Anne Treisman, a psychologist whose pathbreaking research into human perception and attention helped explain how the mind, not the eyes, serves as the true window to the world, died Feb. 9 at her home in Manhattan. She was 82.

The cause was a stroke, said her daughter Deborah Treisman, fiction editor of the New Yorker.

The daughter of an English school administrator and a French homemaker, Dr. Treisman initially studied modern and medieval languages at the suggestion of her father, who wanted her to become more “cultured.”

She eventually switched to psychology and, in a career that spanned nearly half a century, played a leading role in the field’s interdisciplinary evolution, as its focus expanded from human behavior to include neuroscience and other branches of biology.

Psychology, Dr. Treisman once said, provides “ways to link the mind and the brain, not just by finding out where things happen but by illuminating how. This is a quest that is still just beginning.”

Dr. Treisman’s professional quest focused on attention: how the mind can tune out music, laughter and the clatter of plates at a cocktail party to focus on a single conversation, and how humans can focus on individual objects in the world while retaining a general sense of their surroundings.

Studying hearing and then sight, she developed a model that now informs everything from airport baggage inspection to the design of classrooms and traffic signals. Known as feature integration theory, it holds that an object in the world is first perceived not as a unified whole but as a series of discrete features, including color, shape, size and orientation.

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In a 1980 article she co-authored with Garry Gelade, Dr. Treisman said it is attention that unites all these features, as the mind focuses on one object and then another. Different portions of the brain respond to different features of an object, and, in a matter of milliseconds, each feature — the orientation of a tree branch, its green color, its motion in the wind — is bound together in a single perception. For that to happen, attention must be paid.

Dr. Treisman’s theory “changed the way we understood our brains and our perception, as well as what goes into our memory and our whole cognition,” said psychologist Lynn C. Robertson, a former colleague of Dr. Treisman at the University of California at Berkeley.

“We think we see with our eyes, but we actually see with our brains,” she continued. “Your eyes are transferring information to your brain,” which focuses on a particular object while things happening in the periphery remain hazy and unfocused. “What we are getting is the illusion that the world is stable outside the small bit that we’re focused on.”

Dr. Treisman, who after Berkeley taught at Princeton University from 1993 until retiring in 2010, developed her theory through years of trial and error. She worked at times with stroke patients who had Balint’s syndrome, a rare condition in which patients are effectively blind.

Feature integration theory “has been challenged over and over again, but it has stood the test of time,” said Sabine Kastner, a Princeton psychology professor who described Dr. Treisman as a mentor. In large part, she said, the theory was so controversial because it was counterintuitive.

As Dr. Treisman once put it: “The implication was that in some ways we create our experience rather than its being determined directly by a camera-like process. Perception is more like a controlled hallucination than like an automatic registration of stimuli.”

Anne Marie Taylor was born in Wakefield, England, on Feb. 27, 1935. During World War II, she wrote in an autobiographical essay, “My sister and I would be carried down to shelter in the cellar whenever the air raid sirens went off. We took our cat with us, and his gentle purring masked the sound of planes flying overhead.”

Dr. Treisman — she took the name of her first husband, Michel Treisman — graduated from the University of Cambridge in 1956 and initially planned to teach high school French. She was turned down for the job and, after receiving a research fellowship to pursue French literature, decided that a career change was in order.

Psychology, she later wrote, seemed more interesting than years spent studying a 16th-century French poet, though her supervisors believed the discipline was “all about rats in mazes.”

Returning to Cambridge, she condensed an undergraduate psychology education into one year and then received a doctorate from the University of Oxford in 1962, performing her early research in a soundproof cubicle that also doubled as a nursery.

After divorcing her husband in 1976, she married scholar Daniel Kahneman, who was working to incorporate psychological insights into economics. The couple held positions at the University of British Columbia and Berkeley, where they collaborated and shared a lab, before moving to Princeton.

Kahneman received the Nobel Prize in economics in 2002, and Dr. Treisman was awarded the National Medal of Science by President Barack Obama in 2013. Her citation noted “a 50-year career of penetrating originality and depth that has led to the understanding of fundamental attentional limits in the human mind and brain.”

In addition to her husband of 39 years, survivors include four children from her first marriage, Daniel Treisman of Los Angeles, Deborah and Jessica Treisman, both of New York, and Stephen Treisman, who lives near Crowthorne, England; and four granddaughters.

Dr. Treisman said that in the late 1970s she was barred by immigration officials from taking her son Stephen, who has Down syndrome, to Canada or the United States. The family placed him at a village for people with intellectual disabilities in England, where Dr. Treisman said he “thrived” and visited the United States several weeks each year.

Her career was not without its challenges as well. Sexist comments were an occasional part of her studies, and when she joined the psychology department at Oxford, she was the only female faculty member for several years. Still, she said she did not let it bother her. “I assumed that I could do whatever I was capable of and wanted to do,” she wrote, “and that assumption in my case proved to be true.”

Correction: An earlier version of this obituary incorrectly reported the date Dr. Treisman died. It was Feb. 9, not Feb. 10. The story has been updated.