After completing the highly entertaining and enlightening book, An Immense World by Ed Yong, I was browsing at a small book shop on a family trip when a white hardcover book with a one word title slipped behind and between triple images of a cheetah in stride caught my eye. That book is Sentient by Jackie Higgins. It’s every bit as engaging and awe inspiring as Yong’s book, proving that there is so much more than two books’ worth to know about how other creatures sense the world. Higgins more than doubles the classic (and false) idea of the “five senses”, unpacking 12 human senses and linking a different animal to each of these senses to show just how connected all life on earth is – and just how amazing human senses are. While not a science textbook, this type of book inspires readers to learn more, just as scent work has inspired folks to take the leap into search & rescue, medical alert, ecology detection, and other disciplines in the realm of scent and dogs. When you read Sentient I suggest you think of all the ways you can harness your senses to be a better partner for your dog. Let’s explore the book…
Petite Packages Pack Powerful Punches
Chapter 1 of the book focuses on the human sense of color via the amazing eyes of the peacock mantis shrimp; however eyes aren’t what the mantis shrimp is typically known for. This creature about the size of a tube of biscuit dough, has, pound for pound, the most powerful punch on the planet. This is one shrimp you don’t want to bully (PSA: don’t bully any shrimps, or anyone for that matter). Find yourself a slow motion youtube video of one of these pugilists of the Pacific Ocean and try to keep from laughing at this little guy’s double-fisted jab that looks more like a couple pinky fingers flicking boogies than the punch of an arthropod Apollo Creed. Still, to a crab in a shell, this shrimp is the Incredible Hulk of the Indian Ocean. Shrimp smash!
So these shrimp can punch, but how are they able to get in the position to crush clams so successfully? If you took a vote amongst the researchers studying the mantis shrimp, the “eyes” would have it. Packed with rods, cones, and photoreceptors, the mantis shrimp eye is the Bugatti Veyron of the sea – heck, of the planet. The tale Higgins tells is reminiscent of an Ali “rope-a-dope” with researchers thinking they’ve illuminated the mysteries of the mantis shrimp’s eyes only to be surprised with a left hook of a study finding these shrimp to be dramatically worse at color discrimination than humans.
The unexpected findings that mantis shrimp eyes – despite being so souped up on paper – can’t tell red from brick red, or red from crimson, are unexpected because color vision is our primary sense, so we look for evidence of its primacy in the rest of the animal kingdom. Imagine a trichromatic-color-visioned human suddenly endowed with the unimaginably rich and wonderful powers of dodecachromatic color vision – don’t even try to imagine it, you’ll break your mind. Now imagine the mad scientists who wept the day they thought it would finally be possible to make magically psychedelic unicorn vision a reality for humans when they discovered a puny underwater Popeye with some badass eyes from the future – go ahead and imagine it, it probably really went down that way. While a mantis shrimp’s eyes do look like a Marvel super villain’s Mephistophelian peepers, the way in which they’re super awesome is still a mystery to us. So, it’s back to the drawing board – or underwater boxing ring – for mantis shrimp researchers as they search for the knock-out punch revelation explaining how the alien-eyed clam clobberers’ eyes work, what they see, and how it helps them to thrive… and when they figure these shrimp out, the mad scientists will be right there to replace your eyes with ping-pong sized disco balls on chopsticks, and tell you it’s awesome…
When observing a dog search, people sometimes say, “he’s looking for the hide”. They usually mean he’s searching for the hide, yet they use a verb that means “to ascertain by the use of one’s eyes” (definition from Merriam Webster). We can get ourselves into so much trouble when we frame a search as a visual effort. This can easily happen when we search non-blind. We fixate on the location of the hide and we expect the dog to be physically close to the hide in order for his indication to source to be acceptable.
The dog is not “looking” for the hide. He’s searching with his sense of smell. We are looking at the dog as he searches, but we are not looking at the odor. Watching the dog is our best way to “see” the odor. Trying to reconcile our knowledge of the location of a hide and our understanding of the movement of odor as described by what we see the dog doing can be a challenging task. There are many reasons why a dog might not end up at the physical location of a hide. Knowing those reasons (while often a guessing game) is less important than knowing whether your dog is trustworthy or not: When your dog can’t make it to the hide, but is trying to tell you he’s found it, do you believe he’s done everything he can to source the hide and do you believe he deserves a reward?
