Paul Chamberlain and Dr. Mikle South, Department of Psychology

My project was designed to study how autistic children respond to uncertainty and if they respond differently than typically developing children. Psychologists have differentiated between two different types of fear- phasic fear and sustained fear. Phasic fear is fear to a specific threat. For example, if you are hiking and see a snake on the path you are afraid. However, if there is no snake you are not afraid. Sustained fear, or anxiety, is essentially fear of what could possibly happen even when there is no physical stimulus present. Going back to the hiking example, sustained fear would be fear that a snake is going to appear at anytime. The hiker is scared of something that might appear, but is not actually present. We used an experimental paradigm that has been used to study the differences in phasic and sustained fear in adults and applied it to autistic and typically developing children.

I used a paradigm developed to study differences in cued (ie phasic) and contextual (ie sustained) fear (Grillon, 2008). Participants were exposed to 3 different virtual “environments” (i.e., different screen backgrounds) in which they periodically view a cue about possible threat. In the predictable environment (P), the aversive stimulus (a puff of air to the neck that our lab has used in the past for similar tasks) may occur while the cue is displayed. In the Unpredictable environment (U) participants may receive a puff of air at anytime while viewing that background color, either with or without the cue. In the Non-threat environment (N) the participant never receives the puff. Participants are told beforehand what each background means, so no learning is necessary. Participants wear headphones that deliver short (50 millisecond) white noise bursts, which activate eye-blink reflex responses. When people are more anxious or scared, the blink happens faster and with greater force. Psychophysiolgoical measurements of arousal using eye blink were taken using the BIOPAC 1500 system. We also had participants and their parents take several psychological questionnaires to determine their intolerance to uncertainty, general anxiety levels and other related measures.

The project has taken quite a bit longer than anticipated. Originally when I proposed the project I had been looking at similar studies performed by Christian Grillon, and expert in anxiety. Even before being rewarded the ORCA grant I begin working on programming the computerized task in a program called eprime that we use in our lab. While comparing different studies that Grillon had published, I found small differences in the methods that he used. Unable to figure out why the differences were important, I emailed the first author on one of the papers that seemed to be the most clear. She was a graduate student of Christian Grillon and emailed me back a soon-to-be-published copy of a paper that was about the paradigm that they used. Using that as my guide, I programmed the computer task. I had seen the eprime program before but had to learn to use it. After several months the task was ready to go near the end of May.

While programming the task I also had to figure out how to use the electrodes that we used to measure the eyeblink. This experiment was the first time we had ever used them. I worked with Dr. Michael Crowley from Yale University who did graduate work with Dr. Mikle South, my mentor, to get our system ready to take measurements. After learning how to do it myself, I had to write up instructions and train other research assistants in the lab how to place the electrodes on participants and run the computer task. I learned much about training others and got better at it as time went on. By mid June we’d completed several pilot tests and the task was really ready to start giving out to people. All through the summer we brought people in to do the task combined with several other tasks that Dr. South has been working on for other research projects.

Throughout this time I was also working with the software that collects the eyeblink data to extract the values that we wanted. I knew what we wanted, but wasn’t sure how to extract it. I turned to some of the application notes for similar tasks that our software provider has available online, but ran into some problems. I emailed a customer support representative from biopac with an explanation of my problem and he basically said that I had run into one of the problems that there isn’t a work-around for. I kept trying and eventually came up with a solution that is a bit convoluted, but gets us the data that we want. After figuring this out, I again trained other research assistants on how to extract the data. We just completed extracting this data in December. Currently we have run nearly 50 children through the experimental paradigm- about 20 autistic children and 30 typically developing children. All the data from these children has been extracted and is ready to analyze. We want to run 10 more autistic children through the paradigm before we analyze all the data.

I hypothesize that children with autism will show eyeblink patterns that indicate they are anxious all the time- even in the experimental “environments” where they know they are safe. This would be consistent with the high levels of anxiety that are commonly seen in autistic children. The final product of the project will be a paper that we will submit to a scientific journal for publication. In addition, we submitted an abstract to present a poster on the project at the International Meeting for Autism Researchers that will take place in Spain in May 2013. If accepted, Dr. South will present the research there.

References

Grillon, C. (2008). Greater Sustained Anxiety but Not Phasic Fear in Women Compared to Men. Emotion, 8(3):410-3.