Salt really does get under your skin

Salt. It — or rather its sodium ions — are essential for animal life. The Romans used salt to pay their solders, salarium argentums. Ants and termites in tropical forests in the Amazon >100 km inland from the sea have smaller populations than those nearer the coast because they get less wind carried sea salt. Adding salt and sodium can increase their numbers seven-fold. Evolution has given us a taste for sodium ions. Cooks flavor our diet  with salt and we add our own.

But salt is also toxic in excess–ask any bacteria or fungi that seeks to grow and multiple on salt persevered meat or pickle. Brine is usually fatal to life unless cells can find away to protect themselves from its osmotic pressure that "drinks" water out of them. The average diet gives us a massive overdose–15 grams rather the 6 grams we need. How do we get rid of the unnecessary and dangerous sodium ions?

Urine and sweat was the traditional answer. Sweat can remove large amounts. In hot climates hard work can cause the body to bucket out sweat–up to 12 liters a day (though 8 to 10 litres are more normal). With that goes salt –  estimated depending on researchers to be 12–15 grams or even 25 grams (nearly an ounce). But this salt and with it sodium removal by sweat is a byproduct. Traditionally the answer was that the real heavy removal work was done by the kidneys and that was then flushed down the drain.

Now that story has changed. Our bodies also have a previously hidden way of removing excess sodium ions; storing them under our skin. Or rather into our subcutaneous lymphatic system its interstitium fluid (extracellular fluid between tissues).

The lymphatic system is where our body collects the fluid that bathe our tissues so it can be put back into circulation. The lymphatic system also works as the eyes and ears of the immune system. And now it turns out it is the body's salt salter. Excess sodium ions get temporarily stored by being bound to proteins called proteoglycans and glycosaminoglycans. This makes them osmotically inactive.

Not that hiding salt away is what this biosalt salter was evolved to do. Our ancestors faced the opposite problem to us of excess salt–deficiency. Animal bodies that could create a backup buffer had an advantage over those that could not store sodium ions. Animals face the same problem with energy–we are advantaged if we can store it from the times when it is available for when it cannot get it. The answer for energy storage is expanding adipose fat cells. With salt the body faced a similar storage problem and evolved salt salter proteoglycans in the subcutaneous lymphatic system.

Benvenuto Cellini's Saliera (saliera is Italian for salt cellar). This is sometimes called the "Mona Lisa of Sculpture". It shows masses of skin thus suggesting that Benvenuto "appreciated" 470 years before modern science the key link between skin and salt.

That we can biologically squirrel away sodium in this way is no small discovery. The kidney's regulation of sodium links to its regulation of blood volume and through this blood pressure. We are diet aliens to early humans. They eat  with  no salt on the table or in the kitchen a sodium-poor but potassium-rich diet of wild not factory processed meat and veg. (Potassium is an element next down in the periodic chemistry table and in some ways very like sodium–the chemist Dalton gave them very similar symbols as shown left and right to reflect this fact. However in the body they have very different roles its biochemistry). Our kidneys evolved to keep sodium and remove potassium ions. They now face the problem that we eat lots of hidden and not so hidden sodium. How does the system of balance sodium and potassium ions work in us with our evolution alien diet that is sodium rich and potassium poor? It seems that a physiological "bug" is exposed that results in our body's getting rid of too many potassium ions. This causes increased contraction of vascular smooth muscles and changes to the cerebral control of blood volume that ups blood pressure.

Knowing that sodium gets buffered under our skin presents us with a more complex story. For a start it suggests that our kidneys do not face the fall impact of our salt rich food–our skin helps us stop poisoning ourselves with the stuff. The storing of excess sodium is also odd. If experimental animals eat a high salt diet the lymphatic capillaries expand (see the green thicker lines on the right) due to the activation of macrophages (a type of immune cell). Stop those cells getting active and with that this lymphatic capillary expansion and blood pressure goes through the roof.

So the newly discovered salt salter under our skin really matters to us modern people. Thanks to our salt buffering subcutaneous lymphatic system, salt is changed from being a toxic substance that would kill us by dramatically raising blood pressure into a moderately toxic one with which we can live. 


Marvar PJ, Gordon FJ, Harrison DG 2009 .Blood pressure control: salt gets under your skin. Nat Med. May;15(5):487-8.

Machnik A, Neuhofer W, Jantsch J, Dahlmann A, Tammela T, Machura K, Park JK, Beck FX, Müller DN, Derer W, Goss J, Ziomber A, Dietsch P, Wagner H, van Rooijen N, Kurtz A, Hilgers KF, Alitalo K, Eckardt KU, Luft FC, Kerjaschki D, Titze J. 2009 Macrophages regulate salt-dependent volume and blood pressure by a vascular endothelial growth factor-C-dependent buffering mechanism. Nat Med. May;15(5):545-52.

Rabelink TJ, Rotmans JI. 2009 Salt is getting under our skin. Nephrol Dial Transplant. Nov;24(11):3282-3.

