Project Summary/Abstract
Habits make up an essential part of humans' everyday behavior. Habits enable us to perform routine activities,
such as driving to work, in an automated, effortless way, freeing up our cognitive resources for more effortful
concomitant tasks, such as conversing with our passenger. Successfully establishing good habits, such as
regular hand washing, sleep times, or exercise, is essential for a healthy lifestyle. However, because they are
automated and in¿exible, habits can also lead us astray, causing us to inadvertently drive to work when we meant
to go to the doctor or eat snacks when we're not hungry, and in extreme cases, promoting drug seeking behavior
and addiction. Overcoming habits when they are not appropriate for our current goal requires goal-directed
control.
While the balance between habits and goal-directed control has been well-studied in non-human animals,
cognitive neuroscientists have struggled to translate the standard approaches in this domain into human ex-
perimental research. Speci¿cally, humans are more ef¿cient than non-human animals at exerting control that
overrides habits, making it dif¿cult to reveal habits in lab experiments, even after thousands of training trials.
Furthermore, it has proven dif¿cult to attribute habit-like behavioral patterns (such as “slips of action” like go-
ing to work instead of going to the doctor) to the strength of the habit, as opposed to the weakness of control
processes.
This project will develop a new human protocol that will allow researchers to 1) induce habits in hundreds of
trials, making it a practical, single-session task for future research, 2) disengage control enough to reveal habit
behavior, and 3) reveal engagement of control in a way that is separable from the strength of habit expression.
To do so, our approach steps away from successful rodent task designs, and instead relies on the insight that
human decision-making is hierarchical. Speci¿cally, we will leverage the hypothesis that humans make more
abstract choices (e.g. driving, vs. walking to work) in a controlled, goal-engaged way, then naturally disengage
control and execute their high-level decision with habitual routines. Aim 1 will develop and test the validity of the
protocol with regards to the three targets above; aim 2 will directly test the role of hierarchical decision-making
in expressing habits.
If successful, this project will open the doors to a wealth of downstream research on habits and goal-directed
decision-making, including probing their neural substrates in functional imaging, and their role in individual dif-
ferences and clinical conditions. If someone is unusually prone to habit-like mistakes (e.g. ¿nding themselves
at work when planning to go to the doctor), it is currently dif¿cult to attribute this to strong habit expression as
opposed to weak control. Our protocol will enable us to pull this apart, with important implications for the study
of psychiatric conditions such as obsessive-compulsive disorder, eating disorders, and addiction.