Background

Gestalt psychology in general and sensation and perception in particular argued that we view the world in terms of general patterns and well-organized structures rather than separable individual elements (Schultz & Schultz, 1992). Gestalt psychologists were also interested in how edges are perceived in a way to allow the perception of whole objects, an interest that has continued in other approaches to sensation and perception. Gestalt psychologists considered the visual perception of edges as critical to determining what objects were. They also identified several situations in which we see illusory edges on the basis of gestalt principles. One of these is the famous Kanizsa triangle, depicted in in this activity. In the Kanizsa triangle, we see illusory contours or edges, which are suggested by the overall pattern of the figure but are not physically there. The gestalt psychologists established a number of laws, which they argued were constants in visual perception.

Use this activity to explore the some of the factors that can create or impede the perception of illusory contours.

Instructions

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

Settings

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.
Rotate Corners: rotate the corners so that their open areas no longer point to each other, forming a coherent perception.

Reset

Pressing this button restores the settings to their default values.