Watch 'Secrets of Your Mind': The Brain and Love
More 'Nightline' Brain Stories
Photos: Conjoined Twins Share a Brain The Twins Who Share a Brain premieres Tuesday on the National Geographic Channel
Amnesiac Can't Remember Last 46 Years Wife uses photos to help man re-learn life after he hit head in workplace fall.
When Your Dad Is a Mass Killer Son of D.C. sniper John Allen Muhammad lives in infamous dad's shadow.
Blackout! Research Explores Adverse Effects of Football's Hard Hits Research finds that high-impact football may lead to brain injuries.
Want to Lose Weight? Have Brain Surgery
EXCLUSIVE: Obese woman gets deep brain stimulation to control hunger pangs.
Watch: The Man Who Can't Forget
Go inside the mind of a man who remembers everything.
Early Alzheimer's Patient Loses Home
Prominent doctor's loss shows vulnerability of those who are not diagnosed.
Benoit's Dad: 'He Was a Kind & Gentle Man'
Benoit's dad, doctors say brain trauma influenced suicide, murder of family.