Applying Novel Technologies and Methods to Inform the Ontology of Self-Regulation: Binge Eating and Smoking

This study aims to examine targets of self-regulatory function among two exemplar populations for which behavior plays a critical role in health outcomes: smokers and individual who binge eat (BED). This is the second phase of a study that aims to identify putative mechanisms of behavior change to develop an overarching "ontology" of self-regulatory processes.

Health risk behavior, including poor diet, physical inactivity, tobacco and other substance use, causes as much as 40% of the illness, suffering, and early death related to chronic diseases. Non-adherence to medical regimens is an important exemplar of the challenges in changing health risk behavior -- and is common, costly (due to increased utilization of healthcare services), and associated with poor patient outcomes. This may be particularly evident among older adults who experience a disproportionate amount of the chronic disease burden in the U.S. Although an array of interventions have been shown to be effective in promoting health behavior change, much of this work has been siloed (focused on one disorder at a time).

Additionally, interventions are typically intended to engage multiple mechanisms of behavior change, but the mechanisms by which they actually work are infrequently systematically examined. Because the need to alter health-related behavior is ubiquitous across medicine, understanding the extent to which the principles of effective health behavior change, and the mechanisms by which they work, are similar or differ across health conditions and settings is a critically important area of scientific inquiry. Improving medical regimen adherence and promoting health behavior change are also crucial issues in the changing healthcare landscape, where quality, value, cost and patient-centered care are central. This line of research may allow for great strides in crafting "precision medicine" approaches for a wide array of populations.

One promising domain of putative behavior change targets is that of self-regulation -- a person's ability to manage cognitive, motivational and emotional resources to act in accordance with his/her long-term goals. In this proposal, the investigators have assembled an outstanding interdisciplinary team to 'scale up' this work to an unprecedented level by examining putative targets of behavior change within the self-regulation mechanism domain across contexts, populations, and assays - in 3 primary levels of analysis: (1) psychological (e.g., constructs such as self-efficacy; emotion regulation; response inhibition), (2) behavioral (e.g., tasks of reward responsiveness; temporal horizon), and (3) biological (structural and functional MRI of key neural circuitry). The investigators will conduct this work with two exemplar populations for which behavior plays a critical role in the course of medical regimen adherence, health, and health outcomes: (1) smokers and (2) binge eaters.

In these groups, the investigators will evaluate the extent to which participants can engage and manipulate putative targets within the self-regulation domain both within and outside of laboratory settings. 50 smokers and 50 obese/overweight persons will participate in a lab study to complete the identified tasks.

The investigators will experimentally modulate engagement of targets (e.g., stimulus set of palatable foods images or tobacco-related images as well as self-regulation interventions).

Subjects will participate in a 30 minute introductory session and a single testing session at Stanford, which will include testing using a subset of self-regulatory tasks from the following list (stop-signal task, conditional motor selective stop signal task, Stroop task, dot pattern expectancy task, attention network task, Columbia card task, task switching, delay discounting task, tower of Hanoi, and emotion regulation task). The order of assessments will be counterbalanced across subjects. Imaging will allow an assessment of the degree to which the neural systems associated with each element in the ontology can be engaged and manipulated in the clinical samples. Imaging will be performed at the Stanford Center for Neurobiological Imaging, which has a research-dedicated 3T GE MRI scanner with all necessary accessories for stimulation and recording. In addition to task-based fMRI, the investigators will collect resting-state fMRI while passively viewing either a blank screen or a movie that may include smoking or food-related stimuli. The proposed sample size of 50 per clinical group will provide sufficient power to detect delta=0.56 between groups, and a correlation of r=0.2 across the aggregated sample.

As the investigators collect data from all participants, they will include manipulations (or "motivating operations") meant to modulate putative targets within the self-regulation domain in each clinical group - to assess the extent to which participants can shift self-regulatory function both in desired and undesired directions. This will be achieved by (1) exposing subjects to specific stimulus sets relevant to the sample that may promote engagement of appetitive drives (images of highly palatable foods for obese individuals, and tobacco-related images or smokers), and (2) exposing them to an instructional manipulation ("now" vs "later" cues that instruct subjects to engage with the immediate hedonistic properties of the stimulus or the long-term consequences of using the stimulus, respectively) designed to engage self-regulatory processes in the presence of these stimulus sets.

Eligibility Criteria:
Inclusion Criteria:

* Understand English sufficiently to provide informed consent
* Right-handed
* Normal or corrected-to-normal vision and no color blindness

Additional Inclusion Criteria for Smoking sample:

* Smoke 5 or more tobacco cigarettes/day for past year
* BMI greater than or equal to 17 and less than 27

Additional Inclusion Criteria for Binge Eating Sample:

* BMI greater than or equal to 27 and less than 45
* Weight limit of 350 lbs
* Non-smoking (defined as no cigarettes in past 12 months-this includes former and never smokers)

Exclusion Criteria:

* Significant medical illness
* History of mental disorder due to a medical condition
* Lifetime history of major psychotic disorders (including schizophrenia and bipolar disorder)
* Current use of any medication for psychiatric reasons (including stimulants and mood stabilizers)

Additional Exclusion criteria for Binge Eating Sample:

* Lost weight in recent past (\>10 pounds in past 6 months)
* Currently in a weight-loss program (e.g., Weight Watchers, Jenny Craig)
* Currently on a special diet for a serious health condition

Additional Exclusion Criteria for Smoking Sample:

* Binge eating behavior