Final answer:
The optic lobe is the section of the fish brain used to process vision, learning, and motor responses.
Step-by-step explanation:
The section of the fish brain that is used to process vision, learning, and motor responses is the optic lobe. The optic lobe is responsible for receiving and processing visual signals from the eyes. It plays a key role in vision and helps coordinate motor responses based on visual input. For example, if a fish sees a predator approaching, the optic lobe would process this visual information and trigger a motor response, such as swimming away.