Soul Searching...

In the two years since I’ve been writing this blog, we’ve explored just about every aspect of our anatomy, from the beautiful intricacies of its form and function to the bizarre ways we modify and even mutilate our bodies. So as this writing endeavor draws to a close and I focus on other projects, I thought I'd end by discussing an aspect of the body that has eluded scientists and philosophers for centuries – the quest for the human soul.

Throughout history, the soul has been part of our search for understanding how the human body works. Ancient terms to describe the soul – from Latin’s anima to the Greek psyche – usually refer to the vital forces within the body, be they motion, movement, or breath. And since the presence of the soul was believed to separate the living from the dead, it seemed only logical that it should reside somewhere in the body. All we had to do was find it.

Some of the earliest references to the soul go back over five thousand years to the Egyptians, who believed the soul was composed of five parts, the most important of which resided within the heart. The heart was believed to be the animating life force, the source of our feelings, thoughts, and will. In fact, the weight of the heart at death determined the soul’s destiny. If the heart was considered too heavy, it would be consumed by a demon, subsequently ending one’s bid for the afterlife. This cardiocentric view of the soul persisted throughout much of history.

Fast forward a few thousand years to the Greek poet Homer, who claimed there were two types of souls. The first, which resided somewhere in the chest, controlled our emotions, everything from joy to reason to rage. The second type of soul was tied to a person’s individual identity and appeared only in dreams. It had no specific location within the body, but served as the animating life force. Homer believed it was this aspect of the soul that fled the body at the time of death.

The foundations of Western philosophy, forged by the likes of Socrates, Aristotle, and Plato, also contemplated the riddles of the soul. Plato considered the soul to be of celestial origin, the immortal essence of a person that was divided into three parts. The rational aspect, which controlled reason, was of primary importance and thus located within the brain. The spirited aspect, responsible for courage, resided in the chest, and the appetitive portion, which governed love (of food, drink, and “loving delights”) was located in the abdomen. The goal of life was to achieve a balance within the soul, especially regarding spirits and appetites; a human struggle that continues to this day.

Plato’s student, Aristotle, stoked his own ideas about the soul. He agreed the soul formed the essence of an individual but, unlike Plato, Aristotle believed the soul could not be separated from the body. So much for its immortality… He too divided the soul into three parts but, in his view, the soul controlled bodily functions and was therefore defined as such: the vegetative function (nourishment and reproduction); the sensitive function (sensation and movement); and the intellectual function (cognition and deliberation). Aristotle also believed that all animals possessed a soul, although the intellectual functions were confined to humans. And like the Egyptians of long ago, Aristotle believed the heart served as keeper.

Early Christians took a broader view. The soul not only gave form to the body, but could be found in every aspect of our anatomy. It was believed the soul entered the body only after the fetus was fully formed. “Delayed ensoulment” coincided with the “quickening,” thus once the mother felt the baby move, the soul was considered to have arrived.

Around the seventh century AD, as the Dark Ages blanketed humanity, the belief in delayed ensoulment persisted. The Roman Catholic Church decreed abortion acceptable as long as it was carried out before the soul arrived, and this was upheld well into the 19^th century.

With the blossoming of the Renaissance in the 1300s, Leonardo da Vinci incorporated the search for the soul in his anatomical studies, declaring the middle ventricle of the brain as the most logical spot. René Descartes took up the banner a few hundred years later, agreeing with Leo on the general location of the brain, but claiming the pineal gland was a more likely location.

As scientists learned more about the inner workings of the brain, belief in a craniocentric soul persisted, well into the 20^th century. It seemed only natural that the seat of consciousness should also house the soul. But as science advanced and our understanding of the human body crystalized, the soul as animating life force slowly fell away. The mystical realms of life could now be understood in terms of biochemistry, neurology, and genetics, and issues of the soul were gradually relinquished to the theologians.

If you ask me if we possess a soul, I'd have to say I don’t know. The scientist in me embraces the tangible explanations for what constitutes a living body and I’m far more comfortable discussing cellular respiration than arguing the validity of delayed ensoulment.

But that in no way diminishes my fascination with life or the wonder I feel when I contemplate the intricacies of our anatomy. Regardless of our beliefs, we can all agree the human body is a truly astounding machine, one that not only sustains us but enables us to experience our world.

As for the ghost in the machine... I’ll leave that to the theologians.

