Until recently, the human brain was thought to complete its development to a great extent when the child is 5 or 6 years old. This was mostly theoretical, for we did not have the technology to visualize the brain of a living person in order to observe its development. This changed with the magnetic resonance imaging (MRI) technique, which began to be used in various applications in 1970s and enabled us to obtain more clear information about the structure and functions of the brain. As of 1991, thanks to the functional MR (fMRI) technique we are now able to observe activities of a living brain. fMRI technology is used to scan and visualize the specific region of the brain that is activated in the face of stimuli such as noise, vision, and thought. Therefore, the fMRI research carried out during the last ten years has been guiding research studies on how memory, language, pain, and learning occur as well as those on how emotions are formed with brand-new perspectives. New discoveries about the adolescent brain have radically changed our understanding of how students aged 11-18 learn.

Adolescence is a significant process in which great changes are experienced both physically and mentally. The structure and substance content of both the body and the brain are reconstructed during this period. Knowing the changes experienced by the adolescent brain during this period will be very useful for both parents and teachers as they support their children and students in their growth and settling their characters.

White matter

White matter in the brain is mainly made up of myelinated axons and glial cells. An axon is a long, slender projection of a neuron (nerve cell). Myelin is a white layer of a fatty dense sheath that surrounds an axon. The formation of myelin sheath is called myelination or myelinization. Glial cells in human body far outnumber neurons and although they do not transmit electrical signals they have essential functions by producing and maintaining the milieu for neurons to function properly. One of their functions is to destroy and remove harmful chemicals and dead neurons. Glial cells also play an active role in myelination. The electrical signals at axon terminals are transmitted to other neurons at junctions called synapses. There is no physical contact among most of the neurons, therefore the message at the synapses is transmitted chemically to other neurons through neurotransmitters. A myelinated axon transmits electrical signals at a rate 100 times faster than an unmyelinated one and the myelin sheath helps a neuron to regenerate faster. In other words, it restores in a markedly faster way to a state in which it transmits a new electrical signal. Once these two features are combined this results in a 3000-fold increase in the bandwidth if we liken a myelinated axon to an internet cable. Another function of the myelin sheath is to calibrate the coordination of the signals that come from other neurons. It allows for a graceful timing of transmissions so that signals that come from neurons that are both near and far can be received simultaneously. As a result of myelinization, the amount of white matter continues to increase linearly during adolescence until the end of the 20s. Adolescents, therefore, process information in a way much faster than that of children and can thus move, speak, make decisions, and react faster.

Gray matter

Gray matter is mostly composed of neuronal cell bodies, dendrites (short body extensions) and supporting cells. It also contains the connections linking neurons to other neurons, known as the synapses.  A baby’s brain has up to twice as many synapses as it will have in adulthood.  A total of 60% of babies’ energy is used by their brains compared to around 20-25% in adults. The volume of gray matter begins to decrease seriously during adolescence and this decrease can be attributed to a process called “synaptic pruning.” Through this process, the neural links that are not used or stimulated by environmental factors are pruned and eliminated. Although this sounds like a negative process, on the contrary, it is essential for a more efficient brain. The links that are unwanted and unused are destroyed. This is a very significant process that is partially influenced by one’s existing environment with a lasting effect in shaping a person’s life. An increase in gray matter occurs for a short term just at the beginning of adolescence. A second synaptic pruning takes place later during adolescence. This occurs most often in the prefrontal cortex region of the brain. This region has been implicated with many significant and vital functions of the brain such as planning, decision making, prioritization, strategy formulation, suppressing urges and desires, delaying gratification, understanding others and maintaining social interaction, and setting long-term goals.

One biological fact that will help us understand adolescents a little bit more includes the fact that myelination and brain development occur in a back-to-front pattern. That is, the prefrontal cortex, which controls the functions that implicate these vital and adult features, develops last and this corresponds to the years of life after age 20.

One’s social environment contributes significantly to synaptic pruning and regulation of the morphological structure of the brain. One dimension we can add to this fact is that children do not only need convenient physical environments, but also need spiritual environments where they can develop and realize their spiritual lives, feel their humanity, and establish cordial relations with God.

