28 Mar 2017

Jeremy Wolfe Wants to Understand How We See Things

Jeremy Wolfe Wants to Understand How We See Things
Jeremy Wolfe
APA Fellow Jeremy Wolfe's research looks into how people use sight to process information that's out there in the world.

 After four decades of investigating how the human eye works, Jeremy Wolfe, PhD, still finds plenty to keep him curious.

 “I never get bored,” says Wolfe, head of the Visual Attention Lab at Harvard Medical School (HMS) and Brigham and Women’s Hospital, in Boston, Mass., and an APA Fellow. “There’s always something new to consider. My elevator speech is that for the last 25 years, most of my lab’s work has involved studying visual search. Or, how do you find what you’re looking for? We move back and forth between basic science issues and real-world problems.”

How do you locate the mustard in the refrigerator, pick out the weeds from the posies in your garden, or home in on the cereal you like best from the dozens arrayed on the shelf in your local supermarket? Because your eye conveys so much information in a glance, according to Wolfe, professor of ophthalmology and radiology at HMS, that information has to be processed to make perceptual sense. “If we want to know if a specific object is present, we will often need to search for it, even if it is easily visible,” Wolfe says.

The mechanics of those quotidian quests have fascinated Wolfe for his whole career. In 1989, he first published his influential analysis of the process, which he called Guided Search, building on “the two-stage architecture” — preattentive and attentive — of Anne Treisman’s pioneering feature integration theory, and other works. Guided Search tracks the complex process, conducted in fractions of seconds, by which we find “targets” among the “distractors” in our field of vision by applying certain fairly coarse criteria, such as color, shape, size, orientation and curvature, and then “binding,” or assembling, those traits into a “single representation of an object,” according to Wolfe. Some objects are fairly easy to find, while others, like the proverbial needle in a haystack, can take quite a bit of time and attention.

 “The core of GS was the claim that information from the first (preattentive) stage could be used to guide deployments of selective attention in the second (attentive stage),” Wolfe wrote. He is now tinkering with the fifth iteration of Guided Search, to incorporate new data.

Wolfe’s latest research studies some of the limitations on our ability to see what’s in front of us, specifically problems that arise when people are tasked with looking for “rare events,” or things they are not likely to find — the radiologist examining X-rays for breast cancer, or the airport inspector looking for weapons or bombs in luggage. Radiologists miss 20 to 30 percent of visible cancers; for security purposes, the government doesn’t like to share how airport scanners are doing, Wolfe notes. One of the things that happens to expert “searchers” over time is that their vigilance flags, because most of the time what they’re looking for isn’t there.

“There are really profound limits on the human search engine,” Wolfe says.

Computers do much better, typically finding 100 percent of tumors, for example. However, a very high false positive rate is the computers’ downfall (and also for programs designed to improve searchers’ find rate). That’s a serious problem, because identifying nonexistent cancers activates an expensive, irksome and, for the patients, a terrifying recall process, to no useful end. So, people are better prospects for these jobs than computers, at least for now, and Wolfe’s research is aimed at figuring out how to improve humans’ overall performance on screening for rare events.

What Wolfe calls his own “origin story,” or how he got his start in visual research, begins when he was in high school in New Jersey, at a summer job his solid-state physicist dad got him at his workplace, the Bell Labs facility in Murray Hill, N.J.

“He sold me to his tennis buddy, who was a color vision researcher,” Wolfe recalls. He spent stretches of that summer immobilized in a chair, “looking at barely visible spots of light. My job was to say what color they were. What was cool about that was that I didn’t think I could tell. I thought [I]was guessing,” he says, but the experiment showed that he was able to identify the colors more often than he would have if he were merely guessing. On his many necessary breaks from the tedious work, Wolfe roamed the labs’ halls. He spent hours that summer talking to scientists he later discovered were famous in their fields.

“Many of the issues that have been important to my career I was introduced to then,” he recalls. That exposure was so important to him that Wolfe himself now has “an absolute commitment” to bringing high school students into his own lab, providing internships for half a dozen of them every summer.

Wolfe went on to graduate summa cum laude from Princeton in 1977. His doctorate, in 1981, was from the Massachusetts Institute of Technology, where his doctoral thesis was entitled, “On Binocular Single Vision.” Wolfe taught at MIT for 10 years and won the Baker Memorial Prize for teaching there in 1989. He was denied tenure the following year.

 “I was not the first person to win that prize and the following year lose a tenure battle,” he recalls. “It was seen as a zero-sum game, that if you were devoting the kind of time to your teaching to be winning that prize, you couldn’t really be a serious researcher.”

That episode ended with Wolfe moving his lab to Harvard in 1991 (though he was also a popular lecturer at MIT for 25 years; the podcast version of his “Introduction to Psychology” has been a top offering on iTunes U), and he’s had “quite a nice career, but a rather different career” from the one he had in mind. He’s a medical school professor, not a psychology professor, and “I live entirely on grant money, which is an exciting way to live. I’ve done basic research and use-inspired basic research. I’ve gotten grants every which way.”

Wolfe doesn’t mind that his scientific research is expected to lead to useful applications. He says, “When we’re working on the public dime, we ought to be able to make a decent case for why this is a sensible use of taxpayers’ hard-earned money."

Did you find this article interesting?

2 0

Leave a Reply

Your email address will not be published. Required fields are marked *