Children's learning & development
One theory of intelligence sees intelligence in terms of adaptiveness. Thus: "What constitutes intelligence depends upon what the situation demands" (Tuddenham 1963). Intelligence in these terms cannot be understood outside of its cultural context. Naturally to us it may seem self-evident that intelligence has to do with analytical and reasoning abilities, but we are perceiving with the sight our culture taught us.
If we lived, for example, in a vast desert, where success relied on your ability to find plants, water, prey and to remember these locations, an "intelligent" person would be one who was skilled at finding their way around and remembering what they'd seen and where they'd seen it. In a society where people are stuck within a limited social group, where people are forced to get on with each other because they can't escape each other, and where survival requires you to depend on these people, social skills will be highly valued. An "intelligent" person might well be a person who is skilled in social relations.
If I lived in such a society, would I have become skilled in these areas?
If I had spent my childhood playing with construction toys such as Lego, would I be better at spatial relations?
In other words, is intelligence something that you simply have in some measure, which manifests itself in the skills that you practice when young / that are valued in your society or within your family? Or are you born instead with particular talents that, if you are lucky, are valued by your society and thus seen as signs of intelligence?
Here's one of my favorite stories.
An anthropologist, Joe Glick, was studying a tribe in Africa1. The Kpelle tribe. Glick asked adults to sort items into categories. Rather than producing taxonomic categories (e.g. "fruit" for apple), they sorted into functional groups (e.g. "eat" for apple). Such functional grouping is something only very young children in our culture would do usually. Glick tried, and failed, to teach them to categorize items. Eventually he decided they simply didn't have the mental ability to categorize in this way. Then, as a last resort, he asked them how a stupid person would do this task. At this point, without any hesitation, they sorted the items into taxonomic categories!
They could do it, but in their culture, it was of no practical value. It was stupid.
Our IQ tests use categorization, and assumptions of how items relate to each other, to test "intelligence". (And how many of us, when filling in IQ tests, thought of different ways to answer questions, but answered the way we knew would be considered "right"?) These tests measure our ability to understand the mind of the test setter / marker. Do they measure anything else?
One theory of intelligence that has had a certain influence on educational policy in the last 10-15 years is that of Howard Gardner’s idea of multiple intelligences (Gardner 1983). Gardner suggested that there are at least seven separate, relatively independent intelligences: linguistic, logical-mathematical, spatial, bodily kinaesthetic, intrapersonal, interpersonal, and musical.
Each intelligence has core components, such as sensitivity to the sounds, rhythms and meaning of words (linguistic), and has a developmental pattern relatively independent of the others. Gardner suggested the relative strengths of these seven intelligences are biologically determined, but the development of each intelligence depends on environmental influences, most particularly on the interaction of the child with adults.
This model of intelligence has positively influenced education most particularly by perceiving intelligence as much broader than the mathematical-language focus of modern education, and thus encouraging schools to spend more time on other areas of development.
It also, by seeing the development of particular intelligences as dependent on the child’s interaction with adults, encourages practices such as mentoring and apprenticeships, and supports parental and community involvement in educational environments. Because intelligence is seen as developing in a social context, grounding education in social institutions and in “real” environments takes on particular value.
All these are very positive aspects of the influence of this theory. On the downside, the idea of intelligence as being biologically determined is a potentially dangerous one. Gardner claims that a preschool child could be given simple tests that would demonstrate whether or not they had specific talents in any of those seven intelligences. The child could then be given training tailored to that talent.
Should we then deny that training to those who don't have that talent?
Do you know how many outstanding people - musicians, artists, mathematicians, writers, scientists, dancers, etc - showed signs of remarkable talent as very young children? Do you know how many so-called child prodigies went on to become outstanding in their field when adult? In both cases, not many.
The idea of "talent" is grounded in our society, but in truth, we have come no further in demonstrating its existence than the circular argument: he's good at that, therefore he has a talent for it; how do we know he has a talent? because he's good at it. Early ability does not demonstrate an innate talent unless the child has had no special opportunity to learn and practice the ability (and notwithstanding parental claims and retrospective reports, independent observation of this is lacking). (More on the question of innate talent)
The more we believe in innate talent, or innate intelligence, the less effort we will put into educating those who don't exhibit ability - although there are many environmental reasons for such failures.
The whole province of intelligence testing is, I believe, a dangerous one. Indeed, I was appalled to hear of its prevalence in American education. While intelligence was seen as some inborn talent unaffected by training or experience by the early makers and supporters of psychometric tests, recent research strongly suggests that schooling affects IQ score.
If you take two children who at age 13 have identical IQs and grades and then retest them five years later, after one child has finished high school while the other has dropped out of school in ninth grade, you find that the child who dropped out of school has lost around 1.8 IQ points for every year of missed school (Ceci, 1999).
