Our Research

Overview

Our lab uses neuroimaging and complementary methods to explore the neurobiology of addiction and its consequences in humans.  Our studies include those of drug use and reward function, the role of mood and monoamines in drug use and reward dysfunction, drug-induced toxicity, and neural mechanisms of overeating and obesity. Specific research topics include:

MDMA (Ecstasy) Toxicity

These projects attempt to characterize the long-term consequences of recreational MDMA use in humans.  We used multimodal MRI and MRS approaches to examine MDMA effects on brain structure, function, and chemical composition.  We use PET to characterize persistent MDMA effects on brain serotonergic receptors.  We also examine the relationship between brain activation and behavioral performance, personality, psychiatric symptoms, and genetic effects.

• Magnetic Resonance Imaging (MRI) Analysis of Persistent CNS Toxicity in Human MDMA (Ecstasy) Users

• Genetic Factors in Human MDMA Toxicity: A PET Study

Neurobiology of Obesity

These projects explore the neurobiology of obesity from an addiction perspective examining food salience in obesity.  FMRI studies examine the neural bases of brain responding to food cues of varying palatability and caloric density.  Effects of satiety and hunger are assayed.  Eye-tracking studies examine for altered attentional or incentive salience for food cues in obesity.  Because altered food salience may be a major mechanism for relapse in obesity when attempting to regulate food intake, exploring the effects of caloric content, palatability, hunger and satiety on attentional salience is an essential step toward documenting the role of these mechanisms in obesity.

• Neurobiology of Childhood Obesity: MRI

• Neuroimaging Investigation of Hyperphagia in Prader-Willi Syndrome

• Visual Attention and Food Salience in Obesity

Serotonin Genetics

Our studies of serotonin genetics and brain function examine the relationship between common functional allelic variations in genes encoding serotonin receptors and the serotonin reuptake transporter and brain structure, function, receptor expression, and personality. 

• SERT polymorphisms and human cortical 5-HT2A receptors

Neurobiology of Euphoria

Our studies of the neurobiology of euphoria employ functional MRI during drug administration with continuous mood assessment to probe the neural correlates of drug effects and to identify neural substrates mediating self-report of the euphoric mood change. 

• High-Field Functional MRI of Human Euphoria

Neurobiology of Sexual Addiction and Sexual Health

Sexual behavior is mediated by brain systems that have much overlap with those involved in other motivated behaviors. These brain systems are vulnerable to dysregulation as is seen with substance abuse and other behavioral addictions such as pathological gambling. There is currently little research into the neurobiology of sexual addiction and how it parallels other types of addiction. Our research uses functional MRI to examine the brain's response to sexually explicit cues in men who meet criteria for sex addiction and those who do not.