On a cold winter day, when someone opens a door to get into our warm house, a cold blast of air also comes in. How Houdini dreamed of getting in and out without a door! But our body cells do it all the time, with endocytosis and exocytosis, letting thousands of molecules in and out of them constantly—from ingesting bacteria to transmitting memory—without ever leaking anything. For they do it without having to open the cell wall. The cell membrane simply pushes in and encases the bacterium, then closing and pinching off the sac on the inside. The detail of this process, a sort of molecular gymnastics and yoga has been worked out by scientists at the National Institute of Health. For Joshua Zimmerberg,  a co-author of the paper, “It’s the culmination of a 30-year journey.”

Researchers now believe that any misstep in this process may be the cause of serious diseases such as Alzheimer’s, muscular dystrophy, leukemia and many others; also, some parasites and other disease agents can also hijack this endocytosis  process, using  it to enter and infect human cells. And most importantly, it is also the process that nerve cells communicate with each other, making possible our memory; and it shows how we learn from repeated exposure to the same visual image, and why we stop responding. Endocytosis is, in short, a most fundamental of life’s processes – the way a cell communicates with its environment, just like we do as humans.

Okay, you guessed it—it’s about memory. Our art viewing depends on it because of something called beholder’s share. Beholder’s share is, in the words of Eric Kandel, who received a Nobel prize in 2000 for his work on memory, from the cellular and molecular perspectives :

In addition to our built-in visual processes, each of us brings to a work of art our acquired memories: we remember other works of art that we have seen. We remember scenes and people that have meaning to us and relate the work of art to those memories. In order to see what is painted on a canvas, we have to know beforehand what we might see in a painting. These insights into perception served as a bridge between the visual perception of art and the biology of the brain.

So how does our brain respond to portraiture? As we look at a portrait, our brain calls on several interacting systems to analyze contours, form a representation of the face and of the body, analyze the body’s motion, experience emotion, and perhaps, empathy. Along with these instantaneous responses, we form a theory of the subject’s state of mind. (My emphases)

This then is the reason that art is so intriguing and engaging even after hundreds of years and many viewings. Because for the same viewer, the experience changes as his or her own memories have been added to and modified over time.

But of course there’s always something else—especially when it comes to those creative artists. What Kandel has described here applies by and large to classical art, through Renaissance up to around 1900. After that, many artists attempted to cut the viewers’ consciously acquired memories out of art viewing (See my blog post here on de Kooning’s abstraction with his Alzheimer). That is the beginning of abstract art—another story.

But endocytosis will still be a useful thing to know because viewing abstract art depends on another kind of memory that still requires this very basic method of cell communication.