Starting school late or leaving early results in a decrease in IQ relative to a matched peer who received more schooling. In families where children attend school intermittently, there is a high negative correlation between age and IQ, implying that as the children got older, their IQ dropped commensurately.
The most obvious, and simplest, explanation is that much of what is tested in IQ tests is either directly or indirectly taught in school. This is not to say schooling has any effect on intelligence itself (whatever that is).
1. Sternberg, R.J. 1997. Successful intelligence: How practical and creative intelligence determine your success in life. Plume.
I have two sons. One of them was a colicky baby. Night after night my partner would carry him around the room while I tried to get a little sleep. One night, for his own amusement, my partner chose a particular CD to play. Magic! As the haunting notes of the hymns of the 12th century abbess Hildegard of Bingen rang through the room, the baby stopped crying. And stayed stopped. As long as the music played. Experimentation revealed that our son particularly liked very early music (plainchant from the 15th century Josquin des Pres was another favorite).
We felt sorry for all those parents with crying babies who hadn't discovered this magic cure-all.
And then we had another son.
This one didn't like music. No magic this time. And we realized, it wasn't that 12th century music had magical properties to calm a crying baby. No, it was this particular baby that responded to this sort of music.
The years went on. Nothing we saw contradicted that first impression - one son was "musical", and one was not. It seemed pretty clear to us. One son took after me, and one took after my partner.
My partner plays the piano, and the pipe organ, and the harpsichord. He is "into" Bach. He has played in churches and concerts. He has a shelf full of books on music and cupboards full of music scores, CDs by the score.
Me? I like to sing, to myself. I learned the violin for a while in my youth. I like to listen to CDs of jazz, and popular show tunes. I like music, but I'm not sophisticated about it. It's background to me. My partner actually listens to it.
So which child took after which parent?
Well, we believe the "musical" one took after me, and the "non-musical" one took after my partner. Because - he got there by training. By practicing and learning and persevering and taking an interest. He has no sense of rhythm, no particularly keen sense of pitch. But he's the one who can produce music. Me, I have an ear for music. Remembering a rhythm is effortless for me; I respond, instinctively, to music. But I could never bother to practice, and my response to music has stayed at the same level. Instinctive.
Our "musical" son has been involved in learning music the Suzuki way since he was four. We never particularly encouraged our other son to do likewise, simply told him he could if he wanted to. His brother persuaded him he did want to. So, fine, we said.
You can guess, I'm sure, how things have been. It's been obvious, watching and listening to our older son, that he has a talent for music, that it comes easily to him. Equally obvious that it hasn't come that easily to our younger son. But it's the younger son who has made much faster progress in the past year, because he practices more, because he's keen to learn. And it's been amazing to watch his ear for music develop.
Suzuki flew in the face of "common-sense" when he decided very young children with no demonstrable genius could be taught to play the violin. I can only imagine the stunned amazement with which the first Suzuki concerts were greeted. They still amaze today.
Suzuki himself, while he supported the training of all children, believed that, of course, some would be "naturally" gifted, and that outstanding performance would require a gift, as well as training. However, as his experience with children and his method increased, he grew to believe that “every child can be highly educated if he is given the proper training” and blamed early training failures on incorrect methods.
Howard Gardner (inventor of the Multiple Intelligences theory) reviewed the exceptional music performance attained by children trained in the Suzuki method, and noted many of these children, who displayed no previous signs of musical talent, attained levels comparable to music prodigies of earlier times. Therefore, he concluded, the important aspect of talent must be the potential for achievement and the capacity to rapidly learn material relevant to one of the intelligences. That is, since we didn't see the talent before we started training, and since the fact that they do perform so well demonstrates that they must have talent, then the talent must have existed in potential.
This is, of course, a wholly circular argument.
And one that is widely believed. According to an informal British survey, more than ¾ of music educators believe children can’t do well unless they have special innate gifts10. It is believed that saying that someone has a “gift” for something explains why they have excelled at something - although it is an entirely circular argument: Why do they do well? Because they have a gift. How do you know they have a gift? Because they do well.
It is also widely believed that such innate talents can be detected in early childhood.
The problem with this view is that many children are denied the opportunities and support to achieve excellence, because it has been decreed that they don’t “have” an appropriate talent.
The circular argument becomes truly a vicious circle. You don't do this easily first time, therefore you don't have any talent, therefore it's not worth pushing you to do well, therefore you won't do well - which proves what we told you in the first place, you have no talent!
So how much justification is there for believing excellence requires a "natural" talent?
A questionnaire study found that early interest and delight in musical sounds fails to predict later musical competence25.