Kaspari M, Yanoviak SP, Dudley R, Yuan M, Clay NA. 2009. Sodium shortage as a constraint on the carbon cycle in an inland tropical rainforest. Proc Natl Acad Sci U S A. 106(46):19405-9.


The color-blind can be celebrated artists

No surprise that the French etcher Charles Meryon was color-blind. His Vampire (Le stryge), 1853 above is black and white: as a young man Charles realizing he was color-blind, he decided to focus upon exploring the monochrome world of etching. But what about the portrait below by the three-time winner of Australia's Archibald Prize, expressionist painter Clifton Pugh?

Pugh was a protanope like his brother and grandnephew. He failed the color vision test when trying to enlist in the Australian Navy. As a protanope he lacked long-wavelength retinal cones that allow more fully color able people distinguish between  greens, yellows and reds. 

As a result he would have seen his Portrait of Judith 1976 above slightly differently from nonprotanopes as below.

So how did he do it? Perhaps we are a little quick to assume limited color vision is no vision. In the case of Charles Meryon he side stepped his problem with the black and white of etching. But Clifton Pugh seems to have refocused upon the colors he could see. Perhaps he looked at those tubes of green, red and yellow paint next to his easel and saw not  similar colors with different names Olive, Ochre, Safron, Gold, Ruby, Vermilion–but a challenge. These paint tubes contained something visually rich to others in a way that were not to him. Is that not a challenge to explore the secret world of those tubes of paint? "What a beautiful yellow". "What a peaceful green". One could well imagine him taking a greater interest–at least occasionally–in what was just beyond his vision. Disabilities can often be opportunities that drive creativity–as noted by the theoretical psychologist, Nicholas Humphrey in his piece "Deformed transformed". The better ability to hear is well known with the blind but the color blind might have visual advantages–though it is unresearched it seems that many bird-watches are color blind and it is possible that impairing the ability to distinguish color might make them better able to see the visual differences in textures, luminosity shading and movement needed to spot and identify birds. Indeed dichromats that have impaired medium-wavelength retinal cones can have better visual acuity and ability to detect fast oscillating visual stimuli.

Another possibility is that his remaining medium and short-wavelength retinal cones allowed Clifton some sense of the green, red and yellow hues–that the above "decoloring" of his portrait to "protanope vision" does not actually capture what he saw. The missing long-wavelength retinal cones have their peak sensitivity is in the greenish-yellow 564–580 nm region of the spectrum. But this color area is also in the 450–630 nm range of the medium retinal cones. It is only a small part of the spectrum–630-700 nm–that is exclusive to the long cone's 500–700 nm range that would have been entirely lost to Clifton Pugh. It is colors in this small spectrum that are used to test for being a protanope. But such tests and the lived normal vision of seeing natural scenes are different. Tests may be useful for detecting where vision may be defective in regard to artificial stimuli such as warning lights and thin colored lines on paper maps. But is this limitation so dramatic for all color experiences? The human eye usually sees the world as a complex shading of hue and brightnesses. An artist holding their palette when working up a portrait on a canvas is in a very different situation to judging whether a number appears amongst the dots of a color vision test as on the left? (Note due to the variability of color display on monitors those without protanope may not see the hidden digits.) Clifton seems to show it is not. Color vision tests should not rule out people going to art school or art galleries.


Cole BL, Harris RW (September 2009). "Colour blindness does not preclude fame as an artist: celebrated Australian artist Clifton Pugh was a protanope". Clin Exp Optom 92 (5): 421–8.10.1111/j.1444-0938.2009.00384.x 19515095

Humphrey, N. (2002), DEFORMED TRANSFORMED   The Mind Made Flesh: Essays from the Frontiers of Psychology and Evolution, chapter 14, pages 165-199. Oxford University Press.

For some dichromats having better visual acuity see Jägle H, de Luca E, Serey L, Bach M, Sharpe LT. 2006 Visual acuity and X-linked color blindness. Graefes Arch Clin Exp Ophthalmol. 244(4):447-53.

For them having better temporal frequency resolution see Sharpe LT, de Luca E, Hansen T, Jägle H, Gegenfurtner KR. 2006 Advantages and disadvantages of human dichromacy. J Vis. 7;6(3):213-23.


frozen escalators and human origins

Ever walked on an escalator and found that it was "frozen"? You stumble and feel unsteady as you attempt to walk down or up its "dead" steps. That unsettling feeling tells us something unexpected and important about our normal walking–and the complex neurology in our brain that makes us human and unique.

Walking is much much more than the apparently obvious activity of repeatedly putting one foot before the other. For a start the way we walk is different from that of our close cousins the Chimps. They do not normally walk upright like us with a stiff leg gait and vertical upper body but with bent-hips and bent-knees (see left photo below). If we walk like this, it is when do Groucho Marx impressions or when we are on soft surfaces–it also makes good sense on flexible tree branches  since it minimizes steps creating a destabilizing wobble underfoot. But we normally do not walk like this (Groucho looks funny) but chimps do it all the time even on firm ground.