Thank you so much for reading.

Rachel

The Fear Factor

If you had to list the things that scare you the most, what would your list include? Human fears run the gamutt, from the insignificant (spiders and heights) to those that haunt us in the wee hours of the night (loss of a loved one, inevitable death). Fear, like other emotions, is a visceral aspect of humanity. But it goes even deeper than that, for fear transcends the boundaries of humanness. It’s part of our evolutionary heritage.

Want to scare a chimp? Place a plastic snake next to an unsuspecting primate (humans included) and you’ll probably witness pure, unadulterated fear. That’s because the fear of snakes appears to be hardwired into many primate brains; a deep-seated phobia that may have evolved to keep us safe. Since many snakes possess the ability to kill, it seems only logical that animals that avoid a close encounter might have an evolutionary edge over the less cautious.

But where does fear reside? And what actually happens when we are scared? Like any emotion, it all begins in the brain.

Many parts of the brain are activated during the fear response. And the majority of them are located deep within; a testament to their ancient origins. Yes, our fancy cortex also plays a role in fear, but the rest of the hardware we share with other animals, since critters lacking fear would stand little chance of surviving in our dangerous world.

Here’s a quick glimpse at the brainy bits responsible for processing fear.

Our sensory cortexes interpret what we see, hear, smell, and feel. The information is whisked to the thalamus, which decides where to shuttle the data, and the hippocampus then places the data in context. The amygdala decodes the data and determines if a threat exists. And if the threat is real, the hypothalamus activates the fight or flight response, which kicks the body into high gear to respond to the situation.

Of course, these reactions happen with lightning speed and, in many cases, the body simply responds as if threatened, even if the threat turns out to be benign. It’s better to gear up than to sit back and contemplate. A momentary hesitation could spell death.

The hypothalamus activates two separate systems when it launches the “fight or flight” response. The sympathetic nervous system activates stress hormones, adrenaline and noradrenaline, which are dumped into the bloodstream. As they circulate, they increase heart rate and blood pressure, which explains the thumping in your chest that accompanies a scary jolt. At the same time, the pituitary gland gets involved by secreting a hormonal cascade that primes the body for action. Pupils dilate (to improve visual acuity), blood vessels in the skin constrict (to shunt blood to the major muscles), and muscles tense for action (which explains the goose bumps). While the essential functions are enhanced, nonessentials, such as digestion and immunity are sidelined. That way, the body can focus on the immediate threat and conserve energy in the process.

But if fear evolved to improve survival, why is it so many of us love a good scare? I admit, I’m an adrenaline junkie, much of which I blame on the years I spent as a firefighter. Once you’ve rushed headlong into a burning building, daily life can seem a bit monotonous, which probably explains my love of rollercoasters, skydiving, and scary movies.

But the reason many of us love a good scare is because the fight-or-flight response involves many neurotransmitters, namely endorphins, dopamine, and serotonin, that are also responsible for a rush of pleasure (think orgasms). That is why a momentary scare is followed by a blissful blast of relief. Once our brain realizes the fear isn’t real, our body can simply enjoy the rush, which is why screaming is often trailed by nervous giggles.

But humans can do something no other animals can: they can conjure fear. Our sophisticated brains enable us to do some amazing things. But they also come at a price, for although we are gifted with imagination, much of our imagining can evoke fear.

Fear of the future, fear of loss, fear for the ones we love… there are a million ways we torment ourselves by conjuring fear. But it is worth noting that, however much we languish in fear, it has little effect on outcome.

So keep your fear in check and save it for life’s true emergencies. The next one could be right around the corner…

Playing Defense

Last week, my body came under attack. In an ironic twist following last week’s post on contagious pathogens, I picked up a nasty bug that for the past seven days has wreaked havoc on my immune system. Fortunately, whatever I caught was confined to my northern regions – primarily my throat and chest – rendering me febrile, voiceless, and with a bone-rattling cough that could give any tubercular a run for his money.

I’m happy to report that I am now on the mend, but it got me thinking about the immune system and the vital role it plays in keeping us safe. Naturally, I thought I would elucidate its magical machinations, but I found myself resorting to boring military metaphors traditionally employed for such discussions. The trusty lymphocytes that serve as armed forces, always on high alert and ready to mobilize should a foreign invader appear on the horizon. Pathogens, those dangerous usurpers who are just waiting for the opportunity to bust through our protected borders. Blah, blah, blah.

