Scientists who study the brain do so for many reasons. For some, the opportunity to study the most complex living structure in the known universe is itself an exciting quest. So much is still unknown about brain function and development.

Researching the brain and mind requires a major financial investment on a global scale, and takes place in a wide variety of locations and organizations.

Considered the most common mental illnesses, anxiety disorders affect an estimated 18 percent of the adult population in a given year, or 40 million Americans.

To be able to see anything, eyes first need to process light. Vision begins with light passing through the cornea.

Scientist targeted by animal rights activists asks about the ethics of inaction.

The brain uses a variety of chemicals called neurotransmitters to communicate between brain cells.

Insulation covering wires preserves the strength of the electrical signals that travel through them. The myelin sheath covering axons serves a similar purpose.

Medical science offers us a number of different ways to dull or treat pain.

Schizophrenia is a chronic disorder characterized by psychosis (e.g., hallucinations and delusions), flattened emotions, and impaired cognitive function.

Optical imaging relies on shining weak lasers through the skull to visualize brain activity. These techniques are inexpensive and relatively portable. They are also silent and safe: Because only extremely weak lasers are used, these methods can be used to study everyone, even infants.