We have all heard stories of child prodigies who supposedly could do amazing things from a very young age. In no case however, is this very early explosion of skills (in the first three years) observed directly by an impartial observer – the accounts all being (naturally enough you might think), retrospective and anecdotal. Noone denies that very young children, from 3 years old, have been observed to have remarkable skills for their age, but although the parents typically say the child learned these skills entirely unaided, this is not supported by the evidence. For example, in a typical case, the parents claimed (and no doubt sincerely believed) that their child learned to read entirely unaided and that they only discovered this on seeing her reading Heidi. However they had kept detailed records of her accomplishments. As Fowler19 pointed out, it is difficult to believe that parents who keep such accounts have not been actively involved in the child’s early learning.
Music is an area where infant prodigies abound – many famous composers are reported to have displayed unusual musical ability at a very young age. Again, however, such accounts are reported many years later (after the composer has become famous). Early biographies of prominent composers reveal they all received intensive and regular supervised practice sessions29. “The emergence of unusual skills typically followed rather than preceded a period during which unusual opportunities were provided, often combined with a strong expectation that the child would do well."
Art is another area where infant "geniuses" are occasionally cited. However, although some 2 and 3 year olds have produced drawings considerably more realistic than is the norm45, among major artists, few are known to have produced drawings that display exceptional promise before age 8 or so44.
There is no doubt that some individuals acquire some skills more easily than others, but this doesn’t necessarily have anything to do with 'talent'. Motivational and personality factors, as well as previous learning experiences, can all affect such facility.
There are various underlying factors that are at least partly genetic and no doubt influence ability – for example response speed2 and working memory capacity8,9 - but there is no clear neural correlate for any specific exceptional skill.
The closest such correlate is that of "perfect" pitch. There does appear to be a structural difference in the brain of those who have absolute pitch, and certainly some young children have been shown to have perfect pitch. However, even if this difference in the brain is innate and not, as it could well be, the result of differences in learning or experience, having perfect pitch is no guarantee that you will excel at music. Moreover, it appears that it can be learned. It’s relatively common in musicians given extensive musical training before five or six12, and even appears to be learnable by adults, although with considerably more difficulty3,42.
It is always difficult to demonstrate that an observed neurological or physical difference is innate rather than the product of training or experience. For example, many people have pointed to particular physical features as being the reason for particular sports people to excel at their particular sport. However, while individual differences in the composition of certain muscles are reliable predictors of differences in athletic performance, the differences in the proportion of the slow-twitch muscle fibres that are essential for success in long-distance running, for example, are largely the result of extended practice, rather than the cause of differential ability11. Differences between athletes and others in the proportions of particular kinds of muscle fibres are specific to those muscles that are most fully exercised in the athletes’ training22.
There is little evidence, too, for the idea that exceptional athletes are born with superior motor and perceptual abilities. Tests for basic motor and perceptual abilities fail to predict performance15. Exceptional sportspeople do not reliably score higher than lesser mortals on such basic tests.
So-called idiot-savants are widely cited in support of the idea of innate talent. However, studies of cases have found the opportunities, support and encouragement for learning the skill have preceded performance by years or even decades12,23,43. Moreover, their skills are learnable by others.
The only ability that can’t be reproduced after brief training is the reputed ability to reproduce a piece of music after a single hearing. However, in a study of one such savant5 it was shown that such reproduction depended on the familiarity of the sequences of notes. Tonally unconventional pieces were remembered poorly. Thus, musical savants, like normal experts, need access to stored patterns and retrieval structures to enable them to retain long, unfamiliar musical patterns.
Several interview and biographical studies of exceptional people have been carried out (e.g., pianists40,41; musicians31; tennis players35; artists37; swimmers26; mathematicians20). In no case could you have predicted their eventual success from their early childhood behavior; few showed signs of exceptional promise prior to receiving parental encouragement.
Composers21, chess players36, mathematicians20, sportspeople26,32 have all been shown to require many years of sustained practice and training to reach high levels of expertise.
Twin studies support the view that family experience is more important than genes for the development of specific abilities (e.g., The Minnesota Study of Twins Reared Apart found self-ratings of musical talent correlated .44 among identical twins reared apart, compared to .69 for identical twins reared together30; correlations on a number of measures of musical ability were not much lower for fraternal twins (.34 to .83) than for identical twins (.44 to .9)7.
Moreover, the importance of inherited factors reduces as training and practice increases1,28,15.
The performance level of student violinists in their 20s is strongly correlated with the number of hours that they practiced13,14. Similarly with pianists27. No significant differences have been found between highly successful young musicians and other children in the amount of practice time they required to make a given amount of progress between successive grades in the British musical board exams; achieving the highest level (grade 8) required an average of some 3300 hours of practice regardless of the ability group to which the student had been assigned39. Another study found that by age 20, the top-level violinists had practiced an average of more than 10000 hrs, some 2500 hrs more than the next most accomplished group15.