So instead of the usual immunity song and dance, I thought we’d explore the more perceptible means of defense, for our bodies have evolved numerous nifty ways to rid themselves of unwanted guests.

First and foremost is that largest of organs, the skin, which accounts for around sixteen percent of our body weight. Skin serves as a protective barrier against our pathogen-infested world and it does this not only through its layered arrangement, but also by producing specialized peptides that annihilate microbes and sound the alert when danger approaches.

But there are two problems when it comes to skin’s defenses. First, skin tears. And once it is torn – whether through an injury, an insect bite, or on purpose, through surgery, it allows entry to all sorts of dangerous organisms, from bacteria, to viruses, to parasites.

The second problem concerns topography: although our skin is one large organ, it varies from surface to surface, and some of our most vulnerable surfaces are those that house our mucous membranes. For example, the respiratory tract. The moist, gooey surfaces of our respiratory system provide the perfect portals for pathogens. Each time we put a hand to our mouth, pick our nose, or simply take a breath, we can usher in a suite of infectious organisms that would love to plant their flag.

Fortunately, our respiratory tracts have devised a few clever ways of ridding themselves of pesky pests, which explains why we cough, sneeze, dribble, and blow. Our lungs also sport a thin layer of microbe-fighting proteins, which defend against any bugs that manage to weather the snotty storm.

But pathogens are crafty. Some, like influenza, actually attach themselves to our bronchial membranes to prevent their quick expulsion. Others, such as measles and whooping cough, render our cilia inoperable. Those small, hair-like projections are designed to usher pathogens up, up, and away from our lungs, and when they are knocked off-line, bugs can simply run rampant.

The respiratory tract is but one of many portals for pathogens. Our stomachs are prime targets for many food- and waterborne bugs, which cause a wide range of misery, illness, and death. Luckily, our stomachs make for fairly acidic accommodations, with an average pH of about 2 (which you science nerds will recognize as pretty darn acidic). And just like our respiratory tracts, our gastrointestinal plumbing has devised a couple of rapid evacuation methods, namely vomiting and diarrhea.

And speaking of acidic body parts, let’s not forget the vagina. This acidy little tube sports a pH of around 4, which is ideal for warding off bacterial and fungal invaders - not to mention sperm, which explains their desperate swimming. Not so, our urethras, which is why urinary tract infections are so common. Especially in women, for not only do our urethras lack defenses, but they are positioned dangerously close to the anus, which as we all know is a virtual playground for pathogens.

And speaking of that other southerly portal… The anus, like the urethra, is also ill-equipped to ward off infection. And what makes it even more dangerous is that, unlike the vagina, the anus lacks any natural lubrication. So if you’re going to use it for recreational purposes, do yourself a favor and lube up. It will prevent tissue tears, which are great access points for infection. And don’t forget the condom!

So the next time you find yourself sneezing, coughing, vomiting, or worse, take a moment to appreciate the fundamental necessity of such functions and know that as miserable as these symptoms are, they serve a vital role in the fight against pathogens.

Related Posts

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From Oral to Anal: A Gastrointestinal Journey
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A deep read on the subject:

Fire Down Below

Last week, we took a brief glimpse at the long and convoluted history of prostitution, so I thought it only natural to follow up with an infectious postscript.

For as long as humans have been exchanging bodily fluids, pathogens have been part of the mix. And when it comes to bumping genitals, there are a whole slew of contagions getting in on the action. Because a comprehensive overview is beyond the scope of this blog (not to mention my short attention span), we’ll stick to the highlights while we explore the dark and daunting world of STDs.

First, let’s clarify the terminology. You may have noticed that the term STD has lately been supplanted by STI. What differentiates a sexually transmitted disease from a sexually transmitted infection is the presence of symptoms. However, since some STDs aren't accompanied by symptoms, it’s really splitting hairs. So for the sake of today’s post, we’ll stick to the tried and true acronym, STD.

Sexually transmitted diseases most likely evolved along with humans and historians have been chronicling their presence all the way back to the Bible. The Old Testament refers to “the running issue,” referencing the “clothing needing washing as did the man himself,” most likely referring to gonorrhea, which causes that telltale discharge from the penis. And it wasn’t until the Middle Ages (around AD 1200) that the disease was finally linked to sex.

