Star Babies, the Next Generation

by Joseph Vacca

Have you ever really sat down to think about space, that final frontier? Have you ever wondered if one day you may live to see the human colonization of another planet; or maybe even recognize the first child born and raised in space? Well, for all of you active imaginative/sci-fi loving people out there, I am here to give you the low down on the development of space children.

So let’s start with the embryo development!

Embryo Development and baby’s first steps…

May not actually be possible… Sorry to start off on a downer, but it is true. The problem is with fertilization. In cow semen, the cytoskeletal composition that allows for the tail to correctly generate the force needed for propulsion is affected by low gravity environments [1]. It may not have the necessary power to be able to push into the zona pelucida of the egg. However, studies by NASA scientists have also found that the enzyme that phosphorylates the tail and causes motion also acts in a hyper activated state when at low gravity [2]. This means that, although sperm are more motile in space, they are also functionally unable to fertilize a viable oocyte.

Birth is quite another problem, without gravity to help expel the baby, those present will instead have to pull the baby out of the womb. And could you imagine the amount of free floating liquid, gross. As soon as the baby is out, it misses out on its first lesson, orientation.

In the inner ear there are two gravity-sensing areas, the saccule for vertical orientation and the utricle for horizontal orientation. These areas have hair cells within them that are surrounded by little crystals that are known as otoliths. On earth, gravity pulls these crystals down in the inner ear, thereby bending the hairs of the sensory cells downward.

Try not to bend over backwards thinking too hard about this one...

The sensory hairs can be bent in any direction, and the brain interprets the specific bending as specific orientations. However, in space fluid and objects are free floating; therefore, the otoliths cannot contact the hairs quite as well, leading to a loss in the perception of tilting [3]. This will interfere with the baby’s ability to distinguish up from down or movement from side to side. If ever returned to gravity the child would neither be coordinated nor balanced. This is because the neural pathways of the child have not developed to move the body in relation to gravity's pull.

They would probably end up looking something like this on earth

Neural development  

Have you ever heard of muscle memory when talking about a sport or repetitive activity? The same kind of “training” of your muscles must occur during the first few months of birth [4]. Rats born and raised for 16 days at extremely low levels of gravity never learn how to correct their orientation when placed on their backs. It was never necessary before. So when scientists brought the mice back to Earth and placed them on their backs, they were unable to “properly” right themselves by flipping their legs underneath them [4]. The weirdest thing about this discovery is that they continued to improperly turn over for up to a month after returning to Earth! To even further investigate the effect, mice neurons were stained to observe their presence and morphology. And just as expected, there was a lower number of motor neurons branching from the spinal cord to the muscles in the medial part of the body – these neurons are involved in righting the body’s orientation. This suggests that the rat’s motor system was biased towards adaptation to a totally different environment!

Life Alert doesn’t seem so bad now, does it?

These muscles had become used to the weightlessness of space. But 60% of our muscles are skeletal weight-bearing muscle, meant to hold our bodies up against the force of gravity [5]. You are using them just to stand/ sit while reading this. So what does all that muscle do if it has no use in space? Well not only do you not grow the same muscle size and composition as you would on Earth, but you also have weak branching of the nerves into the muscle cell as seen in rats [5]. This leads to a decrease in overall developmental function that cannot be recovered once returned to normal gravity conditions.

Muscle and Bones

Bones require constant stress in order to develop properly. Normally, in Earth’s gravitational pull this isn’t too much of a problem. However, when astronauts are exposed to long periods of time in space, their bones tend to atrophy, and appear similar to osteoporosis patients [6].

In developing children this could be even worse. Such soft bones would easily break and heal incorrectly. These bones would form much like bone formation in the disease, Rickets [7]. Rickets is formed by a lack of vitamin D in the diet, thereby causing poor bone formation. A child grown up is space may look like this:

I could continue on and on about the effects of low gravity on various aspects of the body, but I don’t want to bore you; instead I shall point you towards a great book if you are interested. It’s called The Neurolab Spacelab Mission: Neuroscience Research in Space and it explains all the tests they have done in rats and astronauts on development in space. I know this all seems daunting, but don’t fret, we are a long way off from any type of space travel that would require reproduction in space. However, it is good to think about these implications now so that by the time we are ready to travel to space we will be able to overcome the negative effects of lack of gravity.

Citations:

[1] Miller, K. (2002). Floating Fertility. NASA. Available at http://www.nasa.gov/vision/earth/livingthings/floating_fertility_prt.htm

[2] Tash, J.S., Kim, S., Schuber, M., Seiber, D., and Kinsey, W.H. (2001). Fertilization of sea urchin eggs and sperm motility are negatively impacted under low hypergavitational forces significant to space flight. Biol Repro 65(4):1224-31.

[3] Clement, G., Berthoz, A., Bernard, C., Moore, S., Curthoys, I., Dai, M., Koizuka, I., Kubo, T., and  Raphan, T. (2003). Perception of the Spatial Vertical During Centrifugation and Static Tilt.  In The Neurolab Spacelab Mission: Neuroscience Research in Space (ed. J.C. Buckley and J.L. Homick), pp. 5-10. Huston, NASA.

[4] Kalb, R., Hillman, D., DeFelie, J., Garcia-Segura, L.M., Walton, K.D., and Llinas, R.R. (2003). Motor System Development Depends on Experience: A microgravity study of rats.  In The Neurolab Spacelab Mission: Neuroscience Research in Space (ed. J.C. Buckley and J.L. Homick), pp. 95-103. Huston, NASA.