The source of adolescence problems: limbic system

The integrative parts of the limbic system, or as it is popularly known as the “emotional brain,” are the hippocampus, amygdala, thalamus, and the hypothalamus. The hippocampus is both the center of emotions and an important part of the memory. The amygdala, on the other hand, is the center for strong feelings such as anger, fear, joy, and pleasure. The limbic system is the region of the brain that controls most of the emotions and behaviors underlying the basic problems and characteristics of adolescents such as basic risk taking, motivation, hunger, sleep, long-term memory, excitement-seeking, reward-seeking, novelty-seeking, superiority of emotional expression, and priority of immediate needs. As already stated, the brain matures from back to front. That is, while the development of the limbic system is complete by adolescence the prefrontal cortex is not yet fully developed. If we liken the limbic system to a car’s accelerator pedal, then the prefrontal cortex can be likened both to its steering wheel and its brake pedal. That is, adolescents are like a car with the accelerator pedal fully pressed but the steering wheel and brake pedal not working fully yet. Studies have found that in adolescent brains the nucleus accumbens, the region of the brain related to reward, motivation, and pleasure, is much more activated in the face of big rewards in comparison to the brains of children and adults. However, the impacts of small or uninteresting rewards or goals are even less in an adolescent brain than they are to a child’s brain. I contend that this is an issue that parents and teachers should dwell on.

Studies have also shown that adolescents tend to take bigger risks in environments where their peers are present. It has been found that adolescents can think as maturely as adults in laboratory setting, that is in neutral conditions where emotions do not interfere. However, this completely changes in the presence of emotional interference, peer pressure, or other factors related to one’s peers.

Brain research has revealed that young people’s brains tend to change in line with the external interventions, education, and rehabilitation they are provided with. The environment, which includes education as well, can play a significant role in shaping a young individual’s brain. New information and developments related to brain development have brought about radical changes in the fields of education and pedagogy. New learning theories also necessitated the development of new and alternative teaching techniques that are congruent with the brain development model.

Reference

• Armstrong, T. (2016). The power of the adolescent brain: Strategies for teaching middle and high school students. Retrieved from https://www.weareteachers.com/wp-content/uploads/ASCD-2-Book-Sample-PoweroftheAdolescentBrain.pdf

The miracle of life appears in the form of a baby which develops from a fertilized ovule (zygote) following millions of other events. This series of events, which is almost always the same for every fetus, can be grouped as reproduction, differentiation, and development. The zygote completes its development in the womb; postnatal growth can continue until 20 years of age. Even though every event during the baby’s development seems to take place with chaotic reactions, harmony and order are there for us to discover. One of these astonishing events is the perfectly symmetric growth of the fetus/baby. Most organs in the human body appear in pairs and are symmetric. Babies are born with 300 bones; however, some bones later fuse with other bones, leaving only 208 bones in the adult human. It is still a mystery how long bones such as the humerus, radius, ulna, femur, and tibia are able to grow on both sides of the human body in a symmetrical manner.

Mechanisms that control growth in organs

In vertebrates, both internal developmental programs and the external factors which stimulate or inhibit growth play a role in the ultimate size of an organ. But the relative effects of these two mechanisms can vary significantly in different organs. When pieces of spleen from an embryo that is at a later stage of growth are transplanted to a newly developing embryo, each new piece grows, but not to the size of the original spleen. The total weight of all the transplanted spleen pieces is equal to a normal spleen’s weight. When the spleen reaches a certain weight, growth inhibiting factors are secreted, which stimulate negative feedback mechanisms that limit growth. When a spleen reaches a certain size, the density of the inhibiting factors increases simultaneously, halting growth. Growth in the liver is controlled by extracellular factors (various substances in the blood, hormones, vitamins, minerals, etc.). When a section is cut off of the liver, the section continues growing and developing until it reaches the size of the original liver. The thymus has a growth process that is executed by a cellular genetic program. When sections of a thymus taken from the embryonic period are injected into developing mouse embryos, every section grows until it reaches the ultimate size.

More evidence of cellular growth programs was acquired via an experiment that was carried out with the salamander genus Ambystoma. When the leg bud of the larger species was injected into the smaller species, it would at first grow slowly, but then it would reach the normal size of its own species (the larger species).

Distinguishing growth and symmetry from one another

Both the arms and legs have long bones. A long bone consists of two parts (diaphysis and epiphysis). The diaphysis is the middle (core) part of the long bone. It consists of hard bone tissue, and is like a tube. The hyaline cartilage-covered joint forms the epiphysis of the long bone. In a growing bone, there is a growth plate (epiphysis plaque) made of hyaline cartilage; this is located between the diaphysis and the epiphysis. The epiphysis plaque causes the bone to grow longer; when growth is complete, the epiphysis plaque ossifies (becomes bone). In other words, growth stops. There are some clues that show the existence of positive feedback mechanisms which control the symmetric and balanced development of the arms and legs while the fetus is still growing. The arms and legs grow due to the development and growth of the plaques located at opposite ends of the long bone. The ultimate size of the arms and legs are proportional to the size of the finger bones (phalanx) and the metacarpus. According to current knowledge, growth in our arms and legs is only controlled by internal growth programs and the active growth of the plaques. We do not yet know the mechanism through which how much the bone must grow and symmetrically with the organ (the other arm or leg) on the other side of the body. But even if this is discovered in the future, we will continue to appreciate the perfect and miraculous aspect of this phenomenon.

