cross harp, you’d need a harmonica in the key of D, not E. E harmonica plays in the key of B in second position.
That said, D harps are pretty high pitched and hard on the ears particularly for working the high blow bends. So, you’d probably want a low D harp for playing in A all the time, but the low bends on that are tough for someone new to bending. Better to start with an A harmonica and play along to blues in E: Easier to learn all the bends on an A harp, and the lower pitch is more comfortable for you and those around you.