Final answer:
During Phineas Gage's accident, the tamping rod passed through his frontal lobe, specifically the prefrontal cortex, which resulted in changes to his personality and behavior.
Step-by-step explanation:
During Phineas Gage's accident, the tamping rod passed through his frontal lobe. The frontal lobe is responsible for various cognitive functions, including personality, decision-making, and impulse control.
Phineas Gage's accident resulted in severe damage to his prefrontal cortex, which is located in the frontal lobe. This damage affected his personality and behavior, leading to changes in his temperament and decision-making abilities.
The effects of the injury to Phineas Gage's frontal lobe demonstrate the importance of this brain region in regulating our personality and social behavior.