Automaticity and the Brain Science of Breaking Bad Habits

"When we look at living creatures from an outward point of view, one of the first things that strike us is that they are bundles of habits. The more of the details of our daily life we can hand over to the effortless custody of automatism, the more our higher powers of mind will be set free for their own proper work." —William James, The Principles of Psychology (1890)

Dorsal striatum anatomy in yellow and orange. Subcortical striatal circuits and the dorsolateral striatum (DLS) play a key role in the automaticity of habitual behaviors that occur in a familiar sensory context and require little conscious effort.

Source: Kateryna Kon/Shutterstock

Both good and bad habits become routinized by subcortical regions of our brains that are driven by the "reward molecule" dopamine and other neurotransmitters. One reason that cortical-based willpower often fails is that it relies on cerebral self-control, which many believe is a finite resource that gets used up (ego depletion) by overthinking what you "ought to do" instead of letting the unconscious subcortical parts of your brain instinctively do what they "want to do."

The cortical "thinking cap" of our cerebrum is a thin bark known as the cerebral cortex that drives conscious decision-making. Subcortical "non-thinking" parts of the brain include the basal ganglia system (BGS) and cerebro-cerebellar system (CCS), which interact with cerebral neural networks to optimize whole-brain functions that happen automatically without much conscious thought.

What Is Automaticity?

Together, the BGS and CCS facilitate automaticity, which is described by the APA Dictionary of Psychology as "the quality of a behavior or mental process that can be carried out rapidly and without effort or explicit intention (an automatic process). In brain imaging studies, automatic processes show dramatic decreases in cortical activity."

Automaticity gives us the ability to perform everyday tasks independent of conscious control or attention. It frees up our cognitive reserves to think about other things beyond routinized daily behaviors, but it also perpetuates unhealthy habits related to diet, addiction, compulsive behaviors, and not getting enough exercise.

Historically, most neuroscientists thought that automized habitual behaviors were mediated primarily by cortical regions in the cerebral cortex and that automaticity involved a process of transferring control from cortical to subcortical brain networks. However, accumulating 21st-century evidence suggests that subcortical structures such as the basal ganglia's striatum make significant contributions to initial behavioral learning, habit formation, and automaticity.

Automaticity Engages Willpower-Free Subcortical Brain Regions That Encode Habits

A recent study (Smith et al., 2021) into the habit-controlling neurons of the dorsolateral striatum, which is part of the subcortical basal ganglia system, gives us fresh clues about how different dopamine receptors (D1 or D2) influence the brain's ability to learn new tricks and forget old habits. These findings were published on August 25 in the peer-reviewed journal Nature Communications.

This mouse study by a team of researchers from the Icahn School of Medicine at Mount Sinai found that blocking D2 receptor activity in specific dorsolateral striatum neurons prevented rodents from displaying previously learned habits.

Additionally, their research showed that subcortical striatal circuits in the dorsolateral striatum are also involved in learning new goal-directed actions that lay the foundation for habitual behavior.

"For years, scientists thought that habits and learning new, rewarding actions were most likely controlled by different parts of the brain. Surprisingly, we found that a brain area traditionally thought to specialize in the expression of old habits may also help the brain learn new actions," senior author Paul Kenny said in an August 2021 news release.

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"We were surprised by these results. Traditionally, it is thought that action learning is encoded by the posterior dorsomedial striatum while the dorsolateral striatum only takes care of habits. But that is not what we saw," first author Alexander Smith added. "Instead, our results suggested that in addition to regulating habits, the dorsolateral striatum also consolidates action learning immediately after the new action has been learned."

Nudges That Automate Decision-Making via Automaticity Have Greater Impact

"Nudges" are a way to influence people's behavior and decision-making via positive reinforcement, indirect suggestions, or slight changes to the sensory context and environment in which decisions are made (Thaler & Sunstein, 2008). Nudging people to break bad habits and make healthier choices in their daily lives is tricky. Public health advocates are actively trying to figure out what type of nudges are most effective.

With other variables held at their means, this chart shows that "predicted Cohen's d for nudges that involve automaticity is approximately 50% larger than the predicted Cohen's d for nudges that do not involve automaticity."

Source: Beshears & Kosowsky (2020)/Creative Commons (CC-BY-NC-ND)

Last year, a meta-analysis of 174 articles (Beshears & Kosowsky, 2020) compiled data on what types of nudges tend to succeed. Overall, John Beshears and Harry Kosowsky found that nudges involving automaticity were more effective than nudges that did not use automaticity.

As the authors explain, "While the effects of nudges are statistically robust regardless of whether or not they automate some aspect of the decision-making process, there is suggestive evidence that automaticity produces larger effects."

Taken together, the latest research suggests that the best way to nudge ourselves to break bad habits and make healthier choices in our day-to-day lives involves automaticity, which appears to be driven by D2 receptors and subcortical striatal circuits in the dorsolateral striatum.

Instead of focusing on willpower and self-discipline, which often lead to ego depletion, finding ways to make a new habit something you "want to do" and not what you "ought to do" is key to habitualized behavioral changes that lead to automaticity. One technique that shows promise for triggering this mindset shift is called Functional Imagery Training (FIT). For more on how this unique motivation technique works, see "Why Vivid Mental Imagery Is Like Motivational Rocket Fuel."