[5] Riley, D.A. and Wong-Riley, M.T.T. (2003) Neuromuscular Development Is Altered by Spaceflight.  In The Neurolab Spacelab Mission: Neuroscience Research in Space (ed. J.C. Buckley and J.L. Homick), pp. 105-109. Huston, NASA.

[6] NASA Science – Science News: Space bones. (2001). NASA. [March 4, 2014]. Available at http://science1.nasa.gov/science-news/science-at-nasa/2001/ast01oct_1/

[7] Bricker, N.S. (1979). Life beyond the Earth's Environment: The Biology of Living Organisms in Space. Washington: National Academy of Sciences. Print.

Pictures:

http://fc03.deviantart.net/fs71/i/2011/080/0/9/space_baby_by_cbequette-d3c74wt.jpg

http://www.sciencelearn.org.nz/var/sciencelearn/storage/images/contexts/a-fizzy-rock/sci-media/images/utricle-function/763288-1-eng-NZ/Utricle-function.jpg

https://owners.wyndhamvrap.com/destinations/2006/dec/images/danger_faceplant.jpg

http://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/articles/health_tools/osteoporosis_overview_slideshow/webmd_rm_photo_of_porous_bones.jpg

http://www.theinsidetrainer.com/wp-content/uploads/rickets-vitamin-D-deficiency.jpg

I Can See Your Connectome From Here...

Differences in the Brain - Are men or women really superior to each other at certain tasks?
Nicole Uibel

The difference between men and women’s behavior has been a hot topic for centuries. Personal explanations for why the opposite sex thinks and behaves as they do generally takes on a turn like this:

http://motls.blogspot.com/2010/09/climate-realism-men-are-smarter-than.html

In this image, we can see some generalizations about each sex. Women clearly love chocolate and have 'mystery moods,' while men's brains are dominated by sex. Or something like this, where society has simplified the man's brain to simple switch, while modeling a woman as complicated.

http://ourdailytreasures.blogspot.com/2010/10/difference-between-men-and-womens.html

With the fight for equality between the sexes so publicized and hotly debated, the notion that our brains may actually be different comes as almost an insulting notion. Debated in forums ranging from suffrage to Cosmopolitan magazine, women in particular have fought for cultural acceptance that we are in effect "the same."

http://crackingspines.wordpress.com/tag/men-are-from-mars

Despite the fights and claims, for decades we have been attempting to decipher the behavior of the opposite sex through magazine articles and books such as “Men are from Mars, Women are from Venus.” We constantly complain about the behavior of the opposite sex, exasperated about why we don't understand each other. We are at a crossroads of claiming equality while blaming behavior on other factors. Perhaps instead of looking into these media for answers, we should look to neuroscience.

Now, before we get too uncomfortable with the implications of this research, let’s step back and appreciate the other sex for all of the wonderful ways we complement each other. Now let’s tear down those complements and look at just how different we are.

One touchy subject area has been the finding that men have larger relative brain size than women do. For years, popular science avoided this subject by claiming men’s brains were larger because men are larger. However, studies have found that on average, men do have larger brain size corrected for body size compared to women, by almost 100 grams. Now if you’re a female, you probably have the same reaction I did when I read this:

http://wifflegif.com/tags/550-are-you-kidding-me-gifs

I mostly had this reaction because of research which has supported the hypothesis that larger brains are correlated to increased intelligence. Researches found correlations between brain size and increased IQ's, but did not account for sex. Now, before all the males reading this swell their brains anymore with theories of superiority, read on.

http://www.sciencedaily.com/releases/2005/01/050121100142.htm

Fear not ladies, we have those men beat in a few ways. For one, women’s brains have been shown to contain more white matter, which we know helps to connect neurons together. One study found that women’s brains may contain up to ten times more white matter compared to a man’s brain. All these extra connections mean ladies brains are a bit more complicated in set up, but more connections leads to increase workflow. This evidence, along with new research that suggests women have more neurons compared to men (as much as 12% more), is one reason women’s brains may work faster than men’s. 

However, we can also see in this image that men's brains contain more gray matter than women's brains. Gray matter, which represents the information processing centers of the brain, is shown to be as much as six and half times greater in men's brains. This increased gray matter may result in more information being processed, but the decreased area of white matter means that information will take longer to be processed. 

So are we even? Big brain with more gray matter for increased neurons and more white matter? If only it was so easy.

Recent research has been making huge advancements in brain mapping. One technique, diffusion tensor imaging (DTI), has given us some brilliant insight into the difference between men and women’s brains. Dr. Verma of University of Pennsylvania in Pittsburgh mapped out brain connections in roughly 950 subjects. What he found is incredible.

http://www.sciencedaily.com/releases/2013/12/131202161935.htm

The map-like outcome of this study displaying different neural pathways in the brain was termed ‘connectome.’ What we are looking at, is essentially all of the connections between different parts of our brains. This map is a product of tracing and highlighting the fiber pathways linking different regions of the brain. Interestingly, Dr. Verma noted that these differences are only discernible after puberty.

We can see that the male brain depicted above has more connections laterally, in the same hemisphere. Comparatively, the female brain has more connections spanning the hemispheres, crossing back and forth between the right and left. Some of the extrapolations made from this research include rationales for why men are better at spatial tasks, such as map reading, while women are better at language and memory tasks, like recalling conversations. 