But gonorrhea is only one of many STDs plaguing humans, for the list of potential pathogens is long and varied.

STDs come in three basic varieties: bacterial (gonorrhea, syphilis, and chlamydia, to name a few); viral (Hepatitis B and C, Herpes, HPV, and HIV); and parasites (such as trichomonas, a pesky protozoan that thrives within urethras and vaginas). And it’s the type of pathogen that determines the treatment.

Since the advent of antibiotics, the bacterial bugs can usually be wiped out with a simple prescription, as can trichomonas. Unfortunately, the viral pests are not so simple. Once a person is infected, herpes and HIV are here to stay, and one can only mitigate the symptoms. Hepatitis, however, forms a mixed bag. With Hepatitis B, most people can be cured, although a minority will become carriers for life. Hep C holds a more dismal future, as a majority will suffer long-term infection with chronic liver disease on the horizon.

But try to imagine what these maladies must have been like before the advent of modern medicine. So to keep things in perspective, let’s peruse some of the ancient treatments that were once believed to cure the “fire down below.”

The ancient Greeks were some of the first to record the treatment of venereal disease. In fact, the term “herpes” originates from the Greek, meaning “to creep or crawl.” And how did they attack the creepy-crawlers? By burning off the lesions using hot irons. Despite their torturous treatments, they get kudos for instituting public policies aimed at reducing the spread of herpes, although their “no public kissing” rules probably did little to curb the virus.

By 1746, London’s Lock Hospital was the first to establish public treatment programs for the infected. And the 18^th and 19^th centuries saw the use of mercury, arsenic and sulphur as the primary remedies, although these dangerous regimes caused serious side effects, even death. Despite the danger, arsenic, in the form of salvarsan, was used to treat syphilis well into the 20^th century.

And as scary as these diseases can be, what scares people even more is the social stigma attached to them. However, for those of you harboring an STD, take heart. You are hardly alone in your affliction. Here are a few statistics to bring it all home.

According to the CDC, there are over three hundred million new cases of STDs in the world each year. The human papillomavirus (HPV) is now the fastest growing STD and nearly all sexually active folks will contract it at some point in life.

About one in five Americans has genital herpes, yet about ninety percent of them don’t know they have it. And health officials warn that by 2025, up to forty percent of men and almost half of all women could be infected with this permanent virus.

And of course, HIV is still rampant, still spreading, and still deadly. As the sun sets in South Africa, another fifteen hundred new infections will have taken place today. Yes, I said fifteen hundred per day. And that’s the conservative end of the statistic.

Let’s face it, STDs are scary, and the emotional toll they incur can be as burdensome as their symptoms. But pathogens, like us, are thriving members of the biome and will forever be a part of life on our planet.

So stay informed, stay healthy and, for god’s sake, use a condom.

Related Posts
The Seeds of Syphilis
A Syphilitic Sequel
A Tale of Two Condoms

Hooking through History

No exploration of the human body would be complete without a brief glimpse at that most ancient of professions, prostitution. How can we possibly explore the body without contemplating the sale of said body? So let’s go back in time and trace the evolution of this infamous trade.

As long as man has wandered the planet, I’m sure some form of prostitution has been in place. It comes down to simple supply and demand. I can just imagine a consensual agreement involving sex in exchange for a juicy mastodon shank or some handy work around the cave, for we all know a way to a man’s heart is not necessarily through his stomach. 

Prostitution has many euphemisms; more so for women than for men. Male prostitutes are typically gigolos or hustlers. Females, on the other hand, sport a rash of labels, most of which are hardly flattering. Hooker, streetwalker, whore, and skank are among the most common. In the days of yore, prostitutes were known as strumpets, trollops, harlots, or courtesans. But regardless of gender, history is riddled with accounts proving tricks have been turned for thousands of years.

In the ancient Near East, the Sumerians (conveniently) wove prostitution into their religion. Religious prostitution in Babylon required women to venture forth to the sanctuary of Militta at least once in their lives to have a conjugal confrontation with a foreigner; all in the name of hospitality, of course.

Prostitution among the Greeks was common among women and young boys. In fact, the Greek word for prostitute is porne, which is derived from the word meaning, “to sell,” laying the groundwork for what thousands of years in the future would become a thriving industry.