Macaque monkey trained to walk with stiff human-like postureThis body bendy walking has a great energy cost. Bent limbs drain energy though the need to maintain muscles in isometric tension: dogs hold their limbs bent when standing. The mere fact of that increases their energy consumption 70% more than when laying down. Humans in contrast  use only 7% more energy standing than when supine. Similar efficiencies exist when walking with a stiff upright rather than a chimp-like bent body. Not only is holding the body erect more efficient but the bent-hip bent-knee walking does not reuse the energy of the swing foot. Because the leg is stiff, it raises up the hips a few centimeters (see the stick person below on the right) which then  can power swing forward of the other leg with a fall. In chimp or Groucho walking the hips stay level (see the stick walker on the left below).

Part of the explanation why humans but not other animals walk like this is that it takes a lot of skill. Macaque monkeys (see right photo in white shorts above) in Japan are taught for entertainment purposes to walk in a stiff manner–but it takes years. The first thing is to patiently teach them to balance themselves statically in an upright fully erect stand. After mastering that they can start to stiffly walk like us. Even so they never fully align their bodies in the column anatomical alignment with which we carry our bodies–though that is perhaps to do with the limited adaptability of their hip and knee joint anatomy. 

Brains are important: the way we walk requires a robust sense of balance–and that needs both big brains and lots of practice particularly if walking is to be combined (as normal with humans) with other activities that complicate balance like carrying mobile objects (think of protesting babies).

Walking because it is so easy tricks us to think there is not more to it than, well, walking. But we are in fact engaged in a dance of our whole bodies that is needed to keep ourselves  balanced as an erect vertical column–and as importantly–keep at the same time our head and eyes and our vision steady. Our bodies to control its center of gravity make all manner of adjustments in advance of each step. That not only keeps our bodies vertically upright and in balance but also aids the efficiency of walking by using slight but controlled center of gravity instability to aid push the body forward.

That adjusting is fined tuned in regard to challenges that our brains expect to encounter when we walk. The broken escalator reveals how subtle that fine tuning can be. We quickly adjust how we walk on working escalators to take account of the momentum difference caused by its forward movement. And that experience–research shows–is automatically used to adjust our balance. That anticipation even acts before we put our foot on the escalator–if we "know" in advance that its forward momentum is there to counteract.

So those anticipatory adjustments get activated when we get on escalator and the result is that we feel unsteady when it does not "move" as our bodies anticipate. Our balance is upset since it is adjusting our bodies to a moving escalator that is not in fact moving.

The broken escalator effect is a small window to a world that is normally hidden to us. We balance as narrow based vertical columns so easily either when standing, walking or running that we assume that we can do nothing but be as we find ourselves–upright and erect. Yet this state is biologically unique to us. No other animal stands their whole body "carriage" vertically erect–those upright penguins and meerkats balance with their tails tripod-like. All other bipeds such as birds hold their thoraxes level or near so not upright into precarious columns. And we do it with anatomical alignment. Chimps stand semi-vertically–they lack the gravity line down their skeleton that we have from the base of our skulls down to our ankle heel. That skeletal vertical alignment makes it  easy for us to stand for long periods without strain and walk in a stiff manner–gravity and compression holds us not muscles engaged in active isometric work keeping  limbs and body bend.

That we hold our bodies in this way is thanks to the extraordinary smart balance that comes from our large brains and their very prolonged immaturity. Children may seem to walk and stand but they lack the robust balance agility that comes with being an adult. Young humans are still refining their balance as walkers even into adolescence. Children notably lack the adult robustness to pushes and shoves. So it is perhaps not surprising the way we walk with our bodies vertically erect is unique–no other animal has the big brains nor the prolonged period of immaturity to master the superbalance which makes it safe.

And so the broken escalator shows like a rock fall exposing a fossil a hidden side to our origins. It reveals the incredible smartness of our walking and upright vertical balance. Of course our superbalance does not end with walking. Human bipedality allows much more than simple walking and running. Look at Nureyev or Federer–we have a capability toremain on our two feet in complex quick movement that defies science to understand. No engineer knows how to make a robot that can double rond de jambe en l'air or sprint into an accurately played high backhand volley.  Even simple humanoid robots attempting anything other than a slow walk crash themselves on the ground (the robotists carefully make sure we see only their successful walking).

That unsteadiness on the broken escalator tells us we are rather more special than we realize.

Sources/further reading

The broken escalator phenomenon. Aftereffect of walking onto a moving platform. Reynolds RF, Bronstein AM. Exp Brain Res. 2003 Aug;151(3):301-8

In this site see my: Human origins, and bipedality, dexterity and speech/song

There is a pdf of mine: Respiratory, postural and spatio-kinetic motor stabilization, internal models, top-down timed motor coordination and expanded cerebello-cerebral circuitry: a review".

