Hard to Break: Why Our Brains Make Habits Stick

Psychologist Poldrack (The New Mind Readers) sheds light on the neuroscience and psychology behind habits in this scholarly survey. A habit, he writes, is “an action or thought that is triggered automatically by a particular stimulus,” and isn’t tied to a specific goal. As he explores why humans evolved to be so habit-driven, Poldrack considers dopamine, which is crucial in forming habits for its impacts on brain plasticity; questions the efficacy of mindfulness (now a “billion-dollar industry”); and covers the formation of addictions, which he calls “habits gone bad.” Poldrack’s study is strongest when he describes experiments on interrupting habit formation on a cellular level, which can potentially help one shed such undesirable behaviors as smoking and overeating. (For instance, after cocaine-addicted rats were given drugs that block the formation of a protein that is important for memory, they forgot that a stimulus is associated with the drug.) A plethora of diagrams, italicized key terms (basal ganglia, subthalamic nucleus, corticostriatal loops), and chapter summaries, however, give the survey a textbook-like quality. Still, this is a worthy intellectual adventure, one that’s well articulated for readers looking for rigorous study. Illus. (May)