Nature Archives - Farther to Go!

The Scent of Water;
The Smell of Rain

January 11, 2024 by Joycelyn Campbell 2 Comments

Humans are not the only creatures processing numerous streams of sensory data in order to determine what’s out there in the world and what to do about it. Many of the animals and insects we share the planet with are doing the same thing, of course, some with very different capacities from ours: more taste receptors, wider ranges of hearing, and even sensory systems we don’t have. They inhabit the same physical world we do, but their experiences are vastly different from ours because they have different or different-capacity receptors.

What you are able to experience is completely limited by your biology. This differs from the commonsense view that our eyes, ears, and fingers passively receive an objective physical world outside of ourselves. —David Eagleman, Incognito

What You See Is…What You See

When it comes to visual perception, jumping spiders can see a broader spectrum of light, and geckos have vastly superior night vision. The vision of eagles is eight times sharper than human vision, making it possible for them to track prey from a mile away. Cats and dogs see only two colors, but butterflies and rats see ultraviolet and reptiles see infrared light, both of which humans can’t see.

Then there are bats, who in spite of their reputation, are not really blind. They just have very small and very sensitive eyes that operate effectively in extreme darkness. Their vision isn’t as sharp or colorful as human vision because they don’t need that. On the other hand, they have a sense we don’t: echolocation. According to the National Park Service:

[Bats] produce sound waves at frequencies above human hearing, called ultrasound. The sound waves emitted by bats bounce off objects in their environment. Then, the sounds return to the bats’ ears, which are finely tuned to recognize their own unique calls.

Bats use echolocation for hunting, but also for searching and “social calls.” Each species has its own call, and they can change their calls depending on the purpose. You can hear some bat sounds here. Bat calls sound sort of like birds.

The Scent of Water; the Smell of Rain

Most people know that dogs have a stronger sense of smell than humans, but there are claims that the sense of smell of African elephants, who need to drink 70-100 liters of water a day, is even stronger. They have about 2,000 olfactory sensors and five times as many genes for smell and supposedly can detect water sources over 10 miles away. But water is odorless, so what do they actually smell? There hasn’t been much research to date, but results so far suggest elephants might smell the VOCs (volatile organic chemicals) in the water.

As an aside, the smell of rain most of us are familiar with is called petrichor, a term coined by Australian scientists in the 1960s. Petrichor is a combination of water from the rain and ozone, plant oils, and a chemical called geosmin, which results when the first drops of rain interact with airborne bacterial spores. We can detect geosmin at less than 5 parts per trillion, which needless to say is an extremely small amount.

Other creatures that have a superior sense of smell include silvertip grizzly bears, great white sharks, kiwi birds, turkey vultures, and bloodhounds.

Hear, Hear

Moths, bats, elephants, owls, dogs, cats, horses, dolphins, rats, and pigeons all have hearing that exceeds the human capacity of 20 Hz–20 kHz. The greater wax moth can hear frequencies up to 300 kHz, 15 times higher than the highest pitched sounds we can hear.

While a human ear consists of three muscles and the three smallest bones in the body, a cat’s ears are controlled by around three dozen muscles per ear which allows them to rotate their ears 180 degrees. Cats are able to stalk small, fast prey in low light, so they have to be able to hear sounds that are quiet and that have a higher pitch. They can hear sounds almost two octaves higher than humans can detect and an octave higher than dogs. (So should dog whistles really be called cat whistles?)

Our African elephant friends, on the other hand, can hear and communicate via infrasonic sound which is in a lower range (14 Hz to 16 Hz) than humans can detect. The wide-set ears on their large heads funnel in sound waves from the environment

Cookie Monster Kitty

When it comes to taste, pigs and cows have more tastebuds than humans, 15,000 and 25-35,000, respectively, compared to our 10,000. Both pigs and cows are herbivores and the additional tastebuds help them distinguish poisonous from nonpoisonous plants. So all those additional tastebuds definitely aid in their survival. Birds, on the other hand have far fewer tastebuds than humans. Chickens have only around 30.

It’s not just the number of tastebuds that determines how things taste to animals or humans. Cats don’t have tastebuds for sugar because sugar isn’t important for their survival. I did have a cat many years ago who was really into Stella D’oro cookies—the variety pack that you can’t get anymore. The cookies weren’t safe even when they were in a covered container. She once leapt into the air and grabbed one out of my partner’s hand as he was in the process of trying to take a bite of it.

Carnivores, including dogs and cats, have tastebuds at the tips of their tongues that are especially attuned to water. And catfish have their whopping 175,000 tastebuds spread all over their bodies, skin, and fins. They can detect a taste in the water from miles away. They need this ability to help them find food because the murky water where they hunt has such low visibility.

Reach Out and…

While catfish can taste at a distance, manatees can touch at a distance. Instead of tastebuds, a manatee’s body is covered with tactile hairs that allow it to feel objects without coming into contact with them, even if those objects are not nearby.

