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Question: At what stage is the brain ready for the cognitive challenges of Physics? Are we teaching some stuff too early?
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Michael Thomas answered on 16 Apr 2015:
From the point of view of the brain, ‘physics’ comprises a large set of tasks, some of them sensory, some of them motor, some of them language related, some of them ‘reasoning’ – mapping between different mental representations of the world before generating some language-based or other motor response. These tasks will involve different combinations of brain areas, so asking when the (whole) brain is ready for (the whole of) physics won’t have a straightforward answer.
Part of your question is about the plasticity of the brain and its readiness to learn different skills at different ages. I won’t focus on that part here (here are some articles on brain plasticity and education: http://www.psyc.bbk.ac.uk/research/DNL/personalpages/Thomas_Knowland_PlasticEd.pdf, http://www.psyc.bbk.ac.uk/research/DNL/personalpages/bjep001.pdf, http://www.psyc.bbk.ac.uk/research/DNL/personalpages/Knowland_and_Thomas_2014.pdf)
With respect to physics, our perceptual and motor systems develop pretty sophisticated internal models of how the physical system works in the first few years. Children can catch objects, track the pathways of objects under the influence of gravity or other forces, and show surprise when objects violate the laws of physics (e.g., pass through each other or disappear).
The challenge of teaching physics is making connections between this intuitive knowledge and explicit understanding of physical systems. To begin with, the two may indeed be at odds. What happens when someone runs off a cliff? Based on cartoons, children sometimes answer that the person will move out horizontally, come to a stop, and then drop vertically. However, if you roll a ball off the edge of a table and ask the child to catch the ball as it falls, they can do this: their sensori-motor systems can predict the parabolic trajectory. So their brains both do and don’t know the answer!
How can we connect these two types of knowledge?
Here are a couple of interesting findings emerging from research. First, the processes of linking explicit understanding with intuitive knowledge seems to rely on students being able to talk to each other about the physical systems they are studying. Being able to think about other people’s opinions and views of what may be happening (the forces at play, the underlying principles) seems instrumental in driving the development of hypothesis formation and hypothesis testing skills, allowing construction of explicit understanding.
Second, research in neuroscience suggests that one important neural process involved in utilising abstract principles and knowledge to reason about physical systems is the inhibition of familiar everyday knowledge of those systems. Even in experts (in one experiment, undergraduate physics students reasoning about electrical circuits), when they carry out this type of reasoning (here, which bulb will light up), inhibitory processing can be observed in their brains. That is, part of expertise appears to be the ability to suppress information that is irrelevant to the problem at hand.
In fact, this finding has inspired one of the current projects in the London Centre for Educational Neuroscience and funded by Wellcome Trust and the Educational Endowment Foundation, where we will explore whether training these kinds of inhibitory skills can help primary age children acquire counter-intuitive concepts in maths and science.
Lastly, if you are interested in more of the recent neuroscience about how the brain carries out scientific reasoning, I can recommend chapter 12 of our recent book on educational neuroscience: http://www.amazon.co.uk/Educational-Neuroscience-Denis-Mareschal/dp/1118725891
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Andy Tolmie answered on 19 Apr 2015:
Very little to add to Michael’s very full answer! There is good evidence that before they go to school children have a well-developed intuitive understanding of many aspects of physics from their encounters with them in everyday settings – but also that their more explicit knowledge commonly derives from mistaken explanations by parents and others. The big issue therefore is how to build on the intuitive understanding and use it as the resource it is, whilst inhibiting mistaken ideas. Collaborative group work provides one effective strategy, provided it focuses on making accurate observations, and trying to actually explain these rather than simply repeating fixed ideas. Getting this right means teachers need to think about the actual tasks involved, building children’s skills in assessing evidence, and providing them with some of the vocabulary necessary to capture their thinking in words. Building better inhibitory control is also a key part of that – how best to do that is what we’re working on right now!
Comments
specialsymbol commented on :
Thank you very much to that extensive answer!
However, I have a few more questions:
1. “First, the processes of linking explicit understanding with intuitive knowledge seems to rely on students being able to talk to each other about the physical systems they are studying.”
Does that mean that physics students develop the skills to change their system of reference by themselves (or that they are even particularly good at this due to them studying physics?!), or is communication *necessary* to learn physics?