You are not a mantis shrimp with eyes that look like they were made up by bratty British kids, Oompa Loompas and a purple-suited Jeney Welper (obviously, a Wilder Depp baby, made by mad scientists, obviously), but you certainly have sophisticated enough vision to see between the lines of your dog’s movements. Along with your awesome eyes, you have a big brain you can put to use to process everything you see your dog do. When you and your dog are tackling a complex search, it’s crucial that you see as much as possible – or you won’t have a grand vision of your dog’s movements to process. Even more crucial is that you accurately process what you’re seeing and make decisions that positively affect your dog.
One tip to help you optimize your ocular abilities is to practice relaxing your body and your breathing, and to consciously try to see as much of the world around you as possible. This helps you avoid the opposite behavior, which is to be stressed and narrowly focused. It’s not that a narrow focus is bad – if you’re about to be hit by a car, hyper-focusing on the car and how to get out of its path may save your life.
In scent work, a typical search does not have the very short duration and simple problem structure of a car accident, yet it can sometimes feel like a situation requiring intense and narrow focus. The problem is, when we hyper-focus, we get frozen in time and we latch on to one detail, then we try to make a compelling story from that one detail.
In a search it might be a particular behavior change you observe in your dog, like a quick turn towards a wall outlet. The behavior could lead to many likely outcomes, but you narrow your focus and come up with a story: the hide can’t be there, my dog checked it and moved on. The hide must be somewhere else. This story could be true – but, it rarely is the whole truth. Your narrow focus – and probably elevated stress level – prevent you from seeing other very important clues that your dog is communicating in addition to the interest at and dismissal of the outlet. Within seconds, your dog paints a more complete picture of odor movement in the area around the outlet, but you – while “looking” at your dog – see none of this and have already mentally “left the area”.
Along with relaxed breathing and expanded visual field, you can practice not using your conscious mind to figure out what your dog is communicating to you in the search. As your dog’s search partner, you are most effective when you stay calm, stay in the role of letting your dog move you, and avoid guessing at what your dog’s communication means.
An “Infinitesimal Atom Floating In Illimitable Space”
In 1934, William Beebe (the man who conjured the phrase above) and Otis Barton would descend into the ocean 6 times deeper – almost half a mile more – than any human in history. What they experienced was a gradual shift into a darkness nearly void of photons from the sun. Today, researchers have numerous ways of studying the creatures who dwell in the depths of our oceans, and it appears that nearly all of these creatures rely on their eyes to find prey or evade predators. How is it that eyes can function in almost absolute blackness? Scotopic vision, or vision in darkness, makes use of fewer photons and what photons do reach the eye are received by the rods in the eye which only resolve images in black and white. In the second chapter in her book, Higgins takes the reader on a marvelous and mysterious tale involving the spookfish and discoveries – new and old – ultimately leading researchers to delve into the darkest realms of human vision capabilities.
When Higgins writes about a research experiment measuring the human eye’s ability to detect a single photon, it’s hard to imagine what that experience is even like. First, you need to be in truly total darkness. No photons can be moving through your environment, reaching your eyes. Second, a single photon needs to be aimed and fired at your eye. Third, the photon needs to actually make it to a rod and be sensed by a photoreceptor. Participants in this experiment have varying experiences, likening the perception of the photon to “a dim star in the night sky…” The quantum physicist running the experiment, Alipasha Vaziri says, “It’s even more extreme than that. It is a feeling at the very threshold of your imagination – a feeling that there could have been something but you aren’t entirely sure.”
Think of what has to happen for a human to experience a feeling at the very threshold of his imagination – for example, in this photon experiment. He has to be in total darkness, and have one photon fired at his eye. The spookfish relies on hardware we do not possess to see as much as possible within a nearly lightless environment. A few times throughout her book, Higgins makes mention of human beings with some kind of deficiency (vision lacking color, or no vision whatsoever) becoming more finely tuned in one or more senses through necessity, but not through their deficiency. This means any human could finely tune one or more senses. It all comes down to how important it is to you to create space within which you can begin to live closer to the subtlest perceptions of your sensory system, closer to the threshold of your imagination.
