• Question: Hi, and thank you for this opportunity. I am a teacher and I'm interested in how milestone development correlates with neuro development. (Milestone dev is sometimes referred to as foundation skills and an example often discussed is what is happening in the brain when a child is learning to crawl.) There are heaps of milestones to be met so maybe you could just talk about how the brain is developing while the child is assimilating or integrating primitive reflexes and sensory processing? Thanks plenty.

    Asked by Cara R to Masud, Mark, Lucy, Kathy, Kathryn, Duncan, Andy on 9 May 2015.
    • Photo: Duncan Astle

      Duncan Astle answered on 9 May 2015:

      Really interesting question. Can’t really do it justice here – but here goes (briefly).

      During development the brain goes through a number of important changes… the end result of which is a gradual reorganisation. Small local networks gradually become integrated, meaning that the brain goes from being relatively general in terms of the functions of networks, to being composed of more specialist systems. This process is sometimes referred to as ‘modularisation’. This happens via two routes (that are both non-linear): the first is myelination… in the insulation of particular pathways, thereby enhancing their efficiency and providing pathways for efficient transmission in the brain; the second is synaptic pruning… grey matter is pruned back to produced more specialised and efficient systems.

      This process gradually means that lower-level systems, like primary sensory areas, motor areas etc. can become integrated with higher-level processing areas within the frontal and parietal lobes. This gradual integration means that children can exert increasing control over these lower-level systems… meaning that once ‘primitive’ processes can be direct towards achieving the child’s goals in a task-oriented manner.

      Hope that makes some sense! Great question.

    • Photo: Lucy Cragg

      Lucy Cragg answered on 10 May 2015:

      Duncan’s answered this really nicely already but there’s also a good review paper by BJ Casey on brain development that goes into a bit more detail: http://community.mdecgateway.org/olms/data/resource/8700/Week%209_Imaging%20the%20developing%20brain.pdf

    • Photo: Mark Mon-Williams

      Mark Mon-Williams answered on 14 May 2015:

      Hi Cara

      I think you are referring to motor milestones.

      I’d answer your question by saying that I would phrase things slightly differently – motor milestones (as the name suggests) are markers of neurodevelopment. Duncan and Lucy have given you some good information on brain development but it’s worth emphasising that these motor milestones are a product of the neural changes that are occurring as a function of the child interacting with the environment.

      With regard to your specific question, we know that a failure or delay to reach particular milestones CAN be indicative of neurodevelopmental problems – such as cerebral palsy. In Down syndrome, the children appear to achieve the milestones in the same approximate order as other children but at a later chronological age.

      BUT it’s worth emphasising that the nice ordered progression through the milestones for any child is a LOT messier when you look more closely at an individual’s development. This is because children are not only learning new skills but there bodies are changing – meaning that they often acquire a skill, then lose it and then reacquire that ability downstream.

      It’s also worth emphasising (wrt your question) that MANY children bypass the crawling phase for the simple reason that they find another way of getting between locations (e.g. bottom shuffling) before they manage to toddle. This is just an example of the messy developmental patterns I described earlier – and it’s absolutely fine (i.e. there is no evidence that a child who didn’t crawl is at a higher risk of neurodevelopmental problems).

      I hope that helps!