Now you See It, Now you Don’t

"Visual" represents Area 17; Surrounding red cortex is the Occipital Lobe

You’re eyes don’t see; your brain does.

You believe you see because your brain tells you it is such.  You feel pain because your brain too tells you such a feeling exists.  This can be repeated for all sensations, visions, and perceptions of the world.  Don’t believe me?  The way scientists and physicians have been able to conjure up such theories is through the misfortunes of others.  It is through the deficits of our patients that we begin to unravel in the intricacies of our mind.

You are probably under the false impression that your eyes determine if you believe you see.  The eyes may provide you “sight,” but it does NOT provide you vision. Unfortunately for the less science-inclined, I must bored you with a bit of central visual pathways.  The basic premise is that your eyes contain Retinal ganlion cells (RGCs) (neurons) that project to the Lateral Geniculate Nucleus (LGN) in your thalamus  (this area in your “brain”) to Area 17 (aka Visual Cortex).

Recap:

Eyes –>RGCs –> LGN —> Area 17

Back to the original point.  Let us pretend for a moment (and for many unfortunate individuals it is not a matter of pretending) that you had a lesion to Area 17 and Area 17 alone.  Would you consider this person blind?  By now you are well aware that I never pose simple questions, so I must address it from two perspectives – what the patient believes and what the physician observes.

Patient: The patient believes he/she is blind.  We will call this functionally blind (it will be made apparent why this is the case later).  There is absolutely nothing you can do to convince the patient otherwise.

Physician:  If the physician were to put this patient through a series of tests, he would discover that he/she can still see light through their normally functioning eyes. Big deal, right? Right! These patients were shown random light flashes and were asked to press a button every time one appeared in their visual field (similar to the ones you’ve probably taken part in at an eye exam).  What do you think the patient’s response was? “We’re blind you idiot!” (Perhaps, I shouldn’t put that in quotes, but you know they were thinking it).  The physicians in their cool calming voice simply told them to play along and push the button whenever it felt right.  Well lo and behold, what did they find?  The patients perfomed BETTER than chance.

Therefore, they believed they were blind, but in “reality” they had full vision.  You can even placeobjects in front of these people and they will unknowingly step out of the way to avoid them.  This demonstrates that visions is a cortical construct and that Area 17 is responsible for conscious awareness.  Mind boggling, isn’t it?

You didn’t think I was going to leave you on that note?  I can’t show you one end of the spectrum and have you believing their isn’t another disorder to counterbalance it.  Let us now discuss patients who have a bilateral destruction to their occipital lobe.  As you see in the images above, they are (almost) completely responsible for vision.  These individuals are in fact blind.  Well, what’s so extraordinary abou them?  If you were to ask them if they were blind, they would DENY it!  These patients believe that they have vision.  When put through similar tests as the patients with lestions in Area 17, they actually did at or worse than chance. Clearly, there is a disconnect.

Have I stepped you into a world of unimaginable ambiguity and chaos? Well, if that’s what you perceive, who am I too tell you otherwise?

The Noncompliant Medical Student

I sit patiently in the waiting room, tapping my pen, sifting through the potential questions he may ask and the potential lies I may conjure up in response.  They call my name; I see eyes shifting in my direction as I solemnly walk through those menacing doors.  I am placed in a cold plastic chair, required to put on a bib, seat reclined, and asked to relax.  Yes, you have done quite a splendid job in making me feel comfortable enough to relax in this daunting and isolating environment. “He’ll be with you in a moment,” the assistant proclaims.  I shift in my chair again, hoping that this change of position will speed up his arrival.  I have places to be, errands to run, facebook statuses to check, time to waste…waste anywhere else but here.

Finally, the man of the hour arrives, stretching his hand out in a grand gesture of superiority as I remain awkwardly fixated in my chair and bib.  So, the games begin.  He opens my mouth wide, pokes and investigates around like a child picking at his food attempting to avoid his vegetables.  He sits back up after making his evaluation.  He stares at my judgmentally.

“How many times do you floss?”

“3 to 5 times a week I respond.”  We both know I am lying.  Well, I am half-lying; there was that one week I remember being particularly good about it.  Yes, 3 to 5 times seems appropriate.  It is enough of an exaggeration to get only a slight reprimand rather than the full-blown frown of disappointment.

“You’re gums are bleeding at the touch.  You must not be doing it right.  Are you brushing properly?”

“I have been brushing morning and evening everyday for two minutes; I even time myself.  I think it’s my genetics.  My dad has the same problem too; we just have more bacteria in our mouth than the average person,” I respond in a single breath.  It is true; I am particularly good at brushing, though two minutes may be a slight exaggeration.  It seems extremely unfair that some people can have such little regard for their teeth and never have the problems I encounter.  I am unbelievably frustrated with dealing with these darn teeth.  First the retainers, than the braces, than the retainers again, than the cavities, than the fillings, than the root canals.  When will it ever end?  Can they not just yank them all out and give me Veneers?

