the tunnel vision and laser beam focus are part of the fight-or-flight reaction in situations that involve a lot of stress. i remember they taught us this back in school in the gen ed. health class socionics typings aside, this works the same way for almost everyone. i could relate to most of what has been written in this thread about stress, and I don't even type ESI, which tells me that much of this isn't type related and is generic physiological reactions to stress.