Ever wonder what a day as a COGA participant looks like?

Participants are first contacted by a researcher at one of the study sites. After they explain the study, if the person wants to participate they arrange a time for them to come in.

For most people, there are 4 main parts of the study.


The first part is Questionnaires.  They cover topics like employment, stressors, alcohol use and other health outcomes, and personality. Both the consent and questionnaires can be completed at home, either electronically or on paper, and take about an hour.

The other three parts happen in person when the participants go in to a data collection site.  They are the Interview, the “Toolbox”, and a brain wave measure. A small number of participants may engage in a fourth part, DNA Sampling.

The Interview

The main way we collect information about alcohol use and other outcomes is through an interview that we call the Semi-Structured Assessment for the Genetics of Alcoholism.  This interview is read to participants by one of the research assistants from a computer, either in-person or via telephone.  For each question, the subject is given some choices on how to answer each question.  The interview will contain questions about drinking and experiences that can affect drinking behavior.  Other questions in the interview are concerned with other substance use, moods and feelings.  We ask about all of these things because substance use and mental health frequently affect each other.  The use of a computer allows the research assistant to quickly record the answers. On average it takes a subject about 1 hour and 45 minutes to complete this section.

The Toolbox

The toolbox consists of a series of short tasks administered on a computer tablet — but don’t require previous experience with a computer. These tasks were developed by the National Institutes of Health and measure participants’ thinking skills and emotional functioning. The thinking section takes about 45 minutes and examines subjects’ ability to remember patterns, plan, pay attention, stay on task, and respond accurately. The emotion section takes about 15 minutes and asks subjects about positive and negative emotions (e.g., joy, anxiety), stress, and satisfaction with life.

Brain Waves

The third part of the study measures brain wave activity.  First, subjects are fit with a stretchy cap with plastic, button-like circles with holes in the middle.  These buttons have wires attached to them and are placed on the subject’s scalp.  A special gel will be applied to holes in the inside of these button-like circles to improve the recording quality; this paste washes out easily.
The subject then sits in a comfortable chair in quiet booth.  There are 9 tasks that take place in the booth.  In two of the tasks, the subjects sit quietly in their chair while brain wave activity is collected, a few minutes with their eyes open and a few minutes with their eyes closed.  In the remaining tasks, the subject will be asked to respond to computer generated sounds or pictures by pressing a button on a key pad.  The tasks measure attention, reward processing, response inhibition, how brain waves are passed between different areas of the brain, and working memory processing.  Altogether, the subject spends about 2 hours doing this part of the study.  Participants can always take a break or stop at any point if they become too tired.

DNA Sampling

For some people there’s one additional part. A small number of participants may be asked to have a blood sample collected.  This is only done if the participants’ previous blood sample has been all used up or is no longer usable.  The amount of blood sampled is less than 2 tablespoons.  Researchers who study genetics prefer blood samples because they allow us to have a renewable source of the subject’s DNA and will allow certain studies to be performed that could not be done with other methods.  But if a person really prefers not to donate blood, they could instead donate saliva so that a limited sample of their DNA could be collected. If a participant chooses to donate saliva, they will be asked not to drink, eat, or smoke for approximately 30 minutes prior to giving the sample.  The subject will then be asked to spit into a container until the saliva reaches a marked line in the container, which is approximately 2-3 tablespoons of saliva.
Click here to learn what we do with all that data.