“Let me show you how to properly brush and floss.  Here, hold the mirror while I demonstrate on your teeth.”

Great, for the umpteen time you are going to teach me once again to perform a task I have been doing since the age of three.  By all means, continue humiliating me and directly demonstrating how incompetent you perceive me to be.  Do you know how much you waste when it comes to flossing?  That is money down the drain.  On the other hand, if you fail to floss, you need more frequent dental appointments to fix the damage you have caused.  Who does not love a good Catch 22?

“Get it?  See how easy it is?  If you don’t take care of them, some of those smaller problems will turn into cavities, and you’ll need fillings.  All right, it was a pleasure (firm handshake), see you in six months.”

Does he not know I know it is easy?  It only takes an extra 2 minutes to floss, but sometimes I am in a rush, and it is such a hassle, and I rarely see the immediate effects of not performing it…well, unless there is spinach stuck in my teeth.  How embarrassing!  I am so educated; I should know better.  I will be better at it.  When I return home, I will floss immediately…we all know that will only last for a week until I fall back to old habits again.  What right do I have to expect my patients to listen to my orders, when I am the noncompliant medical student?

The above encounter is a familiar scene for most.  It is for that same reason I will attempt to use it as a means to providing a new perspective on living with diabetes.  In no way is this to delegitimize the seriousness of the disease and the struggles that patients face on a perpetual basis.  Rather, it is my sincere hope that by relating a personal experience like a dental cleaning, society may better understand a pandemic that is quickly sweeping the nation.  We often wonder why those with chronic illnesses do not do a better job in managing their own health.  Why are they so noncompliant when they know that what is at stake is their very life.  It is not that they are plagued with suicidal tendencies or are ill educated about the subject matter, although this may hold true for some, but rather there is a buildup of frustrations.  This ongoing battle with a foe that your peers and even society at large cannot truly understand can be overwhelming and expensive.  It is no surprise that many patients lie about taking their insulin shots or checking their blood glucose because the tremendous amount of guilt and judgment that is passed upon them.  We expect that something that takes only minutes to do and can sustain a healthy life would be innate and clear cut, but when we fail to take the two minutes to floss our teeth, how can we expect them to take countless injections and needle pricks?

Is it unfair?  Absolutely.  Can their situation be changed?  Not currently.  Can we change our attitude towards the diabetic population and the chronically ill at large?  You bet your normal blood glucose we can.

Trimming the Fat: A Story of Judgment

Family, Healthcare, and Medicine

Family –> Health card –> Medicine.

Family, Heat? Car? Medicine?

Fail Eat. Care? Die?

Feat. Cared, i.e…

Fat. Care? Die.

Fare? Die?

Free.

If Cadavers Could Talk

Having just entered the enchanted world of medical school, I am in the delightful disposition of sifting through endless articles of the ethics of science and drawing brash conclusions from them. It was a fortunate coincidence (or perhaps divine providence) that I had recently completed a week course of religious discourses (with a focus on Islam) and am now able to apply that new perspective to an old debate. Though I have previously focused on what is considered hard science, I am going to peer down at this from a new lens. The hope is that I will set a foundation for what is sure to be a tumultuous course ahead.

To quote Julie Andres, “Lets start at the very beginning:” day 1 of medical school.

I don’t think anyone would doubt that every American medical student has been exposed to the Hippocratic Oath (the pledge of ethical allegiance by doctors). How many, however, have encountered “The Prayer of Maimonides,” a Hebrew prayer recited by physicians before seeing a patient. The relevance of this piece in this discussion is not so much its message, but rather, its historical context. A quick blib from our professor informed us that Maimonides was a Jewish philosopher who lived in Cairo from 1166 onwards. Though this date may be unfamiliar to the masses, a little investigative research indicated that it falls during the Fatimid Period, a period of religious freedom in Egypt.  This period is also referred to as the Golden Age for Ismaili Muslims. Growing up in the United States, there is rarely mention of the vast contributions in science, literature, medicine, architecture, etc that Muslims have invested the global bank of knowledge, and it was refreshing to see it recognized. It begins to indicate our acknowledgment of  the diverse society in which we engage in. Let us move beyond religion from a micro scale and discuss it from it as a search for truth.

The second peace of literature discussed came  from a reputable and award-winning immunologist Lewis Thomas, M.D. (1932-1993). Here is an excerpt from his 1962 article “The Meaning of Science in Medicine.”

