Childhood Plasticity (1)

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Childhood Plasticity (1)

The direction in which education starts a man will determine his future life.

Plato

Early childhood education and care has attracted enormous attention over the past decade. This has been partly driven by research indicating the importance of quality early experiences to children’s short-term cognitive, social and emotional development, as well as to their long-term success in school and later life.

The equitable access to quality pre-school education and care has been recognised as key to laying the foundations of lifelong learning for all children and supporting the broad educational and social needs of families.

In most OECD countries, the tendency is to give all children at least two years of free public provision of education before the start of compulsory schooling; governments are thus seeking to improve staff training and working conditions and also to develop appropriate pedagogical frameworks for young children (OECD, 2001).

Neuroscience will not be able to provide solutions to all the challenges facing early childhood education and care but neuroscientific findings can be expected to provide useful insights for informed decision-making in this field.

Very young children are able to develop sophisticated understandings of the phenomena around them – they are “active learners” (US National Research Council, 1999).

Even at the moment of birth, the child’s brain is not a tabula rasa.

Children develop theories about the world extremely early and revise them in light of their experience. The domains of early learning include linguistics, psychology, biology and physics as well as how language, people, animals, plants and objects work.

Early education needs to take good account of both the distinctive mind and individual conceptualisation of young children and this will help to identify the preferred modes of learning, e.g. through play.

Infants have a competence for numbers. Research has indicated that very young infants, in the first months of life, already attend to the number of objects in their environment (McCrink and Wynn, 2004). There is also evidence that infants can operate with numbers (Dehaene, 1997). They develop mathematical skills through interaction with the environment and by building upon their initial number sense (further explored in Chapter 5).

"Understanding the Brain: The Birth of a Learning Science", 2007, page 43

The Breakfast and the Learning

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The Breakfast and the Learning

The importance of nutrition for health and human well-being is clear. It has direct implications for physical health and particularly for how well the brain functions. We can boost learning capacity through what we eat. For example, studies show that skipping breakfast interferes with cognition and learning. However, many students start school with an inadequate breakfast or no breakfast at all.

A landmark study undertaken in the United States examined the effects of school breakfast on academic performance among 1 023 low-income students from third through fifth grades. Results showed that children who participated in the study made significantly greater gains in overall standardised test scores and showed improvements in maths, reading and vocabulary scores. In addition, rates of absence and tardiness were reduced among participants (Meyers et al., 1989).

In Minnesota elementary schools, a threeyear Universal School Breakfast Programme pilot study showed a general increase in composite maths and reading scores, improved student behaviour, reduced morning trips to the nurse and increased student attendance and test scores (Minnesota Department of Children, Families and Learning, 1998).

Another study tested 29 school children throughout the morning on four successive days with a different breakfast each day (either cereal or glucose drink or no breakfast). A series of computerised tests of attention, working memory and episodic secondary memory was conducted prior to breakfast and again 30, 90, 150 and 210 minutes later. Having the glucose drink breakfast or no breakfast was followed by declines in attention and memory, but the declines were significantly reduced following a cereal breakfast.

This study demonstrates that a typical breakfast of cereal rich in complex carbohydrates can help maintain mental performance over the morning (Wesnes et al., 2003).

"Understanding the Brain: The Birth of a Learning Science", 2007, page 61

Brain Fitness

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Brain Fitness
Learning to Delay age-related Cognitive Decline

Age-related decline is due to problems with various cognitive mechanisms rather than having a single cause. It is likely that all of the different executive processes, as well as their speed, decline with age and contribute to difficulties in higher-order cognitive functions such as reasoning and memory (Park et al., 2001).

Studies addressing the differential decline of neurocognitive function with age show that the speed of information-processing declines already in the fourth decade of life, and applies especially to those cognitive processes which are dependent on areas and circuits within the prefrontal cortex.

Thus, the so called “executive functions” are among the first to deteriorate with age, which becomes manifest in such ways as decreasing efficiency in processing of new information, increased forgetting, lack of attention and concentration, and decreased learning potential.

The effect of age differs within the prefrontal cortex, with the dorsolateral and medial areas being more affected than the orbital region. It is possible that this difference leads to lack of integrity of areas within the prefrontal cortex and plays a causal role in age-related cognitive decline (Tisserand et al., 2001; 2002).

Age-related decline in higher-order cognitive functioning does not necessarily affect creativity. Indeed, there is evidence that creativity is largely independent of other cognitive functions. A study examining the effects of ageing on creativity among Japanese adults ranging in age from 25 to 83 found no age differences in fluency, originality of thinking ability, productivity, and application of creative ability. However, gender differences were found on fluency and productivity with women outscoring men. These results suggest that certain creative abilities are maintained throughout the adult years.

In addition to experience, “fitness” is another factor that affects the cognitive function (see Chapter 3). The idea that physical and mental fitness are related is an ancient one, expressed in Latin by the poet Juvenal as “mens sana in corpore sano” (i.e., “a healthy mind in a healthy body”). A review of the animal literature has found reasons for optimism in the enhancement of cognitive function (Anderson et al., 2000).

"Understanding the Brain: The Birth of a Learning Science", 2007, pages 50-51

Use it or Lose it

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Use it or Lose it

Many cognitive processes in the brain decline when we stop using them, confirming the broad thrust of the lifelong learning concept. Instead of the proverbial “you can’t teach an old dog new tricks” the message is instead “use it or lose it”, raising the further question of how best this should be done.

