Gianni A. Sarcone
Italian author, artist, designer, and researcher in visual perception and cognitive psychology · Italy · On the map · Writers · Born 1962 · age 64
Gianni A. Sarcone is a visual artist and author who collaborates with educational publications, writing articles and columns on topics related to art, science, and mathematics education.
Gianni A. Sarcone is read about 6 times a day, in 4 languages.
A typical day, 30 days to 26 August 2026
The middle day of the days counted, so one week of news cannot move it. The line under it is the last 60 days, one point a day.
Something wrong?Media & music
Photos 10
![Here are two relative size illusions described by Italian visual researcher Gianni A. Sarcone in 1997 and 2013. The first relative-size illusion called Sarcone's Crosses contradicts Ebbinghaus illusion (aka Titchener Circles, 1898) and Obonai square illusion (1954). Sarcone's cross illusion consists of a cross (the test shape) surrounded by sets of squares of distinct size (the inducing shapes). As shown in the diagram, the three blue crosses in fig. 1.a, 1.b and 1.c are exactly the same size; the one on the left (fig. 1.a), however, appears larger. The illusion works even when the small squares completely occlude the blue cross (see fig. 1.c).
In conclusion, there isn't always correlation between the size of the surrounding shapes and the relative size perception of the test shape.
In fig. 2.a and 2.b, by effect of assimilation, the diagonal red line within the large ellipse seems subjectively longer, but in fact the blue line is objectively the longest of both lines.[3]](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Sarcone_Relative_Size_Illusions.jpg/1280px-Sarcone_Relative_Size_Illusions.jpg?utm_source=en.wikipedia.org&utm_campaign=parser&utm_content=thumbnail)
Here are two relative size illusions described by Italian visual researcher Gianni A. Sarcone in 1997 and 2013. The first relative-size illusion called Sarcone's Crosses contradicts Ebbinghaus illusion (aka Titchener Circles, 1898) and Obonai square illusion (1954). Sarcone's cross illusion consists of a cross (the test shape) surrounded by sets of squares of distinct size (the inducing shapes). As shown in the diagram, the three blue crosses in fig. 1.a, 1.b and 1.c are exactly the same size; the one on the left (fig. 1.a), however, appears larger. The illusion works even when the small squares completely occlude the blue cross (see fig. 1.c).
In conclusion, there isn't always correlation between the size of the surrounding shapes and the relative size perception of the test shape.
In fig. 2.a and 2.b, by effect of assimilation, the diagonal red line within the large ellipse seems subjectively longer, but in fact the blue line is objectively the longest of both lines.[3]
Sarcone's Puzzle (also known as Puzzle Quirinus or the Quadrix Puzzle), invented by Gianni Sarcone. A geometrically paradoxical puzzle made of 12 pieces.
Awards
About this person
He has contributed to several science magazines, including Focus Junior (Italy), Query-CICAP (Italy), Rivista Magia (Italy), Alice & Bob / Bocconi University (Italy), Brain Games (USA), and Tangente (France). Sarcone has over 30 years of experience as a designer and researcher in the areas of visual creativity, recreational mathematics and educational games.
