How does our brain learn?

This was written with special dedication to Valeria Galván Celis

Everything is in our brain, when I say everything I mean EVERYTHING! From our dreams, our talent, our future, our ideas, our perception of love and pain, and the way we learn. The Brain is the only one item shared by any human being on this planet, no matter the color of our skin, socio-economic condition, culture or age.

The way we walk, understand the world, write, how we learn, our perception of life is regulated by infinite processes based on electric and chemical impulses, effect of proteins, hormones and genes.

While some researches are focus on cure and prevent brain diseases like Parkinson, Alzheimer or understanding the neurodevelopment process, some others are searching how to build a brain, for example the Human Brain Project and the Blue Brain Project leaded by Henry Markham, professor of Neuroscience, whose laboratory is located in the Swiss Federal Institute of Lausanne, who will spend one billion Euros trying to unlock the secrets of consciousness, by using data to trace electronic signals between the neurons (Honigsbaum, 2013).

One of the many goals is using all this knowledge about the brain into schools, creating programs based on brain to help children with or without disabilities to learn better, faster and more effectively. Many authors believe that is possible to “teach” our brain to respond in a particular way, and of course, science fiction has ignited this idea and we can learn everything with a click and finish with the huge differences between gift and mental retarded children.

For good or bad, things are not so easy. Our brain learns in an unknown way. Why can some children understand numbers or science?, why are some children wonderful singers?, what is the difference among talent and passion for learning?

These questions began to bother me some years ago, when I saw children with disabilities. Brain scans showed a perfect brain, but these kids were not capable to speak or follow simple orders. If they have a perfect brain, was there another factor?, where was the problem?

As neuroscientist, I began studying brains; I was capable to explain specific structures related with a particular process (Dzib Goodin, 2013a), if a teacher asks me why a child cannot read, I can explain the process that the brain needs to focus on something so complex, but I could not explain why a specific child does not read.

After some frustrations, my position changed, the brain was the receptor of the stimuli in the environment, all information comes from outside our brain, so what are we putting in it?. The question was not how do we learn? But how did learning process arrived to our brains? (Dzib Goodin, 2013b).

This question takes us to a long and challenged road called evolution. Our brains are the current version of natural prototypes. More time we spend on this planet, new needs must be solved; for example to read these lines, you need eyes and ears.

Reading process is a combination of a sound (identification of sounds of alphabet) and pictures (every letter has a different shape, let’s think that most of alphabets have capital and lowercase letters).

Auditory system is a combination of mechanic and neural impulses; our current prototype has needed to design a perfect relationship between tiny bones and hair cells capable to send information to a nerve and then the brain. We have learned to distinguish between sounds in the environment, music, and language, but not only that, we are efficient to determinate the place of the object of emission, intensity and decide if it's a dangerous/friendly sound. Why? because as specie during long time  humans tried to survive from predators.

Image from: Chitka, L., Brockman, A (2005) Perception Space - The final Frontier. Plos Biology. Available at: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0030137

Let’s think for a second, hearing sounds is not enough to survive in the middle of the night with all kind of hunger creatures, we needed eyes. Let’s keep on mind that during many years we were not humans, we were in the ocean, with not enough light to see, so that eye began needing only systems to see in the dark, and we still need them, or we couldn’t see during the night, those cells are called rods.

Eventually, those primitive eyes had to adapt to light, so those eyes needed new cells, we began to see light, that eye began to see colors, and we needed so much that currently we can see colors between 400 to 650 nanometers and that amazing difference needed maybe few hundred thousands years (Nilsson and Pelger, 1994). Inhuman specie’s case, when the fire was discovered, we had to adapt to a wider range of colors, we add yellow and red to our palette, and this means we were capable to distinguish green fruits to mature fruits.

These two systems, hearing and sight, learned to work together, so when we hear a noise our eyes search that noise…but that’s not all!, we needed a neck to support that movement. Movement is another amazing complex process, because species had to move to survive, some mammals like chipmunks or rabbits have to move fast to avoid to be someone’s dinner, but humans had to move to find a better place to live, find food and care babies. Let's add to all those skills the need of moving  our eyes to focus on an objects.

One more step was necessary to be able to read, maybe I should say another BIG step: after creating a language, based on sounds, we had to learn to recognize those sounds, just like a baby does it, and after that, humans create alphabets, this means we could seethose sounds. That coordination between learning the sounds and see them, is not natural to our brain, because this is a new skill to our specie, and even though it has existed since thousands of years, not all persons had access to reading and writing, this has been a recent addition to our neo cortex. This is the reason many persons, even in college have problems with spelling. Who doesn’t have a spelling mistake now and then? This is because we must coordinate two systems, we write as we hear, but words not always can be written following the sound.