The first Greek brothel was opened in the 6^th century BC, with earnings going toward building a temple dedicated to Qedesh, the patron goddess of commerce. They even had categorical names for the various types of prostitutes, depending on where they worked, be it on the streets, in houses, or near bridges (don’t ask me). As for male prostitutes, they were quite popular among the Greeks, and the profession was usually taken up by adolescent boys, slaves and free alike.

The Romans believed in farming their prostitutes and would round up abandoned children and raise them for future sale. Slaves were also captured in battle or purchased for the sole purpose of prostitution, and sex for sale was even used as a form of legal punishment for women.

By the Middle Ages, the Roman Catholic Church was on a rampage to tamp down the trade in Europe, although it received blowback from those who believed the service helped prevent rape, sodomy, and (god forbid!) masturbation. Most brothels were left to their vices, as long as they resided on the outskirts of the village. That is, until cities caught on to the popularity of red light districts, where clients could window-shop for whatever touched their fancy.

But things changed in the 1490s following the return of Columbus’ voyages to the New World, for hidden aboard his cargo lurked a deadly stowaway: syphilis.

Syphilis became widespread throughout Europe, with prostitutes serving as popular hosts for the bacterium. This only added fuel to the fire of reformationists bent on tearing down this illicit trade. And even though folks were experimenting with various types of condoms, from catgut to sheep bladders, those rudimentary rubbers were no match for the “pox.”

By the 19^th century, France, followed by the U.K., passed laws to ensure regular medical examinations for their prostitutes. The Contagious Diseases Act mandated regular pelvic exams for their “pros” – not only on home turf, but in their colonies abroad.

Of course, around this time in America, prostitutes were as common as cattle among the dusty plains of the Wild West (and treated equally as well). Whoring was one of the few professions available to women of the period and, as America spread westward, so did prostitution. Wherever a new town popped up, so did a brothel that would set to servicing the menfolk, lickety-split.

But by the early 1900s, the buzzkill organization known as the Woman’s Christian Temperance Union marched in and quashed not only brothels, but alcohol, to boot. And by 1917, even New Orleans’ famous Storyville district - sixteen blocks of unfettered frolicking named after the councilman who established it – was closed down, despite public outcry from the locals. One had to travel all the way to Alaska to buy a legal poke in those days.

Today, Nevada is the sole host to legalized prostitution in the US. About thirty brothels support around five hundred prostitutes who work as independent contractors, most without the need for a pimp. As for the rest of the world, it’s a patchwork of legal and illegal selling. In a survey of one hundred countries, prostitution was illegal in thirty-nine, somewhat legal in twelve, and legal in forty-nine others.

And fierce debates abound about whether or not it should be a legalized profession, with advocates claiming legalization protects its practitioners, and women’s rights groups claiming it is inherently abusive.

Despite its legal status, prostitution is part of human culture and, as history goes to show, wherever there's a demand for sex, there will always be someone peddling it.

Eight-Legged Envy

This morning, on my way to my car, I walked through a gargantuan spiderweb. A diligent arachnid had been hard at work, industriously spinning his beautiful web, only to have some bumbling human destroy it in one fell swoop.

Of course I had my hands full, since these incidents never occur when one is unencumbered. I tried swiping the web from my face, only to realize its owner had conveniently hopped aboard my person. I suddenly became aware of a chunky spider the size of a malt ball taking a leisurely stroll down my arm.

Despite the burden of my computer, a coffee mug, and my purse, I managed to flail my limbs with enough vigor to dislodge him. He gracefully sailed down his web, landing gently at my feet and then scampering off into the undergrowth. After giving myself a thorough rubdown to ensure I wasn’t toting a giant egg sack on my back, I gathered my belongings and went on my way.

I’m not particularly afraid of spiders. I hold them in the same regard I hold snakes: cautious respect and deep admiration for the way they ambulate. Image what humans would be like with eight legs instead of two? It would probably render automobiles obsolete.

My eight-legged encounter got me thinking about our own mode of locomotion. In the animal kingdom, walking on two legs (bipedalism) is pretty unique. Only two other bipeds readily come to mind – penguins and kangaroos, both of which have devised their own strategies for getting around. Penguins have sacrificed efficient walking for swimming, and kangaroos took to hopping, which sure beats walking across the Australian bush.

So why did humans evolve such an unusual gait? Perhaps we should first ask, "when?"

