Stroke direction asymmetry in figure drawing: Influence of handedness and reading/writing habits

Abstract

Recent studies suggest that asymmetries noted in certain nonlinguistic tasks used in laterality studies (e.g., facial affect judgment, line bisection) may in part be influenced by prior reading/writing habits. The present study examined the relative influence of reading/writing direction and handedness on the direction of stroke movement in free-hand figure drawing. One hundred twenty right and left handed brain-intact adult readers of scripts with opposing directionality (Hindi vs Urdu) and illiterate controls were observed while drawing a tree, a hand, a house, an arrow, a pencil, and a fish. Right-handers (including right-handed illiterates) and left-to-right readers drew most figures in a left-to-right direction, whereas left handers (including left handed illiterates) and right-to-left readers more often drew the figures from right to left. These results extend previous findings and contribute to a growing body of evidence demonstrating reading scan biases in nonlinguistic perception and production tasks. It would appear that reading/writing habits cannot be ignored as a potential artifact in studies of hemisphere functional asymmetry employing nonlinguistic stimuli.