Of course learning process is amazingly complex. I am sure Henry Markham will spend more than a decade trying to build a brain, if we think that nature has needed thousands of years, maybe millions, 10 years is a very optimistic agenda, specially with a system than never stop adapting to new environments. 45 years ago only few had access to computers, and we continue adding features, every 2 or 3 years another update surprises us. Nature has much more updates, now we can walk on a crowdie street, avoiding cars and other persons and check Facebook at the same time. Some of us won’t create a coordinated system fast enough, and others continue trying.

Can we teach to our brains? I don’t think so, I wouldn’t spend time or money in that direction, we must enrich our environments to create new skills, because at the end, our brain was designed to answer to the environment and adapt, creating new and more sophisticated strategies, like the simple act of reading.

References:

Blue Brain Project EPFL. Available at: http://bluebrain.epfl.ch/

Dzib Goodin, A. (2013a) La arquitectura cerebral como responsible del proceso de aprendizaje.  Revista Mexicana de Neurociencia. 14(2): 81-85.

Dzib Goodin, A.  (2013b) La evolución del aprendizaje: más allás de las redes neuronales. Revista Chilena de Neuropsicología. 8(1): 20-25.

Honisgbaum, M. (2013) Human Brain Project: Henry Markram plans to spend €1bn building a perfect model of the human brain.

Human Brain Project. Available at: https://www.humanbrainproject.eu/

Lamb, TD. (2011) Evolution of eye. Scientific American. Available at: http://www.scientificamerican.com/article/evolution-of-the-eye/

Masaki, T., and Shigeru, K. (2010) History of studies on mammalian middle ear evolution: A comparative morphological and developmental biology perspective. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 314b(6): 417-433.

Mallo, M. (2001) Formation of the middle ear: Recent progress on the developmental and molecular mechanisms. Developmental Biology. 213(2) 410-419.

Nilsson DE., Pelger, S. (1994) A pessimistic estimate of the time required for an eye to evolve. Proceedings of the Royal Society Biological Science .256(1345)53-58.

Adult brain and neuro-plasticity

As I have been sharing in other posts, plastic capacity of young brains has been tirelessly studied, but what does happen with the neuroplasticity of the adult brain?, are brain structures modifiable?. 

 It is known that there are critical periods which depend on the explosion of neural connections and they decay during lifetime, however, new research show a different vision, and now is said that is never too late to make a brain learn new tricks. 

   

  For example, according to preliminary studies in the laboratory of Michael Merzenich of the University of California at San Francisco, who is a pioneer in the understanding of plasticity, memory in pre senile individuals can, with the help of training, be dramatically rejuvenated, and his studies show that plasticity has no limits. Some times even if areas of the cortex, e.g. Broca's area are destroyed by a stroke, a brain attack or a brain tumor, patient is likely to recover function once moved the circuit affected by others who may have other capabilities (Shreeve2005).

Something remarkable both neurogenesis, synaptogenesis is the direct relationship between increased mental activity and physical exercise, which suggests that people could reduce the risk of neural diseases and thereby help to repair brain processes choosing mental challenges and a physically active life, that’s the reason a majority of researches are running environmental stimulation as an important part of the recovering process, demonstrating that the environment can affect on the brain structure, which opens up the possibility a complete new field on areas as architectural designs which could modify the way they build  homes, offices and schools in order to allow more enriched environments that seek better cognitive functioning.

But what about brains who suffers an injury?, current research indicates that plasticity exists, during the pre and post natal, recognizing the existence of critical periods to make this happens, however, once the synaptic connections are established and they break or deteriorate, the pattern of cortical reorganization  the functional recovery of different capabilities is not the same, while the basic mechanisms of plasticity are shared by all the cortex.

