All parts of the brain › Functions › Habits

What part of the brain controls habits?

Mostly the basal ganglia, in a loop with the cortex. As an action is repeated, its control shifts from the goal-directed caudate nucleus to the putamen (the dorsolateral striatum), which runs the routine as one chunk; that habit circuit depends on dopamine from the substantia nigra in the midbrain. The motor cortex feeds the putamen, and part of the prefrontal cortex helps a new habit take hold. [1][2][3]

The putamen, the caudate nucleus, the midbrain, the precentral gyrus and the prefrontal cortex lit in red on a 3D model of the brain, seen from the front left and above

Loading the 3D brain…

Lit: whole parts; region borders not drawn.

Slice

All 5 parts are lit together. Drag to turn, pinch or scroll to zoom, tap a part on the brain or a name in the list to focus it; .

The substantia nigra is a region on the midbrain, not a separate shape. The 3D model has no shape for it, so the whole midbrain is lit; the region’s exact border is not drawn.

Habits: 5 parts lit

Putamen, caudate nucleus, midbrain, precentral gyrus and prefrontal cortex. Tap one to see where it is and what it does.

The parts and their roles

The habit side of the striatum. In rats the dorsolateral striatum, which roughly matches the human putamen, is needed for stimulus–response habits, and its neurons fire in a burst as a well-learned run starts and as it ends, as if packing the steps into one chunk. In people, after extensive training made responses stop tracking a reward’s value, cue-driven activity grew in the right posterior putamen. [1][2] Where is the putamen?
The goal-directed side. Its counterpart in rats, the dorsomedial striatum, works while an action is still chosen for its outcome, and its activity falls as overtraining turns the action into a habit; it takes in the associative loop that starts in the dorsolateral prefrontal cortex. [1][4][5] Where is the caudate nucleus?
Holds the substantia nigra, whose pars compacta sends dopamine to the striatum along the nigrostriatal pathway. Habits depend on these dopamine neurons: in rats, removing the nigrostriatal dopamine supply disrupts stimulus–response habit formation. [1][6] Where is the midbrain?
Holds the primary motor cortex, which with the premotor cortex and supplementary motor area sends the basal ganglia’s motor loop into the putamen; the dorsolateral striatum, the habit part, is the part of the striatum that receives the sensorimotor cortex’s projections. [5][3] Where is the motor cortex (precentral gyrus)?
Two of its parts pull opposite ways in rats: the prelimbic cortex, with the orbitofrontal cortex, supports actions guided by their outcome, while the infralimbic cortex works as a kind of strategy scheduler that promotes a newly acquired habit, alongside the dorsolateral striatum. [1] Where is the prefrontal cortex?

Named areas on the lit gyri

The substantia nigra, on the : A band of grey matter in the midbrain behind the cerebral peduncles; its pars compacta is the dopamine source the habit circuit in the dorsolateral striatum depends on. [6][1]

How they work together

A habit is defined by a test, not by how often something is done. If the reward is made worthless and the animal still presses the lever for it, the action has become a habit; an action that is still goal-directed slows down. Repetition moves an action from the second kind to the first. [1][2]
Habits are packed into chunks. In rats running a T-shaped maze, striatal neurons came to fire mostly at the start and the end of each run, bracketing it, and the rats stopped pausing to deliberate at the turn; the same chunking pattern shows up in the infralimbic cortex. [1]
The basal ganglia appear to remember the context that triggers a habit and can revive the habit when the trigger comes back, which is why a cue, the routine and its reward are described as one loop. In a 2002 study about 43% of daily behaviours were done out of habit; in a study by Lally and colleagues a new daily behaviour took on average 66 days (range 18 to 254) to become as automatic as it would get. [7]
Honest limit: most of this circuit was mapped in rats, mice and monkeys; in people it rests on brain imaging, and matching the rat’s dorsolateral and dorsomedial striatum and infralimbic cortex to the human putamen, caudate nucleus and prefrontal cortex is approximate. The whole putamen, caudate nucleus and prefrontal cortex are lit, not their exact habit subregions, and the page describes how ordinary habits form, nothing about any one person’s. [1][4]

Habits are one kind of learning: the learning page lights the hippocampus, which takes in new facts, and the cerebellum, which tunes skilled movement, beside the same striatum. [8][9] What part of the brain is responsible for learning?

Sources

Facts describe anatomy and normal function only. A part lit here takes part in habits; it does not do it alone, and it does other jobs too. The 3D model is the adult male BodyParts3D brain (credits and licence); on it the brainstem includes the midbrain, pons and medulla, so lighting the brainstem lights all three.