Developmental differences in prefrontal cortex activity in the Tower of Hanoi puzzle with high vs. low motor elements in adults and children with and without developmental coordination disorder
Date
2019
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
The prefrontal cortex (PFC) plays an important role in executive function (EF) as well as motor planning. Recent neuroimaging research has indicated that individuals with developmental coordination disorder (DCD) demonstrate differences in their PFC activity. To explore this, we used functional near-infrared spectroscopy (fNIRS) to compare PFC activity in adults, typically developing (TD) children, and children with DCD as they performed two conditions (2D and 3D) of the Tower of Hanoi (ToH) disk-transfer task that have equivalent EF demands but different motor requirements. Overall, we sought to better understand the role of the PFC in these two conditions to detect if neural activity and behavioral performance differ as a function of ToH condition, and to identify whether any differences exist in these measures among all 3 groups. To do this, we performed 3 studies. In study 1, 20 right-handed, neurotypical adults (10M/10F, x ̅ = 24.6, SD ± 2.8 y.o.) participated. Results showed significantly larger changes in oxygenated hemoglobin, ∆HbO, for 3D compared to 2D condition (p = 0.0211) and a significant interaction between presentation order and condition (p = 0.0015). Notably, a strong correlation between performance and ∆HbO existed between blocks 1 (B1) and 2 (B2; r = -0.69, r2 = 0.473, p < 0.01) when the 3D condition was initially performed, in contrast to the 2D condition where no significant correlation was seen. Findings also showed a significant decrease in ∆HbO between B1 and B2 (p = 0.0015), while performance increased significantly for both conditions (p < 0.005). In study 2, 18 TD children (5F/13M, x ̅ = 11.33, SD ± 2.41 y.o.) participated and were further separated into 2 age bands: younger (N=7, 1F/6M, x ̅ = 9.02, SD ± 1.20 y.o.) and older (N=11, 4F/7M, x ̅ = 12.79, SD ± 1.71 y.o.). In contrast to study 1, results in the TD sample did not show a significant effect when comparing ΔHbO between 2D and 3D conditions for either younger or older children, although neural activity was larger in the 3D than in the 2D condition (p > 0.05). Likewise, a decrease in ΔHbO was seen in B2 as opposed to B1 in both conditions however the relationship was not significant for either group (p > 0.05). Lastly, performance did not significantly differed between blocks for both groups (p > 0.05). In study 3, we performed a descriptive study on 4 children with DCD (0F/4M, x ̅ = 11.81, SD ± 0.58 y.o.). Data displayed larger ∆HbO in the 2D as opposed to the 3D condition in 3 out of 4 participants, and a decreased ∆HbO in B2 compared to B1 for all participants. Furthermore, 2 participants performed above the average TD sample performance score (2.88 for B1 and 2.94 for B2), while one participant performed below, and the other participant performed at average levels. Lastly, 3 participants showed generalized PFC activity for both conditions, whereas one participant showed localized activity to the dorsolateral PFC during the 3D condition, but generalized activity during the 2D. Overall, we plan to use this information to guide future research into elucidating the potential points of impairment on the perception-cognition-action continuum in DCD.