However, there are peculiarities in the patterns of recovery depending on the type of injury, mainly finding the following modalities: linguistic and sensory motor, neuropsychological injuries

Regarding the recovery of a motor injury, it is known that  structures of the cerebral cortex is constantly changing in response to training, or behavioral and motor acquisitions. It is thus that the construction of functional maps of motor areas that have been made possible thanks to the use of three neuroimaging techniques: Transcranial magnetic stimulation: which is one way not-invasive stimulation of the cerebral cortex, it’s one of the latest tools that have built-in neuroscience, both for purposes of study and research; functional magnetic resonance imaging: which are a type of magnetic resonance imaging in which the response is measured hemodynamics (blood flow) related to the neural activity in the brain or spinal cord; also we can find the Positron Emission Tomography: which is a technique used on nuclear medicine that produces a three-dimensional image of the body's functional processes,  these techniques that have made possible the understanding of the way in which the motor cortex adapts and changes in response to injury and therapeutic intervention.

Studies conducted in people with central hemiplegia, show that functional recovery through rehabilitation, produces mechanisms of plasticity that differ depending on the timing of the injury.

When the injury requires a longer recovery time and therefore more long-term treatment, permanent changes in the cerebral cortex are generated. In most of the cases new motor routes are created starting  at the motor cortex in the healthy hemisphere and are directed in a ipsilateral manner (contrary), in a way that takes place the functional recovery of the affected side. While in other less numerous group of patients, new axons from the motor cortex not damaged are wrongly projected bilaterally, producing a less functional recovery with intense movements in mirror, this is an example of wrong adaptive plasticity where the patient moves the left hand, at the same time that moves right hand (Diaz-Arribas, Pardo-Hervas, Tabares-washing, Rios-lago and Maestu, 2006) . 

Talking about linguistic recovery, neurobiological studies provide data corresponding to language and its configuration in a certain moment of neurodevelopmental, have allowed increasingly better understand the role of language and their behavior after injury.

In this sense it is known that children around 4 years old have very well located the representation of language in the left hemisphere, in the majority of cases, virtually unchanged in the adult. However, these studies have found evidence that brain cortex involved in linguistic functions is also sensitive to the experience, so the centers related to the language processes  are not stable over time, and expand or contract depending on the experience, since new words are learned or  we stop employ others throughout our life.

Apparently, this area is initially broader throughout the perisylvian areas, which are focusing as it reaches the competence in the language, on the basis of increased complexity and level of specialization, in such a way that the peripheral areas which originally related to the language retains this ability as a secondary capability latent, capable of supplementing or completing the linguistic function in case of injury of the primary area (Hernandez-Muela, Mules, and Mattos, 2004).

However, it is worth mentioning that lesions of the left hemisphere are associated with greater involvement of the normal activity of the right hemisphere and an atypical asymmetry in activations of the perisylvian during linguistic activities area, to a greater extent when the injury takes place in early stages, that when it happens at later stages in life (Gage, 2007).

In this way, as a result of brain plasticity that happens after injury occurred in early stages, diverse studies have been found an increase in the prefrontal, frontoparietal and lower bottom regions activation, for expressive language, and inferior temporal, temporary front and temporary regions for the receptive language. Probably, because these structures are related with the area responsible for functions associated to the language in early stages, that with the maturing and growing complexity of the neural connections, so these are free depending on the type of tasks, but retain this ability, latent form to resume its function in case of later injury (Gollin, 1981; Maciques, 2004; Tubino, 2004; Ginarte, 2007).

In this sense, an early lesion that took place before the first year of life, leads to an extensive reorganization both of the right and left hemisphere, this is known as adaptive plasticity, as occurs in the motor cortex, but there is evidence of plasticity in the regions responsible for the language after a neurological damage, may be different in the case of the motor domain (Diaz-Arribas, Pardo-Hervas, Tabares-Lavado, Rios-Lago and Maestú, 2006).

However, the plastic changes are not limited only to the motor cortex or the language, but it also occurs in sensory systems. In this regard, an example is the case of hearing, which requires connection with environmental sounds as stimuli and whose processing is important for verbal communication, so it is a decisive step for the acquisition of language. This sensory modality is known that there is an auditory critical period for language acquisition. So was demonstrated in studies conducted in deaf children after application of cochlear implants (Hernandez-muela, mules and Mattos, 2004).

  In this regard, in terms of language difficulties secondary to the existence of a sensory deficit by hearing loss, it is necessary to consider two situations: the first one, is when hearing loss takes place prior to the acquisition of language, in the very early stages, while a second situation occurs when the loss hearing occurs subsequent to the acquisition of the language.

     In the first case, the plasticity will be through a migration of the function, while in the second case, the potentiation will be to more long term and will require the support of cochlear implant (Coplan, 1985; Hernandez-Muela, Mules and Mattos, 2004).