Practice accounts for far more than most of us might realize. Several studies have demonstrated the high levels of performance (often higher than experts had regarded as possible) that can be attained by perfectly ordinary adults, given enough practice4,6,12.
It has been argued that talent encourages children to practice more, but this is contradicted by the finding that, even among highly successful young musicians, most admit they would never have regularly practiced at the required level without strong parental encouragement38,24.
It may well be, of course, that there is a quality to the exceptionally talented person’s performance that is missing from others, however hard they have practiced.
It is also possible that, although practice, training, and other influences may account for performance differences in most people, there is a small number of people to whom this doesn’t apply.
However, there is at this time no evidence that this is true.
What is clear is that “no case has been encountered of anyone reaching the highest levels of achievement in chess-playing, mathematics, music, or sports without devoting thousands of hours to serious training” (Howe et al 1999).
The pattern of learning seems to be the same for everyone, arguing against some qualitative difference between "geniuses" and ordinary folk. Studies of prodigies in chess and music show that the skills are acquired in the same manner by everyone, but that prodigies reach higher levels faster and younger16,17. Moreover, rather than acquiring their skills in a vacuum, it appears that “the more powerful and specific the gift, the more need for active, sustained and specialized intervention” (Feldman, 1986, p123).
The producing of an outstanding talent indeed, seems to require a great deal of parental support and early intervention.
It is particularly instructive to observe the case of the Polgar daughters. With no precocious love for the chess board observable in their three daughters, Laslo & Klara Polgar, simply as an educational experiment, decided to raise their daughters to be chess experts. All did extraordinarily well, and one became the youngest international chess grand master ever18.
It has been noted that the performance of experts of yesteryear is now attainable by many. When Tchaikovsky asked two of the greatest violinists of the day to play his violin concerto, it is said, they refused, deeming it unplayable33 - now it is standard repertoire for top violinists. Paganini, it is claimed, would cut a sorry figure on a concert stage today34. Such is the standard we have come to expect from our top performers.
And we are all familiar with the way sports records keep being broken – the winning time for the 1st Olympic marathon is now the qualifying time for the Boston marathon.
Are we suddenly breeding more talent?
No. But training has improved immeasurably.
It is not, then, simply practice that is important. It is the right practice. Ericsson & Charness distinguish between deliberate practice – which involves specifically tailored instruction and training, with feedback, and supervision - and the sort of playful repetition more characteristic of people who enjoy an activity and do it a lot. Most people reach an acceptable level of performance, and then are satisfied. The "talented" ... keep on.
The conventional view of brain development has been that most of this takes place in utero and in the first three years, with the further development continuing until the brain is fully mature at around 10-12 years of age. The turbulence of adolescent behavior has been deemed to be mostly caused by hormonal changes. Piaget, who identified four stages of cognitive development, assessed that his highest stage — that of formal, abstract reasoning — occurred around 13-14 years (although not everyone reaches this level, which requires appropriate education).
Recent studies, however, are painting a different picture. Evidence is converging that the brain continues to grow and develop throughout the teen years, and possibly even into the early twenties. Indeed, early adolescence appears to be a time of significant growth and development.
The vulnerability of the adolescent brain to drugs and alcohol is well-established. The picture that is now emerging is that adolescence is a time of heightened vulnerability partly because different systems are maturing according to different timetables — adolescence is a time when brain systems are out-of-sync, as it were. Adolescence is increasingly seen as a critical period for a reorganization of regulatory systems. This reorganization is both hazardous and an opportunity.
Adolescence, then, is rightly seen as a time when we take our first steps on the path we will take through adulthood. But this cliché has a deeper meaning than we ever suspected. For one thing, an important part of brain development during adolescence concerns the pruning of unused neurons and connections, resulting in a strengthening of those connections that are most used. In other words, it’s a time to lose the things we don’t care about, and strengthen those we do.
Much of this process seems to occur in the frontal cortex, where our “higher” faculties, such as decision-making, goal-setting, and executive control, reside. Maturation of the brain seems to occur roughly from the back to the front: the cerebellum (involved in motor skills) is the first to mature, and the prefrontal cortex the last (possibly not until the mid-twenties).
Poor decision-making, reckless behavior, rule breaking, the tendency toward emotional outbursts, fewer organizational abilities, and lack of ability to process abstract concepts have all been associated with problems in pruning. The ability to multi-task continues to develop until ages 16-17. The delay in maturation of the prefrontal cortex has also been implicated in difficulties in reading emotional cues, which in turn has implications for teens’ ability to communicate with others.
In other words, we as adults may often expect too much from teenagers. We need to keep these cognitive limitations in mind, particularly when teens are confronting with demanding situations. Truly it has been said, the teenage brain is a work in progress, not a finished product.
