Recent research published in Psychiatry Research: Neuroimaging explored the relationship between choosing to delay gratification, neural functioning, and success or failure in smoking cessation. The findings indicate that individuals who chose immediate rewards rather than delayed ones are likelier to relapse and continue smoking.
In addition, fMRI scans reveal differences in brain activity of those who choose to delay gratification compared to those who do not. This research can help practitioners predict who may struggle to quit smoking resulting in more robust and potentially successful interventions.
Tobacco consumption is the most preventable cause of death across the globe. While many chronic smokers try to quit, only a few achieve long-term abstinence. To better understand the decision-making processes that lead to smoking relapse, the research team examined delayed reward discounting.
Delayed reward discounting is a behavioral and psychological phenomenon where people prefer smaller, immediate rewards over larger rewards that will be received later. The perceived value of the larger reward is reduced or discounted based on the delay time.
Neuroeconomics research has studied the neural underpinnings of decision-making, including delayed reward discounting, using functional magnetic resonance imaging (fMRI). Brain regions that play a role in reward, information processing, and decision-making, such as the striatum, posterior parietal cortex, anterior insula, and dorsolateral prefrontal cortex (DLPFC), exhibit different activation patterns in substance users compared to control groups during delayed reward discounting tasks.
Michael Amlung and colleagues recognized that no fMRI studies have investigated whether activation patterns during delayed reward discounting decisions made before smoking cessation treatment are related to treatment outcomes. The present study aims to identify the neural correlates of delayed reward discounting in adult smokers before treatment and examine whether Blood Oxygen Level Dependent (BOLD) responses are associated with smoking cessation treatment outcomes.
The research focused on enrolling adults seeking treatment to quit smoking, smoking at least 10 cigarettes a day, and expressing a desire to quit. The participants were required to be right-handed and within the age range of 18-65, without any significant medical, neurological, or psychiatric conditions. Initially, 52 participants completed the MRI scan, but only 41 met the selection criteria and were included in the final sample. Most of the participants were of White ethnicity and reported smoking an average of 22.43 cigarettes daily, indicating moderate nicotine addiction.
Participants underwent a 90-minute MRI scan, which included an anatomical scan and three imaging trials of the delayed reward discounting paradigm. After these assessments, participants received a nine-week smoking cessation treatment protocol involving nicotine replacement therapy and weekly in-person counseling sessions. The treatment comprised eight weeks of nicotine replacement therapy and behavioral counseling, incorporating motivational interviewing and relapse prevention strategies.
The study findings support the hypothesis that smokers who maintained smoking abstinence exhibited less steep discounting than those who were unsuccessful in quitting smoking. The study suggested that steep delayed reward discounting could be a valuable tool in differentiating subgroups of smokers based on their ability to quit smoking. Interestingly, the study showed that participants who relapsed were not characterized as generally impulsive but demonstrated a specific difference in delayed reward discounting and immediate reward preference.
The results of the fMRI analysis indicated significant variations in brain activity in several regions, such as the prefrontal cortex, posterior parietal cortex, anterior insula, and striatum, depending on the type of choice made. These regions involve various cognitive processes, such as decision-making, intention, conflict processing, and prospective thought.
Apart from identifying the neural mechanisms underlying delayed reward discounting, the study also explored differences in delayed reward discounting-related neural processing based on smoking cessation outcomes. The results revealed differences only present in specific regions of interest, such as the DLPFC, precuneus, caudate, and putamen.
However, the effects were relatively modest and might not withstand rigorous type 1 error correction. The researchers concluded that the findings should be viewed as preliminary and interpreted cautiously due to the small sample size.
“In sum, the current study advances the link between steep [delayed reward discounting] and smoking cessation outcome, replicating the predictive behavioral relationship and examining, for the first time, the neural correlates,” the researchers concluded. “In doing so, it implicates several brain regions involved in cognitive control, reward, salience, and prospection, albeit revealing small effect size differences. Nonetheless, the results provide preliminary support for the viability of applying a neuroeconomic framework for understanding the determinants of success and failure in smoking cessation treatment.”
The study, “Neuroeconomic predictors of smoking cessation outcomes: A preliminary study of delay discounting in treatment-seeking adult smokers“, was authored by Michael Amlung, Max M. Owens, Tegan Hargreaves, Joshua C. Gray, Cara M. Murphy, James MacKillop, and Lawrence H. Sweet.
