Abstract
Drawing is a highly multimodal process and its developmental trajectory broadly progresses from drawings that reflect mental models to recreations of visual perception. To tease apart the relative roles of the sensory systems involved in the development of drawing, one requires a model in which input is withheld from each system independently and then re-introduced when the other systems have matured. We have the unique opportunity to do this by studying visual development and skill acquisition in children born with curable blindness in rural India. After providing them with sight-restoring surgery, we longitudinally tested these children to measure multiple aspects of graphic production, including copying shapes and drawing known objects. We found that despite the presence of language to support shape recognition and age-appropriate motor control prior to treatment, sight onset itself did not immediately lead to improved copying but did allow for the quick onset of well-developed tracing skills. Within 6-12 months following treatment, performance rapidly improved and contained many milestones reported in the typically developing trajectory, although aspects of tactile-shape exploration and production were often qualitatively different between the patient and control cohorts, both before and after sight-onset. Additionally, when children were asked to draw familiar objects from memory, all sight-restored children’s drawings were far below age-level initially, beginning at the classic ‘scribble’ and ‘pre-schematic’ developmental stages of drawing from mental models (e.g. a tadpole representing a person, an architect’s view of a house). While the onset of visual experience led some children to transition to the ‘schematic’ stage, where they drew what they saw (drawing from perception), most children stayed “stuck” with drawing what they knew (drawing from mental models). Overall, our data provides novel insights into cognitive models of drawing, and their importance for understanding the development of internal representations.