Tomorrow's People

by Susan Greenfield

  In 1999 the psychologist Thomas G. O'Connor and his colleagues explored what the implications of environmental deprivation might be for the human brain by studying Romanian babies who had spent the first years of their lives in the infamous national orphanages where there was very little varied sensory or social stimulation. Perhaps not surprisingly, the researchers found that the children were more likely to have delayed walking and talking skills, as well as impaired social, emotional and cognitive development. The opposite, accelerated skill acquisition, is the aim of the hyper-stimulation in the hothousing of infants – the frantic attempts by some parents to provide intensive stimulation for their children when very young, in the hope that they will excel in later life.

  Whether this strategy is necessarily successful is under considerable debate. There has been some concern that hothousing may have a negative effect – resulting in low self-esteem, a deep sense of failure and a tendency to underachieve. Further, even when the method has the desired academic result, children educated more intensively than their contemporaries frequently experience emotional and social difficulties in later life. ‘I can't understand why people enter their young children for exams, unless it's parental pride,’ says Professor Joan Freeman, author of Gifted Children Grown Up.

  The clear adaptability (plasticity) of brain cells, with scant or extensive branches, reflects the whole gamut of minimal and maximal stimulation that can come the way of the human brain, and although there may be sensitive periods when the changes are most dramatic the burgeoning and withering of dendrites will continue to occur into, and for the duration of, your adult life. As your neuronal connections grow, shaped by your particular experiences, so the dialogue between your brain and the outside world becomes more two-way. Instead of seeing life in abstract, sensory terms – how sweet, how cold, how loud or how soft – those sensations coalesce into people and objects. As these people or objects feature repeatedly in your different experiences a growing number of associations will form around them via your growing dendrites; they will be of increasing significance, will ‘mean’ more. The individualization of the brain will increase as vast ranges of brain-cell circuits configure in extent and power according to the particular types of input they have, that incessant and complex assault on the senses that makes up your daily existence. This forging of new connections, which has a direct basis in the connections between neurons, is surely the essence of learning.

  A few years ago, one fascinating example captured the imagination of the media: the findings, based on brain scans, revealed that a certain region in the brains of London taxi-drivers was physically larger than in non-taxi-driving individuals of a comparable age. Since the area in question (the hippocampus) is related to memory functions and since London taxi-drivers have impressive memories, needing as they do to learn the lay-out and names of all the streets of London by heart, here surely is a clear demonstration of how the brain, even in adults, responds to stimulation.

  In another report, brain scans have revealed that in highly skilled musicians there is an increase of 25 per cent in the size of a key part of the brain related to hearing (auditory cortex) compared with people who have never played an instrument. And more telling still is the observation that this increase matches up with the age at which the individuals began to practise rather than when they achieved proficiency. The critical issue, it seems, is the activity itself of practising music, not how good you are.

  A further experiment, again with adult humans, proves that you do not have to volunteer for a change in career nor practise at music for long to change the size of functional areas of your brain; instead, you can enrol in an investigation of the effects of five days of piano playing for two hours each day. In such a study the subjects were all non-piano-players and were divided into three groups. Group 1 were merely exposed to a piano and left to play around with it as they wished; Group 2 started to practise five-finger exercises, whilst Group 3 had simply to imagine they were playing the exercises. Perhaps not surprisingly, the area of the brain relating to the movement of digits dramatically expanded in Group 2 compared to their uninstructed colleagues in Group 1. However, the truly amazing result was that Group 3, those who had engaged in non-physical mental practice, had brain changes almost as impressive as those who had acted out what they were only rehearsing in their minds. Apart from discrediting once and for all the old dualism of mental versus physical, of mind versus brain, such experiments surely ram home the point that what you do is reflected in the fine architecture of your brain, and that a particular configuration of your brain cells will enable you to perform a particular skill with ever-increasing facility.

  But such exaggerated studies on the effects of experiences are only the tip of the neurological iceberg. As for the rest of the body, the more any particular part of the brain is exercised the more effective it will become. This efficacy, in brain terms, means the proliferation of dendrites and hence the appropriation of more brain territory. On a much more subtle scale everything you do, and everything that happens to you, will leave its mark, literally, on your brain. The human brain, after all, is very good at learning; our ability to adapt to our environment, to learn from experience, distinguishes us from all other primates, even chimps. Our singularly human brains have enabled us to occupy more ecological niches than any other species on the planet; the capacity of our neuronal connections for adaptation has freed us from the genetic tyranny of a generic instinct. Different cultures geographically separate in space, like generations separate in time, differ so much from each other because the respective brains have been exposed to such different influences.

