In order to help you identify between habitual and goal-directed action, your brain's circuits compete for control and make a fine balance between the two actions, an international team of researchers has identified.
They found brain chemicals and neural pathway involved in switching between habitual behaviour and deliberate decision-making -- providing the strongest evidence to date that the brain's circuits for habitual and goal-directed action compete for control.
"We need a balance between habitual and goal-directed actions. For everyday function, we need to be able to make routine actions quickly and efficiently, and habits serve this purpose," said lead author Christina Gremel from the University of California-San Diego.
"However, we also encounter changing circumstances, and need the capacity to 'break habits' and perform a goal-directed action based on updated information. When we can't, there can be devastating consequences," she added.
The study, published recently in the journal Neuron, worked with a mouse model to demonstrate what happens in the brain for habits to control behaviour.
Gremel said the brain's circuits for habitual and goal-directed action compete for control -- in the orbitofrontal cortex (OFC), a decision-making area of the brain -- and that neurochemicals called endocannabinoids allow for habit to take over, by acting as a sort of brake on the goal-directed circuit.
"Habit takes over when the OFC is quieted," Gremel said.
In the study, since endocannabinoids are known to reduce the activity of neurons in general, the researchers hypothesised that endocannabinoids may be quieting or reducing activity in the OFC and, with it, the ability to shift to goal-directed action.
They trained mice to perform the same lever-pressing action for the same food reward but in two different environments that differentially bias the development of goal-directed versus habitual actions.
Like humans who don't suffer from neuropsychiatric disorders, healthy mice readily shifted between performing the same action using a goal-directed versus habitual action strategy.
To test their hypothesis on the role played by endocannabinoids, the researchers then deleted a particular endocannabinoid receptor.
Mice missing these receptors did not form habits -- showing the critical role played by the neurochemicals as well as that particular pathway.