Culturally influenced performance on tasks of line bisection and symbol cancellation in Arabs

Abstract

The objective of this study was to administer line bisection (LB) and symbol cancellation (SC) tasks on a sample of healthy Arabs in Saudi Arabia, to determine if normative performance would differ from that of the Western population. A total of 136 healthy individuals were enrolled. Deviation direction from the veridical center and percentage deviation scores (PDS) were determined for LB. The overall performance on SC was calculated. Differences according to gender, education and age were measured. Out of the 2,287 times lines were bisected, 1025 (44.82%) deviated rightward (p < 0.0001). Mean (SD) PDS showed a rightward bias 1.57(3.4), (p < 0.0001). Rightward deviation odds modestly increased with age (OR 1.04, P 0.038). In SC, 63% started searching from the left and 67.5% used a horizontal strategy. The mean (SD) performance score was 0.468 (0.248) with no significant cancellation asymmetry. Female gender, education, and age significantly associated with performance. No correlation was found between the two tasks (p = 0.09). Line bisection error biases in Arabs are opposite of Western biases. Scanning for symbols started on the left side; however, this was smaller than that seen in existing Western reports. Normative performances are different from Western studies, but similarly influenced by the same demographic variables.