MIT explains why bad habits are hard to break

By John M Grohol PsyD
October 20, 2005

Apparently, habits may form familiar neural pathways which makes it more difficult to break the pattern of behavior. This makes a lot of sense, given people’s difficulties with trying to break a habit they want to be rid of.

Habitual activity–smoking, eating fatty foods, gambling–changes neural activity patterns in a specific region of the brain when habits are formed. These neural patterns created by habit can be changed or altered. But when a stimulus from the old days returns, the dormant pattern can reassert itself, according to a new study from the Massachusetts Institute of Technology, putting an individual in a neural state akin to being on autopilot.

“It is as though, somehow, the brain retains a memory of the habit context, and this pattern can be triggered if the right habit cues come back,” Ann Graybiel, the Walter A. Rosenblith Professor of Neuroscience in MIT’s Department of Brain and Cognitive Sciences, said in a prepared statement. “This situation is familiar to anyone who is trying to lose weight or to control a well-engrained habit. Just the sight of a piece of chocolate can reset all those good intentions,” Graybiel said.

The neural patterns get established in the basal ganglia, a brain region critical to habits, addiction and procedural learning. In Graybiel’s experiments, rats learned via specific cues that there was chocolate at one end of a T-shaped maze. While the rats were still learning, their basal ganglia neurons chattered throughout the maze run. That’s because in the early stages, the brain seeks out and soaks in information that could prove important.

As the rats learned to focus in on guiding cues (in the experiment, an audible tone that guided them toward the chocolate), the behavior of the neurons changed. They fired intensely at the beginning and the end, but remained relatively quiet while the rats scurried through the maze.

Dr. John Grohol is the CEO and founder of Psych Central. He has been writing about online behavior, mental health and psychology issues, and the intersection of technology and psychology since 1992.