While completing his PhD in the 1990s, Irving became interested in how people’s thoughts, especially their perception of time, change as they approach death. He gave volunteers with serious or terminal illnesses voice recorders and asked them to walk around their neighborhoods, speaking their thoughts out loud. In effect, he turned each of his volunteers into an amanuensis of his or her own chattering mind. “I realized that you could see somebody sitting in a chair or walking along the street and it may seem like nothing much is happening—but actually an incredible amount is happening,” Irving says. “In their heads they may be going from childhood to religion to questioning God to trying to imagining what exists beyond death.”

More recently, Irving received a grant to track down these volunteers and find out what happened to them. As a side project, he decided to record the inner dialogues of people walking in New York City—to map part of the city’s thoughtscape, layered beneath its audible soundscape. He approached strangers at different points in the city. “Excuse me,” he would say, “this might sound like a strange question, but can I ask you what you were thinking before I stopped you?” If the stranger did not run away, he would ask them to wear a microphone headset attached to a digital recorder and speak aloud their thoughts as he followed closely behind with a camera. He would not be able to hear what they were saying, Irving explained, and they would be free to walk wherever they liked and continue their business as usual.

“I was surprised by how many said Yes,” Irving says—about 100 in all. By overlaying the recorded audio onto the videos, he has created portraits of individual consciousnesses on a particular day in New York City—transcripts of people’s inner dialogues that remind one of works by Virginia Woolf, James Joyce and other writers who were especially interested in recreating the mind on the page. He calls the project “New York Stories: The Lives of Other Citizens.” Different videos focus on different parts of the city, such as streets, bridges, squares and cafés.

Irving’s videos are simultaneously naturalistic and as objective as possible. In the lab, in front of a researcher, people are often reluctant to reveal exactly what they are thinking. Writing a diary of inner speech is somewhat more private, but many people find it annoying to regularly drop everything and make an entry; sometimes it’s difficult to remember what one was thinking about even minutes earlier. In Irving’s videos people are living their lives more or less as usual, walking and talking to themselves as though they were unaccompanied. Of course, people who are not completely comfortable with the scenario sometimes speak into the microphone as though trying to entertain someone else. And getting people’s inner speech on tape captures only linguistic forms of thought, neglecting the kind of thinking that happens in images and scenes, for example. Still, Irving’s videos are permanent records of fleeting thoughts, of dynamic mental processes unfurling in real time. They give us nearly direct access to a kind of internal communication we usually do not share with one another.

In one video, a young woman named Meredith walks along Prince Street in downtown Manhattan. She briefly wonders if there’s a Staples nearby before reminiscing about a recent visit to her friend Joan, whom, we learn, has cancer. Meredith contemplates her friend’s situation for the next two minutes, tearing up at the thought of “New York without Joan.” Abruptly, she notices a café where she used to sit and people watch, laments how it has changed and resumes her search for a Staples. Fewer than 30 seconds later, she is talking to herself about Joan again—but serious reflection on mortality is punctuated by more provincial thoughts about navigating the crowds. When she remembers how bluntly and simply Joan announced her cancer, Meredith begins to choke up—then interrupts herself with a little burst of frustration while crossing the street: “What is this craziness? Five cars in the middle.” The segment ends with Meredith asking herself, once again, whether she is any closer to a Staples.

Meredith’s meandering thoughts recall Clarissa Dalloway’s roaming mind in Virginia Woolf’s novel Mrs. Dalloway. As she walks the streets of London, Clarissa entertains an ephemeral memory of throwing a shilling into the Serpentine, before transitioning to a more somber meditation on death: “Did it matter then, she asked herself, walking towards Bond Street, did it matter that she must inevitably cease completely; all this must go on without her.” Moments later she is commenting to herself on books in a shop window, then deriding her “pea-stick figure,” then admiring a fishmonger. She converses with herself about war, immortality, past romances and what kind of flowers she should buy for her party.

Woolf would likely have adored Irving’s videos. She wanted to write about “an ordinary mind on an ordinary day.” As opposed to many of her contemporaries, she was far more interested in what was happening inside people’s heads—in thought, memory and consciousness—than in detailed descriptions of buildings, countenances and clothes. She wanted the reader to perceive almost everything through her characters’ minds, rather than dictating a traditional plot with third-person narration. Like a telepathic moth, the narrator in Mrs. Dalloway flits from one person’s consciousness to another as they go about their business in London. Though the characters do not know it, their minds ring with echoes of one another’s inner speech: even when apart, they think of the same events at the same time—of Big Ben’s gonging or a car backfiring like a pistol; they constantly think of each other and lose themselves in memories of shared experiences.

“There’s always this assemblage of voices simultaneously going on in public all the time—but you can’t hear it,” Irving says. “I’m interested in whatever people are thinking about. ‘What should I buy for dinner tonight? Should I buy pasta?’ That’s just as interesting to me as something more dramatic.”