For just the section in the above on bipedality  here

Also see Skoyles. JR Human balance, the evolution of bipedalism and dysequilibrium syndrome.



A cup of strychnine can be nice

Caffeine is a molecularly similar to strychnine and acts upon the same neural receptors, which cause the latter's lethality. Oddly this makes them both in low doses stimulates.

Strychnine was taken to revise for exams, aid endurance in Olympic Marathons and prescribed by doctor as a tonic. It was the Victorian caffeine and high-energy tonic. 

That is not odd: strychnine and caffeine are similar molecules. They both block glycine receptors. The difference apart from strength–caffeine is much weaker is that caffeine also blocks another group of receptors – those for adenosine. But similarity of its stimulant effects with strychnine suggests that its stimulant actions might also be due to its actions upon glycine receptors.

Strychnine was an ingrediant of tonics such as Easton's tablets, Wampole's Preparation and Fellows’s Syrup of Hypophosphites. As recently as 1981 Brent Smith found that 41 commerical products in the US were available for human consumption including proprietary analgesics, digestive aids, cold remedies, cathartics, tonics, vitamins, stimulants, and sedatives. One of the tonics taken by Hitler contained strychnine. As Ronald McGarry and Pamela McGarry note

Another commonly prescribed medication, nux vomica (essence of bachelor button), contained strychnine, a highly toxic central nervous system stimulant. Given that “the bitters”was prescribed for a multitude of ailments, one wonders how many cases of strychnine poisoning there were.

Research by the famous psychologist Karl Lashley in 1917 found it enhanced the training done by rats in mazes. Medical students used it as a pick me up while revising with occasional problems as one Leondard Sandall, recalled in 1896 in a letter to the The Lancet.

Three years ago I was reading for an examination, and feeling " run down" I took 10 minims of strychnia solution (B.P.) with the same quantity of dilute phosphoric acid well diluted twice a day. On the second day of taking it, towards the evening, I felt a tightness in the "facial muscles " and a peculiar metallic taste in the mouth. There was great uneasiness and restlessness, and I felt a desire to walk about and do something rather than sit still and read. I lay on the bed and the calf muscles began to stiffen and’ jerk. My toes drew up under my feet, and as I moved or turned my head flashes of light kept darting across my eyes.. I then knew something serious was developing, so I crawled off the bed and scrambled to a case in my room and got out (fortunately) the bromide of potassium and the chloral. I had no confidence or courage to weigh them, so I guessed the quantity-about 30 gr. bromide of potassium and 10 gr. chloral-put them in a tumbler with some water, and drank it off. My whole body was in a cold sweat, with anginous attacks in the precordial region, and a feeling of "going off." I did not call for medical aid, as I thought the symptoms declining. I felt better, but my lower limbs. were as cold as ice and the calf muscles kept tense and, jerking. There was no opisthotonos, only a slight stiffness at the back of the neck. Half an hour later, as I could judge, I took the same quantity of bromide of potassium and chloral, and a little time after I lost consciousness and fell into a " profound sleep," awaking in the morning with no unpleasant symptoms, no headache, &c., but a desire " to be on the move " and a slight feeling of stiffness in the jaw. These worked off during the day. 28 March 1896. "AN OVERDOSE OF STRYCHNINE." The Lancet, 147(3787):887.

The mention of bromide is interesting because in Agatha Christie's first novel, The Mysterious Affair at Styles, the poisoning happens by the addition of bromide to a normally safe strychnine containing medicine to precipitate  to the bottom of a bottle where they get taken in a single, lethal dose.The medical student presumably took it to precipitate in the strychnine in his gut to stop further absorption.

It was one of the original performance enhancing sport’s drugs. At the 1904 Olympic Marathon, the US runner Thomas Hicks after 30 kilometer his manager following in a car administered 1/60th grain (approximately 1 mg) of sulphate of strychnine and repeated this a few kilometers later when Hicks tried to lie down. He finished the race in first place and then collapsed.

Caffeine and strychine molecules
caffeine strychnine

Duan L, Yang J, Slaughter MM. Caffeine inhibition of ionotropic glycine receptors. J Physiol. 2009 Aug 15;587(Pt 16):4063-75.

Doyle D. Adolf Hitler's medical care. J R Coll Physicians Edinb. 2005 Feb;35(1):75-82.

McGarry RC, McGarry P. Please pass the strychnine: the art of Victorian pharmacy. CMAJ. 1999 Dec 14;161(12):1556-8.

Pain S. Marathon madness. New Scientist. 7 August 2004. 46–7.

Lashley KS (1917) The effect of strychnine and caffeine upon rate of learning. Psychobiology 1:141–170

Smith BA. Strychnine poisoning. J Emerg Med. 1990 May-Jun;8(3):321-5. Jackson G, Diggle G. Strychnine-containing tonics. Br Med J. 1973 Apr 21;2(5859):176-7. 