Children’s understanding, and their use of memory and learning strategies, is a considerably more complex situation than most of us realize. To get some feeling for this complexity, let’s start by looking at a specific area of knowledge: mathematics.
Here’s a math problem:
Pete has 3 apples. Ann also has some apples. Pete and Ann have 9 apples altogether. How many apples does Ann have?
This seems pretty straightforward, right? How about this one:
Pete and Ann have 9 apples altogether. Three of these belong to Pete and the rest belong to Ann. How many apples does Ann have?
The same problem, phrased slightly differently. Would it surprise you to know that this version is more likely to be correctly answered by children than the first version?
Whether or not a child solves a math problem correctly is not simply a matter of whether he or she knows the math — the way the problem is worded plays a crucial part in determining whether the child understands the problem correctly. Slight (and to adult eyes, insignificant) differences in the wording of a problem have a striking effect on whether children can solve it.
Mathematics also provides a clear demonstration of the seemingly somewhat haphazard development in cognitive abilities. It’s not haphazard, of course, but it sometimes appears that way from the adult perspective. In math, understanding different properties of the same concept can take several years. For example, children’s understanding of addition and subtraction is not an all-or-none business; adding as combining is grasped by young children quite early, but it takes some 2 to 3 years at school to grasp the essential invariants of additive relations. Multiplicative relations are even harder, with children up to age 10 or so often having great difficulty with proportion, probability, area and division.
Part of the problems children have with math stems from developmental constraints — their brains simply aren’t ready for some concepts. A recent imaging study of young people (aged 8-19 years) engaged in mental arithmetic, found that on simple two-operand addition or subtraction problems (for which accuracy was comparable across age), older subjects showed greater activation in the left parietal cortex, along the supramarginal gyrus and adjoining anterior intra-parietal sulcus as well as the left lateral occipital temporal cortex. Younger subjects showed greater activation in the prefrontal cortex (including the dorsolateral and ventrolateral prefrontal cortex and the anterior cingulate cortex), suggesting that they require comparatively more working memory and attentional resources to achieve similar levels of performance, and greater activation of the hippocampus and dorsal basal ganglia, reflecting the greater demands placed on both declarative and procedural memory systems.
In other words, the evidence suggests that the left inferior parietal cortex becomes increasingly specialized for mental arithmetic with practice, and this process is accompanied by a reduced need for memory and attentional resources.
But this isn't the whole story. As the earlier example indicated, difficulties in understanding some concepts are often caused by the way the concepts are explained. This is why it’s so important to keep re-phrasing problems and ideas until you find one that “clicks”. Other difficulties are caused by the preconceptions the child brings with them — cultural practices, for example, can sometimes help and sometimes hinder learning.
What's true of mathematics is also true of other learning areas. When we teach children, we do need to consider developmental constraints, but recent studies suggest we may have over-estimated the importance of development.
In an intriguing imaging study, brain activity in children aged 7-10 and adults (average age 25 years) while doing various language tasks was compared. Six sub-regions in the left frontal and the left extrastriate cortex were identified as being significant. Both these areas are known to play a key role in language processing and are believed to undergo substantial development between childhood and adulthood.
Now comes the interesting part. The researchers attempted to determine whether these differences between children and adults were due to brain maturation or simply the result of slower and less accurate performance by children. By using information regarding each individual's performance on various tasks, they ended up with only two of the six sub-regions (one in the frontal cortex, one in the extrastriate cortex) showing differences that were age-related rather than performance-related (with the extrastriate region being more active in children than adults, while the frontal region was active in adults and not in children).
The researchers concluded that, yes, children do appear to use their brains differently than adults when successfully performing identical language tasks; however, although multiple regions appeared to be differentially active when comparing adults and children, many of those differences were due to performance discrepancies, not age-related maturation.
Let's talk about childhood amnesia for a moment. "Childhood amnesia" is a term for what we all know -- we have very few memories of our early years. This is so familiar, you may never have considered why this should be so. But the reason is not in fact obvious. Freud speculated that we repressed those early memories (but Freud was hung up on repression); modern cognitive psychologists have considered immature memory processing skills may be to blame. This is surely true for the first months -- very young babies have extremely limited abilities at remembering anything for long periods of time (months), and research suggests that the dramatic brain maturation that typically occurs between 8 and 12 months is vital for long-term memory.
But an intriguing study (carried out by researchers at my old stomping ground: the University of Otago in New Zealand) has provided evidence that an important stumbling block in our remembrance of our early years is the child's grasp of language. If you don't have the words to describe what has happened, it seems that it is very difficult to encode it as a memory -- or at least, that it is very difficult to retrieve (before you leap on me with examples, let me add that noone is saying that every memory is encoded in words -- this is palpably not true).
This finding is supported by a recent study that found that language, in the form of specific kinds of sentences spoken aloud, helped 4-year-old children remember mirror image visual patterns.
