## Dyscalculia – Part III: The Arithmetic Network

Did you notice that there is an arithmetic network in our brain?

#### By Yang Mirin, MA.

Did you notice that there is an arithmetic network in our brain? Even before the advancement of modern neuroimaging, two major findings have been made clear through neurological patients who suffered from different brain injuries: frontal lobes are involved with unfamiliar calculations or problems and parietal lobes are related to the basic numerical processes.

Our frontal lobe is where everything begins; it is the region where we define tasks and goals when we face a new problem. The intraparietal sulci (IPS), which are bilaterally connected to the frontal lobe, are where the arithmetical network starts to operate.

It is related to number abstraction, meaning it responds to the numbers no matter how it is presented (i.e. arrays of dots, digits, number words) and carries out simple calculation.

Let’s imagine that you are given a problem 3 x 4. Without even thinking about the steps, you will answer 12 right away. Although you come up with the answer right away now, it must have taken a lot of effort and time when you just started to learn about the concept of multiplication.

For most people, lots of practice are required to transit an unfamiliar problem into a known fact and our frontal lobes actively take the role in this stage. When the arithmetical fact is retrieved, the network now shifts to the parietal lobe. Specifically, the retrieval depends on a region called the angular gyrus which is just below the IPS. It was also found from research with children of 7-9 years old: children that can retrieve answers to single-digit addition problems used the hippocampus more than the children that still used basic counting skills to solve the problem (Butterworth, 2019).

Then what about the dyscalculic brain? Although there is still much work to be done on this topic, some significant findings of the dyscalculic brain have been made: lower grey matter density in the left IPS and reduced white matter volume. The grey matter in the brain is where information processing occurs and the white matter delivers the processed information to different grey matter areas in our brain. While the functioning of the grey matter and white matter is essential for a successful arithmetical connection to be made, the dyscalculic brain shows anomalies of structure and activation in the parietal lobes.

Butterworth (2019) suggests that further research on the dyscalculic brain, especially on how the different parts of the network are connected, will provide a deeper understanding of dyscalculia.

I will end the article by throwing a question for all of us to consider – is there any way to construct an arithmetical network for dyscalculic children who have abnormalities in their brain structure through learning?

References:

Butterworth, B., (2018). The dyscalculic brain. *Science of Dyscalculia.* 1st ed. Routledge. https://doi.org/10.4324/9781315538112