In scent work, if you’re hoping to use your eyes to see the barely perceptible behaviors your dog uses to communicate, it does help to have just one hide to search for, and to have limited environmental distractions. It definitely helps to search blind. Another key to the experience is to have some way to qualify the relevance of the behaviors you are perceiving. This is really challenging. You could keep your own records and look for patterns that occur over time. You could have another person run blind with you and see if you both see the same subtle behaviors. If the person who set the hide can be impartial, you can have that person give you feedback. Maybe you can think of what you’re detecting as “important” behavior. Most humans, when asked, can recall the location of and the duration of instances of their dog behaving in a way that – while it didn’t make sense – stood out as important during a search. The photons of communication are reaching our eyes, we just need to practice raising our awareness.
One way to raise your awareness to the dim stars of your dog’s behavior patterns is to prime yourself to be in a state that enables you to feel the presence of these behaviors. As Vaziri said, people don’t so much see a single photon, they feel it. Feeling does not involve conscious thought. Meditation, breath work, relaxation, and intense physical activity can help shut off your thinking brain. Once you become practiced at feeling behaviors from your dog that often fly below the radar of your consciousness, you might begin to see them like one sees the light of a dim star. I wish this were easy to do, but most people find it torturously difficult – just as most people cannot manage to sit still with their thoughts for even a few minutes. If you are one of the many people who prefer to live in a sensory zoo, with the white noise of modern life drowning out all but the most invasive and pervasive stimuli, make sure to do your scent work searching on days where your schedule is not packed, and in environments where you do not have competing distractions. If you feel your focus getting hijacked by your own mind or by outside stimuli, take a deep breath, let your present thoughts out with that breath, and return to letting your dog move you, staying attentive to your dog’s behaviors.
“Poor Human Olfaction Is A 19th Century Myth”
Skipping ahead to chapter 7, “The Bloodhound and Our Sense of Smell”, Higgins cites a 2017 paper (see above for its title) authored by John McGann that calls into question the supremacy of other mammals over humans in the olfaction department. First, McGann notes that humans have a sizable olfactory bulb compared to other animals, second, he references two studies showing that the olfactory bulb itself is somewhat irrelevant when comparing absolute sniffing prowess. Higgins quotes Yale neuroscientist Gordon Shepherd, “what matters more [than the olfactory bulb] are the central olfactory brain regions that process the olfactory input… [these] are more extensive in humans than is usually realized.” Higgins details Shepherd’s list of brain regions that process olfactory input: the olfactory cortex, olfactory tubercle, entorhinal cortex, parts of the amygdala, parts of the hypothalamus, the medidorsal thalamus, the medial and lateral orbifrontal cortex, and parts of the insula. Damn. The human sniffer is legit.
Why can’t we humans out-smell dogs? In some tests, we can. Higgins writes that, “our nose can smell at least a trillion different scents.” Meaning, we can discriminate among scents with increasingly small differences. Higgins also notes that humans can smell “ripe banana” scent at “concentrations as diffuse as -7.02 log parts per million.” This ability outperforms a dog. Still, I know of no human who can get out of a vehicle at a city park and begin a search for a tiny tube filled with banana scented cotton swabs, let alone complete that search to source in mere seconds. If you exist, comment on this post!
Even though humans won’t be outcompeting dogs at scent work trials, the facts are in: we have amazing olfactory processing capabilities. Higgins writes about a party trick that the physicist Richard Feynman would perform where he would ask a person to go to a bookshelf and pull a random book from the shelf, open it, then put it back on the shelf. While this was happening, Feynman would be out of the room. Once the book had been replaced, Feynman would enter the room and sniff the books to determine which book the person had touched. All humans have amazing olfactory abilities, but few humans cultivate those abilities.
Higgins also writes about an experiment that took place at UC Berkeley where participants were blindfolded, earmuffed, gloved, and knee-padded, then asked to get on their hands and knees and sniff out a 30ft long trail of chocolate oil. Two thirds of participants successfully sniffed out the trail in 10 minutes. The search time was cut in half when these human hounds made a second attempt at the exercise a couple weeks later. If you could turn down the volume of noise from your other senses and just take in the signal from your olfactory sense, you might be shocked at what you can learn about your environment.
