There's a personal story that Yale psychologist Brian Scholl often shares when he explains his scholarly interest in the vexing power of what he calls "unfinishedness," or that nagging frustration you experience when tasks are left undone.
"When I accidentally complete a task without having first written it down on my to-do list, it's so painful to miss the opportunity to cross it off that I'm tempted - even though it seems silly and irrational - to write it down and cross it off," said Scholl, a professor of psychology in Yale's Faculty of Arts and Sciences and director of the Yale Perception & Cognition Laboratory. "When I relay this anecdote, a shocking number of people say, 'Me, too!'"
In a new study, published in the Journal of Experimental Psychology: General, Scholl and former lab members Joan Ongchoco and Kimberly Wong explored why humans so badly want to finish what we've started - in matters great and small.
It turns out the brain just doesn't like dangling threads.
The researchers had a hunch that visual clues could help explain the lure of the unfinished. "Why is this state of leaving things undone so salient to us?" Scholl said. "It's an interesting quirk of human nature that science has not previously addressed in quite this way."
His lab began the research last year, led by first author 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), and also featuring co-author Wong (a recent graduate of Yale's Graduate School of Arts and Sciences who is now an assistant professor of psychology at Williams College).
For Ongchoco, who began the research project in the closing days of her time as a graduate student, the issue of "unfinishedness" was resonant. "I had all these projects with my adviser and my lab. I felt pretty unfinished, myself."
And in her research, Ongchoco has also explored the broader impacts of this feeling. "Unfinishedness has been found to decrease work satisfaction, impair sleep, and fuel ruminative thinking patterns," she said. "I wanted to understand why it has such a hold on our minds. As a vision scientist, my inclination was to turn to the visual system. When we see unfinished events, are they somehow prioritized in memory?"
To test their hunch that visual memory plays a role in making unfinishedness feel so sticky, the researchers ran four experiments involving a total of 120 participants who viewed computer animations of simple mazes populated by moving dots or lines.
In several experiments, people were shown moving shapes tracing paths through a maze. Sometimes the paths finished. Other times, they stopped right before the end. Colored squares popped up briefly along the paths. Later, participants were asked to recall where those squares had appeared.
