It’s 8:30 in the morning, and you begin your long but necessary trek from the comfort of your bed to the bathroom. Your eyes narrow in search of the necessary elements—toothbrush, toothpaste, tap water—while you think about the weird dream you had last night or maybe your to-do list for the day ahead. Once you apply the toothpaste to the brush, you bring it to your teeth and begin the routine. You maneuver the brush precisely around each tooth for a total of two minutes, ensuring that you do not miss your molars.
A persons arm, in purple, repeatedly hits an alarm clock with its motion frozen at three points along its path. The days and increasing tardiness in time swirl around the clock as the person sleeps in bed.
When you wake up, you immediately go to the bathroom to perform this task without much thought. Now imagine needing to invest the same mental energy into getting up and brushing your teeth as you would for something like rock climbing, where every movement must be planned and precise. Thankfully, we have habits that automate many necessary actions and behaviors, allowing us to focus on other tasks such as our schoolwork, careers, relationships, and even dreams. This might make you wonder, “If my brain controls my behaviors subconsciously, do I even have control over my life? Is my subconscious making smart choices?” While it may seem daunting that the majority of the decisions we make every day consist of routine habits, the good news is that, by better understanding how habits work, we can intentionally alter these choices. In other words, we have the power to create healthy habits and break bad ones.
Habits can be defined as regularly repeated behaviors that are performed subconsciously, meaning that they do not require attention to carry out . Think of behaviors you might perform on a regular basis that you don’t even question doing, like taking a shower or brewing a coffee early in the morning. According to one traditional definition, habits are “inflexible, slow or incremental, unconscious, automatic and insensitive,” indicating that they might not necessarily be under our control . While you can voluntarily bring these actions to consciousness, habits have the advantage of enabling us to preserve mental energy for other, more complex, tasks [1,2]. Even if our habits seem like they are already established and unchangeable, wouldn’t it be great if you automatically performed healthy behaviors of your choice like exercising, eating healthy, or waking up early without having to think about it? By selecting and working on beneficial activities that we want to automate, we can decide how we want our daily lives to look, building productive habits and removing unhealthy behaviors [3, 4].
How do we form habits?
The basal ganglia is one of the key brain structures responsible for habit formation . The basal ganglia are a cluster of nuclei deep within the brain that are responsible for motor control and learning, emotions, and working memory . Information flows from the basal ganglia to the cortex, a structure on the outer layer of the brain responsible for consciousness, language, and memory, among other higher level executive functions . By interacting with the cortex, the basal ganglia play an important role in connecting motor functions with decision making . They are also involved in implicit memory–memory that is not consciously attended to during action, like brushing your teeth immediately after getting out of bed—and therefore play a large role in habit formation [2, 7].
The striatum, a subnucleus of the ganglia, makes up most of the volume beneath the cerebral cortex, contributing significantly to the function of the basal ganglia . The striatum is also important for habit development [8, 9]. In a study conducted at the Massachusetts Institute of Technology (MIT), researchers trained rats to run through a T-shaped maze by associating a different clicking noise with turning either left or right to receive a food reward [8, 9]. They found that the activity of neurons in the sensorimotor part of the striatum remained constant during the learning phase of the experiment, suggesting that the striatum is important for conscious motor learning [8, 9]. However, once the rats successfully learned the movement pattern necessary to find the food reward, the sensorimotor striatal region activated only at the beginning and end of the maze . This result means that the activity of this motor-control area of the striatum was “chunked,” a term coined by psychologist George A. Miller . Chunking refers to the packaging of pieces of information into fewer, more manageable units . An example of chunking is the way we remember phone numbers in three units or chunks (111-222-3333) rather than trying to remember all ten digits individually (1112223333) . Similarly, the rats chunked multiple actions and movements into broader units within the striatum, representing the entire run as two chunks of neurological information–beginning and end–to more efficiently find the food reward . Interestingly, this study concluded that the habits developed by the rats became automatic, with reduced striatal activity reflecting the need for fewer neural resources [8,9].
Two purple rats, each holding a bucket of popcorn,
watch two rats go along a blue maze, below them.