There is clearly much more research to be done in this field - and an interesting crossover study between neuroscience and psychology could be in order to examine the brain to behavior connection with many of the tasks listed here. 

http://www.neuroscienceblueprint.nih.gov/connectome/

For more information on the 'connectome' project, check out this website! 

References:

Ankney, C. D. 1992. Sex differences in relative brain size: the mis-measure of women too? Intelligence 16:329-336.

Connor, S. 2013. The hardwired difference between male and female brains could explain why men are better at map reading. The Independent. http://www.independent.co.uk/life-style/the-hardwired-difference-between-male-and-female-brains-could-explain-why-men-are-better-at-map-reading-8978248.html. 

Edmunds, M. 2008. Do men and women have different brains? http://science.howstuffworks.com/life/men-women-different-brains.htm. 

Ingalhalikar, M., A. Smith, D. Parker, T. D. Satterthwaite, M. A. Elliott, K. Ruparel, H. Hakonarson, R. E. Gur, R. C. Gur, and R. Verma. 2014. Sex differences in the structural connectome of the human brain. PNAS 111:823-829.

Kimura, D. 1987. Are men’s and women’s brains really different? Canadian Psychology 28:133-147.

University of California, Irvine. 2005. Intelligence in men and women is a gray and white matter. ScienceDaily. http://www.sciencedaily.com/releases/2005/01/050121100142.htm. 

Willerman, L. and R. Schultz. 1991. In vivo brain size and intelligence. Intelligence 15:223-228.

Turn Down For What?

By Travis Suttle

In lecture a few weeks ago, we learned about the physiology of hearing and I was absolutely fascinated!  Though after class, on my walk to get lunch, I distinctly remember contemplating on how the process could be interfered to result in hearing loss.  My parents repeatedly told me as a child to turn down my music, but they never explained to me how it leads to hearing impairment (probably because they have no idea).  With that said, my investigation into understanding the mechanisms behind hearing loss begins!

Physiology of Hearing Background
Hearing loss or hearing impairment is the partial loss of the ability to hear, or perceive sound by detecting vibrations in the air.  To learn how hearing loss happens, it is essential to understand the underlying anatomy and physiology behind hearing. Our ears are comprised of three parts; the outer ear, middle ear, and inner ear. The outer ear consists of the pinna and ear canal, which lead to the tympanic membrane, or eardrum.  The outer ear channels sound from the environment into the ear canal in a way that allows the person perceiving the sound to locate its origin vertically.  One may question why the physiology of the outer ear only allows one to locate the sound vertically; it is because the ears are paired organs, so together they can interpret the location of the origin of sound horizontally.  Therefore, it is necessary that both ears are functional in order to properly interpret the location of the sound origin.

The middle ear is a small air-filled chamber that contains the three smallest bones in the body, the ossicles.  The ossicles transmit vibrations of the tympanic membrane to the inner ear.  The stapedius and tensor tympani muscles are attached to the ossicles and contract to protect the hearing mechanism.  The ossicles transmit sound into the inner ear by vibrating on the oval window, an elastic membrane that separates the inner ear from the middle ear.

Lastly, the inner ear contains the cochlea, a snail-shaped, fluid-filled, organ about the size of an aspirin that translates mechanical waves into neural signals, which are sent via the cochlear nerve to the opposing side of the brain.  If you were to unwind and look down the cochlea, you would find about twenty thousand sensory cells, commonly referred to as hair cells. High sound frequencies (such as a minion voice) depolarize hair cells at the entrance to the cochlea, where low frequencies (such as the voice of the guy who makes all the movie trailers) depolarize hair cells deeper within the cochlea.  The hair cells themselves do not depolarize, but they release neurotransmitters at synapses with auditory nerves that produce action potentials to transmit information about the frequency of the sound to the brain.

Mechanisms Of Hearing Impairment
There are two kinds of hearing loss, conductive and sensorineural.  Conductive hearing loss is when the sound does not reach to the cochlea.  It is commonly caused by wax buildup in the inner ear, perforation of the eardrum, or excessive fluid buildup in the middle ear.  Sensorineural hearing loss is the most common type of hearing loss in adults.  Noise damage, the aging process, or other environmental factors can cause sensorineural hearing loss.  About 10% of the world population is affected by hearing loss, which varies from moderate to severe cases.  Presbycusis, or the gradual loss of ability to hear high frequencies, is a form of sensorineural hearing loss and is considered a normal process of aging.  Presbycusis is caused by hair cell degeneration in the early cochlear canal.  This is because the hair cells at the entrance of the cochlea are the first to encounter sound waves. Though hair cells throughout the cochlea can be damaged when listening to loud music. A great analogy for hair cell-induced hearing loss involves a field of grass; when you walk on it, you compress the grass and it bends down over night, but in a few days, it springs back up and is OK again.  However, if you continually walk on the grass, you will wear a path in it and it will not grow back.  Similarly, briefly listening to loud music will not result in permanent hearing loss, though listening to loud music for extended periods of time will inevitably result in hearing loss. Recently, it has been discovered that the death of hair cells is not the only contributing factor to sensorineural hearing loss.












