Which item is NOT a physiological effect associated with high-speed driving?

• A. Increased heart rate
• B. Tunnel vision
• C. Forebrain shutdown
• D. Increased fine motor precision

Answer: (D)

High-speed driving triggers acute stress responses that heighten arousal and affect perception and control. When the body perceives danger or the need for rapid action, the sympathetic nervous system ramps up, causing the heart to beat faster to supply muscles with blood and oxygen. This level of arousal also tends to shrink the visual field to focus on the most immediate cues, producing tunnel vision. In extreme stress, higher brain processing can be overwhelmed or temporarily dampened, often described as a forebrain shutdown, which can impair judgment and decision-making in the moment. These are typical physiological effects of intense driving situations. Increased fine motor precision, however, is not expected; under high arousal, fine motor control usually worsens due to tremor, distraction, and the brain reallocating resources to rapid threat assessment rather than precise, delicate movements. So the statement that describes increased fine motor precision is not a physiological effect of high-speed driving.