In addition, in growth-plaque transplant experiments, the development of the transplanted growth plaque is dependent only on the age and size of the donor. Growth plaques cause the bone to grow, but the plaques themselves remain the same size for years. The cartilage cells they produce (chondrocytes) exchange places with the bone cells (osteocytes) in harmony and without destroying the length of the bone. Cells from different areas of the growth plaque act differently. Stem cells are found on the upper section, near the epiphysis. Immediately above them is an area where cells reproduce very quickly. At the bottom of the epiphysis, the cartilage cells grow up to 4 to 10 times larger than their normal size (hypertrophy). Cell reproduction here is mostly due to hypertrophic chondrocytes. The chondrocytes die and break up, then change places with the bone tissue. The dynamic process of these events in the growth plaque repels it from the bone area, and as a result, the bone grows longer.

Sustained symmetry despite cell sequence and speed of reproduction

The rapid growth rate in the legs and arms during the embryonic period continues to increase until the child is three years of age. This growth rate slows down until the individual reaches adolescence. During the fastest growth period, which is from adolescence to the early 20s, the growth rate rapidly increases. For example, most people who grow between 30 and 37.5 cm during the first two years of life can grow between another 7.5 and 10 cm every year during adolescence. At the onset of adolescence, rapid growth due to a sudden change in the volume of cells is observed. After adolescence a sudden falling off in the speed of growth can be observed due to the effect of hormones on the growth plaques in the spine and other long bones. The growth plaque now fuses with the neighboring cells and growth stops. However, the fusing of the growth plaque is the result of the cessation of growth, not the cause. After growth stops, the growth plaques begin to disappear. When the reproduction potential of the cartilage cells in the growth plaque has been exhausted, the growth plaque begins to disappear.

Growth plaques in different bones can trigger growth at various rates; these rates can differ as much as seven times. In fact, growth plaques on different ends of a bone can have different growth rates, provided that this rate is consistent with the genetic program. The number of cells on the growth line is 40 times more than in other areas. The number of cells produced here can exceed 10,000 cells per day. For symmetric growth between the arms and legs to be sustained, the number of cells in the growth plaque must be the same or very close. Experiments carried out on rats show that eight cartilage cells leave the growth plaque to exchange places with cells above them every day. It can be said that the growth of the bone is caused by the increase of cells in the growth plaque (which sustains its size). The growth rate caused by the growth plaque can be calculated by multiplying the growth plaque’s cell production rate by the average length of all of its cells. Different growth plaques provide different growth rates. This difference can be caused by the difference in the size of the growth plaques, the difference in cell production rates, and/or the difference in the hypertrophy (growth) rate of every cell. The upper growth plaque in the tibia of mice generates 16,400 cells every day; the average life span of these cells is around 30 hours. Can such harmonious, symmetric, and equivalent growth in the arms and legs-despite the large number and variety of cells-be the work of pure coincidence, mindless nature, or unconscious molecules?

Do hormones play a role?

The main molecular players that organize longitudinal growth in bones during childhood are the growth hormone, the thyroid hormone, and corticoids. The sex hormones (androgens and estrogens) are programmed to influence growth during adolescence. Estrogen is the main determiner of characteristics related to increased height and an increase in bone quality, as well as adolescent-related physiology. These hormones are in charge of coordinating growth throughout the body. It is for this reason for women, after the menopause, the production in estrogen decreases and osteoporosis and brittle bones can occur. According to the current view, cartilage cells have a certain genetic reproduction potential, and when this potential finishes, growth stops. The growth rate during the embryonic period is 20 times higher than that of mid-childhood. The growth rate drops greatly during mid-childhood. If we exclude the noticeable increase during adolescence, the cells responsible for growth have begun to age. The bones on opposite sides of the body stay about the same size, despite all of these changes in growth rates. Circulating hormones and neuroendocrinal factors are believed to play important roles in maintaining symmetric growth. But there is no conclusive evidence to support this belief. Even though one can think of factors such as pressure, tension, and sports as helping control harmonious and symmetric growth of bones, no proof has been attained from controlled experiments. As a person ages, a gradual decrease in growth can be observed. Even if a growth plaque is placed into another organism, be it young or old, the growth rate of the bone does not change. This shows that symmetric growth in long bones is controlled by a program that is operated by internal factors, which is also compatible with the genetic program. When chemical-based medication is given to postpone growth, after the medication has been eliminated, the growth plaques grow faster for a short period to compensate for the lost time. These findings show that timing and the location and circumstances of the cell are critical parameters for reproduction. If the cartilage stem cells in the growth plaque have a certain reproduction potential, then it is clear that cartilage cell reproduction stops when growth comes to an end. If growth inhibiting factors slowly accumulate in the growth plaque, this might cause a deceleration of growth over time. Another possibility is some sort of “meter” in the unconscious and mindless stem cells, which keeps track of the number of cell divisions and thus controls aging. The estrogen in our body has a duty of closing down the growth plaques and speeding up the aging of cells. However, we should not forget that estrogen plays the special role of closing down all of the growth plaques at the same time. Estrogen is one of the visible causes of fertility, growth and development, and resilience. Estrogen also represents femininity and fertility at all levels.

