Exhibition Entry

Exhibition Set:

1. (Un)Tilted Characters

What to do?

Just get the first impression on alignment, i.e. are they all parallel? And then, scrutinize each character to see if they are actually tiled or not. (This pattern was created for this exhibition by Shinsuke Shimojo.)

What's going on?

One may not resist an impression of tilt. But careful examination would reveal that there is hardly any line segment actually tilted. When scientists examine spatial perception, they separate crude scales (low spatial frequencies) and fine scales (high frequencies). The tilt actually exists in low spatial frequencies, but not in the fine-scale segments of horizontal or vertical, thus giving inconsistent impressions.

2. Images In Fog

What to do?

Stand within the observer zone designated on the floor, and look back to watch what's happening in the fog box. (Originally created for this exhibition by Shinsuke Shimojo and Shana Mabari. The photos of azalea flower were taken and edited by Hao-Hsiang You.)

What's going on?

This installation does not aim to yield any particular illusion, but rather to increase awareness of the observer on how optics brings about "images." It shows what is going on before lights hit the eyes to form retinal images (which then were interpreted by the brain as meaningful objects). As J. J. Gibson's ecological options goes, objects' surfaces reflect light to form optical arrays, that are typically invisible unless it hit light-reflecting substances (such as water particles in this case).

3. Line Motion Effect

What to do?

Press the middle button first, and watch. Then, press the left and the right button. Observe how the central line appears differently. What do you think will happen? (Originally created for this exhibition by Shinsuke Shimojo.)

What's going on?

The line probe is always presented physically simultaneously, but it may appear unfolding or extending from the side where you pressed the button on. This is called the "line motion effect" first reported by Hikosaka, Miyauchi & Shimojo in 1993. Their series of studies suggested that when the observer's attention is on one side of the visual field, there is a gradient in efficiency of visual information processing, thus the attended side reaches the consciousness threshold earlier (it may also trigger motion detectors).

4. Snakes Spreading Colors

What to do?

1) Stay relatively far away (2-3m), and just watch the patterns, either with eyes fixated at one spot or moving around. Anything happens in the snake patterns?

What's going on?

1) Various portions of the pattern (snakes) may appear to rotate. This is a very new discovery, whose underlying mechanisms are not yet understood. However, researchers agree that motion detectors and adaptation may be involved.

2) When one moves back and forth at a very close distance with the eyes fixated, the peripheral patterns may cause a "twinkling" kind of impression (called "scintillation effect"). Also, the color of the central elements may spread quickly to the periphery. This is based on the original finding of "color filling out" (Kanai, Wu and Shimojo, 2006), which may reflect the brain capability of compensating weak or noisy signals in the periphery by strong foveal signals.

5. Whose Hand Is This?

What to do?

Stand square to the box, and put your hands into the left and the right compartments of the box, each. Do not touch the bottom or the wall, but keep the hands in the air with a symmetrical posture (with regard to the mirror). Adjust further, so that you do see the mirror-reflected image of your right hand approximately at the felt location of your left hand. (If difficult, ask the instructor for help.) Now, slowly close and open your hands simultaneously and symmetrically, while staring at the mirror-reflected image of the right hand. What do you think will happen? (The original version was created as a therapeutic devise by V. S. Ramachandran.)

What's going on?

One feels one's own hand as its own, and takes it as a matter of course. But according to the latest cognitive neuroscience, it is based on the brain's integration of motor commands and various sensory feedbacks. Here, whereas the hand image you see on your left side is actually that of your right hand, it overlaps with your felt left hand in position. Moreover, there is appropriate proprioceptive feedback of your finger movements. Together with your attention focused there, the visual image may be interpreted as your "real" left hand.

6. Missing Dancer

What to do?

Ask somebody to wear the white cloth (available), and stand still very close to the screen. Then, ask (s)he to slowly move away from the screen, or move hands and legs, dancing, etc. What do you think will happen? (The original version was created by Noriyuki Tanaka and Shinsuke Shimojo, and performed by SAL VAINA at Sogetsu Hall, Tokyo in 2003.)

