METHODS USED IN OUR RESEARCH
Sexual science draws from the methodologies of psychology, biology, anthropology, and more. Explore below to understand the tools and approaches that we employ in studies in our lab as well as in collaborations with others.
VALIDATED SELF-REPORT QUESTIONNAIRES
To link our experimental procedures with qualitative information about the individuals who take part in our studies, we make use of established questionnaires. These measures range from the sex-specific, like the Female Sexual Function Index and International Index of Erectile Function, to general indices of behavior, attitudes, and physical and mental health. All responses are anonymized to protect confidentiality and stored on secure servers for analysis.
Now the most widely used measure of female genital arousal, Dr. Heiman was one of the first to employ the vaginal photoplethysmograph. This tampon-sized device safely emits a small amount of infrared light, which is reflected back from the vaginal walls onto a photovoltaic cell. Increased blood flow during sexual arousal reflects more light back onto the photocell. Data are recorded in real time on a Biopac system and analyzed with AcqKnowledge software.
PENILE STRAIN GAUGES
To measure the vasocongestion that produces erections when aroused, our lab is equipped with penile strain gauges. The rubber loop fits comfortably around the base of the penis and measures the displacement of liquid metal (mercury or indium gallium) due to changes in circumference as the penis becomes engorged with blood. Data are recorded in real time on a Biopac system and analyzed with AcqKnowledge software.
HORMONE AND IMMUNE ASSAYS
Using sterile collection methods, we are able to obtain quick and minimally invasive samples of blood, saliva, urine, and vaginal fluid from our paid research volunteers. These samples are stored in a -80°C freezer until analysis. Enzyme-linked immunosorbent assays (ELISAs) and functional killing assays are conducted to uncover steroid hormones, antibodies, cytokines, and other proteins.
COMPUTER TASKS AND VISUAL MEDIA
From simply watching videos to completing cognitive tasks, our research participants always have an active role in the data we collect. Previous studies have displayed erotic videos, images of food and alcohol, and nature documentaries while asking participants to make subjective ratings of their reactions. Validated tasks of reactivity (e.g. go/no-go, oddball) and decision-making (e.g. delay discounting) have also been programmed in house.
MAGNETIC RESONANCE IMAGING
Our lab is located just down the hall from the Indiana University Imaging Research Facility, equipped with a Siemens 3T TIM Trio MRI scanner. Using functional and structural neuroimaging techniques, our lab has investigated individual differences in the brain's response to sexual stimuli as well as related cognitive processes. These data are analyzed primarily with MATLAB-based packages like Statistical Parametric Mapping (SPM12).
Our lab space is equipped with a variety of non-invasive devices for taking objective measures of the human body. In addition to providing their own self-report, participants in our studies may have the opportunity to learn about their height, weight, fat percentage, body mass index, bone and muscle weights, and/or heart rate.
In addition to studies conducted within our own and our collaborators' research facilities, some work makes use of online platforms to reach a broader audience. Participants have been recruited via Qualtrics and Prolific Academic for experiments entailing scenarios, videos, and questionnaires. Additional descriptive research has used the Kinsey Reporter app to characterize sexual interests and behaviors across the globe.
Though not an area of current research, Dr. Heiman has clinically tested several potential pharmacotherapies for male and female sexual dysfunction (e.g. sildenafil, flibanserin) as well as administered substances like oxytocin to healthy volunteers in laboratory studies. Other research has focused on psychophysiological correlates among those already taking drugs like antidepressants and birth control.