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Tag Archives: Temporal Lobe

This is a followup to my previous comments about black and white photography, and the peculiar spell it casts over us. In short, why would removing information (color) from a picture make it more dramatic and interesting?

What and Where Areas of Cortex

What (or How) and Where Areas

Lacking a good answer to this question, I was helped by a (not altogether flattering) discussion of my post on the Philosophy of Photography Forum on photo.net. In particular, my thanks to Craig Cooper for providing a link to this lecture by Dr. Margaret Livingstone. Here is another interesting link with more detail. For a really fascinating discussion with examples see Phantoms in the Brain, chapter 4, “The Zombie in the Brain,” by V.S. Ramachandran.

Here is a nice drawing representing the visual processing areas which I owe to Dr. David Heeger who posted his lecture notes on the internet here. The small cartoons represent the kind of information being processed in these brain areas: edges, binocular vision, angles, curves, color, location, and face recognition, for instance.

The take home lesson is that after a number of intermediate steps, luminance (black and white) information and color information are processed by separate areas of the cortex. In particular, luminance information is transmitted to the parietal cortex and color information to the temporal cortex.

Luminance information ends up in what is called the “Where” area (marked by a compass) of the parietal cortex. This area is so named because in specializes in analyzing information about location, visually guided movement, contrast, and depth. Ramachandran prefers to call this the “how” area because it directs actions like avoiding objects, reaching out to touch something, etc.

Color information, however, is routed in an entirely different direction to the “what” area of the brain located in the temporal lobe. This area of the cortex is required to identify objects, faces, as well as associated memories and emotions. This evolutionarily newer area of the cortex is involved in attributing meaning, via emotional systems, to what we see.

The Light

Reaching For Light

Now imagine what happens if we look at a black and white photograph. The “where” or “how” area immediately receives input. But the “what” area is deprived of information, particularly color information, that it expects. I suppose that we might expect to find the black and white image devoid of emotion and uninteresting. But this is the opposite of what happens. Why?

My theory is that the brain makes up for this missing information by drawing on memory and imagination. After all, the brain is amazingly good at “filling in the blanks” when expected input is not there. We never miss information from the blind spots in our visual fields. More dramatically, consider the cases of phantom limbs so elegantly discussed by Ramachandran, Oliver Sacks, and others. Following amputations some individuals experience complete feeling, and often pain, in the missing limb.

Hence, black and white photography stimulates our inner imagination and creativity. We make emotional associations that otherwise might be absent. This effect is powerful and dramatic. In fact, many people complain of being “distracted” by color if it is added back to an image. Black and White forces us to look in the shadows of our own perception. There we see reflections of ourselves.

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