  As a developing individual you see the world in terms of what has gone on before, in your unique trajectory, and slowly transform from an undiscriminating data-sponge to an information cherry-picker. The process of assimilating information may not now occur with the same unconditional and effortless facility as when we were young enough for the Jesuits, but understanding – seeing one thing in terms of another – will be increasingly possible. It is this unique personalization of brain-cell circuitry that, in my view, is the physical equivalent of ‘the mind’. Easy to see then how the minds of our cave-dwelling ancestors would be different from our own; easy to see, also, how technology has accelerated as each generation has learnt so effectively from those preceding it, and we have been able to stack up our own discoveries on an existing body of knowledge. In order to explore the extent and manner in which the new technologies will shape the young minds of this century we need to identify the key factors in the learning process.

  The idea that any stimulation is good, simply because it's stimulation, must be simplistic. In any case, we cannot assume that indiscriminate stimulation of any one type is all there is to learning. If a new skill such as taxi-driving in London or playing the piano can enlarge a brain area, it can surely do so only at the expense of some other skill: what might we become less good at? And since we now know that any one brain region will participate in more than one net behaviour how far can we generalize? Would the taxi-drivers with an enlarged hippocampus also be better at the host of other functions with which the hippocampus has been linked?

  Another very basic factor in determining how effectively the brain learns could be sleep. In rats, at least, periods of learning are associated with increased dream REM (Rapid Eye Movement) sleep. And REM deprivation impairs rat memory. More persuasive still, Dr Pierre Maquet and his team showed a few years ago that in humans, during sleep, some brain areas are more active in trained than in non-trained subjects, whilst the effects of that training are improved still further the next day after the opportunity for a period of dreaming.

  Dreaming has been a source of fascination for thinkers down the ages and in the present day continues to be an extensively researched phenomenon among neuroscientists; but the purpose of dreaming is still open to conjecture, as is the precise course of events that unfold in the brain as we enter that eerie, utterly subjective and irratio
nal inner world. Many believe that dreams help us to consolidate the thrills and spills of each waking day, yet this type of ‘explanation’ could just as easily be an effect of dreaming rather than its cause. Dreaming could simply be a form of consciousness not driven by the normal sensory inputs, so that the net experience is very different and far less constrained by the ‘reality’ of the outside world. If so, the main trigger would be the residual activity of the brain, which would happen to reflect most recent events. Memory consolidation would therefore be a corollary of dreaming but not the essential driving force. After all, small babies dream, even in the womb and even more than adults, and they have very few life crises to resolve! So perhaps dreaming is simply that residual brain activity itself, undisturbed as it is by inputs from the senses, and as such is all important in learning. As the connections between neurons in the brain, at any age, rehearse over and over their electrochemical sequences so they become ever more effective and efficient.

  In addition to sleep, further factors are being suggested as influences on how readily the brain learns. One experiment in particular, first performed in 1993, has generated huge controversy and speculation. Volunteer subjects had to work out what a paper would look like after being folded and cut in a certain way, like a paper doily. After the test, one group sat in silence for ten minutes, a second group listened to a Mozart piano sonata whilst a third heard an audiotaped story or repetitive music. All three groups then took the test again: the ‘Mozart’ group accurately predicted 62 per cent more shapes on this second test, whilst the silent group improved by a puny 14 per cent and the repetitive music/story group by only 11 per cent. Although such clear-cut and dramatic results have defied replication so far and many are still very sceptical, Lois Hetland, of the Harvard Graduate School of Education, extended the study to 1014 subjects. She found that Mozart listeners out-performed other groups more often than could be explained by chance.

  In fact, a completely different type of experiment seems to support the notion that for some reason Mozart may be good for the brain: it turns out that rats raised with the music of Mozart run mazes faster and more accurately than other rats. Rodents are hardly renowned for their appreciation of the great composers; clearly, then, whatever the effect is it has little to do with musical sophistication, or even with the notion that listening to music puts you in such a good mood, or so arouses you, that your performance improves too.

  One clue to what might be happening comes from the work of Gordon Shaw, from the University of California at Irvine: amazingly enough, the electrical discharges within networks of neurons sound like music when expressed acoustically. Could the patterns in music conversely drive the formation of networks of neurons, which are consequently primed for more efficient mental function?

  John Hughes, a neurologist from the University of Illinois Medical Center, has shown that a critical factor in the intellect-enhancing effect is how often musical volume rises and falls in surges of ten seconds or longer. The music of Mozart scores two to three times higher than minimalist music or pop tunes in this respect. It seems that the regular, repeating sequences of twenty to thirty seconds may fit best with brain-wave patterns of thirty-second cycles. Only specific music, then, will stimulate the brain in the right way: indeed, brain scans of volunteers listening to Beethoven's für Elise and 1930s popular tunes show that only the auditory part of the outer brain layer (cortex) is activated by these very different types of music – but Mozart makes the cortex light up all over!

  These fascinating findings raise far more questions, for neuroscientists and educationalists alike, than they answer: not least we need to know how outside stimuli can train brain circuits and how acoustic priming, somehow, improves our ability to think. The possibility that activities remote from formal education such as dreaming and listening to Mozart can enhance learning ability may well feature in strategies for education in the future. Imagine ‘covert priming’ sessions as both a pre-school norm and a commonplace warm-up exercise before each formal lesson.

