In her book "Grunt: The Curious Science of Humans at War," Mary Roach discusses a phenomenon called attentional narrowing, which is often referred to in more colloquial terms as "tunnel vision." This response is a remnant from our prehistoric past, originally designed to help humans focus on immediate threats for survival. However, in modern contexts, this intense focus can lead to dangerous lapses in awareness of surrounding conditions and events.

Roach illustrates this concept through an anecdote shared by Bruce Siddle about a doctor and an anxious intern. Tasked with stitching a laceration on a car crash victim, the intern became so absorbed in his work that he failed to realize the patient was already deceased. This example highlights how stress and concentration on a singular task can lead to significant oversights, demonstrating the inherent risks of attentional narrowing in critical situations.