Brain region may switch actions into habits ^{CEFR B1}

A team at Johns Hopkins University is investigating whether a specific brain region controls the shift from deliberate actions to habits. The new study, published in Nature Communications, suggests that this change can occur faster than scientists long believed.

For more than a century researchers assumed habits developed slowly through repeated practice. Traditional experiments used strong rewards and tests at set time points: animals were trained with a reward and then given free access until they were satiated. If an animal continued the task despite satiety, the behaviour was labelled habitual. Those tests could not show when the change to habit happened in real time, so the shift was assumed gradual.

Kuchibhotla and colleagues used a different approach based on taste preference. Mice had constant access to acidic water so they were not overly thirsty, while a sound cue delivered a preferred drink. At first mice acted in a goal-directed way, but at a specific moment many switched strategy and began to respond reliably to the sound. Brain recordings pointed to a region that may act as the switch, and some mice later returned to goal-directed behaviour after long periods of habit. The work received new NIH funding and additional support from the Kavli Neuroscience Discovery Institute.