The other sensory aspect to consider is the visual capacity, even tought plasticity of visual fields is not well known, it’s possible to talk about at least two situations, on the one hand, when the visual cortex is damaged by a traumatic injury, and when, despite the strength of the occipital cortex, or if by peripheral reasons, it is not possible to develop the vision.

With respect to the first situation, some descriptive studies show the transfer of function from the visual cortex to adjacent areas on the occipital cortex, such as posterior regions of the parietal and temporal lobes, similar to the hearing process, which is called plasticity by migration (Castroviejo, 1996; Deacon, 2000; Ginarte, 2007).

Talking about the second situation, which presents peripheral blindness, caused by tumors in the optic chiasm for example, may be determinants of blindness at very early stages, it has shown the existence of the so-called mode cross plasticity i.e. Permanent reorganization that allows in principle do not own capabilities to a certain area, which appears to increase or facilitate compensatory alternative perceptions of deficit sensory. These changes involve mechanisms neuroplasticos in which areas that processed certain information, accept, process, and respond to other types of information from different sensory modality (Hernandez-Muela, Mules, and Mattos, 2004;Ginarte, 2007).

This way is usually explained the process of plasticity of occipital cortex from blind children ocurred at early stages, which facilitates and at the same time is result of the learning to read Braille, which creating occipital cortex networks ranging from motor areas that allow the movement of the fingers on the paper, and the areas that usually is used for viewing the letters in compensation by the absence of vision. This widening of the cortical representation of the index finger may be due to two mechanisms: the first, by unmasking of silent connections (increase of synaptic efficacy), in the same area injured or deficient and adjacent, and the second, structural plasticity, while other studies have shown the expansion, in the cortex somatosensory representation of the finger index, fundamental Braille readingwith what it says is that people can "see" through their fingers, as they achieve recognition of shapes and even colors at the touch of a surface (Poch, 2001).

References:

Díaz-Arribas, M., Pardo-Hervás, P., Tabares-Lavado, M., Ríos-Lago, M. y Maestú, F. (2006) Plasticidad del sistema nervioso central y estrategias de tratamiento para la reprogramación sensoriomotora: comparación de dos casos de accidente cerebrovascular isquémico en el territorio de la arteria cerebral media. Rev Neurol. 42 (3): 153-158

Hernández-Muela, S., Mulas, F. y  Mattos, L. (2004) Plasticidad neuronal funcional Rev Neurol. 38 (Supl 1): S58-S68.

Gage, F. (2007) Brain, repairs yourself. In Floyd E, Bloom (2007) The best of the brain from Scientific American: mind, matter, and tomorrow’s brain. Washington DC. Dana Press.

Ginarte, Y. (2007) La neuroplasticidad como base biológica de la rehabilitación cognitiva. Geroinfo. Vol. 2. No. 1. 31-38

Gollin. E. S. (1981) Developmental and plasticity: behavioral and biological aspects of variation in developmental. New York. Academic Press.

Maciques (2004)  Plasticidad Neuronal. Revista de neurología. 2 (3) 13-17.

Poch, M.L. (2001) Neurobiología del desarrollo temprano. Contextos educativos. 4. 79-94.

Shreeve, J. (2005) Cornina’s brain: all she is… is here. National Geographic. Vol. 207. num. 3.  6-12.

Tubino, M. (2004) Plasticidad y evolución: papel de la interacción cerebro – entorno. Revista de estudios neurolingüsticos. Vol. 2, número 1. 21-39.

Stem cells in adults and embryos

I will continue this time with the topic of neuro-plasticity and I can mention that there are two lines of research which are currently the most studied: on the one hand, it is the idea that postnatal human brain has adultstem cells apparently remain during the adulthood and that they can help rising new neurons, this line of work has opened a door in the field of regenerative medicine because until recently, was believed to be the brain ability to restore its function through neural regeneration was null. 

In this sense some researchers isolated brain live stem cells from human corpses up to five days after the body died. This was possible  keeping frozen the bodies and it was observed that cells obtained from these bodies gave rise to new neurons and glial cells in vitro, so currently, it is believed that the presence of brain stem cells can at least in part, explain the great plasticity and functional improvement seen in patients after cerebral damage, even extensive injury. However, it is not known yet, the specific role and regenerative capacity in response to different congenital and acquired diseases of the central nervous system (Belkind-Gerson and Suárez-Rodriguez, 2004; Aguilar, 2005). 

