Time
In a run of identical things, a rare surprise seems to last longer than it does. Peter Tse, Josée Rivest, Patrick Cavanagh, and I reported this in Perception and Psychophysics in 2004, in "Attention and the subjective expansion of time." The four toys below let you measure it on yourself.
Try it: the oddball
Your own expansion factor
In the paper, the standards were still black circles that each lasted 1,050 ms. Now and then a black disk appeared that grew from 30 to 100 pixels in radius. To feel as long as a standard, the growing disk only had to last 675 ms on average, so it felt about one and a half times as long as it was.
Watch the middle of the box. Circles come and go, each lasting about a second. After each disk that grows, and after a few plain circles, say whether it lasted longer or shorter than the others, with the buttons or the left and right arrow keys. You have until the third circle after it. The Psi method (Kontsevich and Tyler, 1999) picks each disk's length to learn the most from your answers, and the point where you say "longer" half the time is your point of equality. About one question in five comes after a plain circle of changed length. Those catch trials should come out near a factor of 1, so a habit of saying "longer" shows up there and not as a stretch. With 7 to 12 circles between questions, 30 oddballs take about fifteen minutes, and with 3 to 6, about seven. This is an informal measure on your own screen, not a lab result.
- Perception and Psychophysics 66(7), 1171 to 11892004. "Attention and the subjective expansion of time." Tse, Intriligator, Rivest, and Cavanagh. Read it
The paper's account: an unexpected event draws attention to it, and attention raises how much is taken in while the event lasts. More is registered, so it seems to last longer.
The paper's timing was locked to the screen's refreshes. A browser cannot promise that, so these toys time every shape by the frames that drew and cleared it, and report how well your screen kept up.
Try it: hold to match
Show it with your hand
Choosing between two words can lean on habit. Holding a button for as long as something lasted is a second way to ask. The paper used this reproduction method as a control, and it showed the same pattern over time, though without the early peak.
After each growing disk, and after some plain circles, the train stops. Press and hold the button, or the space bar, for as long as that shape lasted, then let go. There are 12 disks and 8 circles. Holding tends to run long for short times and short for long ones, so the number that counts is the ratio: how long you held a disk for its length, over how long you held a circle for its length. A ratio above 1 means the disks felt longer in your hand too. This is an informal measure on your own screen, not a lab result.
In the paper's version, five disks blinked in turn and observers pressed a key for as long as the last one lasted. The last disk either stayed the same size or grew, and the paper compared the two.
Try it: the oddball zoo
Six kinds of surprise
The paper tested other oddballs among 1,050 ms standards: a red circle among black ones, a circle among squares, a square among circles, a large circle among small ones, and a still circle among growing ones. Each felt longer than it was, and each felt as long as a standard at about 760 to 860 ms, against 675 ms for the growing disk.
Pick a kind and run it: 12 oddballs and 3 catch trials, about three minutes. Each bar is your factor for that kind, with its uncertainty, and the dark tick is the paper's average, from the points of equality it reports. The catch bar pools the catch trials from every kind you have run, and should sit near 1. These runs use 3 to 6 shapes between questions to keep them short, where the paper used 7 to 12. This is an informal measure on your own screen, not a lab result.
The paper's averages: red among black, 797.5 ms; circle among squares, 760 ms; square among circles, 823.5 ms; large among small, 808.4 ms; still among growing, 858.8 ms; growing among still, 675 ms. Each was set against standards of 1,050 ms, and the factor is 1,050 divided by that number.
Try it: when does the stretch start?
The stretch over time
With standards from 75 ms to 2,100 ms, the paper found that the stretch did not begin until at least 120 ms after the oddball appeared, and at 75 ms the oddball even seemed shorter. The stretch had a peak near 225 ms, then a dip, then a rise. The paper's account is a quick burst of attention followed by a slower, steadier one.
The sweep runs one short block for each duration you tick, in a random order, with 2 catch trials in each. The growing disk takes the place of one circle, and you answer as before. The chart marks only what the paper states in words: no stretch before about 120 ms, and a peak near 225 ms. It does not redraw the paper's numbers. Nothing here is ever shown for less than 100 ms, because a browser cannot hold shorter times steady, so at 150 ms the disk can be no shorter than two thirds of a standard and a factor above 1.5 cannot show; the chart marks a point that reaches that floor with a small arrow. This is an informal measure on your own screen, not a lab result.
The paper found nearly the same time course for sounds as for sights.