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The Daily Wildcat

The Daily Wildcat

 

UA reseachers study how rats make decisons

The output of cost and benefit analyses people make are discernible: Choosing Chipotle over a salad, or chasing a dream job over a stable paycheck. However, what can’t be seen is what exactly is going on in the brain that ultimately results in these decisions.

Stephen Cowen, an assistant professor of psychology, studies how the brain processes the costs and benefits that are involved in every decision we make at a neuronal level. While in the past people have heavily researched rewards, not much is known about how the brain anticipates or evaluates cost.

“We are trying to see if the similar systems involved in costs are also involved in benefits, and vice versa,” Cowen said. “Is dopamine, for example, which we think is very important in reward and learning about reward, involved in costs, or at least allowing you to overcome the negative parts of costs?”

Dopamine is a neurotransmitter, a chemical signal that is sent from neuron to neuron to illicit a response.

To tackle these questions, the Cowen lab is looking at the activity of individual neurons of rats going through a maze that requires them to make cost-benefit decisions. The individual neurons that are monitored through this process are largely in the frontal cortex and a region of the brain called the striatum. Individual neurons in the striatum are involved in motivation, learning and habit learning, Cowen explained.

“We are learning how the striatum interacts with the frontal cortex during decision-making,” Cowen said. “An example of this decision-making is when the animal is processing the choice of, ‘Should I expend some effort to get this good reward, or should I take the easy-way out?’”

According to Cowen, his research may answer even simpler questions like whether the neurons in this area of the brain respond to the anticipated effort or cost of completing a task, respond to anticipated reward, or combine those two bits of information together to do an evaluation of the value of the decision.

Matthew Schmit, a researcher in the Cowen lab who has two bachelor’s degrees, one in neuroscience and cognitive science and the other in molecular and cellular biology, is developing computer software that will allow the lab to analyze hundreds of gigabytes of neural data.

“We get a lot of data with these rats,” Schmit said. “We have 123 channels. We record every time one of the doors in the maze move; we record every time one of the barriers move. There is just a lot of data to go through. With that much data, the question becomes, ‘Do you get it in a form that you are able to work with to determine what is actually going on?’”

By using thin pieces of wire called tetrodes and placing them near different regions of the rat’s brain, the individual neurons of the brain can be measured, Cowen said.

“In our brain we have about 80 billion individual neurons, but together, they make us think, learn and remember,” Cowen said. “We are very much interested in the activities of individual cells and how they contribute to learning, memory and navigation.”

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Follow Chelsea Regan on Twitter.

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