Another study from my favorite university looked at the role mothers played in developing memory in their young children. The study distinguished between reminiscing (discussing shared experiences) and recounting (discussing unshared experiences). Children 40 months old and 58 months old were studied as they talked about past events with their mothers. It was found that mothers who provided more memory information during reminiscing and requested more memory information during recounting had children who reported more unique information about the events.
In general, parents seldom try to teach memory strategies directly to children, but children do learn strategies by observing and imitating what their parents do and this may in fact be a more effective means of teaching a child rather than by direct instruction.
But parents not only provide models of behavior; they also guide their children's behavior. The way they do this is likely to be influenced by their own beliefs about their children’s mnemonic abilities. If you don't believe your child can possibly remember something, you are unlikely to ask them to make the effort. But when parents ask 2 – 4 year olds to remind them to do something in the future, even 2 year olds remember to remind their parents of promised treats 80% of the time.
By 3 yrs old, children whose mothers typically asked questions about past events performed better on memory tasks than those children whose mothers only questioned them about present events. Observation of mothers as they taught their 4 year olds to sort toys, copy etch-a-sketch designs, and respond to questions regarding hypothetical situations found 3 interaction styles found that related to the child’s performance:
Children whose mothers used the last two styles were more verbal and performed better on cognitive tasks.
A study of kindergarten and elementary school teachers found that children from classes where teachers frequently made strategy suggestions were better able to verbalize aspects of memory training and task performance. Although this made no difference for high achieving children, average and low achievers were more likely to continue using the trained strategy if they had teachers who frequently made strategy suggestions.
What lessons can we learn from all this?
First, we must note that there are indeed developmental constraints on children's capabilities that are rooted in physical changes in the brain. Some of these are simply a matter of time, but others are changes that require appropriate stimulation and training.
Secondly, the importance of language in enabling the child cannot be overestimated.
And thirdly, for children as with older adults, expectations about memory performance can reduce their capabilities. Supportive, directed assistance in developing memory and reasoning strategies can be very effective in helping even very young children.
A Spanish study involving 101 overweight/obese children (aged 8-11) has found that aerobic capacity and motor ability is associated with a greater volume of gray matter in several cortical and subcortical brain regions.
Aerobic capacity was associated with greater gray matter volume in the premotor cortex, supplementary motor cortex, hippocampus, caudate nucleus, inferior temporal gyrus, parahippocampal gyrus, and the calcarine cortex. Three of these regions (premotor cortex, supplementary motor cortex and hippocampus) were also related to better academic performance.
Motor ability (speed and agility) was associated with a greater gray matter volume in two regions essential for language processing and reading: the inferior frontal gyrus and the superior temporal gyrus. Both of these were also associated with better academic performance.
Muscular strength showed no independent association with gray matter volume in any brain region.
The researchers suggest that increases in cardiorespiratory fitness and “speed-agility” may counteract the known harmful effect of obesity on brain structure and academic performance during childhood.
 Esteban-Cornejo I, Cadenas-Sanchez C, Contreras-Rodriguez O, Verdejo-Roman J, Mora-Gonzalez J, Migueles JH, Henriksson P, Davis CL, Verdejo-Garcia A, Catena A, et al. A whole brain volumetric approach in overweight/obese children: Examining the association with different physical fitness components and academic performance. The ActiveBrains project. NeuroImage [Internet]. 2017 ;159:346 - 354. Available from: http://www.sciencedirect.com/science/article/pii/S1053811917306584
A Spanish study investigating the effects of traffic-related air pollution on children walking to school has found higher levels of particulate matter and black carbon were associated with decreased growth in working memory capacity. Working memory capacity grows during childhood (and tends to fall in old age).
The study involved 1,234 children aged 7-10, from 39 schools across the city of Barcelona. The children were tested four times over a year to establish their developmental trajectories in working memory and inattentiveness. Average particulate matter, black carbon, and nitrogen dioxide, were estimated for the children’s walking routes using standard measures.
None of the pollutants were associated with inattentiveness. The effect of NO2 on working memory was inconclusive. However, increased concentrations of particulate matter and black carbon were associated with a reduction in the annual growth of working memory of 4.6% and 3.9%, respectively. Boys were more affected than girls.
The study followed an earlier study showing that exposure to traffic-related pollutants in schools was associated with slower cognitive development. Research has previously shown that 20% of a child's daily dose of black carbon (which is directly related to traffic) is inhaled during urban commutes.
The finding emphasizes that even “short exposures to very high concentrations of pollutants can have a disproportionately high impact on health”, and this may be especially true for children, with their smaller lung capacity and higher breathing rate.
The researchers emphasize that the solution for parents is not to stop children walking to school, since those who commute by car or public transport are also exposed to the pollution. Rather, the aim should be to try and find (or make) less polluted, low-traffic paths to school.