What's going on?

Did the person become invisible, particularly when you looked away and the person stands still very close to the screen? Even when the contour of the person is visible, (s)he may appear transparent. The basic effect (motion induced blindness) is similar to that in the "Tricks to disappear." To make the effect more vigorous and suitable for dancing performance, various other perceptual effects, such as camouflage (the same as biological camouflage by certain insects or animals) and surface transparency effect, are incorporated.

7. Inverted World

What to do?

Borrow the goggles, and wear it tightly on your head (make sure not to drop them). Slowly look around, and start walking carefully. Pay attention to what's there "above" and "below." What do you think will happen? (The original version was created by Noriyuki Tanaka, Atsushi Kobayashi & Shinsuke Shimojo at Shizuoka City Science Museum Ru?Ku?Ru in 2004.)

What's going on?

Due to the lens in the eyes, our retinal images are upside/left-right inverted. Why do we still see the external world upright? The famous astronomer, J. Kepler, raised this question in the early 17th century. The first experiment was done by a psychologist named G. Stratton at the end of 19th century. This and all the following studies have the same implication. At the beginning our behavior is hopeless in this inverted environment, but not only behavior but also perception are readjusted within weeks; that is, the world will appear upright again!

8. Tricks To Disappear

What to do?

Look straight ahead, fixating your eyes tight at the marker on the wall, while slowly count numbers in your mind up to 15. Note what will happen to your body and the entire room. Also, ask somebody to stand still at the designated position(s) along the wall, while fixating at the marker again up to 15 sec. What do you think will happen? (The original version was created by Noriyuki Tanaka & Shinsuke Shimojo at Shizuoka City Science Museum Ru?Ku?Ru in 2004.)

What's going on?

The entire room together with your body may start rotating in the opposite direction to the optical flow. This effect is called "vection." Since your visual field is occupied with a consistent flow of blobs, your brain after habituation switches to the blobs themselves as a new frame of reference, with which the room and the body are interpreted as rotating to the opposite. Did your friend(s) disappear when they stand still? This effect is called "motion induced blindness." Since the brain is designed to detect changes, the motion signals "win" and suppress the static image signals, erasing them.

9. Room Of Coordinates

What to do?

Take off your shoes, and come inside the room. Observe the entire room orientation (tilt) in your upright posture first, and then lie in the spine position as indicated on the floor. What do you think will happen? (The original version was created by Noriyuki Tanaka, Atsushi Kobayashi & Shinsuke Shimojo at Tokyo Science Museum in 1996.)

What's going on?

The brain judges spatial relationship of the self and the environment, by integrating various sensory cues such as visual surfaces, proprioception from the feet, kinesthetic and vestibular sensation related to the gravity, etc. Lying in the spine posture eliminates visibility of horizontal floor, and weakens all the gravity-related cues. The visual system tends to interpret the majority surfaces in the visual field as cardinal, thus the ceiling and the walls are perceived as horizontal/ vertical.

10. Illusions And Sciences: An Interactive Tutorial

What to do?

The purpose of this demonstration is to showcase how neuroscientists study illusions and what they can learn from illusions. In addition, many illusions can be created with a computer and displayed on a screen. Here, we also show some illusions created by faculty members and students of NTU. (This was created by Chien-Chung Chen, Rung-Yu Tseng, San-Yuan Lin, Yung-Chun Lin, Zong-En Yu, and Tien-Lin Wu of National Taiwan University. Part of the demonstration was based upon a lecture given by Shinsuke Shimojo at NTU on January 22, 2007, which was taped and edited by Kuan-Ming Chen. The panel text was written by Chien-Chung Chen, translated by San-Yuan Lin, edited by Hsin-I Liao)

What's going on?

You may try to duplicate some illusions exhibited here, or featured in this tutorial movie at home. Can you then come up with your own illusion? See the "student work" section for some examples.