The Fourth Edition of An Introduction to Brain and Behavior continues to ref lect the evolution of behavioral neuroscience. The major change in emphasis in this edition is the incorporation of epigenetics throughout. DNA, previously believed to be an unchanging template of heredity, is now known to respond to environmental events throughout life, leading to the concept of an epigenome, a record of the chemical changes to the DNA that regulate gene expression.
Epigenetics is especially important for understanding brain and behavior because environmentally induced modifications in gene expression alter the brain and ultimately behavioral development. Thus, experience—especially early experience— modifies how brain development unfolds. These modifications—of at least some behavioral traits—can be transferred across generations, as noted at the end of Section 3-3.
This edition fully addresses the advances in imaging technology, including the development and refinement of such MRI techniques as resting-state fMRI and diffusion tensor imaging, that are fueling the emerging field of connectonomics. As shown in the image on the book’s cover, researchers are working to create a comprehensive map of neural connections—a “connectome” of the brain. These exciting advances are especially relevant in the second half of the book, where we review higher-level functions.