Ancient fossils are hard to come by. The older they are, the less chance they have of being preserved intact. But there are clues to bipedalism among the fragmented remains of our earliest ancestors, and some of the best evidence has nothing to do with legs.

The hole in the base of the skull where our spine enters is called the foramen magnum. And it’s the position of this hole that provides a clue to upright walking. When it’s oriented at the base of the skull, it shows that the creature stood upright. If the hole is located toward the back of the skull, it indicates a quadruped (think about your dog or cat).

And it turns out our bipedal gait evolved much earlier than once believed. It was once thought that walking on two legs evolved in concert with our large brains. But what we find in the fossil record is that bipedalism was in place millions of years before our big brains arrived on scene. Even the seven million-year-old Sahelanthropus tchadensis, unearthed by a group of French paleoanthropologists in 2001, is believed to have been bipedal, based on his foramen magnum. Although scientists are still quibbling…

But the bigger question is why? Why did humans switch from four to two legs?

Theories of bipedalism go all the way back to Darwin, who believed the freeing of our arms allowed us to concentrate on the production of tools and weapons. This makes sense until you take into account that stone tools don’t show up until many millions of years after we started scooting around on two legs.

Others believe climate change had a hand in it. Perhaps humans took to walking as their forests were reduced and food became harder to come by, prompting males and females to partner up for provisioning. Males could gather food (in their arms, of course), and provide for their female and offspring, which would cement their bond and benefit both parties.

Or perhaps the reduction in forests required our ancestors to traverse longer distances. Walking upright, or better yet, running, has been shown to be more energy efficient than the knuckle-walking of our primate cousins, and there’s a whole new line of research examining the role running may have played in the evolution of humans.

Whatever the reason, we humans wouldn’t be human without our unusual gait. Sure, spiders have it made, what with their eight legs and their ability to walk on water. But it’s hard to imagine how humans could have accomplished all we accomplished if we were still ambling about on all fours. Stone tools, pottery, weapons, and art would have been quite a challenge without free hands, as would carrying, whether it be food, firewood, or children.

So you can keep your eight legs, Mr. Spider, and I’ll stick with my two. Your arachnid abilities may grace you with unusual gifts, but it only takes one of my two feet to squash you like a pancake.

Post Script - I would never dream of stepping on a spider...

In case you didn't get enough.

My Father's Daughter

Here’s a thought: if the sperm that created you had come in second in the race to the egg, you would be an entirely different person. Think about it. Among the million or so sperm vying for that egg, the one that contained the recipe for you won, and if any other tadpole had gained entry, you would not be who you are. Quite a gamble, procreation.

As Father’s Day approaches, we naturally think of our dads. Which got me thinking about the process of conception and the traits a father passes on to his children. Man, was I lucky.

First and foremost, there’s the brain. I was fortunate to have a very intelligent father, and he exploited his intelligence to achieve great things. He was born and raised in Mississippi, the son of a prominent architect. But when he was still a boy, his father left to start a new family, leaving him and his mother behind. So he dropped out of school and went to work.

Realizing the grim future in store for a Mississippi kid with a ninth grade education, he enlisted in the Navy when he was just sixteen. And once he left the south, he never looked back.

That young, uneducated sailor went on to travel every corner of the globe, complete a master’s in theology from Northwestern University, and achieve the rank of Captain. All of it through sheer force of will.

He is the reason I pushed on for a PhD. In fact, he’s the reason for much of what I’ve done in my life, for he represented the pinnacle of success, the example of what hard work and hard-headed determination can achieve.

But conception is like life; we must take the bad with the good.

Aside from determination, he also passed on some less-than-desirable traits. For instance, that same hard-headedness, which can border on stubborn; a deep and abiding love of gin; and above all else, a temper.

My father’s temper could go from zero to sixty in a matter of seconds; a trait which in my case has fortunately mellowed with time. Although my father was a chaplain and a man of God, he could swear like any seaworthy sailor. Politics, the economy, or criminal activity would set him off and he would launch into a tirade, cursing all of civilization, damning human weakness.

But he was also one of the funniest individuals I’ve ever known. He loved to laugh and my fondest memories are of sipping martinis and listening, enthralled, as his stories unwound. Like when his ship was torpedoed, plunging him and his crew into the dark depths of the Pacific. And how his commander had silenced him with, “SHUT UP SAILOR, WE’LL GET TO YOU!”

