Impact of phonological processing skills on written language acquisition in illiterate adults.

Illiteracy remains a world-wide problem not only for children but also for adults. Phonological processing has been defined as a crucial factor for the acquisition of written language, which usually occurs in childhood. However, it is unclear to what extent phonological processing is necessary in order for adults to acquire written language skills. We tested 47 illiterate adults before and after a one-year alphabetization course in several cognitive domains relevant to phonological processing and compared their results to 41 matched controls who did not take part in the alphabetization course. Phonological awareness in the narrower sense (e.g., phoneme association) was a stronger predictor of alphabetization outcome than demographic variables such as years of education. In addition, despite improvement of illiterate individuals in phonological awareness, short-term memory, and visual attention from before to after the alphabetization course, they did not reach the phonological processing level of literate controls. Our results confirm that the alphabetization of adults requires and enhances phonological processes similar to those of children. Nevertheless, specific aspects, such as improvements in short-term memory or visual attention, need to be considered in order to improve and optimize alphabetization programs for adults.

Resource allocation and fluid intelligence: insights from pupillometry.

Thinking is biological work and involves the allocation of cognitive resources. The aim of this study was to investigate the impact of fluid intelligence on the allocation of cognitive resources while one is processing low-level and high-level cognitive tasks. Individuals with high versus average fluid intelligence performed low-level choice reaction time tasks and high-level geometric analogy tasks. We combined behavioral measures to examine speed and accuracy of processing with pupillary measures that indicate resource allocation. Individuals with high fluid intelligence processed the low-level choice reaction time tasks faster than normal controls. The task-evoked pupillary responses did not differ between groups. Furthermore, individuals with high fluid intelligence processed the high-level geometric analogies faster, more accurately, and showed greater pupil dilations than normal controls. This was only true, however, for the most difficult analogy tasks. In addition, individuals with high fluid intelligence showed greater preexperimental pupil baseline diameters than normal controls. These results indicate that individuals with high fluid intelligence have more resources available and thus can solve more demanding tasks. Moreover, high fluid intelligence appears to be accompanied by more task-free exploration.