Summary: A new study finds that habit formation is governed by two separate neural circuits: one that determines whether a behavior becomes a habit and another that controls how strongly or how often that habit is performed.
Researchers used an accelerated training protocol in mice to follow the neural shift as behavior moved from goal-directed decision-making to automatic habit. They report that weakening of connections from the anterior cingulate cortex to the retrosplenial cortex permits the transition into habit, while projections from the lateral orbitofrontal cortex to the central striatum set the intensity and frequency of habit execution. These distinct pathways explain why habit strength varies across individuals and suggest targeted circuit-level approaches for treating compulsive disorders such as obsessive-compulsive disorder (OCD).
Key Facts
- Accelerated rapid training protocol: A team at Kyoto University developed a two-stage behavioral regimen that induces habit formation in mice within four days, enabling researchers to compare neural activity before and after habit emergence within the same subjects.
- Circuit 1 — Habit gatekeeper: Neurons projecting from the anterior cingulate cortex (ACC) to the retrosplenial cortex (RSC) control whether a goal-directed action transitions into a habit. Functional connectivity in this pathway weakens as automatic behavior takes over.
- Circuit 2 — Execution regulator: Projections from the lateral orbitofrontal cortex (lOFC) to the central striatum (CS) regulate the volume and frequency of habit execution. Differences in this pathway account for variability in how strongly a habit is expressed across individuals.
- Bidirectional manipulation: Artificial stimulation or suppression of each pathway can respectively induce habit formation or modulate the degree of habit execution, confirming their separate roles.
- Clinical relevance: Identifying a specific circuit that controls habit intensity provides a foundation for more precise interventions for compulsive and addictive behaviors, including OCD.
Source: Kyoto University
Definition and context: Habit formation refers to the repeated performance of a behavior until it becomes routine—shifting control from deliberate, outcome-driven choices to automatic execution. Forming useful habits can streamline daily life and productivity, but the same mechanisms can underlie maladaptive compulsions when unchecked.
While repetition is known to be central to habit development, it has been unclear whether a habit simply reproduces the original behavior unchanged or whether the behavior itself evolves as it becomes automatic. Because habit consolidation typically unfolds over extended periods, it has been difficult to observe both behavioral and neural changes in the same subject before and after habit formation.
To address this, the research team introduced a rapid, two-stage training protocol for mice that first established goal-directed strategies and then applied an intensified four-day regimen to produce habitual responding. This approach allowed direct within-subject comparisons of behavior and brain activity during the transition.
Their experiments revealed a dual-circuit model: weakening of ACC-to-RSC connections acts like a gate that permits a behavior to become a habit, while the lOFC-to-central striatum pathway functions like a volume control, determining how often and how vigorously the habit is carried out. Mice that developed strong lOFC→CS responses continued to execute the habit at high levels, whereas weaker responses corresponded to reduced execution.
Importantly, selectively manipulating each pathway produced distinct outcomes: altering the ACC→RSC circuit changed whether the animal defaulted to habitual behavior, while modifying the lOFC→CS pathway adjusted the intensity of the habit without necessarily changing the decision strategy. This dissociation indicates that habit formation and habit expression are separable neurobiological processes.
These findings challenge the simpler notion that repetition alone copies a behavior into an automatic routine unchanged. Instead, habit development involves circuit-specific plasticity that both enables the shift to automaticity and sets the execution level, accounting for observed individual differences in habit strength.
“Our study uncovers previously overlooked control mechanisms for habit formation, clarifying what determines how strongly a habit is expressed and why habits differ between individuals,” says team leader Yasunori Hayashi. The researchers plan to investigate what factors lead to variation in the execution pathway, with the goal of improving approaches to form beneficial habits and to treat problematic, compulsive habits linked to disorders such as OCD.
Key Questions Answered:
A: Goal-directed behavior is driven by deliberate evaluation of outcomes and conscious choice. Habitual behavior is automated and performed routinely without continuous conscious assessment of the outcome.
A: The ACC→RSC circuit functions as a switch that determines whether an action becomes a habit by reducing connectivity during the transition. The lOFC→central striatum circuit acts as a volume control that sets how frequently and intensely the habit is executed.
A: By identifying the circuit that drives habit execution intensity, researchers can aim for targeted therapies that reduce excessive habit expression while preserving normal goal-directed learning, offering a more precise strategy for treating compulsive behaviors.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The underlying journal paper was reviewed in full.
- Additional context was provided by editorial staff.
About this habit formation and OCD research news
Author: Whitney Hubbell
Source: Kyoto University
Contact: Whitney Hubbell – Kyoto University
Image: The image is credited to Neuroscience News
Original Research: Open access. “Dissociable roles of prefrontal plasticity in decision making strategy and execution of habitual behavior” by Nozomi Asaoka, Diane Pagano & Yasunori Hayashi. Published in Nature Communications. DOI: 10.1038/s41467-026-75706-1
Abstract
Dissociable roles of prefrontal plasticity in decision making strategy and execution of habitual behavior
Habits are crucial for sustaining adaptive routines but can also underpin maladaptive behaviors such as compulsions and addiction. They arise when decision-making shifts from a motivation-driven, deliberate strategy to an automatic mode.
During this transition, the amount of habit execution—its frequency and duration—can remain substantial even as motivational drive declines, raising the question of how execution level is maintained when decision strategy changes.
Using a paradigm that induces habit formation within a defined time window in male mice, the researchers found that the shift in decision-making and the control of execution level are governed by plasticity in distinct cortical pathways. Selective disruption of each form of plasticity altered either the decision strategy or the execution level without affecting the other, supporting a dual regulatory model for habit.
These results provide new insight into the neurocircuit mechanisms that underlie both adaptive habit formation and maladaptive compulsive behaviors, pointing to specific targets for future therapeutic research.