It takes you 260 milliseconds to register the words you are reading on this page and produce a… It takes you 260 milliseconds to register the words you are reading on this page and produce a visual picture in your mind.

Dr. Donald Glaser, who has devoted his life and research to mathematics, physics and neurobiology, described this and many other visual perception issues during his Friday afternoon lecture in Alumni Hall. His lecture, “How Does the Brain Enable Us to See? Perceptions of Motion, Depth and Illusions,” drew an audience that completely filled the auditorium.

Glaser, who has taught at the University of California at Berkeley as a professor of physics and neurobiology since 1959, received the 1960 Nobel Prize in Physics for the invention of the bubble chamber, a research instrument used to trace the movement of high-speed atomic particles. At the age of 34, he was one of the youngest scientists ever awarded the Nobel Prize.

His recent lecture, however, dealt with another area of Glaser’s expertise: the neurobiological processes the brain undergoes when dealing with visual perception. Despite the complexity of the subject at hand, he kept the audience entertained with humor.

“Why do monkeys use only half of their brain and we use one-third of ours? Because monkeys don’t have to sit and listen to lectures,” he said, explaining that visual perception uses more brain space than verbal processing.

Glaser was born in Cleveland, in 1926. After earning his doctorate in physics at the California Institute of Technology in 1950, he went on to teach at the University of Michigan for a decade. He then moved west in 1959, to serve as professor of physics at the University of California.

Glaser presented his lecture in a very visual format, using vivid images and charts to clarify concepts. In one experiment demonstration, he asked the audience to stare at a simulated waterfall for 30 seconds, and then to look away. Audience members still saw the image of the waterfall, but it appeared to flow upward instead of downward.

The waterfall image demonstrated the immense complexity of the optical nerve, which has more than one million fibers.

Glaser repeatedly compared the brain to a luminous spark of energy intertwined in a vast “jungle of neurons.” Glaser also put into perspective the enormity of the brain’s structure.

“We have 100 billion neurons in our brain — that’s the good news,” he said, smiling. “The bad news is that one of them dies every second.”

In another experiment, the audience was instructed to look at 100 tiny dots projected on a screen and rotating in a circular motion. The dots moved in such a way that, when prompted to, an audience member could mentally switch the way the dots appeared to rotate, from clockwise to counterclockwise. As Glaser added flashing dots at a faster pace, it became increasingly difficult to switch the rotation until it eventually became impossible.

Glaser used the demonstration to illustrate the abilities of the brain and the way it processes illusions.

He closed the lecture by discussing a study involving eight marijuana users who experienced delayed reactions and short-term memory loss in the brain. Glaser went on to describe the seven or eight different areas of the brain that marijuana affects.

“This is what happens when you’re stoned,” he said while pointing to a chart, seemingly to offer a warning to the college students in the audience.

Glaser closed the lecture by thanking the many people with whom he collaborated and who made his experiments possible.