When the signals from unconscious cells in the growth plaques and the quite sophisticated interactions among all the factors that influence growth, all of which require an all-encompassing knowledge to be executed, are taken into account, the impeccable genetic programs of different growth plaques on the two sides of the body that leads to the formation of the arms and legs, as if they have been molded in a factory, is absolutely amazing for anyone who reflects upon it.

References

• Wolpert L. (2010).”Unsolved Mystery: Arms and the Man: The Problem of Symmetric Growth.” PLoS Biology. 2010 Vol. 8(9). pp 1-3
• Extremity Development during the Embryonic Period (www.visembryo.com)

Lofland and Skonovd (1981) distinguish six types of conversion patterns-intellectual, mystical, experimental, affectional, revivalistic, and coercive. Of these six, the patterns most common among the 70 converts to Islam studied for this paper, are intellectual, affectional and experimental. The affectional pattern (which may be defined as ‘example and imitation’) and the intellectual pattern (‘response to teaching’) cover the most significant characteristics of conversion to Islam, usually accompanied by the experimental pattern (‘trying it out’). Mystical and coercive patterns were also found though the latter is extremely rare. The revivalist motif, in which the individual undergoes highly emotional stimulation, was non-existent.

The intellectual pattern was found in 50(71%) cases. The affectional and experimental motifs also played a role in conversion, but these individuals revealed how scepticism about their previous beliefs and their intellectual discovery of the ‘logical consistency’ of Islam prompted their conversion. The affectional motif was dominant in 46 (66%) cases who cited personal contact with Muslims as an important factor. These Muslims, whose opinions or behaviour are valued, offered living examples of the Islamic faith, attractive to those with whom they came into contact. Some converts had been most affected by the Islamic concept of brotherhood. Others were deeply affected through periods of stay in Muslim countries where they saw how the religion can really influence the society.

No matter what the motivating factors, the majority of converts went through a period of ‘experimentation’. 42 (60%) came to Islam after studying or spending a considerable amount of time among Muslim friends, families, or in Muslim countries. As well as getting information and impressions from Muslims, and reading about Islam, they visited mosques and attended meetings and even joined the prayers to see and try it out for themselves. 10 (14%) converts reported having a mystical experience before they decided to embrace Islam.

As for the most important motivating factors, the converts cited response to the teachings of Islam with regard to religious beliefs, moral and social issues, and the spiritual aspects of Islam (see chart). 

The converts entered Islam by various paths and for a variety of reasons. Some accepted it after long study, some in order to marry a Muslim, or after marrying a Muslim. Whatever the reasons and purposes of their choice to convert, conversion rarely happened without human contact. All but 9 converts had been in contact with Muslims in one way or another over a long period of time before they made their decision. It is, therefore, suggested that personal contact with an adherent of Islam is nearly always a contributory factor in the conversion of individuals to the faith. However, it must be emphasized that converts were already oriented towards a religious quest, and then found intellectual satisfaction with what was offered to them.

The overwhelming majority of the converts speak of a gradual process involving conversation with Muslims, reading of the Qur’an, and/or other Islamic literature, and in some cases journeying to Muslim lands. 16 (23%) people’s first contact with Islam was through literature. 16 (23%) people were first introduced to Islam when they travelled to a Muslim country. 26 (37%) reported they first knew about Islam through conversations with Muslims. 10 (14%) came into contact with Islam through male/female relations. This included 3 female converts who followed their English husbands’ conversion while 2 had one of their family members or a relative convert to Islam (see chart).

Conversion age

Early studies, at the turn of the century, of converts to or within Christianity found conversion to be primarily an adolescent phenomenon (Starhuck, 1911, p.38 Hall, 1920, pp.288-92). By and large this trend seems to continue today (Argyle, 1958, p.61). In contrast to studies of conversion within Christianity, studies of conversion to contemporary religious cults indicate that conversions take place at a later age, in the late teens or early 20s (Ullman, 1989, p.110).