Not all your bones are needed

The entire clavicle or any portion of it can be excised without causing any disabilityThis remarkable statement comes from a piece, "Expandable Bone" by George Curry and Sydney Lyttle in the American Journal of Surgery published back in 1955 when editors allowed quirky interesting papers. Only one person has cited it so it worth rescuing its observations from obscurity–unfortunately nothing like it has been published since.

It identifies 10 expendable bones or bits of that can be removedat least in adults.


Clavicula  means "little key" in Latin which just about describes this doubly curved long bone. It is the part of the shoulder girdle above the first rib that connects the arm to the body. It seems to act as a strut to support the scapula but in cases of its congenital absence no apparent limitation of shoulder according Curry and Lytte exists. One delivery man without it lifted in his work "heavy packages weighing up to 110 pounds or more".

clavicle minus the end that attaches to the acromion part of the shoulder bladeFor those (such as myself) that have an acromioclavicular joint dislocation the tops of this bone sticks up above a lowered scapula (shoulder blade). This due to the pull of its muscles–the ligaments that are broken not exit to hold it down to the acromion part of the shoulder blade. (They note in passing the acromion process itself can be removed without disability.)

Curry and Lyttle note that for people like me "Excision of the distal end of the clavicle … [may] lessen the period of disability and obviate the late complication of acromioclavicular arthritis ." (See the adjacent X-ray.) The main problem with it seems to them that it "result in a high-riding clavicle which may preclude the wearing of a strapless evening gown". The orthopedic consultant did not offer this and I am not sure the NHS would pay. Indeed, I rather suspect it is no longer done.  But it is oddly reassuring–my shoulder has a "step" deformity and I would worry if I thought the bone sticking up had a function. It does not–it is vestigial just like my appendix.


humerus head removedCurry and Lyttle admit "The head of the humerus is essential for normal shoulder function. Its absence is a severe disability". But they also note people without it can still use their arm: "although they have an unstable shoulder joint, they are able to place their hands in their hip pockets, and wash their forehead." They report that one person that could "hang up clothes" –see the X-ray of the arm joining the shoulder minus its humerus head.


Again Curry and Lyttle also describe that living without your elbow joint leaves you disabled. But again they note that a  much surprising amount of function is left. As they point out: "Full flexion and extension can be obtained but lateral stability is lost. These patients can comb their hair, put their hands in their hip pockets and perform almost any function of the elbow not requiring stability."


Your olecranon is the l curved bony bit of the forearm that sticks out behind the elbow at the end of your ulna (in your lower arm). Curry and Lyttle note that along with the third of ulna that articulates the elbow it can be removed "with little or no residual disability" .

The head of the second bone–the radius–in your lower arm can be removed also at its elbow end. As Curry and Lyttle note "That the head of the radius is expendable has been recognized over many years."


Not only is much your your ulna bone at your elbow is unneeded but so is it at the other end at the wrist. As Curry and Lyttle note:  the end "fifth of the ulna is expendable. Its distal articulation is small and contributes little, if anything, to the stability of the wrist. The ligaments on the ulnar aspect of the wrist are strong and furnish the needed support in the absence of the distal ulna. Its absence causes no disability." The below X-ray shows this (the black is the surgical metal repair bits put in the wrist). In the colored figure below the ulna is bone 2 and the radius bone 1.


In the wrist, one of its bones, the lunate (B in the figure) can be removed. As Curry and Lyttle put it that "Its absence causes little, if any, demonstrable disability of the wrist.". They note also in the introduction that the scaphoid (A) is also surplus.


The patella is your knee cap. It is "completely expendable" according to Curry and Lyttle. Due to this perhaps when paramilitaries knee-cap a victim to punish them they do not aim to injure the knee cap (which would cause only a minor injury) but its surrounding nerves and arteries. Another part mentioned that is surplus is the meniscus (a crescent-shaped fibrocartilaginous structure) of the knee,


Curry and Lyttle observe that the knee joining part of the fibula (also called shin- or shankbone) can be removed without effecting the normal function of the lower leg and knee. They also note that much of its shaft can be removed–as often happens for use in bone grafts. Indeed that "Cases are on record in which the entire fibula, including the lateral malleolus, has been excised for osteomyelitis with little resulting disability."


The medial malleolus is the inner end part of the tibia at the ankle. A large amount of it–25%-50% can be removed without making the ankle unstable. 

Curry and Lytte note there are more expendable bones that they do not discuss such as the ribs and their cartilage and the coccyx. Though my search may be incomplete I cannot find that a similar paper has ever been written.

Curry and Lyttle make one qualification: they above noted bits "are not expendable in children".

They end their paper with this statement.

It is not the intent or purpose of this presentation to recommend the indiscriminate excisions of portions of the skeleton. An attempt has been made, however, to evaluate the usefulness of excision in certain selected cases rather than reconstruction. In many instances the length of disability can be decreased and the late complications of reconstruction reduced or eliminated with no residual loss of function.

Their paper was published in 1955, I wonder if modern orthopedic consultants would still agree with its conclusions.

