Dr. Jekyll & Mr. Hyde : Consciousness And How We “See” Things

Robert Louis Stevenson addressed the theme of split personality in his work, "The Strange Case of Dr. Jekyll and Mr. Hyde". The story revolves around a respected scientist, Dr. Jekyll, who (by consuming a potion) creates an alternate personality for himself -- that of the cruel and animalistic Mr. Hyde. The story line is so impressionable that the very phrase "Jekyll and Hyde" has come to signify bipolar behavior by a single individual.

The "illusion" that I give below reminds me of Dr. Jekyll & Mr. Hyde.

 

 

If you watch the  two  faces from your seat in front of the computer, Mr.Angry is on the left, and Mrs.Calm is on the right.  Get up from your seat, and move back  12  feet, and PRESTO!! they switch places!!

What is significant is not merely that the two faces switch from being "angry" to being "calm".

 

In the "angry" face, the eye lids are almost fully shut, and the pupils are visible only through a narrow slit. The nose is wrinkled, and the gnashing teeth are clearly seen. When the same face "switches" to being calm (when viewed from a distance), the eyes are wide open; the nose is smooth and unwrinkled; and the mouth is shut, and the teeth are fully hidden!

This suggests that we do not see with our eyes what is "actually" out there, but what our brain "interprets" to be ahead of us (based not only on limited inputs through the eyes and other senses, but also based on information regarding the world that is stored in memory as result of past experiences).

 

Here is a formal explanation of the Illusion:-

Both the faces are hybrids -- each face is actually a combination of two faces. The left hand face shows an angry man in fine detail, but within the picture there is also the coarse detail of a calm face. The right hand face shows the calm face in fine detail, but within the picture there is also the coarse detail of the angry face.

 

When maximum information is available, the brain interprets the left face to be angry and the right one to be calm. On the other hand, when information is insufficient or blurred (as when you move to a distance; or if you look through the eye lashes), the brain interprets the opposite!

 

When we look at an object, both the fine and coarse detail are fed to the brain through the eyes. However when we are close to the object being perceived, the brain considers the fine details to be significant. When we move to a distance (or when otherwise, the information reaching the eye is reduced), the brain relies on the coarse detail, and "ignores" the fine details. What we finally get to "see" is a virtual representation of the object in front of us, as created by the software in the brain (based on a computational and probabilistic "interpretation" on what the object could be).

 

If our brains did not have the ability to filter out what it  heuristically interprets to be clutter (or "noise"), we would be incapable of experiencing this illusion.

 

I can make two predictions based on the above computational theory of cognition:-

 

a) A person whose vision is not very good would see (even at normal distances) the left side face as calm and the right side one as angry. In this case, the "switching" of faces can be achieved merely by putting on (and removing) spectacles!

b) A schizophrenic -- with damaged ability to discriminate between "signal" and "noise" -- would not experience the illusion. He would just perceive two equally blurred faces.

 

[This illusion was created by Phillippe G.Schyns and Aude Oliva of the University of Glasgow]

 

Anand Nair

 

References:

 

a) Schyns PG, Oliva A (1994) From blobs to boundary edges: Evidence for time and spatial scale dependent scene recognition. Psychol Sci 5:195–200

 

b) Schyns PG, Oliva A (1999) Dr. Angry and Mr. Smile: when categorization flexibly modifies the perception of faces in rapid visual presentations. Cognition 69:243–265

PS. Originally published 13 years ago at http://creative.sulekha.com/dr-jekyll-mr-hyde-consciousness-and-how-we-see-things_236493_blog