Reality Archives - Page 2 of 2

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.

Supersensory Perception

January 4, 2024 by Joycelyn Campbell Leave a Comment

Our brain is constantly weighing and calculating (interpreting) multiple internal and external factors and inputs to arrive at its predictions—all within the context of what is normal for us—to determine what is going on and to prepare our response.

The neural wiring that generates perception is not identical, person-to-person. One outcome of this is what we could consider a diminishment of perception (color blindness, face blindness, aphantasia, for example). An outcome on the other end of the spectrum of so-called sensory processing disorders is a supersense—not the superhero variety, but an enhanced ordinary sense.

Those of us who don’t have any super senses probably don’t think much about them. But surprisingly, 25% of the population has heightened taste sensitivity. These people, known as supertasters, tend to have more tastebuds on their tongues, and some have a genetic mutation of a receptor for bitter taste.

Other super senses are tactile hypersensitivity, which makes ordinary tactile sensations painful or bothersome, hyperosmia, enhanced sense of smell, which can be a result of genetics, a medical condition, or training, and hyperacusis, super sound, which is generally a result of disease or some other medical condition.

The Color Purple

Tetrachromacy is a genetic mutation that allows some people to distinguish 100 times more colors than the rest of us, which is mindboggling, given we can normally distinguish around a million different hues. But colors are not objective properties of objects in the world. Allen Tager, a Russian American artist and cognitive scientist, noticed that the color violet was virtually absent from paintings completed before the Impressionist era, beginning in 1863. He attempted to determine why this was the case. In reporting on his research in Aeon, he noted:

International surveys showed that people tend to be unsure about exactly what constitutes the colour violet. The same person who describes an object’s colour as violet today might describe it as purple, blue, magenta, fuchsia or burgundy tomorrow. Language plays a role, too—there’s a difference even between British English and American English. The colour beyond blue on the spectrum is called purple in the US, but violet in the UK. Reddish-purple is sometimes called violet in the US, but hardly so in Britain. The complete range of colours between red and blue is often called purple in British texts, but sometimes the word violet is used, too.

Neuroscientist Anil Seth points out that colors only exist in the interaction between our brain and the physical world. They exist neither out there in the world nor in here inside the brain. They are essentially constructed.

Several years ago, I used ink color to differentiate categories in a print document I shared with a number of other people. The shade of green I selected for one of the categories looked green to me both in print and on the computer, and the computer program identified it as green. But so many people saw it as a shade of brown or gray that I changed the color to something more obviously green. Consensus reality as determined by myself, the other people who saw green, and the computer program said that seeing green was the correct perception. But does it make sense to deem a different perception wrong?

People with hypersensitivities don’t tend to experience them as enhancements, meaning they don’t automatically enjoy them. Of course, if the cause is genetic, they have nothing to compare their experience with, just as those of us who don’t have a hypersensitivity have nothing to compare our experience with. But for the most part, moment-to-moment we have nothing to compare any of our experiences with.

Again, we can’t tell by looking at someone, whether or not they have any hypersensitivity, unless perhaps they’re in a situation where they’re confronted with a stimulus.

Additional Senses

The brain also receives additional sensory information beyond the five basic senses. Other sensory systems include vestibular (balance), proprioception (body position), kinesthesia (movement), nociception (pain), and thermoception (temperature).

Scientists are still trying to determine why people with red hair have differences in regard to pain threshold (lower), pain sensitivity (higher), and response to pain medication (higher or lower depending on the type of drug), but they do.

A friend I used to spend a lot of time outdoors with—walking, hiking, or lazing—would start seeking shade when the temperature approached 70 degrees, the point at which I was just starting to enjoy the warmth. She spent New Mexico summers inside with the air conditioner on and the blinds closed. I haven’t used indoor cooling for the past 10 years.

Including these additional five senses doubles the types of sensory data our brain is tracking in order to keep us alive and provide us with a sense of what’s happening to and around us in order to determine what we ought to do about it. Like the original five senses, we tend to take these senses for granted unless we begin having trouble maintaining our balance or we develop chronic pain, at which point the brain will bring the change in the status quo to our attention.

When you’re tempted to fall back on the belief that you experience the world as it is, try to imagine some of the millions of colors you can’t see…and name them.

Sensing and Perceiving
the Physical World

December 27, 2023 by Joycelyn Campbell Leave a Comment

Sensation is the information the brain receives; perception is the result of the brain selecting, organizing, and interpreting this information. We don’t experience the sensory data directly; we experience the result of the brain’s processing of it.