Seals have such finely tuned whiskers they can track fish that are more than 600 feet away in murky water. The nearly-blind star-nosed mole has a nasal appendage covered in 25,000 sensory receptors (compared to 17,000 in a human hand), as a result of which it is the fastest-foraging mammal in the world.

Sci-Fi Senses

As mentioned previously, some animals have senses humans don’t have, such as echolocation (used by dolphins as well as bats), electroreception (the ability to sense electrical currents or fields, used by aquatic and amphibious animals), or magnetoreception (the ability to perceive the Earth’s magnetic field, used by homing pigeons and pregnant sea turtles).

Our Experience is Not an Accurate Reflection of Reality

Whether an individual has a sensory processing disorder, a sensory enhancement, or better or worse sensing abilities than their fellow humans or other creatures, we all exist in the same physical world that contains the same material processes and properties. We do not, however, experience the world in the same way, which means our experience is not an accurate reflection of reality. We have receptors that provide us with the type and quantity of sensory data that is good enough, that is sufficient to allow us to be us, to experience specific aspects of the world (our umwelt, as biologist Jakob von Uexküll named it) but not others, to maneuver within that world, to mate and continue the species, to survive.

If our sensory capacities were different, our experiences would be different, and we would be different. As a thought experiment, try to imagine what your experience might be and who you might be if, for example:

You had the eyesight of an eagle that can identify objects a mile away
You had only 30 tastebuds
You could detect water a mile away
You had the hearing of a cat
You could feel objects without coming into contact with them

What would be the benefit or drawback of any of these—or other—altered sensory perceptual capacities? Is there a sensory capacity you, as a human, have that you’d be willing to trade or have modified for the sensory capacity of another creature?

I would definitely not want to have only 30 tastebuds or the hearing of a cat. I’m not too keen on being able to feel objects at a distance, either. That seems invasive and disruptive. I could take or leave detecting water a mile away; I wouldn’t be willing to trade anything to have it. The eyesight of an eagle is appealing, though. I imagine it would create expansiveness, the sense of inhabiting a larger world. I’m not sure I’d be willing to trade anything I already have to get it. I’ll have to do some writing and thinking about it.

Coming up soon: more on the umwelt and a shift from physiological processing to psychological processing.

A Tale of Two Kitties

July 30, 2023 by Joycelyn Campbell Leave a Comment

Consider the concept of affordance: what exactly is an affordance and why should you care? I think I could write an article on all the different definitions of affordance. In fact, I would be surprised if someone hasn’t already done that. So instead of first defining the word, let’s begin with my cats.

When I adopted Naima (pictured above) in November 2010, she was three months old, and the apartment complex where I live did not require cats to be either leashed or kept inside. My previous cat, Tashi, a California transplant, had decided early in life that she was an indoor/outdoor cat. Her petite size was misleading. Back in California, she acquired a series of formidable panther boyfriends and regularly hung out with the small herd of deer on the hill below.

For one unforgettable 30-day period in 2008 I had to keep her indoors while she recovered from a near-death experience. I barely survived the ordeal. She wouldn’t stop yowling to get out. She even attempted to excavate a tunnel underneath the closed cat door.

I was determined that Naima would be strictly an indoor cat. Given that she was also an only cat—and I was her only person—I endeavored to make the environment cat-friendly and appealing while maintaining certain boundaries.

Preparations for her arrival included the purchase of cat basics: carrier, litter/litter box, food/food bowls, lots of toys, and a bed. They also included a 72” tall cat tree for the living room with a perch on top, a shorter but wider cat tree for my bedroom, and a few smaller scratching posts.

Cats and kittens of all sizes, including tigers and lions, like to climb. Tashi climbed trees in the yard and, when inside, the eight-foot-tall bookcase. Naima began using the cat trees right away, although they didn’t immediately stop her from climbing or trying to climb other pieces of furniture. She eventually got the message, but my dresser still bears the scratches from her tiny sharp claws.

Cats also like to play with their prey. Sadly, the only toy I could ever get Tashi interested in were those bouncy foam balls that look like miniature soccer balls. She could play fetch better than some dogs. She preferred to toy with birds and mice outdoors, bringing one in occasionally (either dead or alive: quite exciting for everyone involved). To be fair, she sometimes took one of her balls outside to play with. Also, she tended to munch on them. Naima, on the other hand, loved her toys, especially the roller-ball track and a certain brand of catnip mice. She would hide and then hunt the mice. She also loved to chase the bouncy soccer balls.

A Chair Affords You an Opportunity for Sitting

A bookcase offers me a place to keep my books, of which I have a few, as well as some photos or keepsakes. For my cats, the bookcase offered something to climb in order to see what’s there and get a better vantage point. Maybe find a good spot for a nap.

For Tashi (on the right, looking very focused), trees offered something to climb, as well as a hiding place, a lookout, and a possible source of food. There were no actual trees in Naima’s environment. But the manufactured cat trees offered her everything but a food source.