2. “Second, research in neuroscience suggests that one important neural process involved in utilising abstract principles and knowledge to reason about physical systems in the inhibition of familiar everyday knowledge of those systems.” should that not be: *is* the inhibition? It was a bit difficult to understand, but I guess that is the correct interpretation as the following sentences are about that ability to inhibit everyday knowledge.
So here’s my question:
How does that inhibition actually work? Let’s assume we believe that heavier objects fall down faster than lighter objects (a feather compared to a marble). We may think that the marble is accelerated faster than the feather. Now let’s observe this in near-vacuum – what does happen in the brain at that very moment, especially in regards to connections between neurons?
Thank you very much so far!
Iroise commented on :
I will try to tackle the last question (there is a recent video about objects falling in a vacuum chamber https://www.youtube.com/watch?v=E43-CfukEgs). Inhibition (or inhibitory control) can take place at different levels. At the response level, research has shown that if a light or a picture is shown on the right side of a screen, we are much faster to look towards the right side, or press the button with our right hand, than we are to look towards the left side, or press a button with our left hand. If we ask people to look towards (or press a key) towards the opposite side of where the light or object is shown, inhibitory control comes into play. The idea is that the stimulus on the right leads to an activation of the neurons leading to a response towards the right (with the eye or the hand) and this competes with the (correct) response towards the left. Both sets of neurons are competing and this conflict is detected, and other neurons become involve to favour the correct response based on a rule.
Another example of response inhibition is showing people a series of letters and they have to press a key as soon as a letter appear, as quickly as possible, except if the letter is an X. If there are few Xs, then people get in the habit of pressing the key quickly and when an X appears find it very difficult to stop their response. (This is call a Go-NoGo task).
In both type of tasks, there are changes in the brain and in the speed of responding and accuracy during development, until late childhood or mid-adolescence depending on the precise task.
Inhibitory control can also play at the level of for example semantic representation. In a famous task called the Stroop task, colour words (like RED, BLUE, YELLOW) can be written in different coloured font. When participants are asked to name the colour of the font, the colour word interfers and they are more likely to make errors or are slower to respond (for example if they see RED written in a yellow font, they have to say “yellow” but in their brain the neurons for the word “red” and the word “yellow” are both activated).
For physics concept, it’s more likely that it is this second level that is at play. If a pupil thinks intuitively that heavier objects fall down faster, but has been taught in class that in fact the acceleration is the same for all objects in a vacuum, when this pupil is asked to solve a problem regarding the acceleration of two objects in a vacuum, he/she will have the two rules activated in his/her brain, competing, and time pressure may end up making it more likely the pupil goes with the intuitive answer, while better inhibitory control may help the pupil inhibits the intuitive answer and instead give the correct answer.
Another thing is relevant regarding the particular situation you describe, which is the idea that there is a theory that the brain works very much by predicting the outcome of actions, events, etc. based on internal models and when the outcome is unexpected, then the model is updated accordingly. So if someone has encoded the model according to which heavier objects fall down faster, when watching the video of objects falling in a vacuum, the brain will predict the speed/acceleration of the objects falling, and when the outcome is not what is predicted (i.e. in fact both objects land at the same time), a prediction error will be generated and the model will be updated. But the issue is that we get a lot more exposure of things that seems lighter falling more slowly because of air friction, than we get of objects falling in a vacuum…
specialsymbol commented on :
Great, thank you!
The Stroop test is a great example.
Wouldn’t then, let’s say, professional gamers that play first person shooters on a competitive level tend to have their screen display potential targets on the side of the hand they control their mouse with?
As, when they’re right-handed have their view looking slightly to the left, so that targets appear rather on the right side than in the center of the screen?
I have observed this while playing myself (though I’m not competitive) and I always thought the preference did arise from being able to move the right hand more quickly to the right than to the left..
As for the physics example:
is there a difference in overriding inhibition if the predictive outcome were actively modeled before seeing the experiment?
Let’s say person A is daydreaming and then sees those two objects falling with the same speed. He would be maybe surprised, but simply accept what he sees.
Person B on the other hand tries to think about what will happen, then sees both objects fall with the same speed. She is surprised, because it didn’t match the model.
Would person B easier remodel than person A?
nicolapercy1 commented on :
Thank you Michael& Andy. Lots to think about here and to process from the discussion at the Intro to Educational Neuroscience conference today