About a month ago, a study published in Neuroscience revealed new insights into the relationship between noise exposure (or acoustic overexposure, AOE) and hearing loss. Tagoe et al. (2014) discovered that the dysmyelination (or the loss of the extracellular protective sheet) of the auditory neurons might also lead to hearing impairment.  Dysmyelination of the auditory nerve axons impairs propagation of action potentials (signals) down the auditory neurons leading to impaired hearing.  The graph above depicts decreased excitatory postsynaptic currents (EPSCs) in nerves from the acoustic overexposure (AOE) group.  The results of this study are very significant because they uncovered a new mechanism in which hearing impairment may develop.  So now that we know how sensorineural hearing loss can happen, what options are currently available for those with hearing impairments?

Assistive Devices for Hearing Impairment
Though no current treatments reverse the underlying cause of sensorineural hearing impairment, there are many devices that can improve ones hearing abilities.  The most popular device is hearing aids, which act by amplifying incoming sound to improve hearing ability.  Though hearing aids often only provide a limited hearing assistance in the high frequency range.  Cochlear implants are a novel device which artificially stimulate the cochlear nerve.  Essentially, they mimic the firing of hair cells within the cochlea in order for the recipient to perceive sound.  Unfortunately, cochlear implant procedures vary greatly in success.  The reasoning behind the varied success of cochlear implants is most likely due to problems in auditory nerve signaling as Tagoe et al. (2014) discovered.

Prevention Of Hearing Impairment
So now that we understand how hearing impairment develops, what can we do on a daily basis to avoid substantial hearing loss in our lifetime (besides not standing behind a jet when it takes off).

1.  Avoid listening to music with earbuds!  Normally, when sound from the air enters your ear canal it bounces off your eardrum and is reflected out of the ear only moving the tympanic membrane a few nanometers.  In contrast, earbuds create a sealed system that creates a column of pressure which moves back and forth within the ear moving the ear a few micrometers (or 1000x further than open air sound).  The dramatic eardrum movement thus triggers the stapedius reflex which tenses the eardrum to dampen the sound.  In response to the dampening, the listener could to turn the volume up higher further amplifying the eardrum movement.  In order to enjoy your music without having to listen to it at unsafe volumes to compete with background noise, use noise-canceling headphones which allow you to hear the full dynamic range of the music at a lower volume.

2.  Wear ear protection!
A common rule of thumb is to wear ear protection if something sounds as loud as a lawnmower.  Since noises above 86dB can damage your hearing and a lawnmower is about 90dB, it serves as an identifier of noises that can potentially cause hearing loss.  Ear protection is widely available, from 50-cent foam ear plugs to electronic ear muffs that allow you to hear normal sounds but muffle loud noises. It doesn't matter what type of ear protection you use, the most important part is using it in the first place.

3. Turn the music down!
Finally, to answer the question that Lil Jon repeats is his currently #11 iTunes ranked song "Turn Down For What?," you should turn down your music to prevent it from damaging the hair cells within the cochlea and the myelin sheath on your auditory nerve.   Remember, like boiling a lobster, damaged ears cannot be returned to their previous state.

P.S. Am I the only one who hates when that song comes on the radio?



References:

Tagoe, T. , Barker, M. , Jones, A. , Allcock, N. , & Hamann, M. (2014). Auditory nerve perinodal dysmyelination in noise-induced hearing loss. J Neurosci, 34(7), 2684-2688.

Matsunaga, T. (2009). "Value of genetic testing in the otological approach for sensorineural hearing loss". The Keio journal of medicine 58 (4): 216–222.

http://www.news-medical.net/news/20140217/Leicester-research-reveals-how-noise-damages-hearing-system.aspx

http://www.hearingloss.org/content/types-causes-and-treatment

http://www.auditoryverbaltraining.com/ha-ci.htm

http://www.wired.com/entertainment/music/commentary/listeningpost/2006/03/70434?currentPage=all

http://www.youtube.com/watch?v=rXg-9ncVrPA

http://weknowmemes.com/2011/12/i-have-no-idea-what-im-doing-meme/

http://www.quickmeme.com/img/56/569b77524c8fced8ad1f3f48e39537be9663f9084a0c57362c1141b32df46e92.jpg

Simulating the Mini-Universe in Your Head

by Joel Stevens

What do you think about when you day-dream? I mean really day dream. Those moments where you are
really deep into your own little world.  Those moments where for a few brief minutes you forget about appointments, parking tickets, homework, reports, car payments, taxes, global warming, job security, the economy, the tea party; those moments where you just drift into existential bliss and tune out the societal noise.

What do you think about?  Maybe you think about yourself and ask what makes you you? Why am I here, why are we all here? In those moments, however do you ever wonder or just sit in awe of the 3 pound organ in your head that allows you to tune out the noise and ask such deep questions?  Do you ever wonder how the human brain works?

As crazy as it sounds, this is still the central question of neuroscience today.  Which, may appear to be surprising to some, seeing as it is one of the most well funded disciplines in all of biology.  However, you really have to take into account the enormous mind-boggling (no pun intended) complexity of the human brain! It is made up of millions of individual neurons all connected with one another by TRILLIONS, yes that's right, trillions of synapses (the small gaps between two interacting neurons).  We have known since the 1950's how individual neurons initiate signals and send them to another neuron. We also have a pretty good idea how the brain performs simple motor tasks such as grabbing a pencil or interpreting sensory information such as someone poking you with said pencil, known as neural circuits. Where it gets really messy and complicated is when we start to investigate things such as decisions making, problem solving, and the big one consciousness. How would we even begin to start doing this?

