Blackspots and Self-Communication

This was something I tried. Please let me if it works for you...
The term 'exact middle' is used over 'middle' as precision appears to make a difference...

When focusing energy to the (exact middle at) rear of the head, there is difficulty in perception, when tried at same time. (Black-spot?)

When focusing energy directly forward (at exact middle), there is difficulty using self-communication, when tried at same time. (Area of extra-communication?)

The most difficult thing was attempting to focus close enough to, and engaging the exact middle...

Any thoughts why this is so?..
Or any people have no difficulty at all?