As an aside, some people consider sensation to be a physical process, while perception is a psychological process. We may talk about and think about the physical and the psychological as being two distinct domains, but the brain that receives sensory data also does the interpreting that gives rise to perception. It doesn’t make a distinction between the physiological and the psychological in this or in any other regard.

An example of the difference between sensation and perception is prosopagnocia, a neurological disorder experienced by about one in 50 people, including neuroscientist Oliver Sacks. More commonly known as face blindness, it’s the inability to recognize faces, including one’s own in a mirror. Prosopagnocia is not a result of memory dysfunction or loss, impaired vision, or learning disabilities. The sensory data is input, so to speak, but the brain can’t interpret it so there is no perception.

While an interpretation—anyone’s, of anything—can be more or less accurate, it is always approximate. As Daniel Gilbert said, there isn’t a view from nowhere. All interpretations are based in a point of view from a particular brain at a particular point in time, so interpretations are inherently limited and slanted—and they vary both from individual to individual and within individuals at different times and under different circumstances.

“Normal” vs “Abnormal”

We tend to think that there is always a correct interpretation (perception) of an object or an event—that objects and events and their properties exist in an immutable state independent of us. And if we apply the appropriate lens, we believe we can achieve complete, or nearly complete, accuracy in our perception. At the same time, we tend to assume (operate as if) we are perceiving correctly.

So it’s tempting, not to mention less troublesome, to view others’ experiences or perceptions—especially when they don’t match ours—as missing the mark somehow. There’s an error in their, or their brain’s, calculations. One example is color blindness (also called color deficiency—see what I mean?), which has a genetic basis. Another example is tone deafness. There are many more, including:

Aphantasia: the inability to create a visual mental image of something that isn’t present.
Synesthesia: a sort of mixing up of sensory pathways in the brain (experiencing letters of the alphabet as having colors or associating a smell with a word).
Misophonia (aka soft sound sensitivity): a disorder in which certain repetitive sounds like gum chewing or paper crinkling automatically trigger powerful negative emotional responses.

And don’t forget prosopagnocia.

Clearly color blindness, aphantasia, synesthesia, misophonia, and other such conditions provide individuals with different experiences of reality than we might consider the norm. But does it make sense to say it’s wrong to experience the letter “M” as orange or the color green as smelling like cilantro? Richard Feynman had synesthesia and saw his equations in colors. Far from being wrong, this sounds pretty great to me, although that’s coming from a point of view of not having the experience.

Is there something wrong with that fellow over there who can’t mentally visualize a field of poppies or fluorescent purple mushrooms or a galloping horse? Aphantasia, unlike synesthesia, seems tragic to me; I can’t imagine I would be the same person if I didn’t have the vivid visual imagination I have. But how could one miss it if they never had it to begin with?

Is it wrong that the crinkling of paper or chewing of gum elicits a fight or flight response in that woman seated the next row over on the plane? She just seems to be overreacting and behaving rudely. Misophonia doesn’t seem desirable to me in any way. Of the few conditions I’ve included here, it’s the one that people who have it are perhaps most likely to view as being abnormal. That’s because it can cause problems beyond the purely sensory. It can create a lot of stress in personal relationships or interactions and in social settings. Many sufferers and the people they interact with tend to think it’s a psychological problem, meaning they could control their response if they tried harder. Or they need therapy. Nevertheless, it is an example of the brain sensing and perceiving (interpreting) sensory data and providing a resulting experience. It’s no different from any other instance of sensory processing.

External vs. Internal

The conditions described above all relate to the processing, interpretation, and experiencing of external sensory data. Enough research has been done on how the brain processes external sensory data to allow scientists to map the parts of the brain associated with them.

But there’s still much to learn about how the brain processes internal sensory information. How does it sense and organize feedback from internal organs to regulate hunger, satiation, thirst, nausea, pain, breathing, heart rate, blood pressure, etc.?

Scientists think that internal sensing may be more complicated than external sensing because, according to cell biologist Chen Ran:

[I]nternal organs convey information through mechanical forces, hormones, nutrients, toxins, temperature, and more—each of which can act on multiple organs and translate into multiple physiological responses. Mechanical stretch, for example, signals the need to urinate when it occurs in the bladder, but translates into satiation when it happens in the stomach and triggers a reflex to stop inhalation in the lungs.

How does the brain determine (interpret) sensory data so that we have an accurate enough experience to allow us to respond appropriately? Researchers do have some leads they’re following as they attempt to get a handle on the coding of internal senses throughout the brain. One motivation for this area of study concerns treatment for diseases that arise from internal sensory system malfunctions—i.e. abnormal feedback.