By this reason, this line of research has focused on studying the fact that under certain conditions, stem cells can be differentiated towards cell type required to regenerate the damaged tissue signals acquired directly on the site of the lesion, since once there is a neural injury, damaged neurons come in contact with the myelin sheath which has released other injured neurons, and since myelin contains several inhibitors, that prevent neurons that have not died to restore their connections, it is not possible even to understand the mechanisms in which it is possible to restore functions (Belkind-Gerson, Suarez-Rodriguez, 2004).

This capacity has generated other kinds of studies searching answers of cell regeneration, which direct their efforts towards the calls stem cells.

 These are embryonic cells, i.e. their destination still has not been decided and will be transformed through a process of differentiation and proliferation in different types of cells. These are very different from any other in the body which can be used to regenerate tissue-specific. The neural stem cells are those which is capable of self-renewal and that can generate other kinds of cells different from them through an asymmetric cell division process, so you are defined by their multipotency. These cells are found in bone marrow and they have been used successfully to generate heart tissue (León Carrión, 2003, Hernandez-Muela, Mules, Mattos, 2004; Shreeve, 2005).

Foto
ian tunkin

Certainly this breaks with the dogma that neurons do not grow spontaneously in every part of the adult brains, however, research pioneers began in the decade of the 90s, when researchers in the field of Neurobiology found that mature brains of some mammals were able to generate new neurons.

Of course, biologists believed that this was only possible in young brains, but Elizabeth Gould of the Rockefeller University, showed that new cells grew in adult brains, in particular, it has been found in the hippocampus (part of the limbic system, responsible for learning and memory processes) hundreds of new cells grow every day.

 Since then, many more researchers have shown the cells destined to become neurons travel from the ventricle of the olfactory bulb, especially in a pair of structures responsible for receiving information that olfactory cells in the nose.

Although no one is sure why the olfactory bulb requires so many new neurons.  It can be speculated that this being a necessary structure for learning new information, it is essential to add neurons to create connections between existing neurons and new, thus increasing the brain power to process and store the new information (León Carreón, 2003, Avaria, 2005, Shors, 2009). 

      

While there are other investigations focus on neurogenesis (growth, spontaneous or induced neurons)and the discovery of new neurons out of the hippocampus and the olfactory bulb, these not have systematized their findings, and one of the reasons is that the methods used to prove the existence of neurogenesis is difficult, although recently they have come to detect neural growth in the bone marrow of adults.

Even when neurogenesis depends on the genetic component, the various contributions to this theme in works with other species such as mice have become so clear that different laboratories have tried to make progress with humans. In fact researchers United States and Sweden, showed that this was possible also in humans, though not with as much clarity as in other species (Shors, 2009; Gage, 2007; Avaria, 2005; Leon Carrion, 2003).

In animal studies, it was found that in only a couple of weeks, most of these newly born neurons, died, unless the animal was challenged to learn something. This new learning, which required much effort, especially kept alive those cells. But works have found that neurons are not necessary for all types of learning, because even though they can play a role in the resolution of problems, based on past experience, they are not generated at specific times, since its production is linked mostly with a large number of environmental factors.

 For example it has been observed that alcohol use delays the generation of new cells, while the rate of neurogenesis can be increased by the exercise. This was demonstrated in research with mice, which spent a great time running on a wheel and increased twice the neuronal production compared with mice with a sedentary lifestyle (Shors, 2009).

      

However, even though this discovery takes a turn to the neurobiological research, unanswered questions remain, which do not allow all the application of these findings to identify the effects of learning on the survival of new neurons, for example: what neurotransmitters and receptors, proteins are involved?, and how do they operate these mechanisms?; Why do these new neurons helps learning to integrate neural networks? or Do they only promotes the survival of those that are already connected?; do these neurons contribute to knowledge?.

The goal is that these studies will help to understand degeneration neuronal, but mainly people health, mainly to avoid diseases such as Alzheimer's and Parkinson's, as well as understand the neural processes related to the developmental disorders. 

References: 

 Aguilar, F. (2005) Razones biológicas de la plasticidad cerebral y la restauración neurológica. Revista Plasticidad y Restauración Neurológica. Vol. 4 Num.1. 5-6.

Avaria, M. A. (2005)  Aspectos biológicos del desarrollo psicomotor.  Rev. Ped. Elec. [en línea] Vol 2, N° 1.

Belkind-Gerson, J.  y  Suárez-Rodríguez, R.  (2004) Regeneración cerebral. Realidades, posibilidades y esperanzas. An Med Asoc Med Hosp ABC. 49 (4): 201-207.

