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Sensitive Periods in Brain Development – Implications for Education Policy
Which Skills Need to Be Taught Later? sustained attention in young school children may have longer-
Do some skills need to be acquired later so that acquisition is lasting and more noticeable effects of academic development than
optimised only after children reach a certain age? It has been directly training domain-specific skills.
shown that many educationally relevant behaviours can be
advanced before they would normally be expected to emerge in Learning After Sensitive Periods
school, from early home experiences promoting reading Have Closed
development prior to starting school
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to enhancing executive An understanding of sensitive periods must also guide educational
functioning in children as young as three years of age.
26
Such practice for teaching individuals who have passed the age at which
training has resulted in the establishment of more focal patterns of plasticity was at its maximum. To predict the best method of
neural activity
27
that parallel longitudinal patterns of change in teaching, we need to know which mechanism is responsible for the
children not exposed to intense input.
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closing of the sensitive period. As we have seen, there are several
candidates. In some cases, more intense training may be necessary.
However, if the goal of education is to achieve the highest point of In other cases, the context of training may need to be altered (e.g.
proficiency as efficiently as possible, it is not enough simply to temporary cessation of competing tasks that may interfere with
demonstrate that training can induce skills at a younger age. First, learning). In other cases, the nature of the training experience may
a number of studies looking at early training have found that it is need to be altered, for instance to highlight particular properties of
more effective for slightly older children. For example, early the task domain that are important for performance.
phonological awareness training in American kindergarten children
was found to be more advantageous for children nearer the first- Second-language acquisition provides one example. Where
grade cut-off point than for their younger peers.
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When Rueda et individuals miss the sensitive period for learning the phonetic
al.
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taught attention skills to children who were four and six years categories of a given language, the principles of repetition,
of age, they found that while both groups benefited from training, feedback, intermittent reactivation
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and incremental learning
39,40
only the six-year-old group showed specific development of have been shown to result in the most dramatic and durable effects
executive attention skills and corresponding adult-like event- in adults. One important strategy for perceptual category learning is
related potential brainwave signatures. Second, advances produced to initially exaggerate the distinctions between inputs such as non-
by early training are sometimes lost simply because children who native phonemes and then incrementally reduce the distinctions to
did not experience the training catch up. For example, it has been bring them in line with realistic phonemes. Less is known about
shown that the early academic benefits of a highly didactic pre- optimal training principles beyond low-level perceptual systems.
kindergarten environment were lost as early as the kindergarten One recent suggestion is that high-level systems such as executive
year.
30
Third, enrichment programmes have been found to be more functions may respond best to incremental increases in complexity,
effective in children from lower socioeconomic backgrounds raised where task demands are kept just above the level at which the
in impoverished environments, with fewer benefits demonstrated learner is operating.
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for children already exposed to a stimulating environment.
The roles of motivation and attention and the use of strategy and
The key to optimal educational outcomes is not teaching as much meta-cognition are the other keys to learning new skills after
as possible as early as possible. However, two principles are putative sensitive periods have closed. While older learners can
emerging that indicate how to put in place stable building blocks sometimes develop new skills more quickly than their younger
that can positively affect later learning and understanding. The first counterparts because of the additional strategies available to
principle is that learning skills in the correct order is often more them,
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adults may require more cognitive resources to learn new
important than the exact age at which these skills are learned.
Within the constructivist framework,
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more complex or abstract
skills are built on top of simpler, perceptually driven knowledge.
Attempts to instruct children in abstract skills (such as reasoning)
It is likely that, beyond late childhood,
may falter not because these children are too young but because
processes of pruning will gradually
the more basic foundations have not been put in place (such
as relevant knowledge). Constructivist approaches to cognitive
reduce spare cognitive resources if they
development have recently been combined with theories of
are not utilised by a cognitively
brain development within the framework of neuroconstructivism.
32
Within this framework, a number of models looking at changes in
challenging environment.
cortical plasticity invoke the idea of ‘cascades’ or ‘waves’ of
plasticity, where each level of processing depends on reliable and
stable inputs from the level below.
3,33
skills.
7
However, it is important to stress that in most cases plasticity
is reduced rather than eliminated. Learning is still possible, but it
The second principle is the importance of developing skills that aid requires more effort and may produce imperfect results. Factors
learning across all domains. Attention, for example, is a key other than age are also important. For example, evidence from
component of academic success that can influence the learning of animal studies indicates that learning in a social context may be
skills with putative sensitive periods, such as first-language one factor that permits later learning of abilities associated with
acquisition in humans.
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It has been found that attention, along with sensitive periods: when songbirds were too old to learn their song
other cross-domain skills such as working memory, can be trained from a passive tape-recording, they could still do so from an
in very young children.
35–37
Enhancing skills such as selective and interactive partner.
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