Well whenever scientists try to investigate something that is to complicated to observe in the field or in a lab setting, we try the next best thing we develop computer simulations, or mathematical models, to create the closest thing we can to reality inside a computer.  This has been done for years, in fact one of the pioneers of computer science Alan Turing goal was to ''build the brain'' and ended up building a computer.  As you might have guessed the mathematics must be extremely complicated in order to program a simulation of a human brain, and you are right! Enter the crazy, complicated field of computational neuroscience.

Even though the idea to simulate the brain using computers has been around for almost 60 years, what has just become available is the computational power to actually perform such tasks.  First, though I just want to briefly give a crash course in how to approach modeling.

There is a trade-off when developing mathematical models or computer simulations, because you want to make it as realistic as possible, otherwise your results could be shaken off as unrealistic.  However, the more variables and dimensions you add to a model, the more complicated the mathematics gets, i.e. the more moving parts there, are and the greater the chance something could go wrong. My graduate adviser goes by the rule that a great model will follow the 80-20 rule, meaning that you cannot account for 100% of the things going on in a system, so you only want to account for 20% of the most important variables.

And this is where neurosciences have struggled, because as I said before, the human brain is IMMENSELY complicated. Some scientists believe that simulations must also account for the genes being expressed in each neuron as well as individual ion channels in each of the millions of individual neurons on top of the trillions of precise connections.  Brain hurt so far? Don't worry so does mine, but stick with me here! What really is going to impress you though is that recently computational power has reached the point in which we can actually do this!

This is heavy stuff, here's probably what your brain is feeling

And the power is pretty intense, these are not your standard laptops used to roam Facebook. These are massive super computers, filled with bull testosterone (well not really, but they're pretty intense). To put it into perspective your laptop that you are reading this on has most likely 2 or 4 core processors, processors are the part of your computer that does actual computations, i.e. the brain of your laptop.  One of the super computer simulation called Blue Brain developed by Henry Markham in Switzerland uses 16,384 total processing cores which are able to simulate the physiological activity of 100 million neurons and 500 million synapses, all while taking into account ion channels dynamics and neural network morphology. This particular model is considered to be one of the most complicated to date, and has been given the 1 billion euro prize by the Human Brain Project.  However, due to the sheer detail and size taken into account in its development, the model has come under some scrutiny for being too complicated, and most likely will require even more advanced computer technology, available in approximately 10 years.

Not all computational models have the detailed approach as Blue Brain. Researchers at the University of Waterloo in 2012 developed a brain model called Spaun which simulates a much smaller scale than Blue Brain, still 2.5 million neurons.  The most interesting thing about this simulation is that it was designed to perform cognitive tasks, while others like blue brain simulate more of the actual physiological connections of an entire brain.  Spaun has the ability to do simple tasks such as look at a set of numbers, remember, and then repeat the numbers back by writing them on a piece of paper, and other tasks similar to ones on basic intelligence tests. Pretty cool eh? The big breakthrough, and in my opinion the most intriguing finding, was Spaun's limitations.

Unlike most computers that just evaluate millions of possible decisions in milliseconds and then finding the best answer (think chess playing supercomputers), Spaun instead paused; it hesitated before giving an answer! It actually thought! To me that sparks a certain sense of fear that one day simulations like this may become self aware and destroy all of mankind! It also sparks some extreme interest and hope that these models become increasingly more accurate.

And I have no doubt that they certainly will! It is just going to require a lot more knowledge of neural connectivity in the brain, as well as you guessed it more computational power.  Which ultimately is the limiting factor, as always, when it comes to really complicated models such as these.  One day however, I have no doubt that we will have cell phones with human-like AI like operating systems, similar to one in the recent Spike Jonze's movie Her, hopefully minus the awkward dating your phone phenomena.  All AI thoughts and/or concerns aside, realistic computer simulation of the human brain will contribute greatly to understand how exactly the human mind works as a whole, as well as, aid in solving diseases in which our minds' machinery goes haywire; such as Alzheimer's, depression, and even schizophrenia. As well as aiding in understanding how we can perform abstract processes such as what problem solving, creativity, and create/store memories. Most importantly however, these models could very well hold the key to understanding the process that gives our species the ability to ponder its own existence.  So keep at it computational neuroscientists!  Math/computer/biology nerds are rooting for you! 

A heavy blog like this requires some heavy music! Enjoy some mind bending music the next time you ponder your own existence!  

References

1.)  Eliasmith, C. and O. Trujillo. 2014. The use and abuse of large-scale brain models.Current Opinion of Neurobiology 25:1-6.

2.) Eliasmith, C., T.C. Stewart, X. Choo, T. Bekolay, T. DeWolf, Y. Tang, and D. Rasmussen. 2012. A large-scale model of the functioning brain. Science 338:1202-1205.

3.) Markram, H. 2006. The blue brain project. Nature Reviews: Neuroscience 7:153-160

4.) Stewart, T.C., F.X. Choo, C. Eliasmith. Spaun: a percption-cognition-action model using spiking neurons

http://www.gizmag.com/brain-computer-simulation/25349/

http://phenomena.nationalgeographic.com/2013/02/14/will-we-ever-simulate-the-brain/

Images
http://www.titaniumteddybear.net/wp-content/uploads/2010/09/lolwut-jurassic-face-thread.jpg
http://www.quickmeme.com/img/1c/1cba02b056944308e72401de0acbf9dbb471aad66deea493613a633be13ab92d.jpg
http://www.troll.me/images/ancient-aliens-guy/computers-how-do-they-work-thumb.jpg
http://www.artificialbrains.com/images/blue-brain-project/blue-gene-p-architecture.png
http://images.scholarpedia.org/w/images/8/86/Encyclopedia_of_computational_neuroscience.gif

What makes a genius?

by: Emily Smith

You can't tell from the bowl cut and missing front teeth, but I was once mistaken for a child prodigy.

