Final answer:
Damage to the orbitofrontal cortex impairs decision-making as it is crucial for planning, judgment, and regulating emotions, as shown by the case of Phineas Gage and further supported by neurological research.
Step-by-step explanation:
Damage to the orbitofrontal cortex can result in impaired decision-making due to its role in planning, judgment, reasoning, and working memory. The case of Phineas Gage, a railroad worker who survived a severe injury to his prefrontal cortex, illustrates how injuries to this part of the brain can bring about marked changes in personality and behavior, reflecting its crucial function in regulating emotional impulses and executing plans. Gage's experience post-injury, with his personality described as irritable, temperamental, and lazy, points to how the frontal lobe damage affected his emotional regulation and social behavior. This is corroborated by research that demonstrates the prefrontal cortex's involvement in decision-making processes and links between the frontal lobe and limbic system which are necessary for controlling emotional impulses.