 Alvarez-Pedrerol M, Rivas I, López-Vicente M, Suades-González E, Donaire-Gonzalez D, Cirach M, de Castro M, Esnaola M, Basagaña X, Dadvand P, et al. Impact of commuting exposure to traffic-related air pollution on cognitive development in children walking to school. Environmental Pollution [Internet]. 2017 ;231:837 - 844. Available from: http://www.sciencedirect.com/science/article/pii/S0269749117318997
Research using data from a population-based birth cohort from Rotterdam, in The Netherlands, has found that children exposed to higher levels of air pollution when they were in womb had significantly thinner cortex in several brain regions. Some of this appeared to be related to impaired inhibitory control.
The study involved 783 children aged 6 to 10, who were given brain imaging and cognitive tests. Levels of air pollution in the mother’s environment during pregnancy were estimated using a standardized procedure. Mean fine particle levels were 20.2 μg/m3, and nitrogen dioxide levels were 39.3μg/m3. Note that the EU limit for mean fine particles is actually above that (25μg/m3), while the NO2 level is at the EU limit (40μg/m3), with 45% of the Dutch population experiencing higher levels. The World Health Organization sets a much lower level for fine particles: 10 μg/m3.
Children whose mothers were smokers were excluded from the study, as were children from areas where pollution measures weren’t available. Children included tended to be from a higher socio-economic position compared to those not included. Moreover, children with ADHD, or developmental or behavioral problems, were also excluded.
Global brain volume was not affected by fetal exposure. However, several brain regions showed significantly thinner cortex — in particular, the precuneus and rostral middle frontal regions, which partially accounted for the observed association between fetal exposure to fine particles and impaired inhibitory control (the ability to control your own behavior, especially impulsive behavior). This sort of cognitive impairment at early ages could have significant long-term consequences in academic achievement, later career success, and even in risk of mental disorders.
The findings are consistent with other studies linking acceptable air pollution levels with problems including cognitive impairment and child development.
 Guxens M, Lubczyńska MJ, Muetzel RL, Dalmau-Bueno A, Jaddoe VWV, Hoek G, van der Lugt A, Verhulst FC, White T, Brunekreef B, et al. Air Pollution Exposure During Fetal Life, Brain Morphology, and Cognitive Function in School-Age Children. Biological Psychiatry [Internet]. 2018 . Available from: https://www.biologicalpsychiatryjournal.com/article/S0006-3223(18)30064-7/fulltext
When you're reading a picture book to a very young child, it's easy to think it's obvious what picture, or part of a picture, is being talked about. But you know what all the words mean. It's not so easy when some of the words are new to you, and the open pages have more than one picture. A recent study has looked at the effect on word learning of having one vs two illustrations on a 2-page open spread.
The study, in two experiments, involved the child being read to from a 10-page storybook, which included two novel objects, mentioned four times, but only incidentally. In the first experiment, 36 preschoolers (average age 3.5 years) were randomly assigned to one of three conditions:
Children who were read stories with only one illustration at a time learned twice as many words as children who were read stories with two or more illustrations. There was no difference in reading time, or in the child’s enjoyment of the story.
In a follow-up experiment, 12 preschoolers were shown the two-illustration books only, but this time the reader used a simple hand swipe gesture to indicate the correct illustration before the page was read to them. With this help, the children learned best of all.
In fact, the rate of word learning in this last condition was comparable to that observed in other studies using techniques such as pointing or asking questions. Asking questions is decidedly better than simply reading without comment, and yet this simple gesture was enough to match that level of learning.
Other studies have shown that various distractions added to picture books, like flaps to lift, reduce learning. All this is best understood in terms of cognitive load. The most interesting thing about this study is that it took so little to ameliorate the extra load imposed by the two illustrations.
Also see https://blogs.sussex.ac.uk/psychology/2016/10/24/how-storybook-illustrat... for a blog post by one of the researchers
 Flack ZM, Horst JS. Two sides to every story: Children learn words better from one storybook page at a time. Infant and Child Development [Internet]. Submitted :n/a - n/a. Available from: http://onlinelibrary.wiley.com/doi/10.1002/icd.2047/abstract
A new issue for parents to stress over is the question of whether reading digital books with your toddler or preschooler is worse than reading traditional print books. Help on this complicated question comes from a new study involving 102 toddlers aged 17 to 26 months, whose parents were randomly assigned to read two commercially available electronic books or two print books with identical content with their toddler (this was achieved by printing out screenshots of the electronic books).
The books included familiar farm animals (duck, horse, sheep, cow) and also wild animals (koala, crocodile, zebra, and lion), some of which were new to the children). After reading, the children were asked to identify three of the familiar animals and three of the unfamiliar.
