Piazza, M. et al. (2010) Developmental Trajectory of Number Acuity Reveals a Severe Impairment in Developmental Dyscalculia. Cognition, 33-41.
Rababah, A. and Alghazo, Y. (2016) Diagnostic Assessment and Mathematical difficulties: An Experimental Study of Dyscalculia. Open Jounral of Social Science, 4, 45-52.
In this study conducted by Manuela Piazza et al, they were trying to determine what deficits result from dyscalculia, specifically. They were under the impression that the acquisition of knowledge of numbers was disrupted, linked with this “number sense” that children/adults should gain with age. The number sense refers to the ability to perceive and discriminate large numerosities (Piazza et al., 2010). They utilized a psychophysical test to measure this number sense, which they then referred to as numerical acuity. The participants tested in this study included non-dyscalculic kindergarteners, school-age children, and adults. They divided the groups into a control group (non-dyscalculics) and one experimental group, which consisted of dyscalculic school-aged children. In the experimental task, it was a non-symbolic numerosity task, which consisted of participants that were presented with two white circles, which contained a different number of dots in each, but varied in terms of size, spacing and quantity. In the first circle, n1, the dots were larger and more spread out and in the second circle, the dots were smaller and grouped more together. The participants had to chose, without counting, the larger amount of dots presented over a white circle. The participants in the experimental group selected n2, which had the smaller dots more clustered together and the control group selected n1, which had larger and more dots spaced more apart (which is the correct answer).
· I found this article to be interesting because it clearly shows the inability for dyscalculic children to differentiate between numerosities.
· I thought that the use of more specific inclusion criteria such as general intelligence, normal schooling, no ADHD and other criteria allowed for a more controlled sample. This helped reduce any biases or skews in data.
· The researchers kept referring to the control as “normally developing,” which I wasn’t to fond of. Why didn’t they continue to refer to them as non-dyscalculic? Are they saying that dyscalculic people aren’t normal? What truly defines normal, the stereotypical person who doesn’t have any disorders, deficits or disabilities—because I find that improper and nonexistent?
· I appreciated how the researchers accounted for comorbidities in this study, as opposed to the last article I read by Ahmad Rababah & Yazan Alghazo, which did not consider that (2016).
· Although the researchers mentioned they screened out for ADHD, how exactly did they do that? What tasks or tests did they utilize to assure that the participants did not have this disorder?
· Why did they have a control group of kindergarteners, school-aged children and adults, but only had an experimental group of dyscalculic school-aged children?
· It would have been nice to see some type of fMRI used to study activated brain regions in this area. This would allow more support for why those with dyscalculia have a more difficult time with numerosities and may help use see whether or not numerosity can be localized (although that might be a bit much for one study).
· In terms of using this article in my grant proposal, it may help with my literature review because it provides background on the disorder itself—which is important in explaining. This article may also be useful and helping me determine the specific types of groups and/or tasks I may consider using.