Like it or not, if man continues, as he will, his ceaseless and, on balance, almost infallible inquiry about everything related to himself, he may eventually, a thousand years or more from now, see God as whole and clear as Augustine hoped to. It may not look like God, and perhaps other names will at first be given to Him, or a Number, or a Code. But everything will have derived from Him, and He will contain all the meaning of things.

Whether you are religious or believe in some greater truth, it is undeniable that this is the prevailing belief of  modern day. How to conform or dissipate that view is quite another story.

Perspectives are evanescent. The search for them is incessant. The ability to search is everything.

As we continue to engage in medicine from the field of sociology, my writing will have those biases, but it will not be too long before a mention of pulsating veins and firing neurons resurface.

Apples and Oranges

I want to take a moment to address an issue of particular interest in present times, gay marriage.  I have chosen to approach this topic from a path of rationality rather than untamed passion.  Let us define gay marriage in its simplest of form, the union between two members of the same sex- a man and a man or a woman and a woman.  However, it is this very point I wish to put into question.

What defines gender?  Is it genetics?  Anatomy?  Perhaps personality?  It is the very notion of categorizing people into two distinct collections that adds to the trouble brooding ominously in the air.  For the majority of the population, these components are in harmony.  We, however, are not dealing with the majority.  If inconsistency comprised the majority, than by nature, our self-governance would be accounted by this.  We are always dealing with the minority, whether imaginary or tangible.  It is derived from our needs to find meaning and purpose to the foreign.

So again, what defines gender?  Think you are up for the task of labeling, then take a gander at the following examples:

(Note: XY = genetically “male” & XX = genetically “female”)

1.    An XY is being circumcised but the surgeon slips and cauterizes his penis.

2.    A transsexual, a person who identifies w/ the other sex and has transitioned to the other sex by means of hormone treatment or sex reassignment surgery (An XY with a clitoris or an XX with a penis)

3.    Congenital adrenal hyperplasia (CAH) = XX chromosomes that possess a genetic defect in corticosteroid synthesis (cannot produce cortisol), which leads to high levels of androgens prenatally because the brain is under the assumption the body needs cortisol.  Since the enzyme to convert androgens to cortisol is defective, it produces increasingly higher doses of its precursor, androgens.  It is eventually converted to testosterone, rather than the targeted cortisol.  This leads to androgenized genitalia, such as an enlarged clitoris and fused labia.  CAH patients tend to play more with boys’ toys, are more active, engage in rough-and-tumble play, labeled as tomboys, and attracted to women.

I challenge you to question a rule about a minority that was created within the constraints of its majority.  Trying to compare apples and oranges… looks like we are all FRUITS in the end.

I Want To Hold Your Hand

It is the sense I value least yet use the most.  It is in constant contact with my environment and provides me with my sense of reality.  I can be easily misled by smells, tastes, sights, and sounds, but the simplicity of a touch can glide me over a spectrum of emotions without losing their sense of meaning.  It is the most pleasurable of all the senses but also the most painful.  I must also mention that this pleasure is no way a sexual reference, but in the broader sense of an affectionate hug or temple massage.  It has the unusual ability of providing comfort, hope, and strength.  How is such an unusual property possible? ”Museums and art stores are also sources of pleasure and inspiration. Doubtless it will seem strange to many that the hand unaided by sight can feel action, sentiment, beauty in the cold marble; and yet it is true that I derive genuine pleasure from touching great works of art. As my finger tips trace like and curve, they discover the thought and emotion which the artist has portrayed.” – Helen Keller

Necessity’s Nagging Mother-In-Law

         The debate between nature and nurture has grown as ambiguous and mutated as my genes themselves.  The answer is obvious; genes provide us with the fabric and thread, while our environment provides us with the creativity to convert the cloth into clothing.  With questions of visual development, researchers have touched on the aspects of what, when, where, and how.

What: Development of a normal visual system

When: Embryo to Newborn Infant to Adult

Where: Eyes, Optic Nerve, and Brain (Visual Cortex)

How: Neurons, Receptors, etc

Now the why question is the true fascinating inquisition that tends to scurry behind his peers.  Why do our genes dictate certain proteins to be synthesized to put in place the vast complications of the visual system?  What is the driving force behind this mechanism?  Why did Ben Underwood’s genes select for echolocation over vision?  In what capacities has this limited our interaction with our environment?  Perhaps I need to set-up an interview through God’s publicist to have these questions answered.  In the meantime, however, I will hypothesize possible theories and explanations. 