The conversion age for Western converts to Islam presents a striking contrast. In fact, Poston’s (1992) questionnaire study of European and American converts to Islam found the average conversion age to be 31.4 years. The average conversion age for the English converts to Islam is 29.7; ranging from 15 to 61 with the vast majority falling into the 23-45 year- old age group.

In Britain less than 15 percent of the population attend church each week. Over half of those who attend at the age of 13 have ceased to do so by the time they are 20. Furthermore, by school leaving age, very few young people still claim any allegiance to the Christian churches (Francis, 1984, p l0). This is, in fact, what most of the converts to Islam experienced in their late adolescence. Some had been religious in their pre-adolescent years, but this religiousness had disappeared, in part because they had been taught at secondary school, or by society in general, to think rationally about religious matters. They then lost their capacity for religious experiences, and Christianity lost its plausibility for them. They became restless with the religious tradition of their family or society, questioning critically its intellectual, moral and religious adequacy. Tony, 17, bitterly criticized the society:

‘This society doesn’t make you know about religion. It is wrapped up in the wrong way of life; just working, sleeping, drinking. Religion is not mentioned to people. I went to a Christian school. They taught us we came from apes. That’s the evolution they believed in, not God. So it was a Church of England school believing in Christianity … their own church made us believe in evolution, whereas evolution is about not believing in God. My age-group now is being taught nothing about religion at all. So this society just wants to bring you up not to live in God or not to worry, just to think about the world.’

Adolescence was the age that the future converts to Islam began questioning the application of their religion in the larger society, or looking for answers to life’s basic questions, or raising questions about the basic creeds of the religion they were taught to believe in in childhood. Again, it was in adolescence that they attempted to fashion a consistent personal code of moral behaviour in a changing culture of uncertain values. Yet it was not in adolescence that they converted to Islam. If we take the figure of 16 years as the age of conversion in a Christian context and 29 for the present sample, this gives over 10 years during which time the person was neglectful of religion or was experimenting with other alternatives. This period may well be explained by Erikson’s concept of a ‘moratorium period’. Erikson observed that many adolescents struggling with the integration process opt to ‘retreat’ for a period of time in order to work out a plan of self-reorganization or integration without disturbance from mundane realities (Erikson, 1962: 43-4). During the ‘moratorium period’ most adopted secular identities by which they accomplished integration without resort to conversion, and some tried to explore other alternatives. Yet this was only a temporary and perhaps incomplete integration, as they eventually searched for a religious alternative. As one convert put it:

‘They let the religious thing lie asleep’ at the back of their minds for a few years.

Conclusion

Conversion is necessarily a multifaceted experience, and it is obvious that not all conversions are of the same type. However, conversions to Islam are usually a complex and gradual process which is prepared by individual conditions over a long period. They are voluntary; not the result of a sudden resolution of spiritual conflicts but, generally, conversions of adults often oriented to points of doctrine. In the light of this study, a process model for English converts to Islam may be outlined as follows:

Firstly, for the religious conversion to occur, the individuals must have rejected the religion and values presented by parents or society in early or late adolescence and enter a period of ‘moratorium’ that lasts several years. At the end of this period they must still he experiencing disillusionment with the old religion and the society at large. During this period they must have either cognitive concerns, sometimes leading to a search for answers from other religions or emotional distress resulting from personal problems like divorce which in the end leads to contemplating religion as the possible answer. Apparently, because of the earlier dissatisfaction with the old religion, the possibility of returning to it is ruled out. By the end of the first stage, the individuals must have something in their background experience that makes them in some measure sensitive to the message of Islam. 

Secondly, by this stage the new perspective (Islam) must be available. The potential converts must encounter Islam through social relationships (this could he through pre-existing ties like marriage or chance encounters), and mass media or any other available source of information. Affective ties to Muslims, though not always necessary, are usually developed. The individual must he favorably affected by the good example of Muslims or by the ethos of Muslim institutions (as they are perceived), and at the same time question the truth of Islam, eventually accepting it.

Thirdly, the individuals go through a preparational period. Before announcing conversion, the individual has to play the role of convert by gradually learning some practices of Islam, and adopting a life-style which becomes a part of a new self-definition. The potential convert investigates the acceptability of the religion, to test it out through an ‘experimental’ orientation to it, rather than blindly embracing it without considerable thought. The decision to convert is therefore rightly characterized as intellectual’, the end result of a deliberate choice made after careful examination and consideration, as opposed to one stemming from a purely emotional response.