From my viewpoint as an evolutionary biologist I think it ignores how radically "soft" our modern lives are compared to those in which our bodies evolved. Maybe if modern humans more vigorously used their bodies, there might be more obvious dysfunction. Without disability means different things given the vigor with which tasks need to be done for survival. Modern humans in the West have very soft lives–things might have been very different on the savannah where our bodies evolved.

On the other hand, evolution selected our bodies when there were no orthopedic consultants. Perhaps the musculoskeletal system involved to be able to compensate through its ligaments and muscles much more than we realize for fractures and injuries. We are after all primates–members of an order of mammals that specialized in climbing in trees. It is reasonable to suppose that our primate bodies evolved also to be robust against tree falls?

Then again it could be that our usual use of our primate bodies have left them with redundancies. I was rather shocked to find when researching my acromioclavicular dislocation that this joint is extremely variable in modern people see the 1949 paper by Marshall R. Urist. In some acromioclavicular joints they are separated by a meniscus attached to the superior acromioclavicular ligament. This meniscus may be a blade of fibrocartilage that extends nearly halfway into the joint or it may form a complete disc that divides the joint into two parts. In other acromioclavicular joints no synovial joint is present with the joint being made by a pad of fibrous tissue attached to the outer end of time clavicle, and no articular cavity. In 49% articular surface of the clavicle overrides the articular surface of the acromion and in 29% of time acromion and clavicle are nearly vertical and lie in same plane. In 6% the two surfaces do not even touch! Clearly this joint is evolutionarily redundant otherwise such variability would not have been allowed to arise. Was my shoulder one without out the proper synovial joint and was this why it came apart?


Urist, M. R. (1946). COMPLETE DISLOCATIONS OF THE ACROMIOCLAVICULAR JOINT: The Nature of the Traumatic Lesion and Effective Methods of Treatment with an Analysis of Forty-One Cases. J. Bone Joint Surg. Am.28: 813 – 837.

Curry GJ, Lyttle SN. (1955). Expendable bone. Am J Surg. 1955 Apr;89(4):819-33. abstract


A ‘dollar’ for your thoughts!


Holding  two contradictory ideas simultaneously is disconcerting. Laying uncomfortably in a MRI machine while being told to respond to sentences as through you were enjoying the experience  "I feel calm, peaceful in the scanner" YES,  for example. Leon Festinger found that people change their attitudes to make such conflicts disappear. Unlike people that also make false sentences but get paid a dollar for false agreements, they report afterwards that they enjoyed the 'scanner experience'.

The scanner allows us to piece together what happens. The more part of the dorsal anterior cingulate cortex—an area long suspected to be involved in detecting and processing conflictlights up, the more people shift attitudes to resolve their cognitive dissonance.  Likewise for part of the anterior insula. This activation is a little trickier to explain. Perhaps it is related to the conflict involving the bodily experience of being in the scanner. The picture shows the activations on an inflated cortical surface.

As with every research, there are reservations. The task set up involved a social element that might have effected it.

They were then told that a patient had been scheduled to be scanned after them and was to perform a similar task in the scanner. This patient, the participants were told, was now in the scanner control room, watching the screen of the experimental control computer, and was very nervous and uncomfortable about the upcoming scanning session. The participants were then told that several  of the sentences were about their attitudes toward the scanner and the task and were asked if they would be willing to respond as though they were enjoying being in the scanner and performing the task, regardless of how they actually felt about the experience. This, they were told, might put the patient’s mind at ease, as the patient in the control room could see the responses on screen.

Perhaps there was an empathy factor to the condition in which cognitive dissonance was induced (the person got a dollar instead, rather than this story). The researchers try and argue this was not a factor but one wonders why they did not give a dollar or some, for a variant of this story. 

Neural activity predicts attitude change in cognitive dissonance.

van Veen V, Krug MK, Schooler JW, Carter CS. (2009).

Nat Neurosci. 12: 1469 – 1474 doi:10.1038/nn.2413


Motor perception and anatomical realism in Classical Greek art


Motor perception and anatomical realism in Classical Greek art

Anatomical realism in art starts with the Classical  Greeks (1). As put by the art historian Martin  Robinson, the Classical Greeks innovated the portrayal  of the 'rhythms of the living body — taut and relaxed  muscles, straight and bent limbs –instead of the  anatomical surface-patterns [of the earlier Archaic  Greeks]' (1). Why they started this is a mystery.

The recent finding that the motor cortex engages  in perception (2-4), however, sheds light upon this  problem. Evidence comes from various sources that  the motor cortex not only executes actions but sees  them.

•  Neurons in the F5 premotor cortex in monkeys  discharge both when performing a hand action and  also when seeing the same action done by another  monkey or their experimenter (2).

•  The patterns of motor evoked potentials in  people's hand muscles during an action are also  evoked by transcranial stimulation when people  look at the same action done by another (3).

