The drawing of squares and diamonds: a perceptual-motor task analysis.

The aim of the present study was to establish the role of perceptual-motor factors in copying an equilateral four-sided figure. Children, 5 to 12 years, and adults, were asked to copy the figure presented in either "square" or "diamond" orientation under five conditions: control; large model presentation; neutral picture frame surround; partial visual information reduction; and total visual information loss. The model was present at all times. Scores were orientation and angular variability. Developmental trends were found for both figures; the diamond was less well performed than the square at all ages tested. Three perceptual-motor factors were found to be important: formulation of the movement plan; movement programming, and sensory feedback. The difficulty of the diamond is thought to be due to the high programming and hence planning demands in drawing oblique lines. Both kinaesthesis and sequential vision are important factors in drawing; and only from 12 years of age are environmental cues used efficiently to orient the figure.