There are many ways to achieve this state; closing one eye is a shortcut that may work for some. For me, achieving extremely high focus on a difficult problem w

There are many ways to achieve this state; closing one eye is a shortcut that may work for some. For me, achieving extremely high focus on a difficult problem will also induce this state, as my brain filters out all incoming signals to become singularly focused on the problem. If I'm pulled out suddenly to attend to something totally unrelated, I'll often be distracted by appreciating just how altered my senses are until they reacclimatize to "normal."