Picking Your Brains

Picking Your Brains is a side quest in the Fallout: New Vegas add-on Old World Blues.

Detailed walkthrough
Dr. 8, if the player has a Perception of 7 or Intelligence, they can understand him. If the player has a Science skill of 75 they can program him to mindlessly do what they want.

Dr. Borous, with a high enough Speech skill the player can talk to him about the fact that his experiments have escaped the Big MT and into the Mojave, although he refuses to believe you.

Dr. 0, if the player has an Intelligence of 9 or higher or the Math Wrath perk, the player can work out his real name is "Dr. Zero".

Dr. Klein, by following various dialogue routes and having a good level of the Medicine or Science skill, the player can gather info about the other courier, Ulysses, and Father Elijah.

Dr. Dala, if the player has a high enough Medicine or Charisma or the Cherchez La Femme perk, they can work out that she misses her body and secretly has some sort of fetish for teddy bears, which can be used to complete her portion of the quest. Teddy bears can be obtained in Dr. Dala's room on the 2nd floor of her home in Higgs Village.