In the center, floating above the mazeis an anatomical
representation of the brain and portions involved
in habit formation/suppression.
The MIT rat experiment also suggests that habits are formed through repetition and reward, eventually leading to action without the need for conscious thought [8, 9]. Repetition aids in habit formation because the feedback loop between the sensorimotor cortex and the striatum activates when behavior is repeated, forming a chunk . Before a habit is created, behavior is goal-oriented and requires repetition while also involving dopamine . Dopamine is a neurotransmitter that acts as the reward for certain behaviors . The amount of dopamine that the brain releases can affect behavior. For example, when dopamine release is too low, it is difficult to perform certain tasks because these low levels are indicative of a lack of reward. In contrast, when dopamine release is too high, it is difficult to suppress unwanted responses. Thus, some individuals may find running early in the morning difficult if running is not immediately rewarding to them, which is caused by reduced dopamine release. On the other hand, some individuals may find snoozing their morning alarms and sinking back into their warm beds rewarding, making it difficult to stop bad habits like these when the brain rewards itself. When you give in to the desire to sink back into your warm sheets and close your eyes, your brain releases dopamine which feels rewarding and reinforces this behavior . If you think of dopamine as a currency for reward, paying the brain structures involved in habits too little will not entice them to work and build a habit, but overpaying them will make them want to work too much, making it difficult to break bad habits.
The dopamine reward mechanism is directly involved in the habit-learning mechanism in the brain. The neurons in the striatum that synapse on the cortex strengthen while learning habits . The repetitive release of dopamine associated with learning a habit through repetition strengthens and increases the brain connections associated with that habit . This process of changing the strength of a synapse, called synaptic plasticity, is essential to the initial stages of habit building . However, once a habit is learned, dopamine plays a less important role since the synapses are already strong . Like building a highway, there must be enough currency (dopamine) to pay for the roads (brain pathways), but once they are built, it does not cost much to maintain the roads. As a result, habits get easier to maintain as you build them.
Once a habit is established, cues in the environment can trigger action without thought, meaning that you might see your phone screen and immediately snooze your alarm . In a study measuring participants’ brain activity behind the specific task of pushing a button, researchers found that electrical activity called a “readiness potential” fired in certain brain regions before people were consciously aware of initiating the action to push the button [14, 15]. Thus, your brain starts some actions before you realize that you are doing them, which may explain why you end up snoozing multiple times without even realizing it .
How do we break habits?
While brushing your teeth is a habit you should probably maintain, there are other habits that you might want to get rid of, such as hitting that snooze button in the morning. Thankfully, habits are breakable; though, it will take some effort to stop doing something you’ve been doing for an extended period of time.
One way to break a habit involves changing contexts. Have you ever experienced going on vacation or moving into a new dorm room at the start of the school year and finding it easy to inhibit yourself from snoozing your alarm even though you did every morning before you left home? This common phenomenon occurs because new environments can interfere with your habits. As a result, it is easier to break habits in a new place or setting [4, 16]. For example, if you wake up in a hotel room instead of your bed at home, you might have to find your phone to hit snooze, and your habit of snoozing would be disrupted. Thus, your habit is not as automatic as it would be if you were still home. In fact, one experiment by Heatherton and Nichols showed that 36 percent of successful habit changes involved moving to a new location . Thus, it’s clear that changing locations can break us out of some of our common unconscious behaviors.
If you aren’t moving away or going on vacation anytime soon, there is still hope for changing your habits. Smaller alterations to your physical environment can also help you break a habit. “Pre-loading” your environment is a way of deciding to perform a healthier habit before you are in the situation where the behavior occurs . This can look like moving your phone or alarm clock out of arm’s reach before you go to sleep. Snoozing the alarm would require you to physically get out of bed in the morning, impeding the thoughtless habit of tapping the snooze button. By the time you reach the alarm, you’ll already be out of bed and more alert than if you remained under the covers, meaning there is no need to snooze! This strategy helped participants in the Heatherton & Nichols experiment, with 13 percent of successful habit changes involving a modification to the immediate environment in which the habit was performed .
