7 (and a half) myths about your brain

Hormones don't just have one specific psychological purpose, and all the chemicals work together in your mind.

• Cortisol boosts the amount of glucose in your bloodstream for a quick burst of energy, such as before you exercise or wake up in the morning, not just when you are stressed.
• Serotonin has many functions. It regulates how much fat is made and helps keep track of your energy. It also helps other neurons pass on information as they create your thoughts, feelings and actions.

All of your sensations are computed in your brain.

• You see with your brain, based on what is in your brain and the sense data from your eyes.
• You hear with your brain as it makes sense of sounds based partly on the data from your ears.
• Your skin has no sensors for wetness. Instead, your brain combines several sources of information, including touch, temperature, and knowledge from experience, to create a feeling of being wet.

During any day, it can seem like your brain is reacting to events around you. You're pricked by a needle and feel a bit of pain.

However, your brain constantly predicts the next moment and compares the guess to the data it receives from the world and inside your body. These predictions turn into your actions.

Decades ago, scientists noticed neurons increase their activity when an individual is taking a particular action, for example, waving when others are waving. They named them "mirror neurons."

But, your brain is really predicting your next action based on what you see, hear, and feel if you move. Seeing someone wriggle their fingers in the air and understanding it as a greeting is a normal part of your brain's predictive processes.

Your brain doesn't store memories like a filing system. Your brain reconstructs your memories on demand with electricity and chemicals.

"Remembering" is really "assembling" and may be influenced by your current situation, so your brain may reshape each occurrence so that it differs in the details.

Most parts of the human brain can't grow new brain cells, but some parts can.

The hippocampus can grow new neurons. The hippocampus is important for learning, remembering, regulating your eating, and other biological functions.