The famous case of Phineas Gage, a railroad worker who lived after a metal bar passed through his brain, offered insights about brain functions. Similarly, some researchers remove parts of the brain in animals to observe changes in behavior. These studies rely on:.

Lesions

Explanation:

LESIONS can be defined as the process that occur when a person or an individual suffers any damage in which such damage leads to abnormal change in the tissue organ of that person and it is usually caused by disease or when the person suffer trauma as well as injury and it may as well occur in plants as well as animals although the common causes of this LESIONS can have causes that aren't due to underlying disease. such as birthmarks, or scars while the most common causes of skin lesions are injury, aging, infectious diseases among others.

Examples in a situation where a perosn has severe diseases it can cause skin lesions.

Therefore based on the scenario some researchers remove parts of the brain in animals to observe changes in behavior which was why the study rely on LESIONS.

These studies rely on lesions.

Explanation:

A lesion is a tissue, area of an organ which has suffered damage to some extent, as consequence of an injury, disease, etc.

The study of Phineas Gage and similar ones rely on lesions because they center on removing parts of the brain in order to physically observe the changes and lesions.

This helps researchers gain insight about brain functions.

acid rain is the answer