Along with the smell of ripe bananas, humans are able to detect four other odors – at least, that’s all that had been documented when Higgins wrote the book – at lower concentrations than dogs. All of the odors humans beat dogs at are plant-based odors. All of the odors dogs beat humans at are related to the dogs’ prey.
The target odors for scent work are plant-based essential oils. Many people have probably experienced taking a whiff of a target odor hide and detecting no scent, then placing that hide in an environment and watching the dog effortlessly sniff to its location. My own experience over the years does lend some validity to the claim that dogs do not consistently and successfully detect plant-based target odors at very low concentrations (although I’ve never formally measured concentrations), but I just don’t encounter any humans who can out-smell a dog.
Higgins opens chapter 7 with a story told by Oliver Sacks, “The Dog Beneath The Skin”, of a patient he called “Stephen D.” This patient spent three weeks living as a dog in New York City. The patient recalled visiting a perfumery: “I had never had much of a nose for smells before, but now I distinguished each one instantly – and I found each one unique, evocative, a whole world.” Stephen D. also shared what it was like to identify his friends by smell: “Each had his own olfactory physiognomy, a smell-face, far more vivid… than any sight face.” This transformation was induced by a mixture of illicit drugs, yet it provided a vivid and hyper-real experience for Stephen D.
Humans are not dogs, yet we clearly share enough DNA, and enough sensory hardware and software, that with the right mix of drugs we can experience the world as – probably – a dog does: through smell-o-vision. One of the great challenges of scent work is to really take the dog’s perspective in a search. I often hear comments from humans during a search that are some variation of: “the dog is not working”. If we could only awaken our inner dog and live by the nose, we might begin to sniff a mile in our dog’s nostrils and truly find meaning in everything they do.
Unless you have a burning desire to compete in scent work for 10+ years of your dog’s life, why not take your time getting to truly know your dog. This doesn’t mean going on walks where your dog gets to sniff and be a dog – it means going on walks where you pay attention to what your dog is communicating about his experience. It also doesn’t mean doing nothing formal with your dog – it means creating a relationship, a partnership, a life together that works for both of you. This life you create can – and should – take form as a unique entity forged from a pool of common ingredients. Some of the ingredients of a fulfilling relationship are: reliability, clarity, chemistry, and shared passion. If you can’t see how those ingredients fit into your life with your dog, you might not end up with the most delectable experiences as a duo.
When you do begin your journey through the world of scent work, really try to imagine the joy your dog gets from communicating with you. Sure, he’ll focus on finding the target odor, and sure, he’ll take your treats when he finds it, but what really brings him satisfaction is when you understand him.
Living “Timeless”
In chapter 10 of Sentient, “The Trashline Orbweaver and Our Sense of Time”, Higgins lowers the reader into the dark, dank, nearly lifeless environment of a cave in the French Alps where speleologist Michel Siffre spent two months in 1962 living outside of time. This experiment – by Siffre’s own account, the creation of the field of human chronobiology – would be followed by similar experiments dubbed as “cave isolation studies”, the most lengthy one, again featuring Siffre, topping out at 205 days spent inside Midnight Cave in Texas. Each of these experiments revealed the same truth: the person in isolation no longer places any meaning on time, yet the person manages to adhere “unwittingly to a regular wake and sleep cycle. In Siffre’s words, “My experiment showed that humans, like [other animals], have a body clock.”
Further into the chapter, Higgins pulls the readers out of the cave experiments and into a case study of a British soldier who went “time blind” after a severe head injury. Sergeant Mark Threadgold lost his sense of taste, his sense of smell, and he was rendered totally blind due to the severing of his optic nerve. To make matters worse, Threadgold lost all connection to time. Unlike the cave isolationists, Threadgold had no consistency to his eating and sleeping patterns, experiencing severe disruptions to his wake/sleep cycle, even within the course of one week. Scientist Russel Foster took an interest in cases like Threadgold’s, and after some time studying mice, he declared all mammals to have eyes with rods, cones, and “some unknown third photoreceptor that grants the sense of time.”