Combating Declining Cognitive Function

Although our brain is flexible enough to permit learning throughout life, there is a general decline in most cognitive capacities from around age 20 to 80. The everyday impression is that the decline starts much later than at 20 years, simply because it becomes more noticeable during late adulthood.

The losses of executive function and longterm memory in middle-aged adults may also not be too apparent to the individual because they are offset by increases in expertise and skill (Park et al., 2001).

Much remains to be understood, however, about the interaction between increasing knowledge and declining executive function and memory across the lifespan so that further research is needed in this area.

Not all cognitive functions decline with age in the same way. The decline has been most clearly noted in tasks such as letter comparison, pattern comparison, letter rotation, computation span, reading span, cued recall, free recall, and so on. By contrast, increases in cognitive capacities across the lifespan up to age 70 (with some declines by age 80) have also been noted.

This is the case for vocabulary, for example, which manifests an increase in experience and general knowledge counterbalancing losses in other cognitive capacities (Park et al., 2001; Tisserand et al., 2001; 2002).

"Understanding the Brain: The Birth of a Learning Science", 2007, page 50

Plasticity in the Adulthood and the Elderly

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Plasticity in the Adulthood and the Elderly

Contrary to the once-popular assertion that the brain loses 100 000 neurons every day (or more if accompanied by smoking and drinking), new technologies have shown that there is no age dependence if one counts the total number of neurons in each area of the cerebral cortex (Terry, DeTeresa and Hansen, 1987). Age-dependence only applies to the number of “large” neurons in the cerebral cortex. These large neurons decline with the consequence of increasing the number of small neurons, so that the aggregate number remains the same.

There is some decrease in neuronal circuitry as neurons get smaller, however, and the numbers of synapses are reduced. While reduced connectivity corresponds with reduced plasticity, it does not imply reduced cognitive ability. On the contrary, skill acquisition results from pruning some connections while reinforcing others. So, people continue learning throughout life.

Do older adults learn in the same way as the young? There is considerable evidence showing that older adults show less specificity or differentiation in brain recruitment while performing an array of cognitive tasks (Park et al., 2001).

A Positron Emission Tomography (PET) activation study was carried out during the word-fluency tasks. Among the young subjects, the left anterior temporal lobe and frontal lobe were activated during the retrieval of proper names. During the retrieval of animate and inanimate names, and syllable fluency, the left infero-posterior temporal lobe and left inferior frontal lobe (i.e., Broca’s area, see Figure 2.3) were activated. By contrast, the activated areas among the elderly subjects were found to be generally smaller or sometimes inactive, though certain areas which were not active among the young subjects were active among the elderly (Tatsumi, 2001).

It is premature to base conclusions on these findings which need further investigation. One interpretation of these activation patterns is that other brain areas are brought into play among the older adults in an effort to compensate for deficient word retrieval. Alternatively and in favour of the vitality of the ageing brain, fluency or experience with a task necessarily reduces activity levels so that with higher processing efficiency, these tasks can also be shuttled to different areas of the brain for processing.

"Understanding the Brain: The Birth of a Learning Science", 2007, page 49

Brain Changes During the Adolescence

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Brain Changes During the Adolescence

There are several parts of the brain that undergo change during adolescence:

• First, the right ventral striatum, which regulates motivating reward behaviour, faces certain changes. These differences may steer the adolescent brain toward engagement in high reward, risk behaviours.
  
• Second, the corpus callosum develops before and during puberty.
  
• Third, the pineal gland, which produces the hormone melatonin critical to lead the body to sleep, is understood to cue the hormones to secrete melatonin much later in the 24-hour day during adolescence than in children or adults.
  
• Fourth, the cerebellum, which governs posture, movement, and balance, continues to grow into late adolescence. The cerebellum also influences other parts of the brain responsible for motor actions and is involved in cognitive functions including language.
  
• Finally, the prefrontal cortex, which is responsible for important executive functions including high-level cognition, is the last part of the brain to be pruned. This area grows during the pre-teen years and then shrinks as neural connections are pruned during adolescence. Recent studies have suggested that the way in which the prefrontal cortex is developed during adolescence may affect emotional regulation.

"Understanding the Brain: The Birth of a Learning Science", 2007, page 46

Teenage Brain “Work in Progress”

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Teenage Brain “Work in Progress”

Before brain imaging technologies became available, it was widely believed among scientists, including psychologists, that the brain was largely a finished product by the age of 12. One reason for this belief is that the actual size of the brain grows very little over the childhood years. By the time a child reaches the age of 6, the brain is already 90-95% of its adult size. In spite of its size, the adolescent brain can be understood as “work in progress”.

Brain imaging has revealed that both brain volume and myelination continue to grow throughout adolescence until the young adult period (i.e., between ages 20-30).

Brain imaging studies on adolescents undertaken by Jay Giedd at the United States National Institute of Mental Health show that not only is the adolescent brain far from mature, but that both grey and white matters undergo extensive structural changes well past puberty (Giedd et al., 1999; Giedd, 2004).

Giedd’s studies show that there is a second wave of proliferation and pruning that occurs later in childhood and that the final critical part of this second wave, affecting some of our highest mental functions, occurs in the late teens. This neural waxing and waning alters the number of synapses between neurons (Wallis et al., 2004; Giedd et al., 1999; Giedd, 2004).

"Understanding the Brain: The Birth of a Learning Science", 2007, page 45