Another word for “offer” is “afford.” Bookcases, real trees, and cat trees are all affordances. When it comes to climbing, both indoor and outdoor cats have access to a number of affordances in addition to those just mentioned: cabinets and counter tops, refrigerators and other appliances, curtains, walls, fences, screens—they excel at figuring out how to get wherever you don’t want them to be. I once watched live video of a kitten whose eyes hadn’t yet opened successfully climb a wire enclosure meant to keep her safely contained in order to get to her mom on the other side.

The concept of affordance was developed by a psychologist, James J. Gibson, in the 1960s and 70s. Gibson was a proponent of the theory of direct, as opposed to indirect, perception, which is just a non-starter for me. Direct perception is an unscientific idea for which there is no supporting evidence. At this point, we know too much about how the brain works to take this idea seriously. (Meaning doesn’t reside “out there” in the environment or in objects in the environment. The brain has to supply meaning by interpreting the sensory data it receives and processes based on our mental model of the world.)

Nevertheless, I’ve been attracted to the possibilities of this concept, so I’m trying to determine whether or not there is something useful in it within the context of behavior change. One task has been to sift out the direct perception nonsense and see what remains. Another task is to wade through some painful verbiage related to so-called “ecological psychology,” which was also the brainchild of James Gibson.

If I sound dismissive, it’s because I’m frustrated. Affordance is used in many different areas (several branches of psychology, design, communications, AI, etc.) and lots of people have added their own spin to it. That makes it difficult to pin down. Maybe that’s OK, though. This fluidity may be the nature of the beast—better viewed as dynamic rather than static. And, well, I seem to be veering toward doing the same thing: defining—or redefining—affordance as it applies to behavior and behavior change.

My current working definition:

An affordance is an action possibility available to an agent within an environment.

As a definition it seems straightforward, if quite dry. But it just scratches the surface. There are different types of affordances, and understanding those differences is key to applying the concept to behavior change. The possibilities are intriguing and anything but dry. In fact, they’re potentially very juicy. More to come!

The Pleasure of Beauty

August 30, 2019 by Joycelyn Campbell Leave a Comment

The brain takes pleasure in beauty; therefore, it finds beauty rewarding.

No matter where our brain finds beauty—in the natural world, a face or body, a song or work of art, a mathematical equation, or a perfect slice of tiramisu—it responds by activating the same neurological processes. Dopamine signals that a stimulus is rewarding and initiates the motivation and the muscle movements we need to move toward it. Mu-opiod and cannabinoid receptors then work together to produce the experience of pleasure.

We may have our own theories about why we like and take pleasure in some things and not in others. But all our aesthetic experiences are rooted in these processes that take place deep inside the brain.

Although we’re consciously aware of only a tiny fraction of them, our brain processes around 11,000,000 bits of information at a time, most of which are related to vision. The objects in our visual field, whether we’re aware of them or not, have an effect on us. As John Medina says in Brain Rules:

Visual processing doesn’t just assist in the perception of our world. It dominates the perception of our world.

But while it’s often said that beauty is in the eye of the beholder, it’s much more accurate to say that beauty is in the brain of the beholder. Consider a few of the many things we can’t see that we can experience as beautiful, such as:

passages of music
scents and aromas: oranges, jasmine, fresh baked cookies
birds singing in the morning
the warmth of the sun on your skin
an embrace
laughter
rain (the scent, the sound, and the feeling of it)

When an epileptic seizure left painter John Bramblitt legally blind, he learned new ways to carry on with his work.

When you break it down the eyes really only do two things for a painter; they allow you to know your placement on a canvas, and they allow you to determine color. … Basically what I do is replace everything that the eyes would do for a sighted artist with the sense of touch.

The result:

Pleasures are more than simple reflexive reactions to desirable things. —Anjan Chaterjee

Many of our aesthetic preferences—including preferences for sugar, for faces and bodies, and for places in nature—developed during the Pleistocene era. The things we experience as beautiful today connect us not only with each other but also with all of our human ancestors.

Our hard-wired aesthetic preferences are an excellent example of how unconscious processes in the brain operating outside our awareness affect us on a daily basis. We think we’re unique in our preferences and beliefs and in the actions we think we’re choosing to take. Because we don’t understand how and why they developed, we come up with explanations that are bound to miss the mark—and can even lead to strife rather than to cooperation.

However, because we find beautiful things pleasant, they activate the reward system in our brain. The purpose of the reward system is to help us learn and remember things, places, people, and experiences that will contribute to our survival. This makes me hopeful. In our modern splintered world in which humans are continually engaged in various forms of brinksmanship, anything that can help us see ourselves as ultimately part of the same species might yet contribute to our ability to survive.

Aesthetics refers to our appreciation of what is beautiful. Neuroaesthetics is the study of the cognitive (mental) and affective (emotional) processes that underlie aesthetic experiences from a combined neurobiological, psychological, and evolutionary perspective.