Growing up, my parents always played a classical music recording when we were eating dinner. One of the more frequent choices was Mozart, so I associated most classical pieces with his name. One night, my family went to a friend's house for dinner. The hosts opened the door and as we walk inside, I hear the familiar sound of a classical orchestra. Without skipping a beat, 4-year-old me says "ah, Mozart!" The hosts were flabbergasted--I happened to be right! They asked my parents if I was some kind of musical genius. My parents laughed, I would have guessed Mozart regardless of what had been playing…

Play this while you're reading to elevate your level of classiness!

My brush with almost-greatness made me wonder, what would the brain of a true genius look like? Was Mozart hard-wired to compose awesome orchestral pieces? Was Einstein destined to confuse physicists everywhere with his Theory of Relativity? Was DaVinci's brain tinkered so he could be the father of invention? How are young teenagers going to college????

Nolan Gould, a.k.a. Luke from Modern Family, is 15 and is taking college courses. Can you taste the irony?

According to Haier and colleagues (2004), individuals having more gray matter in certain Brodmann areas (BA) tend to have a higher IQ.  Hmm…let's take this apart so us "non-geniuses" can understand this phenomenon:

What is gray matter?
Gray matter is the part of your brain that houses all the cell bodies and axon terminals to form synapses, thus allowing signal transduction through chemical (neurotransmitters) and electrical (action potentials) signals. The white matter houses the neural axons, which allow regions of gray matter to communicate.

Basic structure of neurons and how they communicate

What are the "Brodmann areas?"

 The Brodmann areas are simply a way to map and describe the brain's functions. When your brain receives information, it generally moves from the back of the brain to the front. The frontal lobe is responsible for higher thinking and planning (characteristic of modern humans).

So what does this mean?
Basically, it is the physical structure of the brain and not necessarily any chemical change that leads to intelligence of astronomical proportions. For example, Einstein's brain has been analyzed by several labs since his death in 1955. Diamond and colleagues (1985) postulated that there might be differences between the neuron:glia ratio in Einstein's brain. The study concluded, however, that Einstein's neuron:glia ratio in the overall brain was not significantly different from the "control" population (Diamond et al., 1985). Witelson et al. (1999) described differences between Einstein's brain and an otherwise equal male control brain, finding enlarged parietal lobes (~15% wider than the control!) and a complete absence of the parietal operculum (try saying that 5 times fast…). Specifically, the inferior (left) parietal lobe was larger than average; this part of the brain is responsible for mathematical thought and visuospatial cognition (Witelson et al. 1999), leading some researchers to believe the unique brain structure was a large part of Einstein's brilliance.

Figure 2 from Witelson et al. 1999 visualizes the differences between Einstein and a "normal" male human

Furthermore, Shaw et al. (2006) suggests that it is not merely presence (or absence, as the case may be) of brain structures or gray matter, but the path of development that is the most important predictor of intelligence. They found that children with higher intelligence had high cortical plasticity. In essence, the gray matter in their cortexes expanded very quickly in early childhood and rapidly thinned during adolescence, indicating a dynamic system (Shaw et al., 2006). Though this does not fully explain the complex mechanisms involved in determining intelligence, it is a telling story for the importance of early development in children.

Figure 2 from Shaw et al. 2006 shows changes in cortical thickness as it relates to developmental age of different brain regions important for intelligence

What about savants? 
A savant is defined as a person with serious cognitive impairment (either developmental or acquired) who also has a so-called "island of genius," or incredible skills that invariably involve massive memory (Treffert, 2009). Generally, savants have fine-tuned abilities in memory, drawing, music, calculating, reading, and several others (Bolte and Poustka, 2004). Treffert (2009) focused on describing the brain of Raymond Babbit, better known as "Rain Man." He is an autistic savant that is missing the corpus callosum, or the partition between the left and right brain, that allows him to quickly skim and retain information from two pages at once (Treffert, 2009). It appears as though brain structure may play an important role in this class of "genius" as well, though there are many disagreements about whether savants can really be considered geniuses.

Us "non-geniuses" can't read a book with each eye on a different page…I'm going cross-eyed just trying to imagine it!

According to Treffert (2009), 1 in 10 people with autism have at least some sign of savant-like behaviors. Some groups have suggested that testosterone "poisons" the left hemisphere of the prenatal brain and the right hemisphere must make up for this loss (Bolte and Poustka, 2004). According to an informational website posted by Dr. Dave Hiles (2001), prodigious savants (such as Derek Paravicini, below) are defined as people whose brilliance is stellar not only in contrast to the disability, but would be a spectacular feat in a non-disabled individual.

Check out this awesome "60 Minutes" video about one of the more recently famous savants, Derek Paravicini:

So in essence, brain structure and course of development seem to be key for predicting genius-level IQ. There is still much to be figured out about geniuses and savants, but these discoveries could lead to a higher level of understanding of the modern human brain.

Though music might not be my calling, maybe listening to Mozart in my early years has primed my brain for science. Maybe, just maybe, I'll just become the next Nobel Prize-winning biologist!