Sadly, the scientific community rejected Foster’s findings, making it very hard for him to raise funding and bolster his early research with new and more refined experiments. Right around the year 2000, Foster finally succeeded in unequivocally proving the existence of “circadian light receptors”. His discovery was hailed as “arguably the biggest advance in visual science in the past fifty years” by a fellow scientist who opposed the idea early on. A decade and a half later, a group of scientists would win the Nobel Prize for revealing how the “body clock ticks in the cells of a fruit fly”, and pretty much in all animals. It turns out “virtually every cell of our body can generate a circadian rhythm. There are liver clocks, muscle clocks, pancreas clocks, adipose tissue clocks, and clocks of some sort in every organ and tissue examined to date.” Higgins adds to this statement, “But those in the suprachiasmatic nuclei (a paired clump of cells at the base of the hypothalamus) rule the rest, keeping them ticking together in time.”
In scent work, time is so ubiquitous in the mind of the human that it overtakes arguably more important tasks like reading the behavior of the dog. Is time really relevant? In a natural, circadian sense, our conscious awareness of time is irrelevant – as proven by the cave isolation studies. In scent work, time can become completely irrelevant, too. Some humans note having no sense of the passage of time when in deep focus during a search. Other times, humans have an intensely uncomfortable awareness that time is dragging on forever, or time is running out like the sands of an hourglass.
Malcolm McDowell playing Soran in Star Trek Generations quoted a line from a Delmore Schwartz poem when he said, “Time is the fire in which we burn.” Some of the foremost thinkers about time and space say that “we are time”. It’s possible that our fascination – obsession – with time is related to our mortality and the inevitability of death. We can do pretty much anything we choose to do with our time – except to extend it infinitely, and that ever-present truth leads us to try to get the most done in the least amount of time. Why do we call it a “deadline”? Or a “drop-dead date”? Or “sudden death” overtime? Are we rehearsing death by risking it symbolically in trivial ways? When we “beat the clock” is it a micro dose of immortality? Whatever you think, time – and it’s finitude – seems inescapable for the modern human.
Please think carefully before imposing your conception of time on your dog in scent work. I’ve witnessed dogs gift their humans with incredibly expressive searches when spared from the fire of time. I’ve had humans tell me they do not want to compete because they see no way in which the time pressure element of competition at all benefits the dog. I’ve stood patiently with a human as we just “be” with the dog, wanting nothing more than what the dog wants to communicate to us, be it standing still or in motion, solely so we can wake up from the trance that time ensnares us in. Dogs are willing to teach us to stop racing a clock that doesn’t exist. We just need to take their lead.
How do you live “timeless” through your dog in the game of scent work? First understand that your mind is the instigator of time pressure. In order to be pressured by time, you need to be thinking about time. So, practice not thinking about time. Keep your attention on your dog and that is all. Once you can consistently stay focused on your dog without letting your mind wander, you can begin to create a natural rhythm from your dog’s patterns of behavior. Most dogs communicate with certain patterns of behavior when odor is present, when a hide is located, and when a hide is sourced. Each of these patterns of behavior has some variability accounting for increased complexity (hide difficulty, environment, area size, etc.). Most dogs also have a pattern of behavior that reliably expresses an inability to advance. You can feel time through all of these patterns of behavior. I can have someone search for a single hide with their dog with no time pressure, then ask the person how much time they searched for, and the person will be able to accurately assess the passage of time (within seconds, even when searching for 4 or 5 minutes). Not all people can do this, but it does show that a person is capable of sensing the passage of time without consciously focusing on it, and that is the essence of “timeless” searching.
Being in “timeless” partnership with your dog does not mean being in careless partnership. It means taking ownership of your modern tendency toward time anxiety, and purposefully orienting yourself to a more natural rhythm when you search with your dog. This might be a Sisyphean struggle for some people. It means getting the conversation of the search right with your dog before you start using timers and alarms to dictate the duration and depth of that conversation.
For those humans who think they are doing everything they can to search with their dog, on their dog’s clock, yet they are always running into the 30 second warning, don’t be so quick to assume you need to manage how your dog spends his time during the search. Very few searches end unsuccessfully because the human failed to manage time, rather because the human failed to manage communication.
