• Background
  • Instructions
  • Illustration
  • Quiz


Two important processes in perceptual organization are grouping and segregation. Grouping means the process by which elements in a figure are brought together into a common unit or object. In the photograph, we see the wall as one object or grouped together even though the tree and flowers block part of the wall. Segregation is the process of distinguishing two objects as being distinct or discrete. Thus, in the photograph, we need to segregate the wall from the tree from the flowers.

Use this activity to explore the segregration and grouping through illusory contours.


Full Screen Mode

To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.

Illustration Tab


Below is a list of the ways that you can alter the illustration. The settings include the following:

Figure Size: adjust the size of illusory triangle.
Use Lines to Segregate: add an inverted triangle that blocks all of the illusory edges.
Line Width: adjust the thickness of the lines of the inverted triangle.
Rotate Corners: rotate the corners so that their open areas no longer point to each other, forming a coherent perception.


Pressing this button restores the settings to their default values.