When Mona Houjazy ’26 steps into the Aging, Culture, and Cognition Lab each week, she is thinking about what most of us take for granted — how we see, and how those sights remain in our memory. A neuroscience, psychology and biology major, Houjazy is investigating how subtle visual details such as sharpness and brightness affect short-term memory.

Her project, carried out under Prof. Angela Gutchess (PSYCH/NEURO) in the Aging, Culture, and Cognition  Lab and Prof. Robert Sekuler (PSYCH/NEURO) of the Vision Lab, asks a seemingly simple question: When you look at something, whether it be a room, a tree or a blurry photo, what about it engraves it in our memory?

To answer that, Houjazy focuses on two key features of any image: spatial frequency and contrast.

“Spatial frequency tells you how detailed an image is,” she explained in a Sept. 24 interview with The Justice. “Something that has low spatial frequency is blurry or not very detailed, while high spatial frequency is very detailed.”

Contrast, meanwhile, “is how well you can tell brightness levels,” she said. “With high contrast, you can see the lines between the black and the white and they’re not blurring together. With low contrast they blur.”

In other words, the difference between a foggy forest and a fluorescent-lit office goes deeper than the atmosphere. One contains hazy shapes and muted edges; the other has clean lines and sharp distinctions. Houjazy’s study tests how these differences influence how quickly and accurately people can remember what they’ve just seen.

Her experiment uses a series of black-and-white photos with no color to distract the viewer. Some are indoor scenes such as offices or hallways, which tend to have higher spatial frequency and contrast. Others are outdoor scenes like trees or bushes, which are generally softer and less defined.

Participants see one image at a time on a computer screen. “They’re going to be given an image that varies in how blurry it is,” Houjazy said. “It’s either going to be very low blur, sort of a medium amount of blur, or a high amount of blur.”

Then, the image disappears. After a delay, either zero, two or seven seconds, participants must recall the image that they saw. 

“That’s going to tell us a couple of things,” Houjazy said. “How quickly were they able to answer, and how accurate were they? That can tell you about how easy the task was for them and how well they were able to keep it in their brain based on the length of time.”

Short delays force participants to rely almost entirely on short-term memory, the brain’s brief holding space for information. Short-term memory, sometimes called working memory, is what allows you to keep a phone number in your head just long enough to dial it or remember the start of a sentence until you reach its end. It’s limited in both capacity and duration. Most people can only hold a handful of items in mind for a few seconds before they fade or are replaced.

By contrast, long-term memory is the system that stores information more permanently, allowing us to recall events, facts and skills even years later. But transferring information from short-term to long-term memory takes time and repetition through a process known as encoding.

“You’re having to use your short-term memory because there’s not enough time to encode this into long-term memory,” she said. 

This fall’s study builds on a pilot version Houjazy conducted over the summer with 20 participants. The pilot tested 80 indoor and outdoor images in blurred and non-blurred forms. Each participant had to quickly classify what they saw by pressing the “I” key for indoor or “O” key for outdoor.

“We were looking at how accurate a person was and how quick they were,” Houjazy explained. 

By comparing these reaction times, the research team identified which images were most effective. “It gave us information about which stimuli were good and which were hard,” she said. “We wanted a good representation of images [for the fall study], so it’s not too easy, but also not too difficult that you’re just sitting there getting frustrated.”

The data from that pilot helped shape the refined experiment now underway. Houjazy hopes to recruit between 20 and 60 participants this semester.

Previous versions of the experiment looked at differences in scene representation – how people visually interpret indoor and outdoor environments – but not specifically in terms of short-term memory. Houjazy’s project extends that work by combining the visual and memory components.

Although she is not currently collecting cross-cultural data, the broader framework remains important to her. “I joined the ACC Lab because I like looking through science in terms of a cultural lens,” she said. “A lot of research that we do in America, or in science in general, is based on a white male perspective and that is not how the world works.”

Her motivation reflects an inherent truth in psychology and neuroscience that environment and culture shape perception as much as biology does. “The way we see and perceive the world is going to be different based on a person’s environment and what they grow up understanding and doing,” she said.

Ultimately, the results could shed light on what types of visual information people process most efficiently and which are more confusing or forgettable. 

Those findings could have wide implications for how we design educational materials, advertisements and digital interfaces. Understanding which kinds of images are easier to hold in short-term memory could improve how visual information is presented.

For Houjazy, the study also reflects a deeper curiosity about the hidden complexities of ordinary perception. “There’s a lot to it that goes beyond what originally meets the eye,” she said. “Some of these things kind of seem very clear or obvious, but it’s really not as clear-cut as that. I kind of like the nuances behind everything.”

As the study progresses, Houjazy hopes to refine the experiment further. For now, she remains focused on understanding the interplay between sight and memory and on uncovering what our eyes can teach us about the mind.