Falsifizierbarkeit von Theorien zu den Ursachen der Lese- und Rechtschreibstörung / Falsifiability of causal theories of dyslexia

High levels of literacy are required to ensure equality across countries and social classes, leadingto global participation in public and academic life. The ability to understand complex texts has its basis in lower-level cognitive processes, which allow a reader to read and spell single words. 

In an increasingly globalised society, it is important to understand how these processes differ acrosslanguages, and as a function of the characteristics of orthographies, which are the written represen-tations of languages. Orthographies vary on different variables, and these differences are likely toinfluence the ease with which reading is learned. 

The aim of the proposed project is toquantify, in13 European languages, orthography-level differences and similarities, and to determinehowthese differences affect cognitive and learning processes underlying reading and spelling.Such basic research is necessary, in the long term, to develop efficient reading instruction programsin general, and interventions for developmental dyslexia, because it will allow us to target specific as-pects which make it more difficult for children or adults to learn to read or spell in a native or foreignlanguage.

The project will focus on two questions, restricted to first-language speakers of European orthogra-phies. The first question relates to the extent to which the characteristics of one’s native orthographyshape some static parameters of the cognitive reading system. Cognitive parameters of the readingsystem refer to the weight that different processes have during the process of reading, and are sum-marised in Figure 1.

It is often assumed that learning to read changes the neural networks of the brain. For the cognitive reading system, this could mean that the parameters are tuned, over years ofreading experience, in such a way that they provide an optimal reading strategy which is suited to thereaders’ native orthography. Alternatively, it is possible that the orthographic characteristics ofthe text directly influence the way in which it is processed, and that the parameters dynamically ad-just to deal with the orthographic material that is processed. In this view, cross-linguistic differencesin reading do not reflect a different set of parameters of the reading system, but rather the charac-teristics of the text with which the reader is faced. The second, related question focusses onthe extent to which the characteristics of participants’ native orthographies affect the way in whichthey approach a novel orthography. If the parameters of the cognitive system of a reader are biased(temporarily or permanently) towards processes which are optimised to the native orthography, thequestion is if the same parameters will be applied when the reader is faced with a novel orthographicsystem.

Determining if a universal parameter set is sufficient to explain cross-linguistic differences in read-ing and reading acquisition between European orthographies is of theoretical interest. In themedium term, this understanding will contribute to the development of computational models ofreading: these would either need to establish which parameters differ across orthographies, or finda single parameter set that can simulate reading across European orthographies. Understanding ifthe characteristics of one’s native orthography affect the way in which readers learn a new orthog-raphy has practical implications: If this is the case, then foreign-language instruction programs mayneed to be structured differently, depending on the learners’ first orthography. We will address thesequestions using three different approaches: Computational-linguistic studies aiming to quantifyorthography-level differences, a large-scale study, which will allow us to explore similarities anddifferences in reading and reading acquisition across orthographies, and small-scale experimental and learning studies, aiming to isolate the effect of specific orthographic variables on behaviouraloutcomes.