The human brain -- that three-pound mass of gray and white matter between your ears -- is the most complex object in the universe.

It contains as many neurons as there are stars in the Milky Way galaxy, and we know as much (or as little) about how they function as we know about all those stars.

This fascinating article from Discover Magazine takes a look at 10 of the so far unsolved mysteries of your brain, including:

• How is information coded in neural activity? Neurons are specialized cells within the brain that produce brief spikes of voltage in their outer membranes. Each neuron in the cortex receives input from as many as 10,000 other neurons. But what is the code? They used an apt description to describe the problem. It’s like taking the cover off a computer, measuring the chatter of high and low voltage between a few transistors and trying to figure out the content of the Web page being viewed.
  
  
• How are memories stored and retrieved?
  When you learn something new, your brain undergoes physical changes, but no one really knows what those changes are. Even more mysterious is the act of memory retrieval. How is it that certain answers are immediately obvious to you?
  
  
• What are emotions and feelings?
  Brains are often referred to as information-processing systems. But that doesn’t account for your brain’s role in “creating” emotions, fears, and hopes. Emotions are measurable physical responses to stimuli: the increased heartbeat and perspiration that accompanies fear, for example. Feelings, such as happiness, envy or guilt, are even more perplexing. These are entirely subjective experiences that may or may not accompany the emotional process.

One thing’s clear, however -- whether we’re ever able to decode the human brain or not -- and that is the fact that your brain is intricately involved in your overall health, whether mental, emotional, physical, or spiritual. A healthy lifestyle can help protect, nourish, and revitalize that most valuable asset -- your brain.

Discover Magazine July 31, 2007