Higgins closes chapter 10 with the almost unbelievable findings of researcher Darell Moore: several species of trashline orb weaver have the shortest – and longest – known body clocks in the animal kingdom. For example, after ten days in total darkness, the Cyclosa had kept its natural routine, but its day had become very short, coming in at just 18.5 hours. Previously tested, non-modified animals – including humans – generally remained in close sync with a 24hr day. To have such a short body clock, yet exist in nature would mean, in the words of researcher Thomas Jones, “Cyclosa… has to phase shift more than five hours to stay in sync.” Higgins writes, “the scientists liken it to snapping out of five-hour jet lag.” According to researchers, these trashline orb weavers are remarkable creatures, and we humans may learn from them how to safely uncouple ourselves from nature’s daily schedule sometime in the near future. What we already know, is that our notion of time is not objective. We measure time down to the zeptosecond, but we would be much better off, as Higgins writes, “… to jettison manufactured clocks in favor of our own body clock.”
Before you strap that multifunctional timer onto your wrist and set it for 3.5 minutes, with an alarm at 15 seconds remaining, reflect on your dog’s ability to reliably search for and find source odor, and your ability to sense the passage of time through his communication. My dog and I were searching a massive exterior area at an NW3 trial many years ago, and we had 2 hides found with 30 seconds of our 5 minute time remaining. I quickly recalled an area my dog showed some interest in early in the search and rushed to get her back there. In my time-pressure fueled sprint, I failed to see my dog turn her head and source the final hide – I mean, my eyes saw it, but my mind wasn’t taking any new information in. Even once I got my dog to the part of the search area I thought was most important, I didn’t receive her communication telling me that the hide wasn’t there. I just narrowly focused on the only story I could tell myself with the seconds ticking away: the hide has to be here, we have to be close… I burned myself in the fires of time that day, but my dog knew better than to touch those flames.
A Paradox Of Platypuses And Perception
In the Afterword to Sentient, Higgins writes about the duck-billed platypus and masterfully endears the reader to this strange egg-laying, aquatic mammalian mash-up of duck, beaver, otter, and snake, pointing out that humans and platypuses likely share the same experience of the world through their eyes, ears, nose, mouth, and skin, with one major difference: the platypus bill is a finely tuned electric field sensor.
When a platypus dives underwater, Higgins writes, “… its eyes, nostrils, and ears seal tight. Without sight, smell, and hearing, it searches for shrimp and crayfish by tracking its bill side to side over the stony riverbed like a treasure hunter with a metal detector.”
How is it that the real-life play-doh creation of a 2 year old can manage its senses like a well-disciplined master, yet we humans with the master-brains are sensory toddlers? It may have to do with necessity. That and the cotton candy web of sensory distraction that we modern humans spend our lives comfortably trapped in.
What if, instead of being trapped in the sensory web, we humans learned to dance along its many threads, freeing ourselves to direct our awareness and heightening our sensitivity to the subtlest signs vibrating throughout our sensory map of the world? Would we unleash our inner platypus, learning to see the world through electric fields created by the muscle contractions of other creatures? Higgins quotes neuroscientist David Eagleman: “Our brains are tuned to detect a shockingly small fraction of the surrounding reality… The interesting part is that each organism presumably assumes its Umwelt to be the entire objective reality ‘out there’. Why would any of us stop to think that there is more beyond what we can sense?” Before you go into a Starbucks with your eyes closed, sweeping around nose first looking for an outlet to plug in your phone charger, maybe just start with the mental shift of actually stopping to think about the vast world that you do not perceive. Increased awareness begins with curiosity.
Higgins spends the final paragraphs of the afterword to Sentient looking to the future, highlighting the biohackers that believe we humans can be augmented with senses from throughout the animal kingdom. It’s hard to imagine sensing the world in a new way, but by no means is it impossible for our brains to adapt to a new way of processing sensory input. According to David Eagleman, we are closer to a new reality than one might think: “The human Umwelt has been unlocked… We no longer have to wait for Mother Nature to define us – we now need only ask: How do we want to experience our universe?” Higgins closes the afterword with these lines: “What do we want our reality to be? A brave new world of sentience awaits.”
We have control over the reality of our partnership with our dogs in scent work. A new way of sensing what they are communicating does not have to be created, it exists at the threshold of our imagination. Will it come through finer tuning of our eyes, our hearing, or our sense of body? Or will it be a less understood – or yet to be discovered – sense? I wonder…
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