Each year since 2005, neuroscientists Susana Martinez-Conde and Stephen L. Macknik have run a contest for "Best Illusion of the Year". Here are some of the finalists.
The illusion of sex
왼쪽은 여자, 오른쪽은 남자 같으나 사실은 같은 사람이다. 왼쪽 얼굴은 밝게 처리 했고 오른쪽 얼굴은 어둡게 처리했을 뿐이다.
In the Illusion of Sex, two faces are perceived as male and female. However, both faces are actually versions of the same androgynous face. One face was created by increasing the contrast of the androgynous face, while the other face was created by decreasing the contrast. The face with more contrast is perceived as female, while the face with less contrast is perceived as male. The Illusion of Sex demonstrates that contrast is an important cue for perceiving the sex of a face, with greater contrast appearing feminine, and lesser contrast appearing masculine.
Russell, R. (2009) A sex difference in facial pigmentation and its exaggeration by cosmetics. Perception, (38)1211-1219.
Impossible motion: magnet-like slopes
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이 동영상에서 나무 구슬이 경사로를 올라 가는 것처럼 보인다. 이것은 컴퓨터 그래픽이 아니며 실제 장면이다. 경사의 방향이 반대로 인지되어 내려가는 것이 올라가는 것처럼 보이는 것이다.
In this video, wooden balls roll up the slopes just as if they are pulled by a magnet. The behavior of the balls seems impossible, because it is against the gravity. The video is not a computer graphic, but a real scene. What is actually happening is that the orientations of the slopes are perceived oppositely, and hence the descending motion is misinterpreted as ascending motion. This illusion is remarkable in that it is generated by a three-dimensional solid object and physical motion, instead of a two-dimensional picture.
Silencing awareness of change by background motion
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동영상을 돌려 원 안의 작은 흰색 점을 보라. 처음에 원은 움직이지 않아 점이 색을 변하고 있다는 것을 쉽게 알 수 있다.
원이 돌기 시작하면 점들은 갑자기 색이 변하는 것을 멈춘다. 사실은 점들의 색은 내내 변하고 있다.
Play the movie while looking at the small white speck in the center of the ring. At first, the ring is motionless and it’s easy to tell that the dots are changing color. When the ring begins to rotate, the dots suddenly appear to stop changing. But in reality they are changing the entire time. Take a look.
The Leaning Tower Illusion
Here is a novel illusion that is as striking as it is simple. The two images of the Leaning Tower of Pisa are identical, yet one has the impression that the tower on the right leans more, as if photographed from a different angle. The reason for this is because the visual system treats the two images as if part of a single scene. Normally, if two adjacent towers rise at the same angle, their image outlines converge as they recede from view due to perspective, and this is taken into account by the visual system. So when confronted with two towers whose corresponding outlines are parallel, the visual system assumes they must be diverging as they rise from view, and this is what we see. The illusion is not restricted to towers photographed from below, but works well with other scenes, such as railway tracks receding into the distance. What this illusion reveals is less to do with perspective, but how the visual system tends to treat two side-by-side images as if part of the same scene. However hard we try to think of the two photographs of the Leaning Tower as separate, albeit identical images of the same object, our visual system regards them as the ‘Twin Towers of Pisa’, whose perspective can only be interpreted in terms of one tower leaning more than the other.
The Leaning Tower illusion: a new illusion of perspective Frederick A. A. Kingdom, Ali Yoonessi, Elena Gheorghiu Perception. 2007. 36(3):475-477
The Freezing Rotation Illusion
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An object (e.g. airplane) is turning on a surround (greenhouse), which is swaying back and forth. Observe the rotation of the object. Is it turning smoothly all the time? Or does it “freeze” from time to time? Convince yourself by covering the swaying surround that the object is really turning continuously. If the object is swaying back and forth and the surround is turning continuously we do not perceive a slow-down of the surround. Assuming a stable surround, our visual system probably uses the surround as a reference to measure motion of the included objects.
World’s Largest Lightness Illusion
In this illusion, it appears that there is one set of black figures and one set of white figures. In fact, the two sets of figures are exactly identical. They appear different because the surrounding regions they are on cause the visual system to segment the images into layers. Thus one set appears to be white figures behind dark clouds, and the other set appears to be dark figures behind light clouds. If you cut out the figures you will see that they are identi... (more)Loading...
