Archive for the 'Perception' Category

Perception experiment videos

Saturday, August 9th, 2003

The Visual Cognition Lab at the University of Illinois has some cool videos.

In one set of videos, "Real-world person-change events", an experimenter asks a subject for directions. Two people carrying a door come between the experimenter and the subject. While the door is between them, the experimenter switches with one of the door-carriers. Subjects noticed the person change between 35% and ~100% of the time, depending on whether the experimenter was part of the same social group as the subject.

The "Gradual changes to scenes" videos are fun. Over a period of about 10 seconds, part of an image changes. Unfortunately, video compression artifacts make it easy to see the change if you focus on the correct portion of the image. I wrote Gradual image change in JavaScript with the intent of submitting it to the lab. The JavaScript works by superimposing two images and varying the transparency of the top image in increments of 1%. It works well in IE 6.0, but it's about three times too slow in Mozilla Firebird on my 1.6 GHz computer.