Ambiguous Figures

What is Ambiguous Figure?

Ambiguous figure is also known as Bistable or Reversible Figure. It is a visual stimulus (an image) that can have multiple interpretations, but we could see only one interpretation at a time. Ambiguous figures have demonstrated the concept of multistable perception in which an image is able to provide multiple, yet stable, perceptions. When perceiving ambiguous figures, our perception of the image would reverse spontaneously even though the visual information stays unchanged, and hence perceiving another object in the unchanging image.
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The rabbit/duck illusion 🐰🦆, young/old lady 👧🏻👵🏼, and Rubin’s vase are the famous examples of ambiguous figures.

Rabbit duck Illusion

Young old lady Illusion

Rubin's vase

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Jastrow’s rabbit/duck & young/old lady

In Jastrow’s rabbit/duck and the young/old lady illusion, we can see rabbit and duck; young and old lady in the same image respectively. The mechanism of change in perception is similar, where when you identified a feature from the image, the visual system would interpret the remaining parts of the image using the identified feature as a reference, making sense of the perceived object.

For instance:

• In the rabbit/duck illusion, when we see the rabbit ears as the duck’s beak, our visual system would identify the rabbit’s mouth as a part of the duck’s head.
• In the young/old lady illusion, when we identify the young lady’s necklace as the old lady’s mouth, the perception of the young lady’s chin would be shifted to perceiving it as the old lady’s nose.

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Rubin’s vase

For Rubin’s vase (aka Rubin's face), there is a different explanation ---- the figure-ground distinction.

The ‘figure’ in the figure-ground distinction refers to what stands out from the image or the stimulus that our brain is giving attention to. Whereas, the ‘ground’ could be seen as similar to the background, where it is also referring to the stimulus that does not stand out, not requiring any of our attention.

Using Rubin’s vase illusion as an example, when you see the black vase, according to the figure-ground distinction, it is seen as the figure, whereas the white background surrounding the vase would be identified as the ground. Similarly, when you perceive the two white faces (figure), the black vase that was identified before would be seen as the ground (background).

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References/Resources:

1. Ambiguous Image | Psynso
2. Duck-Rabbit - The Illusions Index
3. Figure-Ground Perception in Psychology
4. Kornmeier, J., & Bach, M. (2012). Ambiguous figures–what happens in the brain when perception changes but not the stimulus. Frontiers in human neuroscience, 6, 51.
5. Young Woman or Old Woman - The Illusions Index