Afterimages and Nature - Removal of a stimulus

Afterimages and Nature - Removal of a stimulus

Although we spoke briefly about afterimages in class, I left pondering and slightly confused as to the depth with which we actually perceive an image, and the overlap that lies between afterimages, the real world, the arts of the real world (works by artists like Gaudi or movements such as cubism,) and the general belief of humans that we are able to perceive and categorize everything around us in our daily lives.

Many of our first memories of light as infants probably are of, or intimately altered by the sun and house lights (which we’ve manufactured to expose ourselves to a similar type of light as we find in the real world.) Although one cannot stare at the sun directly due to its’ intense luminance, if one does look up directly and then peers away, that same intensity then manifests itself directly upon any following movements of the eye and will directly effect the following images sent to and categorized by the brain.
This perception of a specific luminance is mentioned by Livingstone, in reference to the pure physical massiveness of the sun. Although many of us would claim to have attained strong intellectual insight into the developments and ways of the natural world, so much so that we can control many of them, Arnheim argues on page 59, that “We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. To this purpose philosophers say that Nature does nothing in vain, and more is in vain when less will serve; for Nature is pleased with simplicity, and affects not the pomp of superfluous causes.”
Arnheim’s point rings true in many senses, and in art, both classical and modern, the influences of luminance and color schemes are constantly present. Within these boundaries, the influence of factors which many, simply cannot quite describe are always present.
To study this, the simple trick of optical illusions seem to consistently provide a basis for describing causes and effects of both natural and artificial stimuli.

 Described as resulting from imperfections in the optical system, optical illusions such as afterimages create a situation in which the eyes continue seeing an object after one has ceased to continue staring at it. Although to me it seems that some sort of fatigue must be present in this situation, it amazes me that afterimages are often hardly present in the original images.  This seems to me to be a similar effect as moving your finger toward your nose and seeing double as your eyes “cross,” both generated in the brain as complementary images to previously viewed objects. Here are a few examples of the afterimage effect I found online;

In the Mamassian article the idea of a three dimensional layout in paintings, and the idea mentioned on page 2144, that we all, have “visual prior expectations,” brings up an interesting thought on perception, that what we know as conventions tend to directly alter the ways in which we perceive the natural world. Mammassian continues on page 2148 stating that “Given that a painting could be seen under various illumination conditions, from natural to artificial lights, how can the colors be reliably conveyed? One convention may be to over-emphasize the contrasts of the edges between objects.”
Paintings make wonderful and difficult case studies because they contain the specific intentions of the artists, and in doing so further the point that as humans we tend to actively disagree about our visual perceptions, because in reality we all see the world in varying realities. To return briefly to paintings though, they contain intentions which often times are exaggerated so as the average viewer will at least be able to form some sort of conclusion as to the artists’ intention(s.) Livingstone expresses a few ideas about the work of Impressionist painters use of tools such as  “low spatial precision” to encourage the brain to fill specific realities of the work itself. 
All in all, the visual system is an amazing feat of human development, and the mere fact that our brains attempt to fill in any missing information is an astonishing calculated endeavor. Painter’s and artists have the unique opportunity to offer altered representations of  images or aspect of images which we have most likely seen many times within our lifespans, but yet can continue to feel fresh and exciting.