 ;)

References
1. Bolte, S., and F. Poustka. 2004. Comparing the intelligence profiles of savant and non savant individuals with autistic disorder. Intelligence 32: 121-131.
2. Diamond, M. C., A. B. Scheibel, G. M. Murphy, Jr. and T. Harvey. 1985. On the brain of a scientist: Albert Einstein. Experimental Neurology 88: 198-204.
3. Haier, R. J., R. E. Jung, R. A. Yeo, K. Head and M. T. Alkire. 2004. Structural brain variation and general intelligence. NeuroImage 25: 425-433.
4. Shaw, P., D. Greenstein, J. Lerch, L. Clasen, R. Lenroot, N. Gogtay, A. Evans, J. Rapoport and J. Giedd. 2006. Intellectual ability and cortical development in children and adolescents. Nature 440: 676-679.
5. Treffert, D. A. 2009. The savant syndrome: an extraordinary condition. A synopsis: past, present, future. Philosophical Transactions of the Royal Society B 364: 1351-1357.
6. Witelson, S. F., D. L. Kigar and T. Harvey. 1999. The exceptional brain of Albert Einstein. The Lancet 353: 2149-2153.


Links
http://24.media.tumblr.com/tumblr_m606xsXwTl1qk6wc3o1_250.gif
http://www.umich.edu/~cogneuro/jpg/Brodmann.html
http://www.indiana.edu/~p1013447/dictionary/greywhit.htm
http://25.media.tumblr.com/tumblr_mbp8h0jyyw1qzpwi0o1_500.gif
http://www.youtube.com/watch?v=Ak2jxmhCH1M
http://bio1152.nicerweb.com/Locked/media/ch48/48_05NeuronStructure.jpg
http://www.psy.dmu.ac.uk/drhiles/Savant%20Syndrome.htm
http://www.youtube.com/watch?v=cbqjxmTNivQ
http://www.youtube.com/watch?v=Rb0UmrCXxVA

Did you taste the purple coming from that song? Synesthesia is a mind boggler.

Seeing sounds and tasting colors

By: Michael Spelman

Alright, alright, take a deep breath and get ready for a trip through what could be described as the brainchild of Hunter S. Thompson, Dr. Suess and Salvador Dali after they all got together for a party that would have put to shame the entire decade of the 1960s. 

But first some background. The concept of perception, be it taste, smell, sound, touch or sight, has been a prominent focus of philosophical experimentation since Plato and Aristotle first asked "Why?". In Plato's Allegory of the Cave, it is posited that the ideas we form from sensations we experience, our perceptions, are more important in generating "reality" than the things eliciting the sensation in the first place. Essentially, reality is based more more in how we perceive things, than the things themselves. But what happens when the mechanisms of our perception get mixed up? How would one's concept of reality be affected? I will delve into that soon, but first let's overview some of the mechanisms behind sensation and perception.

Chemoreception, Mechanoreception, and Photoreception:

Our five senses (seeing, hearing, smelling, feeling, and tasting) result from the stimulation of certain types of sensory receptors in our bodies. Mechanoreceptors in our skin and our inner ears are activated by signals such as pressure that cause a physical or mechanical change in sensory neurons. This physical change is communicated to the brain by way of an electrical signal and is perceived as touch or sound, respectively. Chemoreceptors on our tongues and in our nose communicate with the brain in a similar manner, but in response to the presence of some combination of chemicals. These chemical combinations result in the perception of various tastes and smells. My personal favorite sense, sight, comes from photons of light entering our eyes and being transduced, or changed, into an electrical signal that is communicated to our brains. This is such a gross oversimplification it hurts my Biopsychology bachelor's degree, but it will suffice for now.

Alright, so the question that should be on your minds at this point is "if all of our senses get to the brain by way of these electrical signals, then how are they perceived as different from each other?" The answer lies in the complexity of our brain. The image here shows a schematic representation of our thalamus, the brain region responsible for organizing incoming sensations and sending the information to the appropriate cortical region for further processing (Krettek and Price, 1977). 

Wait, what? What is a cortical region? The cortex is the outermost portion of our brains, essentially the part that anyone would see and say "oh, thats a brain!". Each portion of the cortex is responsible for a specific set of functions, as shown in the image below. For instance, the rear-most portion of the cortex is known as the occipital lobe and is responsible for interpreting visual inputs and telling our brains what we are seeing. There is a dedicated brain area for interpreting each of the five senses after being relayed by the thalamus. 

As you might be thinking, the incoming signals to the thalamus, and subsequently to the cortex are awfully close to one another. And since they are all electrical inputs, couldn't the brain occasionally make a mistake or let one signal go to the wrong area of the brain? Surprisingly, our brain is remarkably efficient in getting messages where they need to go and rarely makes mistakes (unlike the U.S. postal service, am I right?). However when things go wrong things can get real weird, real quick.

Synesthesia, LSD, and Contemporary Art 

When the brain makes mistakes in interpreting incoming signals that are not due to normal aging processes, psychological conditions such as behavioral and mood disorders, and schizophrenia can occur. However, it doesn't always result in such devastating conditions. Synesthesia is one such condition that could, in theory, actually be really friggin cool. 

