Why Leaving Things Unfinished Messes With Your Mind

Leaving tasks unfinished is more than just mildly annoying. According to new psychological research, incomplete tasks actively shape how our minds work, influencing attention, memory, sleep, and satisfaction in ways we may not realize. A recent study from Yale University digs deep into this phenomenon, known as unfinishedness, and shows that the human brain is fundamentally wired to prioritize what is left incomplete.

At the center of this research is Yale psychologist Brian Scholl, a professor in Yale’s Faculty of Arts and Sciences and director of the Yale Perception & Cognition Laboratory. Scholl has long been fascinated by the subtle but powerful discomfort people feel when something remains undone. He often illustrates this with a personal habit: when he completes a task without first writing it on his to-do list, he feels a strong urge to write it down afterward just so he can cross it off. While this behavior may sound irrational, many people instantly recognize it in themselves. That shared recognition was one of the sparks behind this research.

The new study, published in Journal of Experimental Psychology: General in January 2026, explores why humans are so deeply affected by unfinished tasks, even when those tasks are trivial. The research suggests that this effect is not just psychological in a motivational sense. Instead, it is rooted in basic perception and visual memory.

The Researchers Behind the Study

The study was led by Joan Danielle K. Ongchoco, a former graduate student and postdoctoral associate in Yale’s Department of Psychology, who is now an assistant professor at the University of British Columbia. She was joined by Kimberly Wong, a recent graduate of Yale’s Graduate School of Arts and Sciences, now an assistant professor of psychology at Williams College. Scholl served as senior author.

For Ongchoco, the topic of unfinishedness was personally meaningful. She began the project toward the end of her graduate studies, a time when many academic projects were still in progress. That sense of being surrounded by unfinished work made the research question especially relevant. Beyond personal experience, Ongchoco was also motivated by existing evidence showing that unfinished tasks can reduce job satisfaction, impair sleep, and increase rumination, where thoughts loop repeatedly without resolution.

As a vision scientist, she approached the problem from a less explored angle: what role does the visual system play in unfinishedness? Specifically, do unfinished events receive special treatment in memory simply because of how we perceive them?

How the Experiments Worked

To investigate this question, the researchers designed four controlled experiments involving a total of 120 participants. The participants viewed computer-generated animations featuring simple mazes populated by moving dots or lines. These animations were deliberately minimal to isolate perceptual processes rather than emotional storytelling or personal relevance.

In the experiments, shapes traced paths through a maze. Sometimes the path reached its endpoint and completed the journey. Other times, it stopped just short of the finish, leaving the motion unresolved. Along these paths, colored square probes briefly appeared at different points. After viewing the animation, participants were asked to recall the exact locations where those squares had appeared.

One of the most prominent demonstrations was known as the “Unfinished” path animation, used in Experiments 1 and 2. In this setup, two disks appeared inside a maze. A path slowly unfolded from one disk toward the other. During the movement, four probes briefly flashed along the path. Later, participants had to reproduce the probe locations, but without the maze or disks visible.

Crucially, the researchers controlled for factors such as time elapsed and distance traveled, ensuring that any memory differences could not be explained by longer exposure or greater movement.

What the Study Found

Across all four experiments, the results were strikingly consistent. Participants remembered probe locations more precisely when the paths were unfinished compared to when they were completed. This effect held even when all other variables were equal.

In other words, the brain appeared to prioritize incomplete visual events, encoding them more accurately in memory than finished ones. This suggests that unfinishedness is not merely about motivation, stress, or conscious effort. It is built into how people see and remember the world at a fundamental level.

The findings point to the idea that the brain dislikes “dangling threads.” When an event does not reach closure, perceptual systems seem to flag it as important, keeping it more accessible in memory.

A Modern Take on the Zeigarnik Effect

The results align closely with a classic psychological phenomenon known as the Zeigarnik effect, named after psychologist Bluma Zeigarnik. Discovered in the 1920s, the Zeigarnik effect describes how people tend to remember unfinished or interrupted tasks better than completed ones.

What makes this new study different is its focus on low-level perception rather than conscious recall of tasks. Instead of studying work assignments or goals, the researchers examined simple visual motion. This shows that unfinishedness operates at a deeper level than previously demonstrated.

The study’s subtitle, “The spontaneous prioritization of unfinishedness in perception,” captures this idea. The prioritization happens automatically, without deliberate thought or intention.

Why Unfinishedness Feels So Persistent

These findings help explain why unfinished tasks can feel mentally intrusive. Because incomplete events are encoded more strongly, they are more likely to resurface in thought, especially during moments of rest. This can contribute to persistent mental tension, difficulty sleeping, and reduced satisfaction at work or in daily life.

Scholl describes the mind as being wired for cliffhangers. Even when watching a simple visual event, the brain expects an ending. When that ending does not arrive, attention remains engaged.

This also explains why people often feel relief after completing tasks, even small ones. Finishing provides closure that allows perceptual and memory systems to disengage.

Broader Implications for Everyday Life

Understanding unfinishedness has implications beyond academic psychology. It sheds light on why productivity systems emphasize task completion, why cliffhanger endings are so compelling in media, and why unresolved problems can dominate mental space.

It also suggests that strategies such as breaking tasks into clearly completed steps may help reduce cognitive load. By providing more frequent moments of closure, people may reduce the mental burden of unfinished work.

Importantly, the study shows that unfinishedness is not a personal weakness or lack of discipline. It is a natural outcome of how the human mind processes information.

What This Research Adds to Psychology

This work offers a new window into how perception and memory interact with motivation and emotion. By demonstrating that unfinishedness is embedded in visual processing itself, the study expands existing theories and opens new questions about how the brain prioritizes information.

It also highlights how everyday experiences, such as feeling unsettled by incomplete tasks, are grounded in measurable cognitive mechanisms rather than abstract feelings alone.

Research paper:
https://doi.org/10.1037/xge0001884