Goebel, S. M. 1 , Pixner, S. 2 & Kaufmann, L. 2, 3
1 Department of Psychology, University of York, UK
2 Institute of Applied Psychology, UMIT-Private University for Health Sciences, Medical Informatics and Technology, Hall in Tyrol, Austria
3 Department of Pediatrics IV, Medical University Innsbruck, Innsbruck, Austria
In recent years the research into numerical and arithmetic difficulties in children has increased substantially. However, relatively little is still known about number processing and arithmetic performance patterns of adults with a life-long history of numerical and arithmetic difficulties. Clearly, longitudinal studies are needed to investigate the outcome of childhood numerical and arithmetic difficulties in adult life. Currently however, given the absence of those studies, investigating adults with pure numerical and arithmetic difficulties could also tell us more about developmental pathways. We will present data from two adults with severe arithmetic difficulties. Both adults are university students with above average cognitive skills who have experienced difficulties with number processing and arithmetic since childhood. RM is a pure case with no impairments in other cognitive domains. She uses tally marks and finger counting for simple addition and multiplication tasks. AC also uses elaborate strategies to solve arithmetic problems that are commonly used by fact retrieval. In contrast to RM, AC shows arithmetic difficulties in the context of developmental dyslexia. First we will compare and contrast in detail the strategies used by those two adults for single digit addition, subtraction and multiplication. Second we will then compare their performance on symbolic and non-symbolic number comparison tasks and spatial-numerical tasks to the performance of age and IQ-matched controls.