Visuoconstructional abilities in cognitively healthy illiterate Turkish immigrants: a quantitative and qualitative investigation.

Assessment of visuospatial function is an integral part of most neuropsychological assessments and is frequently assessed by visuoconstructional tests. A significant impact of limited schooling and illiteracy has been found on numerous neuropsychological tests and it can be difficult to interpret test results from illiterate individuals. In this study, quantitative and qualitative aspects of performance of elderly cognitively healthy illiterate and literate Turkish immigrants were compared on five commonly used visuoconstructional tests. Significantly poorer performances of illiterate compared to literate subjects were found in copying of two- and three-dimensional geometric designs, and in Clock Drawing Test performance. A systematic qualitative analysis found lacking three-dimensionality, "curved angles", omissions, distorted relation between elements, and spatial disorganization to be common error types in illiterate subjects. Performances were not found to be influenced by duration of residence in Denmark or level of acculturation. The results warrant caution in the interpretation of visuoconstructional test performances in illiterate subjects, as they can easily be misinterpreted as signs of cognitive dysfunction.