The electronic books included background music, animation and sound effects for each page as well as an automatic voiceover that read the text aloud to the child, but there were no actions or hotspots for extra features.
Compared to those who read the print versions, toddlers who read the electronic books:
While parents tended to point at the print book more often, there was no difference between the books in the amount they talked with their children about the story. However, parent–child pairs spent almost twice as much time reading the electronic books than the print books.
Overall, children did significantly better on the learning task when they had read the electronic book. However, analysis showed that the benefit was accounted for by two variables:
The researchers note, however, that this may not be true of all electronic books. Previous research has suggested that highly interactive electronic books may distract from learning.
Additionally, the simplicity of electronic books for toddlers may be much better. Books for preschoolers, on the other hand, are more narrative, requiring readers to integrate content across pages. In this circumstance, electronic books may be more distracting.
 Strouse GA, Ganea PA. Parent–Toddler Behavior and Language Differ When Reading Electronic and Print Picture Books. Frontiers in Psychology [Internet]. 2017 ;8. Available from: http://journal.frontiersin.org/article/10.3389/fpsyg.2017.00677/full
Brain scans of children who have moderate or severe obstructive sleep apnea have found significant reductions of gray matter across the brain.
The study compared brain scans from 16 children (aged 7-11) with obstructive sleep apnea to those from nine healthy children of the same age, gender, ethnicity and weight, who did not have apnea. The scans were also compared to 191 MRI scans of children who were part of an existing database.
The brains of those children with OSA showed reduced gray matter in multiple brain regions, including the frontal, prefrontal, and parietal cortices, temporal lobe, and the brainstem.
Sleep apnea is known to affect cognition in adults, but it may be that it is even more damaging in brains that are still developing. However, adult studies have also shown that treating sleep apnea reverses gray matter loss and improves cognition. This finding therefore emphasizes the importance of treating children's sleep apnea.
Sleep apnea affects up to 5% of all children (and we can only assume that this will get more common, if childhood obesity continues to rise).
Another study of sleep deprivation in children gives weight to the idea that it is particularly important for proper brain development that children get good sleep.
The study measured the brain activity in 13 healthy five to 12-year-olds as they slept. On the first occasion, the children went to bed at their normal bedtime; the second time, they stayed awake until late and thus received exactly half the normal amount of sleep.
The results indicate that children's brains respond to sleep deprivation differently than adults’ brains do. In adults, being deprived of sleep creates a greater need for deep sleep, which is manifested in greater slow-wave activation in the prefrontal cortex. In the children's brains, this slow-wave increase occurred in the back regions of the brain, in the parietal and occipital lobes. This suggests that these areas might be especially vulnerable to sleep deprivation.
Moreover, this difference was linked to levels of myelin in part of the visual system. Myelin increases as the brain matures. Those with higher levels of myelin in certain nerve fibers in the visual system displayed slow-wave activation that was more similar to that of adults.
The researchers conclude that adequate sleep is important for neuronal connections to develop properly.
A study involving 1,046 children whose sleep was assessed at various points in their first seven years has found that children who didn’t get enough sleep in their preschool and early school years were more likely to have problems with attention, emotional control and peer relationships at age seven.
Sleep was assessed through interviews with the mothers when their children were around 6 months, 3 years and 7 years old, and from questionnaires completed when the children were ages 1, 2, 4, 5 and 6. Mothers and teachers filled out questionnaires evaluating each child's executive function and behavioral issues at around 7.
Children living in homes with lower household incomes and whose mothers had lower education levels were more likely to sleep less than nine hours at ages 5 to 7. Other factors associated with insufficient sleep include more television viewing, a higher body mass index, and being African American.
Insufficient sleep was defined as being less than the recommended amount of sleep at specific age categories:
 Philby MF, Macey PM, Ma RA, Kumar R, Gozal D, Kheirandish-Gozal L. Reduced Regional Grey Matter Volumes in Pediatric Obstructive Sleep Apnea. Scientific Reports [Internet]. 2017 ;7:44566. Available from: http://www.nature.com/srep/2017/170317/srep44566/full/srep44566.html
 Kurth S, Dean, III DC, Achermann P, O’Muircheartaigh J, Huber R, Deoni SCL, LeBourgeois MK. Increased Sleep Depth in Developing Neural Networks: New Insights from Sleep Restriction in Children. Frontiers in Human Neuroscience [Internet]. 2016 ;10. Available from: http://journal.frontiersin.org/article/10.3389/fnhum.2016.00456/abstract
 Taveras EM, Rifas-Shiman SL, Bub KL, Gillman MW, Oken E. Prospective Study of Insufficient Sleep and Neurobehavioral Functioning among School-Age Children. Academic Pediatrics [Internet]. 2017 . Available from: http://www.academicpedsjnl.net/article/S1876-2859(17)30047-5/abstract
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