The speed in which you see moving objects around you, can be shifted up or down with the help of a stimulus such as a video.

In their study, Visual adaptation alters the apparent speed of real-world actions, researchers from University of Lincoln and University of Stirling have shown that the perceived speed of a moving object can be altered with a stimulus, such as an adapting video, which was used in their experiment.

In their study, they had participants watch a 30 – seconds slow motion video. Afterward, researchers played several videos in standard speed, that’s when participants reported that the videos being shown to them are too fast and playback had to be slowed down for it to appear natural for the participants. This has revealed to researchers that human brain may have altered the perceived speed of a moving object by slowing it down to match the speed of the adapting video.

Researchers then proceeded with the counterpart of the aforementioned experiment, that is to discover if perceived speed can be shifted to the other direction (speed up). Participants had to watch a fast forwarded 30 – second video, then they were shown several videos in standard speed. Again, participants have reported that these videos were too slow, and playback had to be sped up for it to appear natural.

Researchers have concluded that the perceived speed of a moving object can be shifted up or down towards the speed depicted in the adapting video, which is a process they called “re-normalization”. It’s worth to mention that removing recognizable human figures and coherent motion caused smaller shifts in the perceived speed of moving objects, which means that both levels (low-level and high-level) of the adapting video have contributed to the shifts in perceived speeds.

Read the full study here.