         Obviously, our genes are accompanied by a set of instructions similar to the one associated with its predecessor.  When this basic structure is put into practice, it begins to unfold the limitations, which places the system into over-drive, attempting to repair and renovate gaps to produce the most efficient machine possible.  If you were born and raised in a dimly lighted environment, such as a cave or a movie theatre, you would have a far greater number of rods than cones in your retina.  Now if I were raised in total darkness, yet objects could be differentiated by heat (a concept utilized by snakes), then would I be able to see infrared radiation (IR)?  Since it would be unethical to test this on humans, it cannot be faithfully answered.  However, one could theorize that some sort of mechanism would develop to allow this transition to occur.  Necessity may be the mother of invention, but Purpose is her nagging mother-in-law.

Context, Context, Context!

                        

         All discussions of senses are meaningless unless one important concept is understood: perception is context dependent.  From mirages to Hermann grids, it is the environment in which the illusion is fixated that gives its remarkable effect.  This understanding reveals a far greater insight than expected.  It exposes the true potential of the human mind.  We are able to surpass the simple abilities of detection and discrimination and enter a world of identification through the complexities of Brodmann’s areas.  Regardless of the manner in which we perceive an object, we still have the phenomenal ability to recognize it in different times and space.  This concept is reflected in Epicurean epistemology, a philosophy about the universality of words and ideas.  For example, we are able to identify a new acquaintance as a human being even without being given any prior notification.  We possess a preconceived notion of the concept of a human being.  This also applies to your ability to categorize your Cocker Spaniel and your neighbor’s Husky as dogs.  It is a task we typically undertake subconsciously but are sometimes in quite a shock when we have done so wrongly.  (I.e. When you tried to feed your neighbor’s dog, and it turned out to be a wolf…woops!)

         Overall, we should be quite impressed with our ability to store tremendous amounts of spatial and temporal data and recall it on cue.  It is how you are still able to recognize your childhood friends at class reunions or your parents when you come back from a summer abroad.  We are in part able to perform these miraculous feats by analyzing our environment.  We assume that our Caucasian friend has not turned black in front of our eyes, but he has just walked under the shadow of a large building.  We are able to deduce this through our experiences of both light and the improbability of pulling a Michael Jackson in the blink of an eye.  Just as location is important to a realtor, experience is the biggest selling factor for perception. 

Spread Out too thin

When we have over-committed ourselves in extracurricular activities, schoolwork, and other hobbies, we claim that we are “spreading ourselves out too thin.”  This analogy is both accurate and relatable to the typical college student.  More importantly, it has clear associations with the complex understanding of the visual system and its correlating receptive fields.  The larger the receptive field, the less precision or narrow detection range is associated with it.  On the reverse side, smaller receptive fields are more discriminating and refined.  It is obvious that where the analogy overlaps is with the size of the receptive field, in which spreading too thin is the equivalent to a larger receptive field. 

The next question to ask is about the necessity of having one receptive field size  over another.  Why have we not been selected for an enormous amount of small receptive fields so we can detect finer and finer detail?  Why have these superman traits of remarkable vision not crept into our gene pool?  To make another analogy, without sounding too much like Dr. Seuss, the variety of receptors allow us to distinguish the forest from the trees.  The importance of detailed differentiations is both essential and beneficial, but without having the ability to analyze the environment from a greater perspective, they prove futile.  Without this mixture of dimensions, poor Seurat’s masterpiece would be nothing more than a palette of tiny dots. 

Doctor, Feel My Head. I think my Wavelength is too high

     

It would be quite repetitive for me to engage in another discussion about mirages and optical illusions.  Yet, it is extremely important to understand the limitations of our visual field in the context of our active lives.  We are constantly inundated with a plethora of sinusoidal wave functions and geometric representations, and we must somehow compact this into a streaming video for immediate use and a painting for later storage.  The main limitation of the eye, however, is one that is commonly overlooked yet frequently yearned for.  It is the ability of the eye to see an extended region of wavelengths.  Humans can only detect wavelengths in the region of visible light, spanning from 400 nm (purple) to 700 nm (red).  There is a world of vision that far surpasses this small range, constituting gamma rays, X ray, UV rays, IR, microwaves, and radio waves. 

         Snakes, for example, have a phenomenal ability to capture its prey by detecting differences in body temperature using infrared vision, developed in the trigeminal sensory system.  Since we have no true comparison to what they perceive, we assume that it is similar to a color gradation in which higher temperatures are represented by colors such as red and yellow, while cooler areas are represented by blue and purple.  It is as if these creatures do not detect physical characteristics like humans, but rather, it is as if they detect the presence of life.  This is an obvious stretch of the philosophical domain, but it somehow passes the message.  We are limited in our perception of the world by our perception of our eye.  If we were to mutate into beings with a greater range of wavelength acuity, our entire worldview would need to be reevaluated.  Aspects that were once hidden to us by our own inadequacy would suddenly be evident and obvious.  Houdini’s amazing feats would turnout to be simple child’s play.  Our definition of beauty and health would drastically change.  With greater intuition, there is greater confusion.