MIT neuroscientists are testing a headset that uses a 'disco' of light and sound to treat Alzheimer's disease

• Alzheimer's disease is a complicated and debilitating disease that has no cure.
• One startup is testing whether a "disco" of light and sound can slow the disease in patients.
• Cognito Therapeutics raised $73 million to test this theory in hundreds of people.

For decades, biotech companies have struggled to develop treatments for Alzheimer's disease, a disorder that causes loss of memory and other mental functions and affects roughly 6.5 million Americans.