Psychology/Neuroscience’s Robinson Studies Desires of Gambling, Diet-Induced Obesity

In this issue of The Wesleyan Connection, we speak with Mike Robinson, assistant professor of psychology, assistant professor of neuroscience and behavior, who joined the faculty in January.

Q: Welcome to Wesleyan, Professor Robinson! Please fill us in on your life up to now.

A: I was born and grew up in France, in the west suburbs of Paris, but my parents are both British, so that makes me bi-national and bilingual. I went to high school in France and decided to go to university to study neuroscience at the University of Sussex in the U.K. Then I went to McGill University in Montreal, Canada to do a master’s and a Ph.D. in experimental psychology. From there, I went to the University of Michigan for a post-doc before coming to Wesleyan. So I’ve almost jumped a country per position.

Q: What brought you to Wesleyan?

A: I was attracted by the balance Wesleyan offers—both the work-life balance, and the work balance between the amount of research and the amount of teaching. I really enjoy both teaching and research, but I always felt like I’d have to compromise one or the other if I went to a research institution or a more teaching-intensive small liberal arts school. I feel like Wesleyan has the perfect balance. Plus the opportunity to be with really high-quality students, which I thought would be really stimulating and almost like working with grad students. I currently have four students in my lab, and so far I’ve been very impressed by them.

Q: What classes are you teaching this semester?

A: I’m teaching one course called “Motivation and Reward.” In the fall, I’ll be co-teaching “Intro to Neurobiology” with Jan Naegele (professor of biology, professor of neuroscience and behavior, director of the Center for Faculty Development), and a research methods course on research in animal behavior. Next spring, I’ll be teaching “Motivation and Reward” again, and an advanced research course looking at where a lot of my research is focused, which is gambling, diet-induced obesity and drug addiction.

Q: Please tell us more about your research interests.

A: I’m interested in understanding how the brain works. I’ve always wanted to do something that helps people in as direct a way as possible, considering I’m not doing human research. I started out doing research on drug addiction. My Ph.D. work looked at the ability that we may have to affect memory after it’s been created and consolidated, either strengthening or weakening it. In this case, the idea was to weaken the environmental cues associated with a drug that might induce craving and relapse. Through my post-doc, I developed that area more generally as far as how it pertains to desire—every kind of craving that’s involved in the abuses associated with addiction. Through collaboration with several different people, I became interested in the role of uncertainty in gambling, and how in a certain environment, the lack of predictability can spur us into more malicious, compulsive, gambling.

My research is strongly focused on the concept of individual differences in behavior like gambling, and in diet-induced obesity. I strive to understand what the mechanisms are that will drive any individual to do more of something—more so the people who are especially susceptible to those influences.

Q: How do you study diet-induced obesity?

A: We give animals free access to a junk food diet. We mix chocolate chip cookies, peanut butter, Nesquik chocolate powder and Lay’s potato chips into one chocolate cookie dough type concoction. We see that some animals gain incredible amounts of weight, while others gain the same amount as if they were given a regular, healthy lab diet. That really suggests that there’s an underlying individual difference. We’ve been looking at differences in how individuals react to cues associated with rewards. What’s interesting is that we’ve looked at the brains and behavior of animals that gain weight and those that don’t on a high-fat diet. In both cases, their brains are more sensitized to reward, although there are some differences and adaptations that strictly affect those animals that gain excessive amounts of weight. So whether you ward off weight gain by controlling intake or having a higher metabolism, the repeated exposure to junk food is still having an impact. There’s a silly story I saw on the Internet about a guy who claimed he was living off only pizza. He looked healthy and fine, but I would argue that it’s still having an impact on his brain, changing his reward system. Doctors would probably say it’s having an impact on his body, too! Sometimes the impact of our diet runs deeper than our outwardly appearance. Moving forward, my lab’s interest in this research focuses particularly on the impact that a high-fat junk food diet has on our younger generation. If chronic exposure to a junk food diet can cause such drastic changes in the brains of adults, just think of the impact it might have when individuals are repeatedly exposed during gestation, lactation and early development.

Q: How do you examine brain activity associated with the behaviors you study?

A: Once my lab is set up, we’ll employ a new technique called optogenetics that allows us to control brain activity using laser light. We can use viral vectors to inject the genes that code for photoreceptors into the brains of rats, which allows us to affect any type of neuron we want. The genetic material will be incorporated into the cells, and the cells will act as if it’s their own. The outcome is that those cells will have photoreceptors on their membranes. We can then painlessly put very thin optic fibers into the brain and use a laser light to turn those cells on or off at a given time. We can target a specific structure and activate it moment to moment to determine the involvement of different parts of the brain in certain behaviors. It allows us very precise control and timing. That’s the best way we have to understand how the brain is acting and what different parts are involved in different functions. It can be applied to a huge number of things.

Q: What future research do you have planned in your lab?

A: This summer, a few students will be working with me on a gambling study using rats to help us better understand individual differences in gambling behavior. This is something that hasn’t been studied much in animals or in humans. I’m primarily interested in looking at slot machine-type gambling, rather than high-rolling poker. (And playing cards with rats is always going to be a challenge!) We have designed a simple task that looks at how the uncertainty associated with gambling can be attractive. Rats are presented with a lever that predicts a reward 100 percent of the time, or a lever that half the time predicts no reward, and the other half provides either one, two or three rewards. The reward outcome for both levers is the same at the end of the day, but we find that rats are much more attracted to the unpredictability of the second lever. What this might suggest is that our brains are intrinsically wired to seek out uncertainty, possibly in an attempt to understand and resolve it. This propensity to display attraction to uncertainty may show a large amount of individual variability, particularly in how individuals respond to loss and risk. This is something that is often hard to model in animal research but our efforts over the summer will focus on how when faced with negative consequences, at least two populations emerge–those that are risk-averse and those that are risk-resistant. Individuals that are prone to being risk-resistant seem far more willing to overcome negative consequences in order to be in contact with rewards or cues that predict them. Ultimately this may help us understand which parts of the brain are involved in these behavior and which particular circumstances hijack this system, making certain individuals more susceptible to developing pathological gambling.

Q: What do you like to do when you’re not working?

I’ve been keeping quite busy at work lately! I like to play basketball and soccer when I have time. I like to spend time with my 14-month-old daughter. My wife and I enjoy cooking and foreign food, in particular, and we also love to travel.

Read more about Robinson’s work on his lab’s website.

#THISISWHY