Teaching science by the peck

The Baltimore Sun

Margaret McDevitt placed a pigeon in an experimental chamber, closed the glass front and shut off the overhead light before leaving and heading to a nearby room.

There she flipped on a monitor to watch the bird.

Squishy, the pigeon, waited for lights to come on in two circles on the side of the chamber. The bird then pecked at the green circle and was rewarded with food.

"It sounds simple, but it's not," said McDevitt, an associate professor of psychology at McDaniel College. "You can't just tell the pigeons what to do. Working with pigeons is like working with infants. You have to put them in a situation and wait until they learn what you want them to learn."

The session was part of an ongoing project in which McDevitt uses pigeons to teach students research methods.

Despite what she says is a decrease in animal labs being used at many colleges and universities, McDevitt's program is thriving.

"The trend is not to have an animal lab," said McDevitt, who earned a bachelor's degree in psychology from California State University in 1990. She also earned a doctorate from the University of California in San Diego in 1997.

"Animal labs are expensive and require extra staff to care for the animals," she said. "As a result, many universities are closing their animal labs."

Working with animals is an experience McDevitt said she believes is invaluable for students.

Psychology major Emily Paull agreed.

At the start of the semester, Paull, 22, said she was afraid of birds. McDevitt did behavior modification experiments with Paull to help her overcome her fear.

"She would bring the bird into a room in a cage and sit it on a table in front of me. Eventually I was able to take the bird out of the cage myself," Paull said. "By the end of the class, I was playing with the bird."

Paull said she was able to teach the bird new skills.

"I actually taught a bird to jump out of a cage and stand on a weight scale," she said. "Then I taught the pigeon to turn and walk back into the cage. I just loved it."

Knowing the impact that using animals could have on motivating students, McDevitt started her research project for her students in a class on the psychology of learning using the pigeons.

Each student in the class is assigned a pigeon to work with throughout a semester. During labs, the students place the pigeons into chambers with glass doors that have three small circles on one side. Below the circles is a small chute that delivers food to the pigeons when they respond correctly.

Bruce Hesse, a professor of psychology at California State University, Stanislaus, said McDevitt is making a name for herself in the field.

"I'm proud of Margaret as my student," said Hesse, who introduced McDevitt to pigeons in 1989. "She has become well regarded for her work with pigeons among people in the behavioral analysis field."

In the latest experiment, McDevitt said, the pigeons were trained to respond to four different trials: A+B-, B+C-, C+D-, and D+E-. Each letter represents a color: A is green, B is red, C is blue, D is yellow and E is white.

The plus sign means that if that stimulus is chosen, it is correct. The minus means if that stimulus is chosen it is incorrect.

A is the most valuable stimulus because the pigeon always receives food for selecting A, said McDevitt. B, C and D are reinforced with food some of the time, depending on what color they are presented with, she said.

For example, if green and blue light up, green is correct, because it is always correct. And E is never reinforced with food, so it is always the wrong answer, said McDevitt, who specializes in research involving choice behavior in humans and animals.

When she started the research, she said she had the students in the room with the pigeons. But it proved too distracting, said McDevitt.

"I wanted to see if humans could participate in research if they had to learn like a pigeon," said McDevitt. "It was interesting because at first the students copied the pigeons. It wasn't that the pigeons always got the answers right, it was just that the students thought the pigeons were doing better."

McDevitt began research with pigeons as a student in 1989 when she enrolled in a class taught by Hesse.

"I had no idea what to expect, but I ended up loving it," she said. "And once I worked with pigeons, I knew when I began teaching I wanted an animal lab."

Although the heyday for labs was during the 1970s and 1980s, some schools still prefer using live specimens, said Hesse. Students prefer having a pigeon sitting on the table in front of them, he said.

"It's more effective to use live research animals," Hesse said.

McDevitt realized her dream to start an animal lab when she began teaching at McDaniel in 2000. At that time, she acquired about 21 pigeons from breeders. The birds are perfect for research, she said.

"To race pigeons, the owners have to take good care of them," said McDevitt. "They have to get the pigeons shots and get them regular health care. But by the time we get the birds, they are no longer racing and are going to be euthanized."

One of the things replacing the animals is virtual programs and other technology, said McDevitt. For example, some schools are using Sniffy the Virtual Rat, a software program used in place of an animal.

"It is used to completely replace an animal lab and to show the principles of learning," said McDevitt. "They don't use them because they are so much better, but because they are so much cheaper. The students purchase them like textbooks."

Paull said it does not compare to working with the real thing.

After observing students working with the program, she concluded it wasn't as effective as working with animals.

"The hands-on experience I had with pigeons was much more of an educational experience than the students had working with the computer program," she said. "Working with the pigeons was more rewarding than anything you can learn on a computer."

For Hesse, too, there is nothing like the real thing.

"Pigeons are important because they can be a learning motivation," he said.

"They are good for experimental analysis. Research can be boring for some students." Hesse said. "So we have to do whatever we can to make research interesting."

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