If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Unit 9: Brain function and mental health

About this unit

Aristotle said that what separates humans from other animals is our ability to engage in high reasoning. This reasoning includes problem solving, making decisions, and recalling memories. Learn about different states of consciousness and how our brain responds and adapts to stimuli.