Of course this is a bit oversimplified since this so-called feedback involves sensation, perception, and interpretation. Feedback might relate to external or internal sensory data or what we think of physiological or psychological sensory data. No matter what it relates to, however, there’s feedback that occurs at the unconscious level and feedback that we are aware of at the conscious level. Most feedback occurs at the unconscious level and doesn’t make it into conscious awareness.

What We’re Aware of

When feedback does make it into conscious awareness, we have thoughts about it (our interpretation, usually in the form of an explanation).

We also experience an emotion, which neuroscientist Antonio Damasio would refer to as a homeostatic indicator. Emotions constitute a sort of personalized, constantly updated, running report to consciousness, indicating the status quo of the organism—as the brain sees it—both internally and externally. This is pretty damn amazing, when you think about it.

If the interpreter (see last post) is like a play-by-play announcer calling a game (your life) over the radio, emotion is your response to what you perceive to be happening both on the field (externally) and internally. There’s lots of information available to you. Are you tuned in?

Making Sense of
Sensory Information

December 21, 2023 by Joycelyn Campbell Leave a Comment

On a continuous basis, our brain receives multiple streams of exteroceptive sensory data about the physical world and other people. At the same time it receives a steady stream of interoceptive data about us: our physical, mental, and emotional states.

We don’t have the necessary machinery, and we wouldn’t even want it, to process carefully all of the amount of information that we’re constantly bombarded with. —Susana Martinez-Conde, neuroscientist

We have to filter it, sort it, and make sense of it. The lenses or filters through which our brain views and processes the streams of information include:

Our mental model, which consists of our personality (much of which is genetically determined), our beliefs, and our experiences.
Our current situation or circumstances.
What we know or don’t know that’s relevant in the moment.

All of this data processing takes place in an environment in which everything everywhere is in motion all the time, everything is a process, and everything is an interpretation.

Perception vs. Reality

However, the previous statement, while true, does not reflect our experience. Our experience is that the world is full of relatively stable things that are inherently meaningful (that is, we’re not interpreting them; they simply are as we perceive them to be).

My brain manages to create for me the experience of a constant, unchanging world through which I move. —Chris Frith, neuropsychologist

Our brain creates this illusion and many, many more, all of which we take for granted. But in fact, nothing is static, fixed, or permanent; nothing is unchanging.

Because nothing is fixed or unchanging, there are no things—tangible or intangible—there are only processes. Each of us is a process composed of multiple processes: purely physical processes (blood flow, digestion) as well as personal identity, emotions, memories, thoughts, and relationships. Processes, both physiological and psychological, are a result of the multiple interactions (motion) of complex adaptive systems. Each of us is continuously in the making, becoming, being constituted.

Identity as a programmatic—but not deterministic—process welcomes innovation through small, recurring changes. Under these metaphysical assumptions, a meaningful life is less about finding your ‘real’ self than expanding its boundaries. —Celso Vieira, philosopher

The solar system, climate, ecosystems, life cycles, plants, and also the device you’re reading this on, your vehicle, and the mug you drink coffee or tea from are processes, too. Some of them just happen to be much longer processes than the process of you or the process of me.

The Interpreter Explains Everything

As previously stated, in order to make sense of what is happening externally and internally the brain has to interpret the data it’s exposed to.

[Your brain is] locked inside a bony skull, trying to figure what’s out there in the world. There’s no lights inside the skull. There’s no sound either. All you’ve got to go on is streams of electrical impulses which are only indirectly related to things in the world, whatever they may be. So perception—figuring out what’s there—has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations or beliefs about the way the world is to form its best guess of what caused those signals. The brain doesn’t hear sound or see light. What we perceive is its best guess of what’s out there in the world. —Anil Seth, Professor of Cognitive and Computational Neuroscience, University of Sussex

Since the conscious brain only processes about 40 bits of information at a time, it has no idea of what the unconscious is dealing with. Thousands (perhaps millions) of brain activities go on relatively independently of one another and all outside the realm of conscious experience. Once these brain activities are expressed [action, thought, emotion], the expressions become events that the conscious system takes note of and that must be explained.

That is the job of an interpreter, so-called, in the left hemisphere of the brain that essentially explains us to ourselves. The interpreter constructs theories about why we act and behave the way we do based on the limited and fragmentary data available to it. (It’s a little bit like listening to a play-by-play announcer calling a game over the radio.)

Our conscious life is essentially an “afterthought” constructed by the interpreter.

