FarmApp: a new cognitive assessment method for young people with intellectual disability

Background A major challenge when investigating intellectual disability (ID) is the selection of assessment tools that are sensitive to cognitive diversity within the ID population. This study introduces a new touchscreen-based method, FarmApp, which aims to measure competence in relatively low-level cognitive processes (selective attention, short-term visuospatial memory, longer-term recognition memory) which contribute to complex aspects of learning and behaviour. Methods Here we describe the FarmApp design, testing and analysis procedures. We report the feasibility and validity of the method, and demonstrate its utility for measuring change over time, and for comparing groups defined by aetiology. Results We found that FarmApp can be completed by a higher proportion of young people with ID than traditional psychometric tests. FarmApp performance correlates with standardised neuropsychological tests of attention and working memory, and with questionnaire measures of ADHD-relevant behavioural difficulties. Individual performance slopes over a two-week period correlate with general ability and behavioural difficulties, indicating that FarmApp is sensitive to meaningful dynamic variation in cognitive performance. Finally, we compared the FarmApp performance of two groups of young people with ID, defined by the physiological function of ID-associated genetic variants (functional network groups: chromatin-related and synaptic-related), and found that groups differ on attention parameters but not on memory ones. Conclusion FarmApp is a feasible, valid and useful alternative to traditional neuropsychological tests. It can increase access to cognitive assessment for individuals with ID. It adds the opportunity to monitor variation in performance over time and determine capacity to acquire task competence in addition to baseline ability. Our comparison between functional network groups supports the proposal that cognitive processes contributing to ID are differentially influenced by specific genetic aetiologies. In summary, we introduce a new tool for cognitive assessment in ID, with the potential for multiple future applications in clinical practice and research.