Perception of Random Dot Interference Patterns

Description/Instructions:

The random dot pattern consists of 400 pseudo-randomly selected dots on a (100,100) coordinate matrix, with no repeating dots of the same coordinate values. The transformations of the dots via the "Draw Pattern" while under the "Manual" selection is determined by:

x' = a*x*cos(theta) - b*y*sin(theta)
y' = a*x*sin(theta) - b*y*cos(theta)

If the "Theta=Pi/N" checkbox is selected, then the theta value in the textbox is divided from pi for the transformation. If theta = 0 when this happens, the checkbox defaults to false/unselected.

The "Superimposed" checkbox determines if the new transformed image is superimposed on the old random dot pattern image.

The other items in the list at left are for preset figures from the article this applet is based on (Nature Vol. 246 Dec. 7 1973). See below the applet for individual descriptions.



Specifications of the List Selections

Fig: a: b: theta: superimposed?
1b 1.05 1.05 0 NO
1c 1.05 0.95 0 NO
2a 1 1 pi/30 YES
2b 1.05 1.05 0 YES
2c 1.05 1.05 pi/30 YES
2d 1.05 0.95 0 YES
23 1.05 0.95 pi/30 YES