Youth is not wasted on the young: Late-in-life sight restoration in congenitally blind children leads to the emergence of some visual constructional skills but not others

Whenever we draw, copy a pattern or assemble a structure we rely on the scaffolding of multiple skills acquired early in development. Roughly defined as Visuospatial Construction, the ability to spatially organize individual elements into a whole relies on visuo-spatial processing, motor planning, and executive functioning. While many assessments characterize the nature of these skills and observed impairments, little is known about the fundamental contribution of early visual experience for acquiring visuoconstructional skills. Here, we describe our work with children, born blind and left untreated for several years, until they are identified and provided with sight-correcting treatment by our team. To characterize these children’s visuoconstructional skills following late sight onset, we designed a series of assessments to track their progression on multiple tasks, including graphomotor (e.g. drawing to command and copying) and assembly (e.g. pattern reproduction of M&M spatial patterns) tasks in 2D space. Through a combination of computationally derived performance scores, known measures of visuoconstructional impairments, and characterization of strategy and looking behavior, we found that in the assembly task children showed huge improvements in the quality of their final production almost immediately after vision onset, despite having minimal visual experience. However, certain aspects of their final product continued to be impaired even years after treatment, including spatial distortion of the overall form and its proportions. In comparison, improvements on the graphomotor tasks follow a gradual progression but still mirror the sustained form distortions observed in the assembly task. Overall, vision onset seems sufficient to allow reconstruction of a generally coherent pattern, but the lack of early visual experience results in the continued use of localized pairwise error correction as a primary strategy, resulting in pattern deformations that the children seem unaware of, despite the rich visual experience they have gained in the years since treatment.