Welcome at Mind Mystery!

Keep your phone ready! An employee will shortly open the left door to the park for you. This employee will give a short explanation, which you can follow in English on your phone.

Just a moment please...

Click the button with the arrow when the employee opens the door for you.

Welcome in the Illusion Depot!

Welcome in Mind Mystery’s Illusion Depot! Don’t touch anything and be very quiet, no guests are actually allowed here! The place is full of illusions that have been on display in the park, or still have to go there. The employee will quickly show you a few of the most impressive ones!

Click the button with the arrow when the employee reveals the first illusion.

1: The Calculation

Along with the employee and the rest of the visitors, finish the calculation. Do you know what the outcome was?

Click the button with the arrow only when you and the employee have added up the sum!

1: The Calculation

Big chance that you calculated 5000. However, the correct answer is 4100!

4 x 1000 is 4000, and 40 + 30 + 20 + 10 is 100. 4000 + 100 is 4100. How is this possible?

Our brains like to categorize information in groups. This sum consists of a whole bunch of thousands and some tens. In the last sum of tens (90+10), our brain accidentally categorizes the 100 in the group of 1000, and thus makes it 5000 to finish off at a round number.

Click the button with the arrow only when the staff member starts explaining the next illusion.

2: Adelson's Checkerboard

Another illusion with similar effects on the brain is Adelson’s Checkerboard. Look carefully at boxes A and B. Do these boxes have the same colour?

Click the button with the arrow only when the employee has shown the difference between box A and B!

2: Adelson's Checkerboard

As you can see, A and B have exactly the same colour!

It is a colour illusion that fools your brain. What happens is that the green cylinder projects a shadow on the checkerboard, and your brain automatically adjusts the colours based on what it expects to see following the pattern of the board. The shadow has soft edges, making it look like there is a colour transition between the light and dark parts of the field. Your brain here expects the colour of box B to be white because that fits the pattern of the checkerboard. So your brain adjusts the colour to white. So if you take away the environment (and thus the pattern) by putting this board on top, then you see the real colour of square B because your brain no longer adjusts the colour to the environment.

Click the button with the arrow only when the staff member starts explaining the next illusion.

3: The Jastow-illusion

A lesser known illusion is the Jastow-illusie. We see two orange figures here. Looking at these figures, which appears to be longer? Figure A or figure B?‘

Click the button with the arrow only when the employee has shown the difference between figure A and B!

3: The Jastow-illusion

It seems like figure B is longer, but in reality, they are the same size!

If you look closely, you can see that the figures are not directly above each other, as figure B is tilted more to the right. This is also noticable when you look at the letters A and B. These letters are aligned vertically, but the letter A is centered in the middle of figure A, while the letter B is not centered in the middle of figure B.

Click the button with the arrow only when the staff member starts explaining the next illusion.

4: Benham's Turntable

Here we have a round disc (Benham’s Turntable) which has a black side and a white side. The white side has black, bent lines as you can see. But what happens to these lines when spin the disc?

Click the button with the arrow only when the employee has spun the wheel!

4: Benham's Turntable

As you can see, the lines are no longer black when spinning! What colours do you see?

The fact that you can see the lines change colour here has to do with the so-called cones and cells in your eyes. Cells are used to see in low light (albeit only in shades of grey). Cones allow you to see only when it is light, and cones allow you to see colours as well. There are 3 types of cones in your eyes: cones that respond to red light, blue light and yellow/green light. Because each line is a different distance from the centre of the turntable, they don’t spin at the same speed and this causes each line to ‘stimulate’ a different type of cone in your eye. When the different cones work together they ensure that you can perceive all colours, similar mixing all colours with paint of the three primary colours.

You are now directed to the Kaleidoscope by the employee. After you have enjoyed the Kaleidoscope, you are free to visit Mind Mystery.

Enjoy your visit!