  Further into the future still a new phenomenon in the classroom might be even more precise and direct exploitation of inherent brain mechanisms. We have seen already that awesome strides are being made in brain-imaging techniques; quite soon, perhaps, the time frames over which we can monitor brain events will be commensurate with the split-second real time over which neurons operate. Yet so far no one has really given much thought to improving such windows onto the living brain in space as well as in time. Surely one day some bright technocrat might come up with a way of monitoring the plasticity of the brain – the atrophy and growth of dendrites – on the fine spatial scale of individual neurons in the living, conscious brain.

  Let's imagine the implications, if such high-resolution combination of time and space frames were possible. The subject of a brain scan currently has to journey to the lab or hospital in order to be buried within the huge cylinder that houses the colossal magnets needed. Yet this might be comparable with the first computers, which occupied whole rooms and had only a fraction of the capabilities of a present-day palmtop. By analogy perhaps one day the expensive, technically capricious and clunky imaging equipment we have now might be replaced by an elegant helmet. In this way it would be possible to monitor the formation and disbanding of dynamic neuronal networks in normal environments such as the classroom, and indeed to watch the brain processes that accompany learning. The teacher could then observe a console of screens and see how effectively a child was primed by, say, Mozart before commencing formal instruction.

  Let's speculate still further. Once patterns of connectivity could be precisely documented, localized and matched up with certain types of learning, then it would be just a small step from monitoring to manipulation. Perhaps non-invasive radio-stimulation, transmitted via the helmet to certain neuronal assemblies, would drive the pattern of connections into the desired configuration. Lest anyone think that this whole notion is completely absurd, please note that the neuroscientist Dr Michael Persinger is already stimulating the brains of human subjects in just this way, admittedly without anything near the anatomical precision that would be required to manipulate specific neuronal networks. The focus of his experiments has been to stimulate the mind into having a ‘religious experience’ – although exactly what the experience might be varies considerably from person to person, and the area to be stimulated cannot be accurately targetted.

  Yet already a greater finesse in brain location can be achieved with a ‘Gamma Knife’ – a device that uses ionizing radiation to allow neurosurgeons to operate on abnormal areas of the brain without making an incision. This technique might not yet be able to stimulate select neuronal groups but is still capable of destroying minute amounts of target brain tissue or tumour, with great precision. Perhaps, then, in the future some combination of these two techniques – a stimulation confined to highly specific groups of brain cells – could realize the most direct method of ‘teaching’ of all, where no active learning was required…

  Yet the invasive programming of the brain with facts, like the non-invasive strategy of hothousing, does not necessarily deliver the desired result. Moreover, in the cyber-age facts will be so accessible that there will be little need to internalize them. And even when a fact is learnt, that doesn't guarantee understanding. Facts on their own have always been intrinsically meaningless. A fact acquires a meaning only once it is associated, linked to another fact. For example, when my brother was very small I taught him the famous soliloquy from Macbeth, where the eponymous hero despairs: ‘Tomorrow, and tomorrow, and tomorrow, / Creeps in this petty pace from day to day/ To the last syllable of recorded time; / And all our yesterdays have lighted fools / The way to dusty death…’ Graham, at three years of age, could recite the whole piece word perfect but he didn't understand it. After all, how could a toddler grasp the metaphor of ‘petty pace’ and understand the meaning of ‘dusty death’? He would have had to acquire a huge database of prior information first, and then
been sufficiently adept at linking those facts – been educated – to make the multilayered cross-references that we recognize as ‘understanding’. Then again, wholesale yet precise brain stimulation would be all the more sinister if it circumvented both these drawbacks by driving connections between isolated facts, thereby inducing an automatic understanding, a complete programmed mindset.

  But back to the foreseeable future, where children will still be relying on the more haphazard and indirect stimulation of everyday life to configure their brains, and hence shape their minds. Another factor that is and will continue to be highly relevant is learning-by-doing, as anyone would testify who ever tried to learn to drive by watching someone else. Children's main sensory and cognitive learning achievements come from their own experiences in the course of activities such as play, exploration, everyday talk and social interaction with peers and siblings. Inevitably then, early experiences constitute an important factor in how well children assimilate information in more formal learning situations later on. The negative effects of low-income backgrounds are now well known, publicized by a programme in the USA designed to offset the disadvantages.

  This scheme, Head Start, aimed to provide pre-school compensation for infants not, perhaps, as deprived as Romanian orphans but socio-economically disadvantaged nonetheless; the experimental curriculum aimed to develop a whole range of physical and mental skills, including sharing and counting objects, fitting objects together, anticipating and remembering sequences of events, role playing, imitation, recognizing objects, playing simple musical instruments and talking with others.