The new edition continues the Brain and Behavior tradition of incorporating the latest research throughout the book. Revisions include new material discussing current research on genetic mosaics and modification, including transgenic techniques and optogenetic techniques, neurotransmitters, hormones, brain development in adolescence, psychobiotics, color perception, and biorhythms, as well as updates to the discussion of specific disorders to reflect the current state of understanding, including Parkinson's disease, Alzheimer's disease, depression and drug dependency, sleep disorders, schizophrenia, glaucoma, and abnormal development related to prenatal experience.