since June 4, 2004; access since August 12, 2008
The seventh quiz
(Extinguishing illusion quiz)
How many s are there in the image shown below?
December 10, 2012
The sixth quiz
(Color constancy illusion quiz)
Which of the lower three circles is physically the same color as the moon?
November 23, 2012
The fifth quiz
(Munker illusion quiz)
Which is the same color as the left heart, (1), (2), or (3)?
August 17, 2012
The fourth quiz
Which of the right line segments is aligned with the left one?
April 9, 2010
The third quiz
There is a girl different from the others. Which is it?
August 12, 2008
The second quiz
Which pair of squares are the same in luminance among a-d?
August 12, 2005
The first quiz
There is (are) color(s) that is (are) not used in the figure shown above. Which is (are) it (they), A, B or C?
June 4, 2004