Santa Clara University

Associate professor Tracey Kahan (second from right) and her students used SCU’s Sleep and Neurocognition Lab to study what the mind does in sleep and in waking.

Cognitive Psychology Research

Cognition in Dreaming and in Waking

Are the cognitive skills we use when dreaming qualitatively different  from those we use when awake? Many dream theorists, including Freud, have said yes—though there is little empirical evidence to support the claim. On the contrary, recent research suggests that dreaming and waking cognition are fairly similar and that the differences are more quantitative than qualitative in nature.

When Shakespeare wrote  “To sleep: perchance to dream,” he surely did not foresee how clinical sleep labs would one day dot the landscape. As for research sleep labs, though, Associate Professor of Psychology Tracey Kahan can count on one hand the number of them at undergraduate institutions. And that includes her own—the new Sleep and Neurocognition Lab at Santa Clara University.

“My students are almost more excited about the lab than I am,” she says. “The opportunity for undergraduates to participate in this kind of research and develop these kinds of technical skills is quite unusual.”

Much of the equipment is the same as what you would find in any  clinical sleep lab, and includes  video cameras, audio recorders, and time-syncing software for handling gigabytes of measurement data per session. The Santa Clara University facility will only be used for research, however, not for clinical diagnosis.

Powerful New Tools
In typical sleep labs, subjects volunteer to tuck in for 40 winks wearing a Medusa’s cap of electrodes and wires. The equipment records a host of  electrophysiological measurements—including eye movement, muscle  tension, and brain wave activity— that scientists use to identify sleep stages and other research measures.

“My past work hasn’t allowed me to firmly identify the sleep stage associated with random awakenings,” Kahan says. “Now I’m able to, and I have all of the standardized measures of psychophysiology that a sleep  scientist could want.”

One important tool in Kahan’s new lab is an Event Related Potentials (ERP) capability that enables accurate electrophysiological measurements during waking cognition. This involves a similar kind of recording of electrical activity in the brain as in sleep, but allows more than twice the number of electrode placements.

“The ERP lets us localize more precisely the area of the brain that’s active under certain kinds of cognitive tasks,” Kahan explains, “and to measure very subtle and rapid changes in brain activation. It’s a very powerful tool.”

Waking vs. Dreaming Cognition
For Kahan, the problem of what characterizes waking is just as important as the problem of what characterizes dreaming. In effect, studying sleep requires studying waking—so her approach to systematically comparing cognitive abilities during sleep and during waking requires sampling both states in as similar a way as possible.

With sleep, subjects are typically woken up at random and asked to report whatever they were experiencing. Their answers to questions, which are recorded, describe their dream experiences in detail.

With waking, outside the lab, the parallel assessment requires subjects  to wear a beeper. When it goes off at a random time, they stop what they  are doing, describe what they were experiencing, and fill out an evaluation of the quality of the experience—a process as similar as possible to the sleep subjects’ process.

Inside the lab, waking cognition subjects can be assessed in a variety of ways. Subjects might be asked to listen to an audio stimulus of some sort or to look at a computer screen flashing a visual stimulus, then make a judgment about what they heard  or saw. Or they might be asked to imagine something, or imagine doing things.

“Say you were hooked up to the ERP,” says Kahan. “If I asked you to switch from imagining the shape of an apple to imagining the sound of crunching an apple, I could actually look at the change in brain activation as you shifted from one sensory modality to the other.”

Meaningful Student Participation
Kahan, who heads the psychology department, thoroughly involves  her student assistants in her research work. It will be no different with  the new lab.

“I don’t want them doing just a  little isolated piece of the research,” she says. “They need to be involved in the whole range of activities centered in the sleep lab, from data collection and technical training, to conference presentations and potential co-authorship of papers.”

Kahan wants undergraduates exposed to where the research is coming from, too. The issue is involving students meaningfully in research activities, not just using them to code data.

“In some institutions that have research as their primary charge,  students can be exploited for the benefit of others’ research projects,” says Kahan. “We have a different model here. We’re fully committed to mentoring our students in the development of their skills, in  bringing them along.”