•  PET imaging detects activation in the caudal part  of the left inferior frontal gyrus of the motor cortex  when people look at hand actions (4).

•  This link between motor action and perception also  applies to the movements of facial expressions:  similar electromyographic (EMG) activations  occur when people look at facial expressions as  when they make them (5). 460-BC

This link between perception and the motor cortex,  changes how we understand the aesthetic of ana- tomical realism. Presently, realism is understood in  terms of artists' capturing visual likeness — and thus  surface similarity. The above research opens up the  possibility that realism might also result from artists'  capturing the motor look (through accurately repre-  senting its muscle tautness and pose) of a body in  action (or state of rest). Thus while Archaic Greek  and other artists might have sought to stimulate the  look of a body as recognized by the viewer's visual  cortex, Classical Greek artists went further and sought  to stimulate the viewer's motor cortex and so give  them a sensation of a living body. It was to do this  that they learnt how to detail the body not only in  surface terms (as before) but also anatomical ones  and what art historians call the 'rhythms of the living  body'.

This proposal makes a strong prediction. If Classical  Greek artists, but not Archaic ones, sought realism  which activated the motor cortex, then their works  should also activate the motor cortex of modem  viewers. This should be detectable with fMRI or  PET brain scanners by comparing brain activation in  response to Archaic and Classical works.

One would further predict that good artists (both  ancient and modem) discover ways to heighten the  sensation of movement in a body and so the activation  of the motor cortex. Thus anatomical real works  should stimulate it even more than real bodies. For  instance, most of us are familiar with how the work  of Auguste Rodin heightens the sensation of move-  ment and posture. I would predict the greater a work  gives this aesthetic sense, the greater it activates  the motor cortex. The recent discovery that the motor  cortex engages in perception therefore could be important, not only for research into the nature of  aesthetics and the history of art but also into motor  perception and the functions of the motor cortex.


1.         M. Robinson. In: The History of Art Vol. 1, Oxford University Press, Oxford (1975), p. 175.

2.         G. Rizzolatti, L. Fadiga, V. Galese and L. Fogassi, Premotor cortex and the recognition of motor actions. Cogn Brain Res 3 (1996), pp. 131–141.

3.         L. Fadiga, L. Fogassi, G. Pavesi and G. Rizzolatti, Motor facilitation during action observation. J Neurophysiol 73 (1995), pp. 2608–2611.

4.         U. Dimberg, Facial reactions to facial expressions. Psychophysiology 19 (1982), pp. 643–647.

5.         G. Rizzolatti, L. Fadiga, M. Matelli et al., Localization of grasp representation in humans by PET, 1: Observation versus execution. Exp Brain Res 111 (1996), pp. 246–252.

Medical Hypotheses 51 1998 69-70 doi:10.1016/S0306-9877(98)90257-2


Logically religious belief is rare


Vulcans do not lack religion any more than Earthers. If they are said to lack religion it is because they are logical and do not pretend to hold beliefs they logically do not hold.  For Vulcans to have religious belief is to act with logical consistency as if there is a God. They do not consider religion to be a social identity emotion or "lifestyle" belief where behavior and beliefs can exist in logical inconsistency.  Religion for Vulcans is a truth that determines the choices — often hard ones –that people make.

A lifestyle choice is a group emotional involvement that is not important in regard to truth but display of group membership. The cloths Earthers buy, the teams Earthers support, the hobbies Earther pursue – they fill the social hours of Earthers, provide a topic of conversation for Earthers and offer Earthers a membership. In doing this, they create intense emotions  as when an Earther's team wins or loses. They can boast up the confidence of an Earther and their ego.  But that excitement has nothing to do with actual truth.

Yet that is what all Earther religion assert: they are about the truth not life style. Though they may not seem religious, Vulcans unlike Earthers respect this.

Logically whether an individual is animated by truth or life style can be seen in their behavior. Is an individual's behavior consistent with what they claim to be true.

The “tsunami test” shows this. Imagine a warm tropic beach where families of Earthers are playing and enjoying themselves in the sun. Tell one of those Eathers that a tsunami is on the way. How does a logician know when they are merely parroting what they have been told as if it were true without actually believing its truth, and when they are actually believing the truth of its coming? The test is not what individuals say. It is not whether Earthers tell you “We came here for a holiday and now a tsunami that will drown everything off on the beach at 10.45”. Merely saying that could be part of a life style choice or a ritual of a group membership said without serious thought– like providing the right answer on ""Who wants to be a millionaire" or some other quiz show merely because the correct answer has been shown to you in advance. To know what an Earther actually believes the logician looks at what the Earther does. Do they run or put on more sun cream and open another beer?

Actions speak louder than words, as Earther mothers say, and in the question of whether an Earther believes or not a tsunami warning, what speaks is not what they babble forth in Earth tongue about what they "believe" but how fast they run.