In truth, when we set out to explain our actions, they are all post hoc explanations using post hoc observations with no access to nonconscious processing. Not only that, our left brain fudges things a bit to fit into a makes-sense story. Explanations are all based on what makes it into our consciousness, but actions and the feelings happen before we are consciously aware of them—and most of them are the results of nonconscious processes, which will never make it into the explanations. The reality is, listening to people’s explanations of their actions is interesting—and in the case of politicians, entertaining—but often a waste of time. (Michael Gazzaniga)

If you recall from the last article, our brain is more concerned with utility than with accuracy. As a result, the most satisfying explanations are the ones that are simple, straightforward, and unambiguous. If we find a satisfying explanation, we accept it as true and move on. Consider the implications.

Our Brain Creates Our Experience

December 12, 2023 by Joycelyn Campbell Leave a Comment

As Rodney King famously asked in 1992:

Can we all get along?

While we may accept the notion that people disagree with each other all the time, we tend to believe and operate as if we’re right and the people with whom we disagree are wrong. We also tend to believe and operate as if we all have access to the same information and the same thinking processes, and if we just tried hard enough, applied ourselves correctly, we could get on the theoretical same page. We think the truth is out there, and we could all see it if we wanted to.

That’s very kumbaya, but since it’s not in fact the case, believing in and operating from that perspective is detrimental to our collective wellbeing and possibly to the survival of the planet.

We are wired not to experience the world as it is, but rather to apprehend it just accurately enough to function effectively in it. And contrary to the perception of many, including David Williams, as expressed in The Trickster Brain, this isn’t a design flaw.

Instead of being elegantly designed—the most efficient and marvelous epitome of creation—the brain is in many ways a botched construction job leading to endless contradictory impulses as the new and old parts of the brain attempt to work together.

Williams goes on to quote neuroscientist David J. Linden of John Hopkins as declaring the brain to be:

… a cobbled together mess…quirky, inefficient, and bizarre…not an optimized, generic problem-solving machine, but rather a weird agglomeration of ad hoc solutions that accumulated throughout millions of years of evolutionary history.

If you’ve tried to get your brain to do one thing, but it keeps on doing something you don’t want it to do, you might be tempted to agree with these assessments. Or if you’ve realized your memory of something is oddly distorted, missing altogether, or missing significant details. Or if you’ve been absolutely certain about something that proved not to be the case.

The Brain According to Linden?

Linden published a book in 2008 titled The Accidental Mind. I haven’t read it but part of his agenda appears to be a refutation of the idea that the brain was designed—something I’m totally in agreement with. I would probably enjoy the book: he has an engaging writing style and he covers topics of interest to me. But—and it’s a big but—you can’t describe the brain the way he’s described it (inefficient, not optimized, bizarre, etc.) unless you have in mind some other way you believe the brain should be.

I think that’s not an uncommon belief. It doesn’t, however, add anything useful to the conversation. We weren’t present throughout the course of the brain’s evolution. So how it developed, or how it should have developed not only can’t be known by us, it’s also essentially irrelevant. All we can do right now is acknowledge that this is the brain we have and put neuroscientists to the tasks of identifying how it work. Then once we figure out what we want, we can use the brain effectively to get more of that (individually and collectively) and less of what we don’t want.

We Perceive both Less than Is There, and More than Is There

It turns out that it’s actually more functional to have a brain that screens out from our awareness most of the sensory data it encounters and streams a stripped-down version into our conscious awareness. Our brain is more concerned with utility than with accuracy, which is why our experience is not an accurate reflection of reality.

Our experience of the world and our experiences of self within the world are forms of perception, a form of hallucination that’s incredibly useful in staying alive. We perceive both less than is there, and more than is there. —Anil Seth, neuroscientist

Consider the way the brain processes external visual stimuli and turns them into what we see. We have no conscious awareness of the brain’s complex visual processing operations that involve multiple pathways and the coordination of many different parts of the cerebral cortex; all we are aware of is the result, which seems much more straightforward than it actually is. We’re also not aware of our visual blind spot (everyone has one) because our brain does such a good job of filling it in with what we expect to see in that location.

You’re not perceiving what’s out there. You’re perceiving whatever your brain tells you. —David Eagleman, Incognito

The result is that in terms of what we see, both figuratively and literally, we miss quite a lot of detail, are easily fooled by visual and other illusions, fail to notice significant changes, and may not observe something that’s directly in front of us. This is somewhat shocking, really, given that over 10 million of the 11 million bits of information our brain processes moment-to-moment are devoted to visual perception.