Brain Activity, Reality and Illusion

A man sits at a computer screen, watching two disks, one red and one yellow. At times, one of the disks seems to disappear, and he taps a certain to key to report this.

Is it possible to know what he thinks he is seeing, without his reporting of it?

Based on existing data and data collected in a research project at Borough of Manhattan Community College (BMCC/CUNY), Professor of Psychology Marjan Persuh believes the answer is “yes.”

“I am trying to understand how our brain activity relates to our conscious experience of the world around us,” he says. “In this project, we are using a visual illusion called ‘motion-induced blindness’, in which continuous motion on computer monitor results in momentary disappearance of a bright yellow disk presented on the screen.”

The yellow disk, Persuh explains, remains present on the screen at all times — but even as the disk remains constant, a person’s perception of it can change, making it appear to go away.

Participants report this perceived change manually, he says, “but we are trying to develop a new measure of their conscious perception that is independent of their report.”

To give some context, he explains that in the human eye, the pupil responds not only to light intensity, but also to perceivedlight intensity.

“We are hoping to use pupil size in this experiment as a measure of conscious perception of the yellow disk,” he says. “The long-term goal is to use these types of report-independent measures of awareness in patients with disorders of consciousness, such as patients in coma or vegetative state, unable to move or speak.”

Finding the link between Biology and Psychology

Persuh, who holds both a Ph.D. in Molecular Biology and Biochemistry from the University of Ljubljana in Slovenia, and a Ph.D. in Psychology from the CUNY Graduate Center, brings a unique blend of expertise to the project.

“I never planned to get a second Ph.D.,” he says. “Towards the end of my graduate training in biochemistry and molecular biology, I felt that major questions in the field have been answered. At the same time, I became increasingly interested in the relationship between brain activity and our awareness of the world around us. I was not equipped with knowledge or experimental expertise to tackle these questions, so I decided to fix that by getting a Ph.D. in Psychology, in the area of Cognitive Neuroscience.”

Putting it another way, he explains that molecular biology offers understanding of the brain at the cellular level, while cognitive neuroscience and psychology address questions at the higher level of brain organization.

“For each question that I have about human behavior, I try to think about how the same problem is solved by less complex organisms,” he says. “In fact, even methodological approaches in molecular biology have many parallels in cognitive neuroscience.”

Insights into the human brain, and career opportunities

Science major William Yu is assisting Persuh in the lab, where he helps set up the activities and ensures that they conform to the same standards.

“Subjects sit in front of a screen where they will see a bright yellow disk coupled with a blue rotating grid,” Yu says. “In the subjects’ perspective, the disk is disappearing but in reality, the disk is visible for the entire duration.”

Next, he and Persuh examine any pupil changes that occur. They also use an EEG, or Electroencephalography, to evaluate the electrical activity in the brain, with the goal of tracking brain activity that occurs in response to perceived changes on the screen.

What fascinates Yu about the work, “is that we can sit two subjects in completely identical environments and expose them to the same exact illusion; yet, achieve completely different results.”

One day, Yu hopes to contribute to the discovery of the mechanisms behind mental disorders as a researcher, while helping those with mental disorders as a psychiatrist.

“I’m looking towards transferring to NYU to pursue my passion for the brain as a Neural Science major while minoring in Childhood and Adolescent Mental Health,” he says. “Then if all goes well, in ten years, I’ll be practicing psychiatry while doing research in neuroscience. This project contributed to the skillset required to succeed in the field of neuroscience, such as coding and problem solving.”

One surprising observation from the research, Yu says, “is how easily our experience, or perception of the world can be manipulated. It leads me to wonder how often we miss things that are there, but our brain chooses to ignore. This was an insight that was surprising, exciting and truly scary for me.”

This article is part of the 2019 Marks of Excellence, an annual publication from the Office of Public Affairs that highlights the outstanding accomplishments of students, faculty and staff. This issue features research projects at BMCC. Please note, the stories are also presented in a flip-book version.