Talk is cheap and fakeable. Behavior, however, does not lie. It has not counterfeit. An Earther that actually believes a tsunami warning acts as if one is on the way. Their belief is spelt out in panic at their imminent fate. But not so, the Earther who only says that they believe it but behaves as if they do not. If a Earther stays on the beach, a logician can be confidently sure whatever they may say about “the tsunami being on its way”, that they are only saying words without regard to their truth. Behavior here trumps  what Earthers say.

Christian faith is a tsunami faith – if its claims are actually believed, it offers the Christian no easy choices. It claims there is a coming. Christianity is about an Earther's present life where it is a kind of tropical beach holiday and Christ’s message is a tsunami warning. A spiritual warning about what will happen on death or the promised return of Christ. Prepare correctly and an eternity of heavenly Bliss awaits the Earther; ignore the message, and the Earther get sucked into an everlasting brimstone mega-tsunami. Christianity is not a lifestyle or emotion (they it contains many subtle emotions) but at core the reality that this present life as an Earther is not the ultimate reality in which an Earther lives. Vulcans do not judge whether the claims of Christian are or not true. They have religious tolerance. They are merely cultivators of logic and have great curiosity about how Earthers consider themselves rational when they are patently not. 

The scientific evidence both by Earther and Vulcan researchers is overwhelming that religious belief for most Earthers is a lifestyle choice. Earthers asserting they are Christians rarely engage in Earther Christian behavior.

Pollsters have sampled Christians. 7-8% of American Earthers (for this is where the research has been done) are “evangelical”. To be counted as evangelical, an Earther in such surveys must be totally uncompromising in the rightness of their beliefs. They proclaim with utter certainty that they “believe that when they die they will go to heaven because they have confessed their sins and accepted Jesus Christ as their Savior”. They state, “they have made a personal commitment to Jesus Christ that is still important in their life today”. That Satan exists they take not as a possibility or hypothesis but as hard fact.

Logically,  this should change their Earther behavior.  But no it does not. Consider a behavior upon which the Bible is unambiguous: marriage. Matthew 19:4-6 states, “what God has joined together, let no one separate”. Matthew does not assert the logical proposition, “what God has joined together, let no one – except those that got married  if they decide otherwise – separate. The Bible does not offer a logical clause for Earthers. No if Evangelical Earthers believed their Bible as true, logic would ensure that   a marked difference exists in the divorce rate between them and other American Eathers. A divorce rate of 0% for Evangelicals, and 30% for everyone else. That is logic. But what do logicians find about Earther behavior here. Evangelicals separate at the same rate as non-Christian Earthers.

Other Christians groups are even more likely to divorce than nonChristians Eathers. Those Christians that claim to be born again (about 30 -40 % of American Eathers) actually divorce at a higher rate than non-Christians ones — a remarkable 90 percent of them after they find Christ. As the Earther Professor Brad Wilcox observes, "Compared with the rest of the population, conservative Protestants are more likely to divorce." This Earther has also pointed out that the divorce rates are higher in the southern U.S., where conservative Protestants make up a higher percentage of the population than elsewhere in the country. Indeed, high divorce rates in the Bible Belt as he notes they are "roughly 50 percent above the national average"

The Bible — and nearly every message from the evangelic pulpit — is also unambiguous about sex for Eathers. The Southern Baptist Convention, for example, runs the “True love waits” pledge program so teenage Evangelist Eathers can resist sin and not engage in premarital sex. Since 1993, about 2.4 million young Eathers have signed the pledge. If the faith of these Earthers is a real belief not merely an emotionally based lifestyle choice then the statistics should be simple. True love waits pledge Christian Earthers: 0% sexual intercourse before marriage, 99% the nonChristian Earther rest. But do these Earthers keep themselves virgins for their wedding night? You bet Beta Zeta V they do not. Researchers from the Earther universities of Columbia and Yale have followed for seven years 12 thousand teenager Earthers that had taken the pledge. 88 percent admitted having sexual intercourse before marriage. (And remember that is only the percentage who admit to losing their virginity after making this very public commitment). And the rates of having sexually transmitted diseases the researchers observe "were almost identical for the teenagers who took pledges and those who did not." Religious belief is not the road least taken it would seem for Earthers at least in terms of logic but the road never taken.

Vulcan are tolerate about religious belief. If Earthers want to make “True love waits” pledge that is fine. What Vulcan find curious and raises their eyebrows is that Earthers are so illogical. They claim to be religious but their Earther behavior shows that do not in fact hold the truths of their religion. Instead, religious belief amongst Earthers is a lifestyle activity that  provides them with an emotional identity. Earther religius faith is not logical.

This it should be noted is a separate issue to that of faith–that requires a logical leap. But even Earthers make that leap they cannot act logically with what that faith in consistency requires.

For details about Christian behavior in Earthers including Prof Brad Wilcox’s comments and the Columbia and Yale university research see “The Scandal of the Evangelical Conscience: Why don't Christians live what they preach?” Ronald J. Sider, Christianity Today, January/February, 2005, Vol. 11, No. 1, Page 8.