Synesthesia is defined as the involuntary physical experience of a cross-modal association (Cytowic, 1995). In layman's terms, it means that experiencing one sense, simultaneously activates another sense. For instance, seeing sounds, or hearing colors, or tasting geometric shapes. It may seem like something out of a science fiction book, but it is actually a diagnosable psychological condition that is estimated to occur in 1 in 2,000 people (Martino and Marks, 2001). Though, synesthesia is not found in the Diagnostic and Statistics Manual of Mental Disorders because it does not generally interfere with daily life, and synesthetes generally enjoy their added sensory perceptions (Jensen, 2007). Martino and Marks described that synesthesia can be either strong or weak; strong synesthesia refers to the full experience of a sensation not related to the modality being experienced, whereas weak synesthesia encompasses such experiences as seeing colors when reading words or numbers. 

I know, I know, you're thinking to yourself "how could this possibly happen, and how can I get in on this action?" Well, as with any other psychological disorder, it is largely unknown how synesthesia comes about. According to Grossenbacher and Lovelace (2001), synesthesia is thought to have a genetic basis and is thought to be inherited according to X-linked dominant patterns. There are a number of theories on the physical basis of synesthesia. The one that seemed most reasonable and worth mentioning was that of Local Crossactivation (Hubbard and Ramachandran, 2005). Essentially, neurons existing in brain areas connecting the sensory input from a certain modality to the brain region that interprets it actually send unusual connections to brain areas involved in perceiving other senses: basically the brain of synesthesetes (people who have synesthesia) have extra wiring that usually is not present in the brain. A large amount of research has supported this theory using neuroimaging techniques such as diffusion-tensor imaging (DTI) and functional magnetic resonance imaging (fMRI).

It has also been hypothesized that there are three classifications of synesthetes. The first type of synesthete experiences strong synesthesia from an early age and is classified as a developmental synesthete. The second is considered an acquired synesthete, and the condition can arise later in life as a result of injury. Now for the part Mr. Thompson was an expert on. The third type of synesthete is an induced synesthete, and their experience of synesthesia results from the ingestion of hallucinogenic substances such as LSD or mescaline (by no means am I promoting the recreational use of such compounds, but as a result of my undergraduate studies I find the subject totally fascinating). 

Although it is likely the quickest way to induce synesthesia, drugs are far from the only thing that can evoke the experience of multiple senses at the same time. In fact, we experience synesthesia on a regular basis (to a much milder extent). Reading a fiction novel for example can stimulate our imagination so much so that we create a visual representation of the most minor details from the story. Advertisers and cinematographers regularly generate imagery that is meant to evoke and stimulate emotions. Music videos such as this Blockhead video, directly pair sound with visual effects to create a really awesome video (and this song/artist is just the bees knees overall).

My favorite part

Now for the REAL trippy philosophical stuff. As a Neurologist, Dr. Richard Cytowic has extensively studied perception and synesthesia, interviewing patients and documenting various case studies. From his experiences he has expanded on the hypothesis of "form constants". Such form constants are what Cytowic and Dr. Heinrich Kluver describe as the four basic types of hallucinatory constants. These include gratings and honeycombs, cobwebs, tunnels and cones, and spirals. 

What do these form constants have to do with synesthesia? Kluver proposed that the experience of form constants is due to some fundamental aspect of visual perception. Amazingly, the visual cortex is mapped in such a way that the perception of these shapes correlates to a sweeping activation of neurons responding to individual line orientations, similar to when we perceive a moving object! (more on visuospatial mapping here) Now get this. The likely reason that these hallucinatory forms are "constant" is due to the presence of the Golden Ratio in nature, and our brains innate propensity to process it. While only a theory, the golden ratio has been posited as the mathematical explanation of perceived beauty, and patterns in nature. So much so that some little-known artists such as Leonardo DaVinci and Salvador Dali prominently planned paintings around this golden ratio. The band Tool has even made this awesome song lyrically centered on it (and paired some cool imagery with it too). 

Now, if you'd please humor me while I do some philosophizing of my own. What if, because the incoming information from the outside world (such as a vibrating photon of light entering our eyes, or vibrating molecules of air on our skin or eardrums, or vibrating chemoreceptor channel enzymes in response to chemical binding) is so similar across modalities, it could be considered abnormal NOT to experience synesthesia? What if we were meant to experience more than one sense at a time, and synesthesia as a trait was evolutionarily selected for? Think about THAT.

Bibliography:

Cytowic, R.E. 1995. Synesthesia: Phenomenology and neuropsychology. PSYCHE 2(10).

Grossenbacher, P.G., and C.T. Lovelace. 2001. Mechanisms of synesthesia: cognitive and physiological constraints. TRENDS in Cognitive Sciences 5:36-41.

Hubbard, E.M., and V.S. Ramachandran. 2005. Neurocognitive mechanisms of synesthesia. Neuron 408:509-520.

Jensen, A. 2007. Synesthesia. Lethbridge Undergraduate Research Journal 2(1).

Krettek, J. E. and Price, J. L. (1977), The cortical projections of the mediodorsal nucleus and adjacent thalamic nuclei in the rat. J. Comp. Neurol. 171:157–191.

Martino, G., and L.E. Marks. 2001. Synesthesia: Strong and weak. Current Directions in Psychological Science 10:61-65.

Parts of the brain thalamus of anatomy. (2012). Retrieved from http://www.rudyard.org/parts-of-the-brain-thalamus/

Sanderson, K. J. (1971), The projection of the visual field to the lateral geniculate and medial interlaminar nuclei in the cat. J. Comp. Neurol. 143:101–117. 

Ramachandran, V.S., and E.M. Hubbard. 2003. Hearing colors, tasting shapes. Scientific American 288:52-59.