Human being brain

Out. It has to do with the way our brains work, more specifically, with how our eyes collect the information and how we interpret that information in our visual cortex.

At a recent Being Human event at San Francisco’s Public Works, Margaret explained that our central vision is better at more precise information gathering while our peripheral vision is better at seeing larger objects. That’s why when you look at a page, you can’t read all the text on it at once – your eyes need to focus in on the text one line at a time to be able to recognize the words.

In the case of the Mona Lisa, if you were to look at the entire painting with your central vision, you’d get a very tight image, with everything in detail, but if you looked at the entire painting with just your peripheral vision, her features are blurry. In the central version, she doesn’t look like she’s smiling very much at all, whereas in the peripheral version, her grin looks like it stretches from ear to ear. In other words, when you look at the painting, your brain is receiving contradicting signals so it is challenging to define her expression.

In addition to the Mona Lisa example, Margaret walked us through a wide range of visual experiences and explained what each demonstrated in terms of our vision.

She told us that a whopping 25% of our brain is dedicated to processing vision. Within that 25%, humans have different areas that specialize in analyzing different aspects of images. For instance, one of the oldest parts of our brain (evolutionarily) is focused on more basic visual information such as depth and motion. Margaret stressed the importance of luminance (how light or dark something is) for those more ancient processes.

André Derain’s portrait of Henri Matisse is an example of this. At first glance, his use of greens and purples strikes you as jarring but yet, it actually works – you can still make out the contours of his face. That’s because of luminance (or what artists call value) – the greens and purples are darker than the yellows and peaches so register as further away/and or in shadow.

Humans have a more recently evolved part of their brain that is dedicated to deciphering objects. Only other primates share this section. Arguably, the most important object for us (and primates) is the face. In fact, Margaret explained that our face recognition system works by assessing how much the face in front of us deviates from an average face.