• Question: What is the current understanding of 'plasticity' of the developing brain in children <7. I ask this in terms of reductionist teaching.

    Asked by ange21 to Crawford, Dana, Iroise, Mark, Sarah on 20 May 2015.
    • Photo: Iroise Dumontheil

      Iroise Dumontheil answered on 20 May 2015:

      I am afraid I am not sure what you mean by reductionist teaching.
      In general, it is difficult to distinguish plasticity, maturation, development and learning. Humans learn throughout their lives, and this is associated with changes in the brain, for example in the number and strength of connections between brain cells (neurons). So in this sense there is plasticity throughout life.
      However, there is evidence that certain skills/cognitive processes need an individual to have received particular input at key stages of brain development, and that after a certain time it may be too late and these cognitive processes to be implemented. This has been shown for example for certain aspects of vision processing (http://www.brainfacts.org/brain-basics/brain-development/articles/2012/critical-periods).
      So really there seems to be a spectrum of plasticity, with some aspects of cognition and brain function that can be changed or learned at all ages, while other aspects that are less susceptible to change or need to be learned before a certain age.
      Children develop and acquire a whole range of skills and their cognitive processing changes, along with significant changes occurring in the structure of their brain (both in grey and white matter, i.e. in the number of connections between neurons and the properties of the tracts that connect neurons to each other). There is some evidence from studies of musical training that depending at which age children learn a musical instrument, they will show differences in their white matter tracts in different locations, which seem to correspond to the tracts that were maturing at the time the child learned to play an instrument (http://www.ncbi.nlm.nih.gov/pubmed/16116456). However more recent needs to be done before we have a better understanding of what happens in the brain when you learn new skills at different ages.

    • Photo: Crawford Winlove

      Crawford Winlove answered on 22 May 2015:


      Like Iroise, I am not quite sure what you mean by “reductionist teaching”. However, recognising that we may not have time for you to provide clarification I will hazard a guess that you are concerned about proposals, seemingly based on neural-level explanations, about how teaching could be rendered more effective……

      Many of the neural processes identified so-far, for example plasticity, are necessary components of overall processes. However, this component necessity does not mean that the processes are also sufficient to explain the overall process. At the very least, there may be other neural processes that remain to be identified. Quite possibly, a neuroscientific explanation is not the most appropriate source of this missing sufficiency…….

      These general issues are elegantly explored, in much greater detail, in the following article: http://tinyurl.com/7v8pft3

      Considering plasticity more directly, we should first observe that the brain is dynamic – it exists in a state of constant change. These changes may last moments, or a whole lifetime, and fundamentally arise from neurons that are active at the same time as each other become more strongly connected to each other. This, then, is the cellular manifestation of memory.

      Many neuroscientists would endorse the hypothesis that during sensitive periods the changes in connectively between neurons are substantial and enduring. Outside of these sensitive periods, changes in connectivity can still occur, but only within the constraints established during the sensitive period. This theory is described in more detail in this paper: http://tinyurl.com/phnfgvf

      Importantly, and as highlighted by Iroise, sensitive periods are not the same across all circuits. Thus, the areas involved in language are most sensitive in early childhood, whilst many areas of motor control show broadly similar levels of plasticity throughout life.

      As such, the issue is probably not so much about whether plasticity exists, but whether it is subject to a sensitive period within the behavioural domain of interest. Of course, teachers are best-placed to judge which behavioural domains are most important for learning……

      Hope this makes sense!