What are the physiological effects of high-speed driving?

• A. Enhanced reaction time, improved peripheral vision
• B. Calmness, steady breathing
• C. Heightened hearing, improved hand-eye coordination
• D. Increased heart rate, tunnel vision, reduced depth perception, forebrain shutdown, and decreased fine and complex motor skills

Answer: (D)

Going fast triggers the body’s fight-or-flight response, flooding the system with adrenaline and stress hormones. That causes the heart to race, breathing to quicken, and pupils to dilate. With heightened arousal, the visual field often narrows into tunnel vision, and depth perception can suffer as processing resources are diverted to the most immediate threats rather than precise spatial judgments. Cognitive resources and motor control can also decline under extreme stress, making fine and complex movements harder and impairing higher-level thinking. This combination—higher heart rate, narrowed vision, impaired depth perception, reduced executive processing, and decreased precision in skilled actions—best matches how the body realistically responds to high-speed driving.

The other options describe states that don’t align with this physiological reality: calmness or steady breathing contradicts the arousal response; enhanced reaction time or peripheral vision ignores the common narrowing of attention and sensory tunnel at high speed; and while hearing can be sensitive, “heightened hearing” and “improved hand-eye coordination” don’t reflect the overall degradation of perception and coordination that occurs under extreme speed.