Gage, F. (2007) Brain, repairs yourself. In Floyd E, Bloom (2007) The best of the brain from Scientific American: mind, matter, and tomorrow’s brain. Washington DC. Dana Press.

Hernández-Muela, S., Mulas, F. y  Mattos, L. (2004) Plasticidad neuronal funcional Rev Neurol. 38 (Supl 1): S58-S68.

León Carrión, J. (2003) Células madre, genética y neuropsicología. Revista Española de Neuropsicología. 5 (1) 1-13. 

Shors, T. (2009) Saving new brain cells. Scientific American. Vol. 300. num. 3. 41-48.

Our brain is not programmed to reading or writing

The title is certainly somehow confused, but here I'll explain you how I came up to this.

I am advisor of a very intelligent woman who is studying musical cognition and her work proposes a relationship between the processes of reading and writing music and natural language. We have written a couple of articles which we hope to publish soon, but while we were working with her thesis I made comments, and about a paragraph I wrote her the following note: remember that our brain is not evolutionarily programmed for reading and writing.  

She knows me very well and of course she has read my writings both scientific as my blog, so I never could imagine that a simple comment would take us to a fascinating explanation which I would like to share with all of you.

"Our brain processes learning, including the process of reading and writing, tell me how come is not evolutionarily programmed to do this?"

The evolutionary process has led the species to acquire different skills, which have taken thousands of years to become part of the system, and therefore conquer a brain structure which command it. 

Vision is for example, a victory that has taken much more time to development than the language. Each evolutionary triumph is a process of adaptation, which involves different prototypes that never seems to arrive at the final product, since nature makes adjustments depending on the environment, and although sometimes we take for granted that we are born with our fabulous capabilities  to understand the world but not all of them have a genetic complement.

That is the case of the reading and writing acquisition, it's not something  even ontogeny arises from the moment of birth, because children require at least between 4 and 6 years to start the acquisition process, and many more years to consolidate it.

When we think in terms of history of human evolution, we can see how language is a process that requires  hearing the differences of every letter of the alphabet, and language recognition, and that involved the development of hearing, and probably the first acoustic traits were environmental, which allowed beginning to distinguish different sounds such as rain, singing of birds or wild animal sounds, and through many years and effort, led to the conquest of the language, which is, is a trophy of homo sapiens, as some claim.

The development of the vision began as is estimated around 600 million years ago in vertebrates, maybe after hearing. If we think of the cosmic calendar that Carl Sagan gave us to find life on Earth, we will be able to see that language arose more or less in November and literacy, which involves integration of signs at eye level and its relationship with the sounds of the alphabet, (see the sound of language) I think arises around the last minute of December...

Babies can listen through the medium within the womb, although hearing in an air environment is different from the aquatic environment, even though a few days old baby is able to recognize sounds, although it does not distinguish them, and gradually begins the process to make differences with the sounds of the language, to begin an amazing preparation to modulate it, repeat it and finally begin to talk and conversations If this is culturally stimulated. 

The same should happen with the reading and writing process, since we can find find people who know how to speak, but cannot read and write. This step requires environmental stimulation and the reason is simple, the emergence of the reading - writing, it was not an ability shared by all people, only a few had access to learning and developing skill, the bulk of the population had no access to the alphabet, books or writing.

With the arrival of Gutenberg's printing press, many more people could have access to the books, provided they could pay them... so it took many years before literacy became a learning with open access among the population, but if we think  that this happened at the last moment of December 31st in the Cosmic Calendar, then is easier to understand why our  brain does not have sufficient practice to develop it without help.

What my student and I are exploring, is the way that our brain is using are sharing the musical and natural language (We think music was first, and we have shared for many thousands of years, so no one teaches us how to move hips when we heard drums), and this same brain structures are shared by literacy, to conform this new  cognitive skill.

For this reason that when a child has difficulties in the acquisition or consolidation school learning process, we recommend to thinkabout baby steps, finally the human specie has need thousands of years to learn and we never stop.

References:

Lamb, T., Collin, SP., Pugh, Jr., e. (2007) Evolution of the vertebrate eye: opsin photoreceptors, retine and eye cup. Nature reviews Neuroscience, 8, 960-976.

Masterson, B., Heffner, H., and Ravissa, r. (2005) The evolution of human hearing. The Journal of the Acoustical Society of America. 45, 966.

Wright, S. (1931) Evolution in Mendelian populations. Genetics. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1201091/pdf/97.pdf