Necker Cube - Ambiguity

Ambiguity

See also: Ambiguity#Visual art

The Necker cube is an ambiguous line drawing.

The effect is interesting because each part of the picture is ambiguous by itself, yet the human visual system picks an interpretation of each part that makes the whole consistent. The Necker cube is sometimes used to test computer models of the human visual system to see whether they can arrive at consistent interpretations of the image the same way humans do.

Humans do not usually see an inconsistent interpretation of the cube. A cube whose edges cross in an inconsistent way is an example of an impossible object, specifically an impossible cube (compare Penrose triangle).

With the cube on the left, most people see the lower-left face as being in front most of the time. This is possibly because people view objects from above, with the top side visible, far more often than from below, with the bottom visible, so the brain "prefers" the interpretation that the cube is viewed from above. Another reason behind this may be due to the brain's natural preference of viewing things from left to right, therefore seeing the leftmost square as being in front.

There is evidence that by focusing on different parts of the figure one can force a more stable perception of the cube. The intersection of the two faces that are parallel to the observer forms a rectangle, and the lines that converge on the square form a "y-junction" at the two diagonally opposite sides. If an observer focuses on the upper "y-junction" the lower left face will appear to be in front. The upper right face will appear to be in front if the eyes focus on the lower junction.

It is possible to cause the switch to occur by focusing on different parts of the cube. If one sees the first interpretation on the right it is possible to cause a switch to the second by focusing on the base of the cube until the switch occurs to the second interpretation. Similarly, if one is viewing the second interpretation, focusing on the left side of the cube may cause a switch to the first.

The Necker cube has shed light on the human visual system. The phenomenon has served as evidence of the human brain being a neural network with two distinct equally possible interchangeable stable states. Sidney Bradford, blind from the age of ten months but regaining his sight following an operation at age 52, did not perceive the ambiguity that normal-sighted observers do.

Read more about this topic:  Necker Cube

Famous quotes containing the word ambiguity:

    Legends of prediction are common throughout the whole Household of Man. Gods speak, spirits speak, computers speak. Oracular ambiguity or statistical probability provides loopholes, and discrepancies are expunged by Faith.
    Ursula K. Le Guin (b. 1929)

    Unlike the ambiguity of life, the ambiguity of language does reach a limit.
    Mason Cooley (b. 1927)

    Indeed, it is that ambiguity and ambivalence which often is so puzzling in women—the quality of shifting from child to woman, the seeming helplessness one moment and the utter self-reliance the next that baffle us, that seem most difficult to understand. These are the qualities that make her a mystery, the qualities that provoked Freud to complain, “What does a woman want?”
    Lillian Breslow Rubin (20th century)