Sarah E. Hoff'02, who has a campus job as part of her financial aid package, said the money she earns from the studies helps pay for extra expenses.

"My psych money doesn't make a significant contribution to my tuition, but with the whole cost of living it's good to have extra cash," Hoff said. "It really adds up fast if you do it a lot." Hoff said she has participated in about 20 psych experiments already this year.

"I do it mainly to make money. It's a good way to get a couple of extra bucks for the weekend," Pinto agreed.

While the studies are ostensibly voluntary, some students also participate as part of their Psychology 1 course requirements. Students can replace one of the three required course papers with three experiments.

Adda Kridler '01, who took Psych 1 last semester, appreciated the option.

"It gave good leeway in case I did bad- ly on one of the papers or didn't have time to finish one," Kridler said.

"It also provided a good perspective on what psychological studies are like and what kind of things I would be doing if I decided to do a psych concentration," she said.

Others agreed that participating in psych studies felt less like enforced labor and more like a good way to decide whether to pursue a concentration in psychology.

"It definitely helped [me decide to concentrate in psychology]. I got to talk to people and asked them questions and I saw that I'd like to be on the other side doing that," Olivia M. Hall '02 said.

Most students described having participated in visual studies, surveys and cognitive tests, but a few decided to check out some of the more unusual opportunities advertised on campus.

Hall spent the night in a lab with electrodes attached to her head as part of a sleep study. She was woken up periodically throughout the night so that those observing her could administer cognitive tests.

"[The researcher] woke me up in a certain phase of sleep and I had to do math problems for three minutes and then I was allowed to go to sleep," said Hall.

Overall, she said the experience was a good one.

"It was really nice to finally get so much sleep--I was supposed to sleep for 8 hours and I don't usually get that," she said.

James Y. Stern '01 also participated in an overnight sleep study and an experiment in which they took an MRI of his brain.

"The MRI was kind of scary because it was this experimental level twice the MRI strength... They locked me in this little tube for two hours and I was not allowed to move," said Stern, who is also a Crimson editor.