Dad was also a philosopher. His world view was an intriguing blend of religion, philosophy, and the hard life lessons of his youth. He had several famous sayings, such as, “If it’s worth doing, it’s worth overdoing,” a creed he employed whenever he ordered Chinese takeout. Or his other motto, “Why do today what you can put off until tomorrow?” which is ironic, considering all he achieved in his lifetime.

He spent forty-two years in the Navy and survived two wars – a feat no man can endure without being forever altered. But his cynicism was balanced by a love of laughter, a warmth of spirit, and a clever mind that never failed to see the humorous side of life.

My father is gone now. A slow-growing tumor bloomed deep within his frontal lobe, dimming and eventually snuffing out that most vibrant of personalities. I still see him in the mirror. I share his eyes, the shape of his face, and his strong, white teeth. But his most important traits reside within me, for he graced me with a curious mind, steely determination, and a will that has sustained me through every crisis in life – one of the hardest being his death. 

To all the fathers out there, I wish you a warm and wonderful Father's Day.

I See Dead People...

It happens as it always does, whenever I pass through that particular intersection. As I cross the lanes of traffic, I think about the dead girl.

I’m in Orlando for the weekend, visiting family and friends, returning to all the places I love in the city where I’ve spent so much of my life. I moved here when I was twelve, left when I was thirty-six, and spent thirteen of those twenty-four years as a firefighter/paramedic before moving on for a PhD. And I find when I come home, the city is haunted with the ghosts of my past.

As I navigate the city’s streets, scenes from my life as a medic flash before me in vivid detail. For instance, that intersection I mentioned.

I was a new medic, working grueling hours on the ambulance, when a young pedestrian tried to cross the many lanes of traffic, only to be taken down by a semi. Her body was defleshed from the waist down, a condition known as “degloving,” and I can still remember the heat radiating off the pavement, the stench of the truck’s smoldering brakes, and the roar of nearby traffic as we wrapped her shredded limbs.

There’s the schoolyard where my partner and I performed CPR beneath the gawking gaze of schoolchildren. The sidewalk where I tried in vain to staunch the flow from a suicidal gunshot wound to the head. The strip mall, where the young man set himself on fire. And the trauma center to which I delivered countless patients, victims of the city’s unrelenting violence. My brain is a virtual card catalog of tragedy.

I know why this happens. These memories are part of my past, forever etched into my psyche. The bigger question is how it happens. How does the brain pull forth memories buried deep within the subconscious?

It turns out neuropsychologists have been hard at work studying the processes involved in memory retrieval.

It all starts with retrieval cues: clues or prompts that trigger the brain to recall information. But it’s the type of retrieval cue that determines just how the brain pulls forth long-buried events.

Recall involves the straightforward retrieval of information, such as answering a simple question. There’s little work involved and the information simply pops up when prompted. Recollection requires a bit more effort. Your brain reconstructs the memory by pulling together bits of information, such as clues or partial memories, reassembling them into a greater whole.

Recognition retrieval occurs when your brain latches on to something familiar, like selecting your favorite dish from a menu. And finally, relearning is just as it sounds – retrieving information you have learned on some previous occasion, which often results in stronger memories that are easier to recall.

But where do these memories reside?

The brain stores memories in one of two ways. Short-term memories are processed in the prefrontal lobe, that clump of brain located just behind your forehead. The short-terms are translated into long-term memories in the hippocampus, a small horseshoe-shaped structure within the limbic system that rounds up memories from various sensory regions in the brain and binds them into a single memory episode. Over time, the neuronal connections associated with that memory become fixed and can be replayed at will.

The hippocampus also helps solidify the connections that form our memories and each memory serves as an index for our recorded thoughts and sensations. Through functional MRI, scientists have been able to observe the brain as it reconstructs memories. And as each memory is recalled, different regions of the brain light up as various sensations and thoughts are replayed.

So when I return to Orlando, memories of my patients reemerge, triggered by the sights, sounds, and smells of the city. I recall their faces, their injuries, and their pain, and once again I experience the intense emotions they evoke whenever they resurface in my mind.

These memories are relics from a previous life, carved into my subconscious, and forever part of who I am. 

"Memories are bullets. Some whiz by and only spook you. Others tear you open and leave you in pieces."

                        - Richard Kadrey, Kill the Dead