Elizabeth Tricomi, Ph.D. (Rutgers-Newark)
“Making and breaking habits: motivational control and its relevance to ADHD”
Behavior can be motivated by a goal or executed habitually in response to a cue, without consideration of the outcome. People with ADHD have symptoms of impulsivity and distractibility, along with impairments in reward processing. We hypothesized that adults with ADHD might differ from neurotypical adults in their development of habits and the responsivity of the brain’s corticostriatal reward circuity to cues associated with rewarded behavior. Compared to a neurotypical control group, adults with ADHD showed increased activity as training progressed in response to behavior-linked cues in the posterior putamen, a region of the striatum previously implicated in habit learning. The ADHD group also displayed increased functional connectivity between this region and the prefrontal cortex over the course of training. Next, we sought to investigate how habits could be broken. To do this, we needed to develop a task that did not rely on building a new habit in the lab, but rather made use of an existing habitual association, as existing habits are likely to be more robust and less trivial to break. We developed a response inhibition task that capitalizes on existing green-Go and red-NoGo associations to study well learned habit expression and disruption in neurotypical adults. To break the habit and shift the motivational control of behavior to being goal-directed, we provided performance-tracking information paired with monetary reward. We found that outcome-insensitive habitual performance, demonstrated by errors of commission on green-NoGo trials, dissipated after this monetary reward for performance was delivered. Finally, we replicated this experiment in a within-subject design while measuring preclinical ADHD symptom severity in the general population. We found that while performance was independent of ADHD symptom severity, hyperactivity did predict prepotency in habit execution. In sum, these studies suggest that ADHD presents corticostriatal abnormalities during motivational control, and that well-established habits can be weakened by making the goal more salient through extrinsic reinforcement.
Elizabeth Tricomi received her Ph.D. from the University of Pittsburgh in 2006, where she worked with Julie Fiez in the Psychology Department and the Center for the Neural Basis of Cognition. She then went on to do a postdoctoral fellowship at Caltech with John O’Doherty. She was hired as an Assistant Professor in the Psychology Department at Rutgers-Newark in 2009, and she was promoted to Associate Professor in 2016. Research in her lab focuses on understanding the neural mechanisms supporting learning, motivation, and decision making.