Why Does the Vibrancy Slider Feel So Good!?

What do oversize truck tailpipes, paleolithic sculpture, and the vibrancy slider have in common? And what might they have to do with helping us create more engaging photographs? Why do some abstract paintings move you and others don't? Why should we react to an abstract work of art at all?

What Is Neuroaesthetics?

Questions like the ones above are studied in the fascinating field of neuroaesthetics. It’s the branch of science that addresses the evolutionary development and biological underpinnings of the experience of art. Ramachandran and Hirstein published a fantastic article in the late nineties, The Science of Art, proposing that eight “laws” govern the artistic experience. The laws reflect visual capabilities and preferences that have evolved over the eons as a result of the survival advantages they confer. We experience these visual preferences as an emotional response to visual stimuli. And given that these preferences evolved to keep us alive, the emotions they elicit can be quite strong.

The laws concern things like the peak shift effect (which we’ll explore in this article), perceptual grouping, isolation, contrast, symmetry, etc. They’re typically lower-level visual functions that have to do with how we perceive abstract arrangements of lines, shapes, colors, and tones — and often have little to do with what those arrangements symbolically represent. This is why we can have such a strong response to abstract works of art. Even bare arrangements of color and tone can tickle the reptilian part of our visual system in pleasing or unnerving ways.

As artists, understanding these laws can help us to identify aspects of images that are likely to resonate with or draw the attention of our viewers, as well as facets of those images that might prove distracting or unsettling. Perhaps even more importantly, they can help us to understand why. Understanding how the brain responds to the different elements within an image can provide us with some very strong tools that we can use to guide a viewer’s eye or to evoke an emotional response. In this first post, we’ll focus on a law known as the peak shift effect. In subsequent posts, we’ll delve further into some of the other laws.

What Is the Peak Shift Effect?

The peak shift effect is a little different than most of the other “laws” in that it more broadly reinforces knowledge generalization rather than reinforcing a single aspect of visual perception. It was discovered when Nobel Prize winning zoologist Niko Tinbergen performed a series of fascinating experiments on animal behavior in the late 1940s while he was at Oxford. What he found was that not only was it possible to deceive animals with fairly simple, mock-up representations of their parents, their offspring, potential mates, or their competition, but that if he altered the proportions or coloring of the models, many animals preferred exaggerated fakes to the real thing. At a neurological level, animals’ response to visual stimuli appears to reflect an innate predisposition to feel that if some is good, more is better. One can find numerous examples where such a preference may have led to the evolution of spectacular displays of bird morphology (see two examples below).

The extravagant bill and facial markings of the Southern Yellow-Billed Hornbill. Northern Namibia.

Fun fact: the incredible blue skin of the Southern Cassowary, and many other similarly colored species, isn't achieved by pigment, but by the constructive interference of light reflected from microscopic arrays of collagen fibers.

Us humans aren’t any different. We appear to be driven by the same predilection for exaggerated features. Sculptures of the female form — some of the earliest known works of art dating back 20,000 to 40,000 years — have been found at a number of sites across Europe. They are collectively referred to as the Venus figures. They frequently lack the representation of a face — and sometimes even a head or feet — yet, the breasts, belly, buttocks, and pubic region are nearly always present, detailed, and exaggerated in size. They’re caricatures of what was important to the artists and (at least some of) their viewers: If some is good, more is better. In neuroaesthetics this is known as the peak shift effect. It is thought that evolutionarily, it helps us to generalize knowledge while we’re learning.

The Venus von Willendorf sculpture discovered near Krems, Austria is estimated to be about 30,000 years old. Image credit: Matthias Kabel, unmodified (CC 2.5).

How Can We Use the Peak Shift Effect to Our Advantage?

There are a number of things that can be done to leverage the peak shift effect while we’re in the field. Super wide-angle closeups of puppy and kitten faces, for example, are always popular. They exaggerate the relative size of those big puppy dog eyes and soft kitten noses. We’re already innately predisposed to find such characteristics of the young cute. Their “cuteness” makes us want to care for them, protect them. This is good for their survival as well as ours as a species. And according to the peak shift effect, if big, googly, baby eyes are good, more is definitely better (check out the image below). Similarly, selfies taken from up and to the side intentionally exaggerate some of our own features and slim others. We become more pleasing caricatures of ourselves. Taking photos during the golden or blue hours, when colors are naturally more saturated, serves to exaggerate features of the landscape in color space.

The original image is on the left. In the image on the right, the eyes have been enlarged slightly and lowered just a bit on the face, exaggerating two characteristics we innately associate with cute babies.

In addition to informing the choices we make while capturing images, the peak shift effect can inform our choices during the processing phase as well. Check out the two images below. They are identical except that the contrast and saturation have been reduced in the image on the right. I suspect you’ll find one image a bit more emotionally pleasing than the other. Ansel Adams, in fact, embraced the peak shift effect over the years, as he continued to reprint his famous image, Moonrise, Hernandez, New Mexico. The contact sheet shows that the original capture is very flat, boringly so. When he first printed it, he increased the contrast somewhat. Over the years, however, the degree to which the contrast within the image was exaggerated grew significantly. In later prints, what would have in reality been a fairly bright sky appears nearly completely black. (One might wonder why we have a preference for contrast or saturation in the first place, though. Great question, and a great subject for a future post or two.)

Which image do you find more pleasing? They are identical except that the contrast and saturation have been reduced in the image on the right.

Adjustments like this needn’t just be applied globally. Locally leveraging the peak shift effect — by playing on our innate preference for saturation and contrast — can provide visual cues to guide a viewer’s eye within an image, drawing it toward areas that it finds more pleasing. Differences in the relative saturation can also impact the emotional response viewers have to different subjects within an image, perhaps strengthening the overall efficacy of the story a photograph tells.

Local adjustments to the saturation can be used to draw the eye toward a preferred region of your images or alter the emotional tenor of something within them. In the left image, the saturation of the window display has been increased while that of the rest of the scene decreased. In the image on the right, the reverse is true. Notice how they have a different emotional ring and your eye moves differently through the two.

One can obviously get carried away. Films are always going for bigger explosions and gorier special effects. The peak shift effect suggests that outrageousness pays. Yet, it can be taken too far. I ran across an Instagram page a while ago that was full of landscape photos, each with a Fielder-esque composition — and each with the saturation cranked to a hundred. They were so far beyond anything even plausibly real that they were painful to look at. They punctured viewers’ suspension of disbelief.

We’ll explore some of the other “laws” in future posts, but think about examples where the peak shift effect might come into play, both in photography and in the world around us: breast implants, butt augmentation, and oversize truck tailpipes, for example, always seem to get bigger and bigger.

If some is good… more is better?