An outline of the person is obscured by two calendar months.
The calendars count off the days with two days circled, one in January
and one in February. An arrow leads from the circled dates to two
scenarios on the left and right of the person. On the left is a person with
thought bubbles about future plans of walking; on the right is a person
with thought bubbles that are empty or are thinking of staying in bed.
A person’s willpower is just as crucial as one’s environment to building or breaking habits. In maintaining healthy habits, when the context of a habit is changed, but a person’s intentions or values behind the habit remain the same as when it was formed, that habit will tend to continue . On the other hand, if someone’s intention of maintaining a habit is weak, then habits might be broken . This phenomenon can become a problem when it affects healthy habits. For example, when moving to college, a student’s exercise routine might be temporarily thrown off with the change in environment if working out was not a top priority before moving away. Conversely, professional bodybuilders’ strong prioritization of exercise may lead them to hit the gym even in a new environment, like when they go on vacation.
Groundbreaking research has investigated brain activity involved in changing habits. The neocortex, located in the cerebral cortex, works with the striatum to influence behavior and decision-making . The neocortex monitors our external environment to automatically trigger our habits, such as how we subconsciously reach into a bowl of popcorn during a movie [8, 17]. It is as though habits are always there, waiting to be implemented when the neocortex determines that the circumstances are right. The neocortex can be deactivated in rats using optogenetics, a technique that expresses light-sensitive channels in neurons, allowing us to activate or deactivate these neurons depending on the channels being expressed . In another iteration of the MIT rat experiment, after training the rats to successfully navigate the maze, the researchers proceeded to inject a virus into the neocortex that led the infected neurons to turn off when exposed to light . They found that deactivating these neurons disrupted the rats’ habit of automatically turning to a specific part of the maze . This result has the potential to help with therapy related to breaking undesirable habits, such as drug abuse; however, further research is needed.
What can we do to stick to our habits?
An effective technique called “implementation intention,” developed by New York University professor of psychology Dr. Peter Gollwitzer, can help create habits . The structure for an implementation intention is: “If I find myself in situation X, then I will do behavior Y” [13,19]. For example, “If I find myself in the bathroom in the morning, then I will brush my teeth.” Implementation intentions allow you to make decisions ahead of the action, increasing the likelihood of implementing the particular behavior [13,19]. You can write them down or recite them, and they essentially serve as a reminder to perform a habit . In one study, patients who underwent knee or hip replacement surgery used booklets to help them outline their implementation intentions during recovery and were able to stand on their own after 3.5 weeks . One page of the booklets said, “My goals for this week are? Write down exactly what you are going to do. For example, if you are going to go for a walk this week, write down where and when you are going to walk” . In contrast, the control group who did not use implementation intentions took longer to stand on their own, needing about 7.7 weeks [13, 20]. This significant difference indicates that implementation intentions are useful in high stakes situations, where participants used them to develop habits that helped them recover from surgery faster.
Actively repeating a behavior and rewarding yourself, like rats being immediately rewarded with food, is crucial to developing habits . For example, if you want to develop the healthy habit of running in the morning, reward yourself when you get back from your run by eating your favorite healthy snack or watching an episode of your favorite TV show. Another form of reward can be social rewards . Maybe you can find a running partner or connect with someone who also runs on their own in the morning and share the details of your run with them every day. Both of you can keep each other accountable, and the social rewards of encouragement and knowing that a friend is building the same habit as you can keep you both on track, reinforcing your new healthy habits.
No matter the habit you are trying to make or break, understanding the neuroscience behind habits can help you on your journey. When you start using scientifically proven techniques, you’ll be surprised by how much easier it can be to automate healthy habits and remove unhealthy ones. Habits often feel like things that just happen to us. However, when we bring them back to our consciousness, think about what we want to change, and begin implementing these changes, we can take a step towards making our daily lives more productive and meaningful.
A woman is brushing her teeth in a green-themed bathroom. Her hair is transparent and glow along with her plans for the day, the future, and with her friends.
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